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This project assessed ethnic differences in objectively-measured sedentary behavior and cardiometabolic risk biomarkers among overweight/obese postmenopausal women (n=518; mean age 63 ± 6 years). Data from hip-worn accelerometers were processed using validated machine-learning algorithms to measure total daily sitting time and mean sitting bout duration (an indicator of sedentary behavior patterns), both of which are associated with cardiometabolic disease risk. Hispanic women (n=102) differed significantly from non-Hispanic women (n=416) having less total sitting time (41 minutes less/day, p=0.00012) and shorter mean sitting bout duration (3 minutes less, p=0.049). After adjusting log-linear regression models for socio-demographic and other confounding factors including moderate-to-vigorous physical activity, Hispanic women, compared to non-Hispanic women, had significantly greater fasting glucose, insulin, and insulin resistance (HOMA-IR; p

Introduction The purpose was to investigate the age effects on central versus peripheral sources of strength, fatigue, and central neural excitabilities. Methods 42 healthy subjects were recruited as young group (23.73 ± 2.15 years; n = 26) and middle-aged group (57.25 ± 4.57 years; n = 16). Maximum voluntary contraction force (MVC), voluntary activation level (VA), and twitch force of quadriceps were evaluated to represent general, central, and peripheral strengths. Central and peripheral fatigue indexes were evaluated using femoral nerve electrical stimulation. Cortical excitabilities were evaluated using transcranial magnetic stimulation (TMS). Results The middle-aged group had lower MVC and twitch force of quadriceps, but not VA, than young group. No between group differences were found in fatigue indexes. The cortical excitability in middle-aged group was different from young group in paired TMS with inter-stimulus interval of 7 ms. Conclusion The age-related strength loss at early stage was primarily caused by peripheral muscular strength. The deviation of central neural excitability can be detected but the activation level was not impaired in middle-age adults.

The needs of children and their vulnerability to diseases, violence and poverty are different from those of adults. The Sustainable Child Development Index (SCDI) was thus developed in previous work to evaluate the status of sustainable development for countries with a focus on children and triple-bottom-line thinking. This study proposes application options to put the SCDI into practice. The SCDI can be performed similarly to existing development indices, for comparing and tracing the performance of sustainable development on different geographic levels and between population groups. In addition, the SCDI can be integrated into existing social sustainability assessment approaches (e.g., Social Life Cycle Assessment and Social Organizational Life Cycle Assessment) and databases (e.g., The Social Hotspots Database) to take children into account and enhance impact assessment of social sustainability assessment approaches. As an exemplification, this study demonstrates the application of the SCDI framework to support the development of social impact pathways. Due to the importance of tertiary education in reducing poverty, a preliminary social impact pathway addressing completion of tertiary education was established. By putting the SCDI into practice, the SCDI can support decision making in child as well as sustainable development policies.

Despite the relevance of children in inheriting and shaping society, an index assessing sustainable development with a focus on children is missing. To tackle this gap, this study established the Sustainable Child Development Index (SCDI) by considering child development topics in the context of inter-generational equity and applying indicators with available statistical data on country level. The SCDI at present addresses health, education, safety, economic status and environmental aspects described by 25 indicators. By taking reference points derived from the targets of the Sustainable Development Goals (SDGs), the SCDI scores for the year 2015 were calculated for 138 countries and then classified into four sustainable child development levels (very high, high, medium and low). The results showed great regional inequality on the status of sustainable child development. European countries generally have better status of sustainable child development. By contrast, 90% of African and 76% of Asian countries were classified as countries with medium and low levels. Moreover, the comparison of the SCDI, the Human Development Index (HDI) and the Child Development Index (CDI) based on correlation analysis and 10-year (2006–2015) country rankings demonstrated that the SCDI can complement existing development indices to provide a more comprehensive evaluation of sustainable development.

While cell-based immunotherapy, especially chimeric antigen receptor (CAR)-expressing T cells, is becoming a paradigm-shifting therapeutic approach for cancer treatment, there is a lack of general methods to remotely and noninvasively regulate genetics in live mammalian cells and animals for cancer immunotherapy within confined local tissue space. To address this limitation, we have identified a mechanically sensitive Piezo1 ion channel (mechanosensor) that is activatable by ultrasound stimulation and integrated it with engineered genetic circuits (genetic transducer) in live HEK293T cells to convert the ultrasound-activated Piezo1 into transcriptional activities. We have further engineered the Jurkat T-cell line and primary T cells (peripheral blood mononuclear cells) to remotely sense the ultrasound wave and transduce it into transcriptional activation for the CAR expression to recognize and eradicate target tumor cells. This approach is modular and can be extended for remote-controlled activation of different cell types with high spatiotemporal precision for therapeutic applications.

Life Cycle Assessment (LCA) is applied in evaluating environmental impacts of state-of-the-art welding technologies. Manual Metal Arc Welding (MMAW), Laser Arc-Hybrid Welding (LAHW) and two Gas Metal Arc Welding (GMAW) variants are used to join a plate of 20 mm thick structural steel. The LCA results indicate that for 1 m weld seam, MMAW causes the highest environmental impacts in global warming potential (GWP), eutrophication potential (EP), acidification potential (AP), and photochemical ozone creation potential (POCP) among the selected processes, and the LAHW variant performances the least. Filler material and electricity consumptions generally dominate the impacts and reach shares of up to 80% and 61% in the respective impact categories. However, electrode coating consumption in MMAW remarkably contributes impacts on AP and EP, for instance 52% of AP and 76% of EP. Strategies for improvement of the applied welding technologies are discussed.

