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The worldwide proliferation of COVID-19 poses the urgent need for sterilizable and transparent air filters to inhibit virus transmission while retaining ease of communication. Here, we introduce copper nanowires to fabricate transparent and self-sterilizable air filters. Copper nanowire air filter (CNAF) allowed visible light penetration, thereby can exhibit facial expressions, helpful for better communication. CNAF effectively captured particulate matter (PM) by mechanical and electrostatic filtration mechanisms. The temperature of CNAF could be controlled by Joule-heating up to 100 °C with thermal stability. CNAF successfully inhibited the growth of E. coli because of the oligodynamic effect of copper. With heat sterilization, the antibacterial efficiency against G. anodireducens was greatly improved up to 99.3% within 10 min. CNAF showed high reusability with stable filtration efficiency and thermal antibacterial efficacy after five repeated uses. Our result suggests an alternative form of active antimicrobial air filter in preparation for the current and future pandemic situations.

A photothermal conversion of sol precursor by selective laser sintering (SLS) process has opened a novel patterning way for advanced electronic applications. The SLS process bases on the photo-thermal-chemical effect and features for high precision, fast processing, and room temperature processability without inert gas. Therefore, the effectiveness of the interaction between the nanomaterials and laser has examined on the various conductive metal nanomaterials such as gold, silver, and copper. Although the laser sintering process has shown many achievements on the metal nanomaterials, it has rarely studied for the interaction for the metal oxide nanomaterials. In this study, WOx thin film layer employs the SLS process for post-processing which enables patterning and annealing simultaneously with inducing photochemical redox reaction as well as photothermal effect. The SLS-processed WO3 thin film has shown similar electrochemical performances for the electrochromic application to the thermal annealed WO3 thin film. We have demonstrated a facile and fast fabrication of the electrochromic device (ECD) with the SLS-processed WO3 thin film layer.

The patterning of polydimethylsiloxane (PDMS) into complex two-dimensional (2D) or 3D shapes is a crucial step for diverse applications based on soft lithography. Nevertheless, mould replication that incorporates time-consuming and costly photolithography processes still remains the dominant technology in the field. Here we developed monolithic quasi-3D digital patterning of PDMS using laser pyrolysis. In contrast with conventional burning or laser ablation of transparent PDMS, which yields poor surface properties, our successive laser pyrolysis technique converts PDMS into easily removable silicon carbide via consecutive photothermal pyrolysis guided by a continuous-wave laser. We obtained high-quality 2D or 3D PDMS structures with complex patterning starting from a PDMS monolith in a remarkably low prototyping time (less than one hour). Moreover, we developed distinct microfluidic devices with elaborated channel architectures and a customizable organ-on-a-chip device using this approach, which showcases the potential of the successive laser pyrolysis technique for the fabrication of devices for several technological applications. A laser-based patterning method enables the fast fabrication of high-quality two- and three-dimensional features in polydimethylsiloxane for microfluidics and biomedical applications.

Our study aimed to confirm the therapeutic effects of using a trunk stabilization training robot (3DBT-33) in patients with chronic stroke. A total of 38 patients with chronic stroke were randomly assigned to either an experimental or a control group. The robot group (n = 19) received 30 min of trunk stability robot training in addition to conventional physical therapy, while the control group (n = 19) received a similar conventional physical therapy as the robot group. All participants were assessed using the following: the Functional Ambulation Categories (FAC), timed up and go (TUG) test, Berg Balance Scale (BBS), Korean Modified Barthel Index (K-MBI), and Fugl-Meyer Assessment of Lower Extremity (FMA-LE). There were statistically significant improvements in all parameters at follow-up assessment after 4 weeks of intervention (P < 0.05). There were statistically significant differences in the FMA-LE, K-MBI, and BBS between the robot and control groups (P < 0.05). There was no significant difference in FAC (P = 0.935) and TUG (P = 0.442). Minimal detectable change was more significantly observed in the FMA-LE and BBS than in FAC, TUG, and K-MBI. The findings in the present study showed that trunk stabilization rehabilitation training using a rehabilitation robot in patients with chronic stroke was effective in improving the balance and functions in the lower extremities.

