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BACKGROUND: Although millions of people with osteoarthritis (OA) have altered biomechanical alignment, movement, and knee joint pain during gait, there are no effective and sustainable interventions. To mitigate such impairments, we developed an untacted self-automated robotic and electromyography (EMG)-augmented upper-trunk-lower reciprocal locomotor training (SRGT) intervention. OBJECTIVE: To compare the effects of SRGT and conventional treadmill gait training (CTGT) on the medial knee joint space width (JSW), hip adduction moment (HAM), knee varus deformity, pain, and physical function in community-dwelling older adults with OA. METHODS: Older adults diagnosed with medial compartment knee OA (5 men, 35 women; mean age = 78.50 ± 9.10 years) were recruited and underwent either SRGT or CTGT, 30 min a day, 3 times a week, over a 4-week period. Outcome measurements included the JSW, HAM, knee varus angle (VA), and Western Ontario McMaster Universities osteoarthritis index (WOMAC). RESULTS: Analysis of covariance (ANCOVA) showed that SRGT ed to greater changes in medial knee JSW (p= 0.00001), HAM (p= 0.00001), VA (p= 0.00001), and WOMAC (p= 0.00001) scores. CONCLUSION: This study provides the first evidence for the long-term clinical and biomechanical effects of SRGT on JSW, knee joint kinematics, kinetics, and WOMAC scores in older adults with OA. Most importantly, self-automatic robotic gait training may be an alternative, effective, and sustainable treatment for the upper-trunk-lower reciprocal locomotor training in older adults with OA.

Cracks are common in nature. Cracking is known as an irreversible and uncontrollable process. To control the cracking patterns, many researchers have proposed methods to prepare notches for stress localization on films. In this work, we investigate a method of controlling cracks by making microscale pyramid patterns that have notches between the pyramids. After preparing pyramid patterns consisting of colloidal particles with organic residue, we annealed them to induce volume shrinkage and cracking between the pyramids. We studied the effect of film thickness on cracking and the generation of rectangular fragments consisting of multiple pyramids. The area of rectangular fragments was in good agreement with the results of scaling analysis. The concept of controlling cracks by imprinting notches on a film and the relationship with the film thickness can guide the study of cracking phenomena.

Microneedles (MNs) are micron-sized needles that can penetrate the stratum corneum, enabling the non-invasive and painless administration of drugs and vaccines. In this work, fabrication conditions for high-aspect-ratio MNs by the photopolymerization of polyethylene glycol diacrylate (PEGDA) were investigated. Ultraviolet (UV) light was used to crosslink photocurable prepolymers in specific areas defined by a photomask. The aspect ratio of solidified MNs is too small to penetrate the stratum corneum if the degree of polymerization is insufficient. However, if the degree of polymerization is too high, a film is formed between the MNs by solidification of an undesired area owing to the scattering effect, reducing needle height. The influence of prepolymer molecular weight and the degree of UV absorption by the photoinitiator (PI) were studied to optimize the conditions for obtaining high-aspect-ratio MNs. Additionally, the effect of spacing ratio on high-aspect-ratio MNs without film formation has been discussed. A penetration test was conducted with porcine skin to analyze the effect of mechanical properties of MN. This study could guide the fabrication of MNs by the photopolymerization of biocompatible polymers with a photomask.

Liquid-mediated patterning, which is a fabrication method exploiting the nature of liquids, has achieved great advances in unconventional micro- and nano-fabrication techniques. The easily deformable nature of liquids enables template-based...

With the development of IoT devices, wearable devices are being used to record various types of information. Wearable IoT devices are attached to the user and can collect and transmit user data at all times along with a smartphone. In particular, sensitive information such as location information has an essential value in terms of privacy, and therefore some IoT devices implement data protection by introducing methods such as masking. However, masking can only protect privacy to a certain extent in logs having large numbers of recorded data. However, the effectiveness may decrease if we are linked with other information collected from within the device. Herein, a scenario-based case study on deanonymizing anonymized location information based on logs stored in wearable devices is described. As a result, we combined contextual and direct evidence from the collected information. It was possible to obtain the result in which the user could effectively identify the actual location. Through this study, not only can a deanonymized user location be identified but we can also confirm that cross-validation is possible even when dealing with modified GPS coordinates.