Current product social life cycle assessment (SLCA) addresses social aspects from a life cycle perspective, but it is not yet broadly implemented in practice. We propose a new organizational perspective to boost SLCA—the social organizational LCA (SOLCA). The paper answers four guiding questions: Why do we need SOLCA? How can we apply it? How can its implementation benefit from existing experience? Which are the foreseen limitations? First, challenges of SLCA which may be overcome by an organizational perspective are identified, and potential solutions are described. An analysis of the indicators proposed by SLCA is conducted. Second, first ideas for a conceptual framework for SOLCA are developed. The two underlying methodologies: the guidelines for SLCA of products and the guidance on organizational LCA (OLCA)—which adapts product LCA to the organizational perspective—were reviewed, compared and adapted to a social organizational perspective. Third, different implementation pathways were identified, showing how SOLCA could be applied in practice by considering different levels of organizations’ experiences with social and environmental assessments. Existing SLCA case studies do not really evaluate the social performance of products. From the 189 indicators proposed in SLCA, only eight refer to the product level, while 127 and 69 refer to the organizational and country level, respectively—including overlaps and according to the methodological sheets. This fact clearly favors an organizational approach to social LCA. SOLCA may streamline allocation, data collection, and application in practice. The conceptual framework for SOLCA is focused on scope and inventory, which were found to differ most from SLCA and OLCA; all relevant steps like definition of unit of analysis or multi-functionality are addressed. Three SOLCA implementation pathways are proposed. Existing experience of organizations in social organizational approaches —like Global Reporting Initiative (GRI) or product SLCA— and environmental approaches —like environmental management systems (EMS) or OLCA— can be used as starting points as they can provide useful information on the organization´s structure, value chain, etc. SOLCA helps to overcome some major challenges of SLCA and thus is a promising approach for putting it into practice. The frameworks of SLCA and OLCA can be integrated into SOLCA, and existing experience from organizations can be used for implementing it. However, new challenges arise. This includes potential difficulties for primary data collection in complex organizations with many different sites or the difficulty to distribute or aggregate social aspects within the organization. Further development and testing of SOLCA is recommended.

In this study, we aimed to seek for different ways of measuring cardiac stress in terms of heart rate variability (HRV) and heart rate (HR) dynamics, and to develop a novel index that can effectively summarize the information reflected by these measures to continuously and quantitatively characterize the cardiac stress status during physical exercise. Standard deviation, spectral measure of HRV as well as a nonlinear detrended fluctuation analysis (DFA) based fractal-like behavior measure of HR dynamics were all evaluated on the RR time series derived from windowed electrocardiogram (ECG) data for the subjects undergoing cycling exercise. We recruited eleven young healthy subjects in our tests. Each subject was asked to maintain a fixed speed under a constant load during the pedaling test. We obtained the running estimates of the standard deviation of the normal-to-normal interval (SDNN), the high-fidelity power spectral density (PSD) of HRV, and the DFA scaling exponent α, respectively. A trend analysis and a multivariate linear regression analysis of these measures were then performed. Numerical experimental results produced by our analyses showed that a decrease in both SDNN and α was seen during the cycling exercise, while there was no significant correlation between the standard lower frequency to higher frequency (LF-to-HF) spectral power ratio of HRV and the exercise intensity. In addition, while the SDNN and α were both negatively correlated with the Borg rating of perceived exertion (RPE) scale value, it seemed that the LF-to-HF power ratio might not have substantial impact on the Borg value, suggesting that the SDNN and α may be further used as features to detect the cardiac stress status during the physical exercise. We further approached this detection problem by applying a linear discriminant analysis (LDA) to both feature candidates for the task of cardiac stress stratification. As a result, a time-varying parameter, referred to as the cardiac stress measure (CSM), is developed for quantitatively on-line measuring and stratifying cardiac stress status. We seek for different ways of measuring cardiac stress that occurs when exercising.Both the SDNN and fractal exponent α produced a decrease during the cycling exercise.Both the SDNN and fractal exponent α were negatively correlated with the Borg index.A time-varying index CSM was devised for quantitatively measuring the cardiac stress.The study may be used in sports medicine or stress tests for heart stress monitoring.

Hypertonia is one of the major causes of movement disorders in individuals with central nervous system lesions. Robot-assisted therapy can minimize the immobilization side-effect such as severe hypertonia by providing repetitive motor practice with minimal labor assistance. The purpose of this study was to design a robot-assisted passive exercise device and establish optimal parameter settings for reducing both reflexive and non-reflexive muscle tone. A custom-made device with a built-in force transducer was developed to provide ankle cyclic passive exercise at various speeds and measure the total resistance during stretching. Ten individuals with spinal cord injury received 8 min of low-speed passive exercise (20 cycles/min), 8 min of high-speed (50 cycles/min) passive exercise, and repeated contractions elicited by electrical stimulation (ES), in randomized order over 3 consecutive weeks. Maximum ES-elicited isometric torque, M waves, H reflexes, and total resistance during stretching were measured before and after each of the treatments. The results show that the H reflex was reduced after passive exercise at both speeds but not after repeated ES-elicited contractions. The reduction of the total resistance during stretching was speed-dependent. Significant fatigue was induced only after repeated ES-elicited contractions. This study successfully developed a robot-assisted passive exercise device, evaluated parameter settings, and provided evidence of the reduction of both reflexive excitability and total muscle tone in hypertonia muscles.

A bifunctional Schiff base fluorescent sensor 2 (receptor 2) was prepared and its metal ions and anions sensing properties were investigated. Receptor 2 exhibited an excellent selective fluorescence response toward Al3+ and colorimetric response (from yellow to colorless) toward CN−, respectively among a series of ions. Moreover, the detection limits of receptor 2 for Al3+ and CN− were determined to be 14 nM and 73 nM, respectively. The two detection limit values were sufficiently low to detect nano-molar concentration of Al3+ and CN−.

A combination of various therapeutic approaches has emerged as a promising strategy for cancer treatment. A safe and competent nano-delivery system is thus in urgent demand to facilitate the simultaneous transport of various therapeutic agents to cancer cells and a tumor region to achieve synergistic effect. Gold nanoparticles (GNPs) and mesoporous silica nanoparticle (MSNs) were fabricated herein as potential candidates for drug delivery. Serving as gatekeepers, GNPs (5 nm in diameter) were attached onto the amino-functionalized MSNs (denoted as NMSNs) via a relatively weak gold-nitrogen bonding. The resulting nanohybrids (denoted as GCMSNs) were uptaken by cells, and the detachment of GNPs and subsequent intracellular drug release from NMSNs were achieved by competitive binding of intracellular glutathione to GNPs. In addition to the function of gatekeeping, GNPs also play another role as the oxidative stress elicitor. Our in vitro studies revealed that GCMSNs induced higher oxidative stress in lung cancer cells (A549) than in normal cells (3T3-L1). This growth inhibitory effect found in the cancer cells was likely induced by mitochondria dysfunction originated from the GCMSN-induced, oxidative stress-triggered mitochondria-mediated autophagy. The redox-responsive nanohybrids were further loaded with camptothecin and the intensified synergistic therapeutic effects were observed associated with combined chemotherapy and oxidative stress strategy. The results clearly demonstrate that such unique nanohybrids hold great promise for selective and effective cancer treatments.