The timing of transcranial direct current stimulation (tDCS) is essential for enhancing motor skill learning. Previously, tDCS, before or concurrently, with motor training was evaluated in healthy volunteers or elderly patients, but the optimal timing of stimulation has not been determined. In this study, we aimed to optimize the existing tDCS protocols by exploring the timing-dependent stimulation effects on finger movements in healthy individuals. We conducted a single-center, prospective, randomized controlled trial. The study participants (n = 39) were randomly assigned into three groups: tDCS concurrently with finger tapping training (CON), tDCS prior to finger tapping training (PRI), and SHAM-tDCS simultaneously with finger tapping training (SHAM). In all groups, the subjects participated in five 40-min training sessions for one week. Motor performance was measured before and after treatment using the finger-tapping task (FTT), the grooved pegboard test (GPT), and hand strength tests. tDCS treatment prior to finger tapping training significantly improved motor skill learning, as indicated by the GPT and hand strength measurements. In all groups, the treatment improved the FTT performance. Our results indicate that applying tDCS before training could be optimal for enhancing motor skill learning. Further research is required to confirm these findings.

A charge-domain SRAM-based CIM macro is proposed to implement efficient neural accelerator with variable input/weight/output precisions. A versatile All-Around-Wire-Capacitor (AAWC) is introduced to enable accurate charge-domain MAV operation with 1-5 bit variable-precision weight capability with 10T SRAM cell structure. The AAWC also allows variable-precision array-embedded 1-5 bit digital-to-analog (DA) conversion for input, and 1-6 bit analog-to-digital (AD) conversion for output without additional passive devices. Such array-embedded DA/AD conversion scheme significantly reduces area overhead and simplifies peripheral circuits to achieve high array efficiency while achieving high energy efficiency of 24-330 TOPS/W.

The electrolyte additive of LiPO2F2 was injected into 18,650 Li ion battery cells composed of LiNi0.6Co0.2Mn0.2O2/graphite at 25 °C to avoid the formation of the undesirable solid electrolyte interface (SEI) layer. The potential distribution on the cathode surface was studied using electric force microscopy. The average potential distribution on the surface of the cathode in the cell where the additive LiPO2F2 was injected showed ~ 100 mV higher potential than the average potential on the surface of the cathode in the cell without the additive. X-ray photoemission spectroscopy results showed that the average potential distribution characteristics were correlated with the chemical composition of the surface reactants. These results indicate that the LiPO2F2 additive controls the formation of the SEI layer on the surface of the LiNi0.6Co0.2Mn0.2O2 cathode during the electrochemical reaction in the cell and has the decisive effect of inhibiting the decomposition of LiPF6, which is the main component of the electrolyte solution. In this study, the addition of the LiPO2F2 additive to the electrolyte improves the electrochemical performance of the Li ion battery by improving the surface potential of the cathode surface and controlling the formation of the SEI layer on the surface of the LiNi0.6Co0.2Mn0.2O2 cathode.

Early researches have actively attempted to measure the thermal conductivity since the thermal conductivity of graphene was predicted to be extremely higher than that of any other existing materials. At the beginning of graphene discovery, the characterization of thermal properties of graphene was extremely challenging work due to its atomic-layer thickness. In order to resolve problems regarding its sub-nanoscale thickness, many experimental techniques have been designed to demonstrate properties of graphene. Among various techniques, however, Raman-based techniques are regarded as highly effective tools for characterizing thermal properties of various types of graphene. In addition, techniques based on Raman spectroscopy can be similarly applied to unveil secrets of newly emerging two-dimensional materials like silicene, MoS2, h-BN. In this paper, we will review several representative experimental techniques for investigating thermal properties of graphene. In particular, Raman-based techniques will be introduced in detail. Furthermore, we will discuss on how each technique has been developed to supplement the shortcoming of the initial techniques.