Both iliopsoas (IL) and quadratus lumborum (QL) muscle tightness are associated with lower back pain, which limit activities of daily life, such as squatting and walking. High-frequency diathermy (HFD) treatment generates heat as a result of molecular vibrations in deep soft tissues. HFD increases blood flow and tissue flexibility following muscle relaxation, and improves pain thresholds by lessening pain and facilitating maximum muscle stretch without destruction. We examined the effectiveness of HFD therapy on pain in the IL and QL in nonsymptomatic participants with IL tightness. A convenience sample of 15 nonsymptomatic participants with IL tightness ([Formula: see text], [Formula: see text] years) was recruited, based on participants obtaining a positive value on the Thomas test. The treatment was applied to each muscle (IL and QL) for 15[Formula: see text]min: 5[Formula: see text]min of capacitive mode was applied, and 10[Formula: see text]min of resistive mode was subsequently applied using the WINBACK tool. The whole participants were assessed pre- and post-intervention. Clinical variables contained visual analog scale (VAS) scores. The Wilcoxon signed-rank test was used to analyze the VAS scores, to determine whether HFD influenced pain control. The alpha value was set at 0.05. A significant reduction in IL and QL pain was observed when HFD was applied to participants ([Formula: see text]). Our findings offer therapeutic proof that HFD is effective in controlling IL and QL pain in participants with IL tightness.

BACKGROUND: Impaired sensory in acute stroke patients results in dynamic balance, gait and activities of daily living (ADL) impairment. OBJECTIVE: The aim of present study was to examine the correlation between somatosensory-evoked potential (SSEP) parameters and motor recovery in balance, gait and ADL performance in hemiparetic stroke survivors. METHODS: One hundred and one participants with hemiparetic stroke (43 males, 58 females; mean age, 6538 ± 1222 years; post-stroke duration, 199 ± 0.74 month) participated in this study. The Electro Synergy system (Viasys Healthcare; San Diego, CA, USA) was applied to measure SSEP measurement. The 101 stroke survivors were divided into three groups consistent with their SSEP results: sensory normal group; sensory impaired group; sensory absent group. All the subject participated the inpatient rehabilitation intervention for 4 weeks. Analyses of variance (ANOVA) were used to verify the group difference among the three groups after the treatment. RESULTS: ANOVA revealed the significant difference (p< 0.01). The Scheffe test demonstrated that the sensory normal group showed greater increasement in Modified Barthel Index (MBI), Fugl-Myer Assessment (FMA), Trunk Impairment Scale (TIS), Berg Balance Scale (BBS) and Functional Ambulation Category (FAC) scores than the sensory impaired and absent group (p< 0.05). CONCLUSIONS: Our research provides therapeutic evidence that correlation of somatosensory functions on motor recovery, balance, gait, and ADL in patients with hemiplegic stroke.

When various optically and/or electronically active materials, such as conjugated polymers, perovskites, metals, and metal oxides, are confined at the nanoscale, they can exhibit unique nano-confined behavior that significantly differs from the behavior observed at the macroscale. Although controlled nano-confinement of functional materials can allow modulation of their electronic properties without the aid of any synthetic methodologies or additional chemical treatments, limited assembly approaches for nano-confinement and insufficient analytical tools for electronic characterization remain critical challenges in the development of novel optoelectronic materials and the investigation of their modulated properties. This review describes how the nano-confined features of organic and inorganic materials are related to the control and improvement of their optoelectronic properties. In particular, we focus on various assembly approaches for effective nano-confinement as well as methods for nano-electronic characterization. Then, we briefly present challenges and perspectives on the direction of nano-confinement in terms of the preparation of optoelectronic materials with desired functionalities. Furthermore, we believe that this review can provide a basis for developing and designing next-generation optoelectronics through nano-confinement.