This paper presents a set of selection criteria for identifying indicators for sustainable production of the manufacturing industry. Starting from a condensed overview of over 500 general sustainability indicators, such focussing on sustainable production are discussed, including the three dimensions of sustainability and the indicator qualities. Based on the Collaborative Research Centres (CRC) 1026 Framework and with the understanding that manufacturing industries may differ, the authors suggest to use the ABC judgement method - a semi-quantitative systematic method to prioritize indicators based on expert judgement and supporting evidences - to select core and supplemental indicators. Concise questionnaires considering sustainability targets are used and combined with a scoring system to support the decision process. The method can use either top-down indicators (i.e. on the impact level e.g. acidification, climate change) or bottom-up indicators (i.e. on inventory level e.g. energy consumption, recycling rate, volume or weight of solid waste/hazardous waste). Proof of concept of the proposed approach in a life cycle based case study are presented by three demonstration cases focusing on manufacturing sector i.e. elevator, refrigerator and welding. Based on these cases result, we conclude that this is the first step in the right direction to use the ABC method to identify the suitable impact category sets for conducting LCA studies. The three simple questions that transfer selection criteria, i.e. robustness, relevance, effectiveness, practicality and clear and easy to measure, are found operational and appropriate.

Disrupted triphasic electromyography (EMG) patterns of agonist and antagonist muscle pairs during fast goal-directed movements have been found in patients with hypermetria. Since peripheral electrical stimulation (ES) and motor training may modulate motor cortical excitability through plasticity mechanisms, we aimed to investigate whether temporal ES-assisted movement training could influence premovement cortical excitability and alleviate hypermetria in patients with spinal cerebellar ataxia (SCA). The EMG of the agonist extensor carpi radialis muscle and antagonist flexor carpi radialis muscle, premovement motor evoked potentials (MEPs) of the flexor carpi radialis muscle, and the constant and variable errors of movements were assessed before and after 4 weeks of ES-assisted fast goal-directed wrist extension training in the training group and of general health education in the control group. After training, the premovement MEPs of the antagonist muscle were facilitated at 50 ms before the onset of movement. In addition, the EMG onset latency of the antagonist muscle shifted earlier and the constant error decreased significantly. In summary, temporal ES-assisted training alleviated hypermetria by restoring antagonist premovement and temporal triphasic EMG patterns in SCA patients. This technique may be applied to treat hypermetria in cerebellar disorders. (This trial is registered withNCT01983670.)

Life Cycle Assessment (LCA) and Social Life Cycle Assessment (SLCA) are applied in evaluating possible social and environmental impacts of the state-of-art welding technologies, such as Manual Metal Arc Welding (MMAW), Manual Gas Metal Arc Welding (GMAW), Automatic GMAW and Automatic Laser-Arc Hybrid Welding (LAHW). The LCA results indicate that for 1 meter weld seam, MMAW consumes the largest amount of resources (like filler material and coating on electrodes) and energy, which contributes to comparatively higher environmental impacts in global warming potential, acidification, photochemical ozone creation potential and eutrophication than other chosen processes. With regard to social aspects, the health issues and fair salary are under survey to compare the relative potential risk on human health caused by fumes in different welding technologies, and to indicate the sufficiency of current salary of welders in Germany. The results reflect that the wage status of welders is still fair and sufficient. The manual processes bring much higher potential risk of welders’ health than the automatic processes, especially MMAW.

Hemiplegic shoulder pain is a frequent complication after stroke, leading to limited use of the affected arm. Neuromuscular electrical stimulation (NMES) and transcutaneous electrical nerve stimulation (TENS) are two widely used interventions to reduce pain, but the comparative efficacy of these two modalities remains uncertain. The purpose of this research was to compare the immediate and retained effects of EMG-triggered NMES and TENS, both in combination with bilateral arm training, on hemiplegic shoulder pain and arm function of stroke patients. A single-blind, randomized controlled trial was conducted at two medical centers. Thirty-eight patients (25 males and 13 females, 60.75 ± 10.84 years old, post stroke duration 32.68 ± 53.07 months) who had experienced a stroke more than 3 months ago at the time of recruitment and hemiplegic shoulder pain were randomized to EMG-triggered NMES or TENS. Both groups received electrical stimulation followed by bilateral arm training 3 times a week for 4 weeks. The primary outcome measures included a vertical Numerical Rating Scale supplemented with a Faces Rating Scale, and the short form of the Brief Pain Inventory. The secondary outcome measures were the upper-limb subscale of the Fugl-Meyer Assessment, and pain-free passive shoulder range of motion. All outcomes were measured pretreatment, post-treatment, and at 1-month after post-treatment. Two-way mixed repeated measures ANOVAs were used to examine treatment effects. Compared to TENS with bilateral arm training, the EMG-triggered NMES with bilateral arm training was associated with lower pain intensity during active and passive shoulder movement (P =0.007, P =0.008), lower worst pain intensity (P = 0.003), and greater pain-free passive shoulder abduction (P =0.001) and internal rotation (P =0.004) at follow-up. Both groups improved in pain at rest (P =0.02), pain interference with daily activities, the Fugl-Meyer Assessment, and pain-free passive shoulder flexion and external rotation post-treatment (P

Since children are the key stakeholders supporting and being affected by sustainable development, the framework for the Sustainable Child Development Index (SCDI) was proposed. It addresses social, economic and environmental dimensions of sustainable development by considering seven relevant themes of child development, i.e., health, education, safety, economic status, relationship, environmental aspects and participation. However, an indicator set for initiating the SCDI is still missing. In this study, indicators for the themes, subthemes and criteria of SCDI are identified from literature and then analyzed regarding data availability. Sixty-six indicators with statistical data covering at least 100 countries are selected as the indicator set for the SCDI. The results indicate that data availability is best for indicators describing the themes of health and education, and worst for indicators addressing the themes of relationship and participation. Furthermore, 21 subthemes and 50 criteria described by indicators with limited data availability are identified for future indicator and data development. By providing an initial indicator set and screening the indicators with regard to data availability, the practicality of the SCDI framework is expected. Furthermore, the indicator set can serve as a potential indicator pool for other child and sustainable development related studies.

Welding is the most important joining technology. In the steel construction industry, e.g. production of windmill sections, welding accounts for a main part of the manufacturing costs and resource consumption. Moreover, social issues attached to welding involve working in dangerous environments. This aspect has unfortunately been neglected so far, in light of a predominant focus on economics combined with a lack of suitable assessment methods. In this chapter, exemplary welding processes are presented that reduce the environmental and social impacts of thick metal plate welding. Social and environmental Life Cycle Assessments for a thick metal plate joint are conducted for the purpose of expressing and analysing the social and environmental impacts of welding. Furthermore, it is shown that state-of-the-art technologies like Gas Metal Arc Welding with modified spray arcs and Laser Arc-Hybrid Welding serve to increase social and environmental performance in contrast to common technologies, and therefore offer great potential for sustainable manufacturing.

Sustainability assessments considering the three dimensions environment, economy, and society are needed to evaluate manufacturing processes and products with regard to their sustainability performance. This chapter focuses on Life Cycle Sustainability Assessment (LCSA), which considers all three sustainability dimensions by combining the three methods Life Cycle Assessment (LCA), Life Cycle Costing (LCC), and Social Life Cycle Assessment (SLCA). Existing LCSA approaches as well as selected ongoing work are introduced, both regarding the individual approaches as well as the combined LCSA approach. This includes, for instance, the Tiered Approach. This approach facilitates the implementation of LCSA, for instance, within the manufacturing sector, by providing a category hierarchy and guiding practitioners through the various impact and cost categories proposed for the three methods. Furthermore, ongoing developments in LCC and SLCA are presented, such as the definition of first economic and social impact pathways (linking fair wage and level of education to social damage levels) for addressing the current challenges of missing impact pathways for economic and social aspects. In addition, the Sustainability Safeguard Star suggests a new scheme for addressing the inter-linkages between the three sustainability dimensions. These approaches foster the application and implementation of LCSA and thus contribute to developing sustainable processes and products.

A real-time muscle fatigue monitoring system was developed to quantitatively detect the muscle fatigue of subjects during cycling movement, where a fatigue progression measure (FPM) was built-in. During the cycling movement, the electromyogram (EMG) signals of the vastus lateralis and gastrocnemius muscles in one leg as well as cycling speed are synchronously measured in a real-time fashion. In addition, the heart rate (HR) and the Borg rating of perceived exertion scale value are recorded per minute. Using the EMG signals, the electrical activity and median frequency (MF) are calculated per cycle. Moreover, the updated FPM, based on the percentage of reduced MF counts during cycling movement, is calculated to measure the onset time and the progressive process of muscle fatigue. To demonstrate the performance of our system, five young healthy subjects were recruited. Each subject was asked to maintain a fixed speed of 60 RPM, as best he/she could, under a constant load during the pedaling. When the speed reached 20 RPM or the HR reached the maximal training HR, the experiment was then terminated immediately. The experimental results show that the proposed system may provide an on-line fatigue monitoring and analysis for the lower extremity muscles during cycling movement.

Suboptimal repair occurs in a peripheral nerve gap, which can be partially restored by bridging the gap with various biosynthetic conduits or cell-based therapy. In this study, we developed a combination of chitosan coating approach to induce neurosphere cells from human adipose-derived stem cells (ASCs) on chitosan-coated plate and then applied these cells to the interior of a chitosan-coated silicone tube to bridge a 10-mm gap in a rat sciatic nerve. Myelin sheath degeneration and glial scar formation were discovered in the nerve bridged by the silicone conduit. By using a single treatment of chitosan-coated conduit or neurosphere cell therapy, the nerve gap was partially recovered after 6 weeks of surgery. Substantial improvements in nerve regeneration were achieved by combining neurosphere cells and chitosan-coated conduit based on the increase of myelinated axons density and myelin thickness, gastrocnemius muscle weight and muscle fiber diameter, and step and stride lengths from gait analysis. High expressions of interleukin-1β and leukotriene B4 receptor 1 in the intra-neural scarring caused by using silicone conduits revealed that the inflammatory mechanism can be inhibited when the conduit is coated with chitosan. This study demonstrated that the chitosan-coated surface performs multiple functions that can be used to induce neurosphere cells from ASCs and to facilitate nerve regeneration in combination with a cells-assisted coated conduit.

A simple Schiff-base receptor 1 was prepared. It exhibits an “off–on-type” mode with high sensitivity in the presence of Al3 + and shows a high association constant (5.89 × 106 M− 2) toward Al3 + in DMSO–H2O (4:6 v/v) solution. The addition of EDTA to receptor 1·Al3 + complex quenches the fluorescent intensity, indicating that receptor 1 serves as a reversible chemosensor.

Sustainability 6(8), 4839 - 4857 (2014). doi:10.3390/su6084839, Published by MDPI, Basel

A simple indole-based receptor 1 was prepared by a simple Schiff-base reaction of 1H-indole-3-carbaldehyde with ethane 1,2-diamine and its fluoroionophoric properties toward anions were investigated. Indole-based receptor 1 acts as a selective turn-on fluorescent sensor for HSO4− in methanol among a series of tested anions. Fluorescence spectroscopy, ultraviolet and nuclear magnetic resonance imaging support that the HSO4– indeed interacted with imine nitrogen and the proton of nitrogen in indole ring. Copyright © 2013 John Wiley & Sons, Ltd.

Current hemodialysis has functional limitations and is insufficient for renal transplantation. The bioartificial tubule device has been developed to contribute to metabolic functions by implanting renal epithelial cells into hollow tubes and showed a higher survival rate in acute kidney injury patients. In healthy kidney, epithelial cells are surrounded by various types of cells that interact with extracellular matrices, which are primarily composed of laminin and collagen. The current study developed a microfluidic coculture platform to enhance epithelial cell function in bioartificial microenvironments with multiple microfluidic channels that are microfabricated by polydimethylsiloxane. Collagen gel (CG) encapsulated with adipose-derived stem cells (CG-ASC) was injected into a central microfluidic channel for three-dimensional (3D) culture. The resuspended Madin-Darby canine kidney (MDCK) cells were injected into nascent channels and formed an epithelial monolayer. In comparison to coculture different cells using the commercial transwell system, the current coculture device allowed living cell monitoring of both the MDCK epithelial monolayer and CG-ASC in a 3D microenvironment. By coculture with CG-ASC, the cell height was increased with columnar shapes in MDCK. Promotion of cilia formation and functional expression of the ion transport protein in MDCK were also observed in the cocultured microfluidic device. When applying fluid flow, the intracellular protein dynamics can be monitored in the current platform by using the time-lapse confocal microscopy and transfection of GFP-tubulin plasmid in MDCK. Thus, this microfluidic coculture device provides the renal epithelial cells with both morphological and functional improvements that may avail to develop bioartificial renal chips.