Due to the increasing energy consumption, smart technologies have been considered to automatically control energy loss. Smart windows, which can use external signals to modulate their transparency, can regulate solar energy by reflecting excess energy and retaining the required energy in a building without using additional energy to cool or heat the interiors of the building. Although many technologies have been developed for smart windows, they still need to be economically optimised. Here, we propose a facile method to synthesise magnetic microrods from magnetic nanoparticles by alignment using a magnetic field. To maximise the transparency difference in the ON and OFF states, we controlled the nanoparticle concentration in a dispersion liquid, magnetic field application time, and viscosity of the dispersant. Interestingly, the magnetic microrods remained stable when we mixed short-chain polymers (polyethylene glycol) with a liquid dispersant (isopropyl alcohol). Furthermore, the Fe2O3 microrods maintained their shape for more than a week, while the Fe3O4 microrods clustered after a day because they became permanent magnets. The anisotropic features of the magnetic rods were used as a light valve to control the transparency of the smart window.

This paper describes a facile method for fabricating polyaniline (PANI) films with well-defined three-dimensional (3D) porous networks and improved electrochemical activity. The PANI hydrogel pastes with different compositions are directly cast into thin films by the doctor blade technique. After a dehydration step, the conductivity of the PANI drastically increases, while the porous structure with hierarchical macro- and meso-porosity is formed in the PANI film. The electrical conductivity tends to increase with the thickness of the porous PANI film until it fails to form a mechanically stable film not exhibiting cracking problems. We found that the amount of the initiator, the aniline monomer, and the crosslinker significantly affect not only the micro-morphology of PANI films, but also their electrical and electrochemical characteristics. Importantly, when the amounts of the crosslinker and the initiator increase, the polymer film forms with a dense internal morphology with smaller pores. Based on the engineered synthesis composition, we demonstrate a supercapacitor with porous PANI electrodes. Due to the hierarchical porous structure, large surface area and the improved conductivity, the resulting devices show excellent volumetric capacitances, which are comparable to or much higher than those previously reported.

BACKGROUND: Although patients with frozen shoulders have the range of motion (ROM) of their shoulder’s abduction movements measured at hospital and the physical therapy visits, multiple visits to check for progress is often difficult. Thus, we developed an artificial intelligence-based image recognition detectable sensor (AIRDS) intended for easy use at home. OBJECTIVE: The purpose of this study was to determine the accuracy of a sensor (AIRDS) measuring shoulder abduction angle, thus offering a valid and feasible system for monitoring patients with frozen shoulder. METHODS: Ten patients with frozen shoulder (5 males, 5 females) performed shoulder joint movements while being measured with the AIRDS system and the 3-dimensional Vicon system. The measure of the outcome included the linear regression of the shoulder abduction joint kinematics. RESULTS: Linear regression analysis of the AIRDS system and the Vicon system demonstrated a significant correlation coefficient of R2= 0.9979 (P< 0.05). CONCLUSIONS: Our results provide novel, promising evidence that AIRDS can accurately measure the timing and total spatial characteristics of clinical movements. AIRDS is designed to provide real-time ROM measurements for joint mobility using artificial intelligence instead of the judgement of the physical therapist.

Knee osteoarthritis (OA) is a degenerative articular disease. The knee joint space width (JSW) is used for grading the severity of knee OA. However, there is a lack of research on differences in the widths of knee joints between both lower limbs in unilateral OA. The purpose of this research was to examine the radiological difference in the affected knee joint and contralateral knee joint by analyzing unilateral older adults with medial knee OA using both knees’ JSW differences. Twenty-five subjects with unilateral medial knee OA participated. X-ray radiographs were used to assess knee JSW, and the paired [Formula: see text]-test was performed to assess the knee joint gap width between the affected side and the unaffected side in the respective medial and lateral sides. The independent [Formula: see text]-test compared the differences between the lateral and medial knee JSWs on the affected side and unaffected side. The paired [Formula: see text]-test did not show a significant difference in the medial and lateral knee JSW on the affected side compared to the unaffected side ([Formula: see text]; 0.11). Meanwhile, the independent [Formula: see text]-test revealed a significant difference between the affected and unaffected sides ([Formula: see text]). This study showed no significant changes in affected knee JSWs compared to unaffected sides, but the difference between the lateral and medial JSWs was significant between the knees affected and unaffected by OA in the older adults with medial knee OA.

Background: Cervical dysfunction is a common pathomechanical marker in individuals with forward head posture (FHP). To overcome the limitations of the isometric chin-tuck (ICT) exercise, dynamic neuromuscular stabilization (DNS), which emphasizes an entire spinal chain exercise, has recently shown promising clinical results.Objects: Purpose of this study was to compare the immediate effects between ICT and DNS techniques. Methods: 43 young subjects (mean age, 24.0±5.0 years) were recruited. Group of subjects with FHP were measured under baseline, ICT, and DNS conditions. Outcome measures included sitting height, longus colli (LC) and sternocleidomastoid (SCM) muscle thickness and LC/SCM thickness ratio. One-way repeated measures ANOVA was used to compare the continuous dependent variables among FHP, ICT, and DNS conditions at p

This study analyzed how Korea’s quarantine policy manages personal information to prevent and control COVID-19. Korea effectively halted the spread of COVID-19 through epidemiological investigations and cell-broadcast systems. In this process, the route of infection is presented without identifying the patient, and the necessary participants are selected only through authentication. We found a correlation between the number of emergency text messages sent by the Ministry of Interior and Safety in 2020 and the number of confirmed cases (R2 = 0.465, p < 0.001). Based on Korea’s case, we propose a new concept for solving the personal information problems that might arise during a pandemic response.

The importance of core stabilization exercises for extremities associated with dynamic spinal stabilization prior to movement has been demonstrated. However, no previous studies have investigated the muscle-coordinated effects on the upper trapezius (UT), anterior deltoid (AD), pectoralis major (PM), bilateral transverse abdominis (TrA), bilateral internal oblique (IO), and bilateral external oblique (EO) in healthy adults. The purpose of this study was to compare the effects of the dynamic neuromuscular stabilization (DNS) breathing technique and the abdominal bracing (AB) technique on UT, AD, PM, bilateral IO/TrA, and bilateral EO motor control in healthy participants during horizontal shoulder adduction. Thirty-six participants, eight of whom were female, were randomized into an AB and a DNS group and performed horizontal shoulder adduction with loads (8 and 17 lb). The clinical outcomes were UT, AD, and PM muscle activation and TrA/IO and EO muscle activation. Paired t-tests were used to analyze electromyography (EMG) data to determine statistically significant differences in muscle activity between the two techniques. For the EMG analysis, the maximal voluntary isometric contraction was measured for normalization and then divided by the EMG amplitude value. The results showed that UT, AD, and PM muscle amplitudes were lower and TrA/IO and EO muscle amplitudes were higher with DNS than with AB ([Formula: see text]). Our findings provide clinical evidence that core exercise with DNS is more effective in lessening UT, AD, and PM muscle activation and improving bilateral TrA/IO motor control than with AB.

The production of hierarchical structures has an important role for applications such as superhydrophobic surfaces, structural colors, and energy devices. Microscale wrinkling of surfaces decorated by nanoscale patterns can be one of the most efficient methods to realize hierarchical structures. Here, we investigate wrinkling of films embedding anisotropic nanopatterned surfaces prepared by nanoimprint lithography. After transferring nanoimprinted polystyrene thin films onto stretched elastomeric substrates, we achieve microscale wrinkles by releasing the strain. We examine the anisotropic wrinkles of well-defined nanolines with various widths, heights, and spacing ratios and propose a model that considers only bending stiffness of the patterned film. We compare the approach with a model that considers inplane stiffness and confirm that our scheme matches well with that of nanopatterns with thin residual layers.

Mechano-optical materials are of great importance in smart window, security, display and camouflages. However, fabricating ultrasensitive optical devices with wide range still remains great challenging. Inspired from the fast tail amputation of gecko utilizing weak non-ossificated septum, herein, we report an ultrasensitive mechano-optical membrane based on weak dye layer between silica nanoparticles and soft polydimethylsiloxane matrix. Owing to the light scattering from dye-induced internal cavitation, the transmittance dramatically decreases by ～44% at initial small strain level (15%) and a high sensitivity (S > 2) is kept within an abroad strain range (0～35%). Moreover, a high total transmittance tuning range of ～75% is exhibited. Simulation and experimental monitoring demonstrate the effective weakening of interface energy. The potential applications in smart window, sensor, anti-counterfeiting also exhibit the multifunctionality of our smart membranes. This facile and low-cost approach enables the large-scale production and applications of mechano-optical membranes and this interface design provides a general way to develop ultrasensitive mechano-responsive materials.