The associations between variants of human papillomavirus (HPV) 16 and risk of cervical neoplasia have been reported, but nucleotide variations of HPV 16 in Asian populations and their association with cervical neoplasia have not been evaluated extensively. During 1991-1992, 11,923 women from seven townships in Taiwan were enrolled. The HPV DNA in cervical cells was detected and genotyped using EasyChip HPV blot. Nucleotide variations in the long control region (LCR), E6, and E7 genes were determined using DNA sequencing for 170 HPV 16-positive cervical samples. The Asian variant was the most prevalent variant (81.8%) of HPV 16 in Taiwan, and was also associated with increased prevalence of histologically confirmed cervical intraepithelial neoplasia grade 3 or worse, showing an age-adjusted odds ratio (exact confidence limits) of 10.70 (1.62-451.05; P = 0.0049) compared to the HPV 16 European variant. Similar significant associations with cervical intraepithelial neoplasia grade 3 or worse were also observed for distinct nucleotide substitutions, including T178A/G, A647G, A7730C/G, T7781C, G7842A, and C24T/G. These results demonstrate that non-European variants (non-E) of HPV 16, predominantly Asian variants, are associated with increased risk for severe cervical neoplasia, compared with European variants. Molecular mechanisms accounting for varied cervical neoplasia risk among different HPV 16 variants warrant further investigation.

Introduction In patients with obstructive sleep apnea (OSA), intermittent apnea and hypopnea might cause different adaptations in inspiratory and peripheral muscles. In this study we aimed to determine the changes that occur in muscle activation characteristics during incremental exercise testing in patients with severe OSA. Surface electromyography of inspiratory muscles and knee extensors was performed. Methods Eleven men with severe OSA and 11 matched controls were recruited. Changes in muscle activity were compared by determining root mean square (RMS) and median power frequency (MPF) values obtained at different exercise intensities. Results The ratios of RMS to oxygen consumption in inspiratory muscles and vastus lateralis increased significantly at peak workload in the control group (P < 0.05), but not in the OSA group. Conclusions Patients with severe OSA demonstrated an inability to increase motor unit recruitment of inspiratory muscles and knee extensors during incremental exercise. Muscle Nerve, 48: 212–218, 2013

BACKGROUND: Trunk muscle endurance training is used by most high school baseball or softball coaches. However, evidence demonstrating a relationship between trunk muscle endurance and batting performance is lacking. OBJECTIVE: This study aimed to establish a relationship between trunk muscle endurance and bat swing velocity in a high school baseball team. METHOD: Sixty-one high school (15–18 years old) baseball players, taken from the same team, with 6.5 ± 1.3 years of training experience, participated in the following tests: static trunk flexion/extension endurance tests, dynamic trunk flexion/extension endurance tests and a maximum bat swing velocity test. RESULTS:Bat swing velocity showed significant low-to-moderate negative correlations with static trunkflexor endurance (P = 0.001, r = �0.404), dynamic trunk flexor endurance (P = 0.016, r = �0.308) and the ratio of static flexor/extensor endurance (P = 0.021, r = �0.298). CONCLUSIONS: These findings support the concept that better trunk flexor endurance might not benefit batting performance. Trunk flexor endurance training should not be over-emphasized when the targeted training goal is to enhance bat swing velocity.

Objective To investigate the possibility of restoring the adapted spinal circuit after spinal cord injury (SCI) by means of long-term continuous passive motion (CPM) of the ankle joint. Design Randomized controlled trial with repeated measures. Setting Research laboratory in a general hospital. Participants Individuals with motor complete SCI (N=14) were recruited from a community. Intervention CPM of the ankle joint for 1 hour a day, 5 days a week for 4 weeks. Main Outcome Measures Modified Ashworth Scale (MAS) scores for evaluation of spasticity and postactivation depression (PAD) were documented prior to and after intervention. Results MAS scores improved after 4 weeks of CPM intervention, indicating a reduction in spasticity of the ankle joint. PAD was restored after 4 weeks of training. Conclusions Passive motion of the ankle joint alone was sufficient in reversing the adapted spinal circuit, and therefore indicates that spasticity after SCI could possibly be managed by CPM intervention. The results of this study support the use of the passive mode of robot-assisted therapy for humans with complete SCI who cannot exercise actively.

Intro: Primary Sjogren’s syndrome is a chronic systemic autoimmune disease. Although ocular and oral dryness are the hallmarks of this syndrome, renal involvement when present most commonly has the histological appearance of tubointerstitial nephritis and less often glomerular involvement. We report, a unique case of renal manifestations of primary Sjogren’s syndrome with a proven histological focal proliferative and crescentric necrotizing glomeru-lonephritis. Case: A 30 years old man with Kimura disease presented with four months of subjective fevers, migrating skin erythema, dry mouth, and dry eyes. On further workup the patient was found to have a positive ANA, positive anti-SSA, and was evaluated by ophthalmology who found keratoconjunctivitis sicca. The patient was started on hydroxychloroquine in combination with prednisone. On follow up, the patient was found to be hypertensive with acute kidney injury, a creatinine of 3.65, proteinuria and hematuria. Renal ultrasound was unremarkable. Cytoplasmic ANCA was positive and kidney biopsy was performed revealing non pauci-immune focal proliferative and necrotizing glomerulonephritis with cellular crescents and mesangial dense deposits by electron microscopy. Conclusion: To our knowledge, the association between biopsy proven focal proliferative and necrotizing glomerulonephritis with primary Sjogren’s syndrome has never been previously described in the literature, nor has there been a reported case of association between Kimura disease, ANCA serology and primary Sjogren’s syndrome.

Scientific Reports 6: Article number: 26436; published online: 23 May 2016; updated: 14 November 2016 The original version of this Article contained errors in the affiliations. “Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, 701, Taiwan” was incomplete, and now reads

Perinatal cerebral hypoxic-ischemic (HI) injury damages the architecture of neurovascular units (NVUs) and results in neurological disorders. Here, we differentiated adipose-derived stem cells (ASCs) toward the progenitor of endothelial progenitor cells (EPCs) and neural precursor cells (NPCs) via microenvironmental induction and investigated the protective effect by transplanting ASCs, EPCs, NPCs, or a combination of EPCs and NPCs (E+N) into neonatal HI injured rat pups. The E+N combination produced significant reduction in brain damage and cell apoptosis and the most comprehensive restoration in NVUs regarding neuron number, normal astrocytes, and vessel density. Improvements in cognitive and motor functions were also achieved in injured rats with E+N therapy. Synergistic interactions to facilitate transmigration under in vitro hypoxic microenvironment were discovered with involvement of the neuropilin-1 (NRP1) signal in EPCs and the C-X-C chemokine receptor 4 (CXCR4) and fibroblast growth factor receptor 1 (FGFR1) signals in NPCs. Therefore, ASCs exhibit great potential for cell sources in endothelial and neural lineages to prevent brain from HI damage.