This study was conducted to investigate the effects of the degree of dual-task (DT) interference on gait, dual-task cost (DTC), cognitive ability, balance, and fall efficacy in people with stroke. In this cross-sectional study, people with chronic stroke (N = 36) performed a DT gait assessment (gait and cognitive task). During the evaluation, DT interference in motor and cognition was evaluated simultaneously. Thus, the group with severe interference in both tasks (mutual interference) was compared with the group with mild interference in either. The main effects for the degree of motor interference were observed on gait performance, DTC in motor, time up and go, and trail-making test B. In the cognitive interference, the main effects were observed on correct response rate, DTC in cognition, time up and go, and trail-making test B. An interaction effect was observed in the trail-making test B. The degree of motor interference affected gait, balance ability, and executive function (EF), and the degree of cognitive interference influenced the correct response rate in the DT condition, balance ability, and EF. Furthermore, mutual interference led to a significant reduction in EF in people with stroke.

The 3D printing of biocompatible materials is very promising due to their potential for use in biological applications, such as the development of artificial organs. Among various 3D printing methods, stereolithography is a good candidate due to its ability to produce high-resolution structures. Although the 3D printing of hydrogels has been investigated, few studies on printing complex structures have been conducted. In this study, we investigate various challenges during the construction of complex structures such as tilted ratchets and ladders which has T-shapes using UV-curable PEG materials as well as the mechanisms to address these problems. We study the effect of UV absorbing pigments to control the UV penetration depth and the relation with the slice thickness. Also, we design ladder-type structures with different neck widths to verify the mechanical strength of the prepared hydrogel polymers.

Cracks observed in brittle materials are mostly regarded as defects or failures. However, they can be a valuable tool when implemented in a controlled way. Here, we introduce a strategy to control the crack propagation of mesoporous micropatterns (prisms and pyramids), which leads to the isolation of well-defined microstructures. Mesoporous micropatterns were fabricated by the soft imprinting technique with wet TiO2 nanoparticle (NP) pastes, followed by sintering to remove organic components. Since the volume of the paste significantly shrinks during the sintering step, stress is localized at the edge of micropatterns, in good agreement with finite element method simulations, creating well-defined cracks and their propagation. It was demonstrated that the degree of stress localization is determined by the thickness of residual layers, NP size, and heating rate. After controlled crack propagation and delamination of microparticles from the substrates, mesoporous microwires and microparticles were successfu...

The unidirectional clustering induced by capillary force of drying liquids between pillars is investigated and a theoretical model to set a criterion of the unidirectional clustering of the slanted nanopillars is proposed.

Generally, the fabrication of curved structures such as microlens arrays has been regarded as an expensive and complicated process. Here, we propose a facile method to form a microlens array with controlled lens curvature by combining residue-free nanoimprint lithography (NIL) with V-shaped molds and the successive thermal reflow procedure of the printed polymeric structures. The V-shaped molds used in this study enable the bottom substrate to be exposed after the NIL process when the initial thickness is controlled. Then, we use the thermal reflow to realize hemi-cylindrical curved lenses by applying heat. The polymers are self-pinned on the exposed substrate, which is strong enough to fix the boundary to not dewet or be flattened in the broad temperature range of the reflow process, which is essential for a large-area fabrication. Furthermore, we demonstrate the modulation of the focal lengths of the lenses by controlling the initial polymer thickness coated on a substrate.