Little is known regarding the interplays between the mechanical and molecular bases for vein graft restenosis. We elucidated the stenosis initiation using a high-frequency ultrasonic (HFU) echogenicity platform and estimated the endothelium yield stress from von-Mises stress computation to predict the damage locations in living rats over time. The venous-arterial transition induced the molecular cascades for autophagy and apoptosis in venous endothelial cells (ECs) to cause neointimal hyperplasia, which correlated with the high echogenicity in HFU images and the large mechanical stress that exceeded the yield strength. The ex vivo perfusion of arterial laminar shear stress to isolated veins further confirmed the correlation. EC damage can be rescued by inhibiting autophagy formation using 3-methyladenine (3-MA). Pretreatment of veins with 3-MA prior to grafting reduced the pathological increases of echogenicity and neointima formation in rats. Therefore, this platform provides non-invasive temporal spatial measurement and prediction of restenosis after venous-arterial transition as well as monitoring the progression of the treatments.

Background In plastic surgery, skin flap is an important approach to reconstructive wound repairs. The rat dorsal skin flap is a clinically relevant and popular animal model to investigate and evaluate flap survival and necrosis. Nonetheless, flap survival is often unstable with unpredictable outcomes, regardless of previous attempts at design modification. Methods & Results In the present study, we report a novel flap chamber that provides stable and reproducible outcomes by separating the dorsal skin flap from its surrounding skin by in situ immobilization. The flap chamber blocks circulation that disturbs flap ischemia from both basal and lateral sides of the flap tissue. Demarcation of skin necrosis is macroscopically evident on the flap and supported by distinct changes in histological architecture under microscopic examination. The utility of the novel skin flap chamber is further proven by applying it to the examination of flap survival in streptozotocin-induced diabetic rats with an increase in skin necrosis. The flap chamber also affords size modifications where a narrower flap chamber increases ischemia and provides manipulable therapeutic windows for studying cell therapies. Accordingly, intradermal injection of endothelial cells 3 days before flap ischemia significantly increases the survival of skin flaps. Conclusions The novel flap chamber not only may stabilize the skin flap and provide reproducible outcomes that overcome the shortfalls of the traditional ischemic flap but also may afford size modifications that support research designs and test therapeutic approaches to regenerative repair.

Little is known regarding the interplays between the mechanical and molecular bases for vein graft restenosis. We elucidated the stenosis initiation using a high-frequency ultrasonic (HFU) echogenicity platform and estimated the endothelium yield stress from von-Mises stress computation to predict the damage locations in living rats over time. The venous-arterial transition induced the molecular cascades for autophagy and apoptosis in venous endothelial cells (ECs) to cause neointimal hyperplasia, which correlated with the high echogenicity in HFU images and the large mechanical stress that exceeded the yield strength. The ex vivo perfusion of arterial laminar shear stress to isolated veins further confirmed the correlation. EC damage can be rescued by inhibiting autophagy formation using 3-methyladenine (3-MA). Pretreatment of veins with 3-MA prior to grafting reduced the pathological increases of echogenicity and neointima formation in rats. Therefore, this platform provides non-invasive temporal spatial measurement and prediction of restenosis after venous-arterial transition as well as monitoring the progression of the treatments.

Intradermal adipose tissue plays an essential role for hair follicles (HFs) regeneration by regulating hair cycles. However, the effect of reconstruction of HFs and the involvement of adipose-related cells are poorly understood. We investigated assembly strategies for the interactions of dermal papilla (DP) cells with adipose-derived stem cells (ASCs) in promoting hair formation. DP cells lose DP traits during adherent culture, but preserved DP markers with a unified sphere diameter by seeding on chitosan-coated microenvironments. Next, ASCs isolated from rats were co-cultured with DP spheres by different assembling approaches to determine their interactions; a mixed sphere of ASCs with DP cells (MA-DPS), or a core-shell structure, outer ASCs shell and an inner DP core (CSA-DPS). CSA-DPS exhibited superior DP characteristics compared to MA-DPS. Conditional medium from ASCs, but not differentiated adipocytes, promoted DP markers and functional alkaline phosphatase activity from the DP cells. In vivo patch assay showed the core-shell assembling of CSA-DPS can reconstruct cellular arrangements and microenvironmental niches as dominated by PPARα signal in ASCs to induce the greater hair induction than MA-DPS or DP spheres alone. Therefore, the assembling of a core-shell sphere for DP with ASCs could reconstruct the HF cellular arrangement for hair formation. This paper set the groundwork for further evaluation of the input of other cell types.

Lung adenocarcinoma cells harboring epidermal growth factor receptor (EGFR) mutations are sensitive to EGFR tyrosine kinase inhibitors (TKIs), including gefitinib. Acquired resistance to EGFR-TKIs develops after prolonged treatments. The study was prompt to explore effective strategies against resistance to EGFR-TKIs. We established gefitinib resistant PC-9 cells which harbor EGFR exon 19 deletion. Known mechanisms for intrinsic or acquired EGFR-TKI resistance, including KRAS mutation, HER2 mutation, EGFR T790M mutation and MET gene amplification, were studied, and we did not observe any known mechanisms for intrinsic or acquired resistance to EGFR-TKIs in the resistant cells. In the parental PC-9 cells, labeled as PC-9/wt, gefitinib completely inhibited EGF-induced phosphorylation of EGFR, AKT and ERK. Gefitinib inhibited EGFR phosphorylation, but was unable to block EGF-induced phosphorylation of ERK in resistant cells, labeled as PC-9/gef cells, including PC-9/gefB4, PC-9/gefE3, and PC-9/gefE7 subclones. We detected NRAS Q61K mutation in the PC-9/gef cells but not the PC-9/wt cells. MEK inhibitors, either AZD6244 or CI1040, inhibited ERK phosphorylation and sensitized gefitinib-induced cytotoxicity in PC-9/gef cells. Whereas MEK inhibitors or gefitinib alone did not activate caspases in PC-9/gef cells, combination of gefitinib and AZD6244 or CI1040 induced apoptosis. Our in vivo studies showed that gefitinib inhibited growth of PC-9/wt xenografts but not PC-9/gef xenografts. Furthermore, combination of a MEK inhibitor and gefitinib inhibited growth of both PC-9/wt xenografts and PC-9/gefB4 xenografts. To conclude, persistent activation of ERK pathway contributes to the acquired gefitinib-resistance. Combined treatment of gefitinib and MEK inhibitors may be therapeutically useful for acquired gefitinib-resistance lung adenocarcinoma cells harboring EGFR mutations.

Voltage-controlled neuromuscular electrical stimulation has been considered to be safer in noninvasive applications notwithstanding the fact that voltage-controlled devices purportedly generate forces less predictable than their current-controlled equivalents. This prompted us to evaluate relevant electrical parameters to determine whether forces induced by voltage-controlled stimuli were able to match to those induced by current-controlled ones, which tend to evoke forces that were more predictable. Force magnitudes corresponding to current- and voltage-controlled stimuli were aligned with respect to electric charge (equivalent to average current intensity) and electrical energy (equivalent to average power) of the same stimulation pulse to determine which provided a better coherence. Consistency of forces evaluated with energy was significantly (p

The polyphenols in mulberry leaf possess the ability to inhibit cell proliferation, invasion, and metastasis of tumors. It was reported that the p53 status plays an important role in switching apoptosis and the cell cycle following adenosine monophosphate-activated protein kinase (AMPK) activation. In this study, we aimed to detect the effect of the mulberry leaf polyphenol extract (MLPE) on inducing cell death in p53-negative (Hep3B) and p53-positive (Hep3B with transfected p53) hepatocellular carcinoma cells and also to clarify the role of p53 in MLPE-treated cells. After treatment of the Hep3B cells with MLPE, apoptosis was induced via the AMPK/PI3K/Akt and Bcl-2 family pathways. Transient transfection of p53 into Hep3B cells led to switching autophagy instead of apoptosis by MLPE treatment. We demonstrated that acridine orange staining and protein expressions of LC-3 and beclin-1 were increased in p53-transfected cells. These results implied induction of apoptosis or autophagy in MLPE-treated hepatocellular carcinoma cells can be due to the p53 status. We also found MLPE can not only activate AMPK but also diminish fatty acid synthase, a molecular target for cancer inhibition. At present, our results indicate MLPE can play an active role in mediating the cell death of hepatocellular carcinoma cells and the p53 might play an important role in regulating the death mechanisms.

Background. Individuals with incomplete spinal cord injury (SCI) are predisposed to muscle fatigue during voluntary exercise. However, the origin of fatigue is unclear. Objective. The authors examined the motoneuron excitability, muscle activation level, and fatigue properties of the flexor carpi radialis muscle, just below the level of injury. Methods. Nine individuals with chronic, incomplete cervical cord injury and 9 age-matched healthy individuals were recruited. The authors tested maximum voluntary contraction (MVC), motoneuron excitability by the maximum amplitude of the H-reflex (Hmax at C-7), and muscle voluntary activation level measured by the interpolated twitch technique. Subjects were fatigued by repetitive maximal voluntary isometric wrist flexion. General fatigue index (GFI), central fatigue index (CFI), and peripheral fatigue index (PFI) of flexor carpi radialis were examined before, during, and immediately after exercise. Results. The Hmax in the SCI group was significantly higher ( P = .0028) than in controls. The MVC ( P < .001) and voluntary activation level ( P = .016) in the SCI group were significantly lower. The GFI and CFI decreased in both the SCI and the non-SCI groups. The PFI in the SCI group was significantly higher (ie, less fatigue) than that in controls at 30 repetitive contractions. Conclusions. In individuals with incomplete SCI, the deficit in central drive is an important source of muscle weakness and fatigue in the muscle below the level of injury.

Background. Muscle fatigue prevents repetitive use of paralyzed muscle after spinal cord injury (SCI). Objective. This study compared the effects of hybrid patterns of muscle stimulation in individuals with acute and chronic SCI. Methods. Individuals with chronic (n = 11) or acute paralysis (n = 3) underwent soleus muscle activation with a constant (CT) or doublet (DT) stimulation train before and at various times after a fatigue protocol. Results. The chronically paralyzed soleus was highly fatigable with a fatigue index (FI) of 19% ± 6%, whereas the acutely paralyzed soleus was fatigue resistant (FI = 89% ± 8%). For the chronically paralyzed group, the DT protocol caused less than 5% improvement in peak and mean force relative to the CT protocol before fatigue; however, after fatigue the DT protocol caused an increase in peak and mean force (>10%), compared with the CT protocol ( P < .05). As the chronically paralyzed muscle developed low-frequency fatigue, the DT protocol became more effective than the CT protocol ( P < .05). The DT protocol increased the rate of torque development before fatigue (42% ± 78%), after fatigue (62% ± 52%), and during recovery (87% ± 54% to 101% ± 56%; P < .05). The acutely paralyzed group showed minimal change in peak and mean torque with the DT protocol. Conclusions. Chronic reduced activity is associated with muscle adaptations (slow to fast) that render the muscle more amenable to force enhancement through doublet train activation after fatigue. These findings are applicable to patients using neuromuscular stimulation.

Hypotension is frequently reported during hemodialysis. This study aimed to examine the effect of the intermittent pneumatic circulator on blood pressure during hemodialysis. Sixteen subjects with chronic hemodialysis were recruited. Each subject randomly received two test conditions on separate days, hemodialysis with and without the circulator. The circulator was applied to the subject on lower extremities during 0.5–1 hr, 1.5–2 hr, 2.5–3 hr, and 3.5–4 hr of hemodialysis. Systolic and diastolic blood pressures (SBP and DBP) and heart rate (HR) were analyzed at pre-dialysis, 1 hr, 2 hr, and 3 hr of hemodialysis. Stroke volume (SV) and cardiac output (CO) were evaluated between 2.5 and 3.0 hr of hemodialysis. Blood chemicals (sodium, calcium, potassium, and phosphorous) and Kt/V before and after each hemodialysis session were analyzed. The number of episodes of hypotension was also recorded. The circulator intervention significantly improved SBP and DBP across all time points (P = 0.002 for SBP, P = 0.002 for DBP). The frequency of hypotension was significantly decreased (P = 0.028). SV and CO were significantly improved with the circulator intervention (P = 0.017 for SV, P = 0.026 for CO) and no statistical significances were found on blood chemicals or Kt/V analyses. The results suggested that the circulator intervention helps stabilize blood pressure and appears to be a practical treatment. Future studies are suggested to develop new circulator innovations with sensor feedback systems to enhance safety and maximize treatment efficiency.