The fabrication of nanoscale patterns over a large area has been considered important but difficult, because there are few ways to satisfy both conditions. Previously, visually tolerable tiling (VTT) for fabricating nanopatterns for optical applications has been reported as a candidate for large area fabrication. The essence of VTT is the inevitable stitching of the nanoscale optical component, which is not seen by the naked eye if the boundary is very narrow while the tiles are overlapped. However, it had been difficult to control the shape of the spread of liquid prepolymers in the previous work, and there was room for the development of tiling. Here, we propose a method for transferring various shapes of tiles, which can be defined with a shadow mask. The method of using a transparent shadow mask can provide a wide process window, because it allows the spreading of a liquid prepolymer to be more easily controlled. We optimize the coating condition of a liquid prepolymer and the ultraviolet (UV) exposure time. Using this method, we can attach tiles of various shapes without a significant visible trace in the overlapped region.

Here, we propose a simple mechanoresponsive system on patterned soft surfaces to manipulate both anisotropy and orientation of liquid wetting. On the poly(dimethylsiloxane) embedding line patterned structures, additional topographies, such as wrinkles and cracks, can be provided by applying compressive and tensile stress, respectively. This tunable hierarchy of structures with the different scales and directions of lines, wrinkles, and cracks allow the mechanoresponsive control of anisotropic wetting in a single platform. In addition, the wetting behavior on those surfaces is precisely investigated based on the concept of critical contact angle to overcome the ridges in a step flow.

High-aspect-ratio (HAR) nanopillars are of interest for wetting, adhesion, and energy harvesting due to their superior surface properties, including large surface area and high compliance. However, their intrinsically low mechanical stability has been a major obstacle for practical applications that require repeated use and in wet and humid environments. Herein, we show a method that can recover the clustered or deformed HAR nanopillars to their original shapes by taking advantage of the mechanical compliance of the nanopillars toward pulling during a demolding process. The pillars can be repeatedly clustered and recovered many times. Our method is simple yet powerful to recover the clustered nanopillars over a large area (7 × 10 cm2). By taking advantage of the different optical properties of the clustered pillars vs. the straight ones, we demonstrate display and erasing of patterns and tunable wettability by stamping the nanopillars to induce clustering, followed by shape recovery via demolding of the pillars.

Folds, highly deformed structures, have received extensive attention for their nonlinear responses due to a large strain on soft matters. To investigate the folding phenomena, here, we exploit residual tensile stress during metal deposition, which is large enough to compress a thin film coating and introduce a photocurable viscous fluid to decrease the resistance of the substrate against compressive stress. The system has the advantages of the abilities for freezing the highly deformed surfaces by post-UV exposure to the UV-crosslinkable substrate and manipulating the substrate effect by controlling the thickness of the substrate. We theoretically investigated the dependence on the substrate thickness using scaling analysis and demonstrated self-generated ladder and flower-like graphoepitaxial structures originated from the thickness design of the viscous substrate.

Asymmetric micro/nano structures in nature provide diverse multifunctional properties including directional water transport, light transmission and adhesion. Due to these intriguing features, the fabrication of an anisotropic surface has been extensively studied as a broad research area. Herein, we present a novel strategy to fabricate asymmetric ratchet-like polymeric structures with various tilting angles by using photo-polymerization and controlling light refraction. We used a prism array that allows directional light transmission through the refraction on one face of it. To construct symmetric ratchets by negating the refraction effect in a specific area, we filled the region of the array with a refractive index matching liquid. To make a ratchet structure with a higher tilting angle, we used two films of the designed prism arrays to refract twice. Furthermore, we demonstrate one step fabrication of ratchet structures with tilting angles of 0°, 24.4° and 49.7° through the combination of the refractive index matching method and double-refraction on two layers of prism arrays.

This paper introduces an FPGA self-test architecture reusing FPGA boundary scan chain as self-test circuits. An FPGA boundary scan cell is two or three times bigger than a normal boundary scan cell because it is used for configuring the function of input/output pins functions as well as testing and debugging. Accordingly, we analyze the architecture of an FPGA boundary scan cell in detail and design a set of built-in self-test (BIST) circuits in which FPGA boundary scan chain and a small amount of FPGA logic elements. By reusing FPGA boundary scan chain for self-test, we can reduce area overhead and perform a processor based on-board FPGA testing/monitoring. Experimental results show the area overhead comparison and simulation results.