Objective Falling is an important health maintenance issue for the elderly and people with movement disorders, strokes and multiple sclerosis. With the development of light, low-cost wearable technology, inertia-based fall detection has gained much attention. However, some large movements, such as jumping and postural changes, are frequently confounded with falls. For example, commonly used fall detection methods based on acceleration amplitude produce a large number of false alerts unless they are combined with post-fall posture identification. In this paper, we propose two new inertial parameters to improve the selectivity of threshold-based fall detection methods, and evaluate strategies to distinguish falls from other activities of daily life (ADLs). Approach We define two new inertial parameters, acceleration cubic-product-root magnitude (ACM) and angular velocity cubic-product-root magnitude (AVCM). Along with acceleration magnitude (AM), we test threshold-based fall detection methods based on single parameters and combinations. We collected inertial data on four types of simulated falls and eight types of ADLs from a study with 15 participants wearing a chest-mounted sensor with accelerometer and gyroscope. Two public datasets, UMAFall and Cognent Labs, were also included to evaluate fall detection methods. Main results We chose the detection threshold with 99% sensitivity and the best possible specificity. The hybrid of AM, ACM and AVCM method had a lower rate of misclassification than single-parameter methods. Leave-one-out cross-validation shows that the hybrid fall detection method can achieve both high specificity and high sensitivity. Significance Using multiple inertial parameters improves the specificity of fall detection.

Background Fatigue is a common symptom in the general population and has a substantial effect on individuals’ quality of life. The Multidimensional Fatigue Inventory (MFI) has been widely used to quantify the impact of fatigue, but no Traditional Chinese translation has yet been validated. The goal of this study was to translate the MFI from English into Traditional Chinese (‘the MFI-TC’) and subsequently to examine its validity and reliability. Methods The study recruited a convenience sample of 123 people from various age groups in Taiwan. The MFI was examined using a two-step process: (1) translation and back-translation of the instrument; and (2) examination of construct validity, convergent validity, internal consistency, test-retest reliability, and measurement error. The validity and reliability of the MFI-TC were assessed by factor analysis, Spearman rho correlation coefficient, Cronbach’s alpha coefficient, intraclass correlation coefficient (ICC), minimal detectable change (MDC), and Bland-Altman analysis. All participants completed the Short-Form-36 Health Survey Taiwan Form (SF-36-T) and the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) concurrently to test the convergent validity of the MFI-TC. Test-retest reliability was assessed by readministration of the MFI-TC after a 1-week interval. Results Factor analysis confirmed the four dimensions of fatigue: general/physical fatigue, reduced activity, reduced motivation, and mental fatigue. A four-factor model was extracted, combining general fatigue and physical fatigue as one factor. The results demonstrated moderate convergent validity when correlating fatigue (MFI-TC) with quality of life (SF-36-T) and sleep disturbances (PSQI) (Spearman's rho = 0.68 and 0.47, respectively). Cronbach’s alpha for the MFI-TC total scale and subscales ranged from 0.73 (mental fatigue subscale) to 0.92 (MFI-TC total scale). ICCs ranged from 0.85 (reduced motivation) to 0.94 (MFI-TC total scale), and the MDC ranged from 2.33 points (mental fatigue) to 9.5 points (MFI-TC total scale). The Bland-Altman analyses showed no significant systematic bias between the repeated assessments. Conclusions The results support the use of the Traditional Chinese version of the MFI as a comprehensive instrument for measuring specific aspects of fatigue. Clinicians and researchers should consider interpreting general fatigue and physical fatigue as one subscale when measuring fatigue in Traditional Chinese-speaking populations.

Falls are a major health concern leading cause of fatal and non-fatal injuries for neurological disorders. Balance dysfunction is one of the common factors to determine fall risk in neurological patients. Preventative measures may help to reduce the incidence and severity of falls for detecting balance function and fall risk factors. However, the objective measures for balance require expensive equipment with the assessment of clinical expertise. A main gap remains in the evaluation method to objectively characterize the balance functions in individuals with high risk of falling. With the development of wearable and mobile devices, recent advances in smart mobile devices may provide a potential opportunity to manage the gap in the detailed quantification of balance impairments. The purpose of this study is to identify whether the biomechanical data measured by the mobile device is reliable to characterize the posture stability in various balance test conditions. A total of 39 children with Down syndrome completed four balance-testing tasks under altered base of support and vision. Simultaneous biomechanical measurements were gathered from the iPod and force plate analysis system during functional balance testing. The force plate and mobile system provided similar patterns of stability across groups. Correlation ([Formula: see text] between two systems for path length, 95% ellipse area, peak-to-peak, standard deviation and mean ranged from 0.60 to 0.99. We expect that the smart mobile device can provide reliable and accurate information to quantify the postural stability in individuals with elderly people or neurological disorders. The objectivity, portability and easy use of such mobile device make it ideal to apply in clinical environments for detecting balance functions and reducing the risk of falls in Down syndrome or other neurological patients.

Interpolated twitch technique (ITT) is a non-invasive method for assessing the completeness of muscle activation in clinical settings. Voluntary activation level (VA), measured by ITT and estimated by a conventional linear model, was reported to have a non-linear relationship with true voluntary contraction force at higher activation levels. The relationship needs to be further clarified for the correct use by clinicians and researchers. This study was to established a modified voluntary activation (modified VA) and define a valid range by fitting a non-linear logistic growth model. Eight healthy male adults participated in this study. Each subject performed three sets of voluntary isometric ankle plantar flexions at 20, 40, 60, 80 and 100% maximal voluntary contraction (MVC) with real-time feedback on a computer screen. A supramaximal electrical stimulation was applied on tibia nerve at rest and during contractions. The estimated VA was calculated for each contraction. The relationship between the estimated VA and the actual voluntary contraction force was fitted by a logistic growth model. The result showed that according to the upper and lower limit points of the logistic curve, the valid range was between the 95.16% and 10.55% MVC. The modified VA estimated by this logistic growth model demonstrated less error than the conventional model. This study provided a transfer function for the voluntary activation level and defined the valid range which would provide useful information in clinical applications.

The purpose of this study was to evaluate whether agonist muscle fatigue changed the coactivation time and the co-contraction magnitude of the agonist and antagonist muscle, and if the agonist muscle fatigue produced bias (constant error: CE) and inconsistency (variable error: VE) of the force. Subjects are 10 healthy people and one person with impaired proprioception. EMG and force for fast (0.19 ± 0.06 s) and slow (1.20 ± 0.44 s) targeted isometric dorsiflexions were recorded before and after fatigue of the dorsiflexors. The results revealed that the coactivation time increased after fatigue only in the slow contractions but the co-contraction magnitude did not change. The postfatigue increment of the CE was greater in the fast contractions than in the slow ones. We conclude that the postfatigue compensatory strategy can reduce the fatigue-induced bias. The change of muscles activation level after fatigue might be under the influence of the common drive. Impaired proprioception is a possible cause of the fatigue-related increase in bias and inconsistency.