One of the exceptional properties of graphene is its extremely high thermal conductivity, which makes graphene a promising material in thermal engineering. The superlative thermal conductivity of graphene itself provides excellent functions, however, advantages from controlling it are so immense that there has been a rapid growth of interest in adjusting it for recent years. In this respect, defect engineering in graphene has become a critical and strong technique to manipulate the thermal conductivity of graphene and thus gives graphene great opportunities to be used for innovative applications totally different from previous thermal applications. Furthermore, the thermal conductivity of graphene can be effectively adjusted by defected engineering since the type of imposed defect and its concentration determine the thermal conductivity of modified graphene. Therefore, it is necessary to thoroughly examine the properties of diverse defected graphene. In this paper, we will introduce various types of defects applicable to graphene and discuss how the thermal conductivity is altered by the induced defects. Moreover, we will also review a variety of engineering applications pertaining to the inhibition of heat dissipation using defected graphene.

Objectives. The newly developed therapeutic deep heating device can generate deep heat in focal tissue using high-frequency wave stimulation. The objective of this study was to evaluate and compare the effectiveness of this deep heating device (HIPER-500®) with ultrasound in alleviating pain and improving function in patients with shoulder disability. Methods. This noninferiority trial was designed to compare the treatment effect of HIPER-500® to that of SonoStim® (ultrasound) on shoulder pain and disability. Thirty-eight patients with shoulder problems were assigned to either the HIPER-500® or SonoStim® group, and each participated in 10 min therapy sessions, five days a week for two weeks (for a total of ten sessions). Shoulder pain and disability were evaluated using the Visual Analogue Scale (VAS), the University of California at Los Angeles score (UCLA score), the Shoulder Pain and Disability Index (SPADI), and the Constant score in both groups before, immediately after, and four weeks after treatment. Statistical analysis was performed to compare the effects of treatment within and between the groups. Results. A total of 34 patients completed the study. The 18 patients in the HIPER-500® group and 16 patients in the SonoStim® group all showed significant improvements in shoulder pain and function when comparing pretreatment values with the results immediately after treatment and four weeks later. The results before and after treatment did not show a statistically significant difference between the two groups. Conclusions. The newly developed HIPER-500® for high-frequency deep heat therapy showed similar effects to those of SonoStim® for relieving pain and improving physical performance in the patients of this study. HIPER-500® may be a useful modality for treating shoulder pain and improving physical activity in patients with shoulder disease.

Spin-coated silver nanowires (AgNWs) on graphene show a significantly improved thermal conductance of the composite in comparison with pristine graphene with no nanowires. CVD-synthesized graphene is transferred onto an 8-nm thin TEM grid substrate, and AgNWs (average diameter 150-nm and average length 30-μm) are chemically grown from an AgNO3 reagent solution. The AgNW bridging overrides the negative effect of the grain boundary scattering of the electron/phonon energy carriers propagating in the polycrystalline CVD graphene and ultimately enhances the grain-to-grain heat transport by widening their passages. This boosting contribution of AgNWs is quantitatively assessed by measurement of thermal conductance for synthesized AgNW/graphene composite samples. The Raman thermometry measurement locations are selected to be beside a single AgNW (G-1), two AgNWs (G-2), and three or more AgNWs (G-3), so that the effect of AgNW density can be examined. The average enhanced thermal conductance values for the three AgNW-laid graphene samples are 319.27 nW/K, 343.66 nW/K, and 455.26 nW/K, respectively.

Flexible micro/nano metal grid transparent conductors emerged as an alternative to the fragile/rigid indium tin oxide electrode. They are usually fabricated by the combination of the conventional photolithography and the vacuum deposition of regular metal grid patterns, however, seriously suffer from moiré and starburst problems induced by periodic regular pattern structures. In this paper, we demonstrated flexible and imperceptible random copper microconductors with an extremely high figure-of-merit (∼2000) by the thermal conduction layer-assisted photonic sintering of copper nanoparticles without damages in the plastic substrate. This process can be easily applied to complicated structures and surfaces including a random pattern which is imperceptible and free of interferences. As a proof-of-concept, a transparent windshield defogger in a car was demonstrated with a Cu transparent random conductor at an extreme and reversible fogging state.

The thermal conductivities of monolayer graphene with 4.1 μm grain size and multilayer graphene with 0.3 μm grain sizes are measured by optothermal Raman technique. The number of layers and average grain sizes of graphene are controlled by copper thickness and synthesis conditions in chemical vapor deposition system. In addition, the graphene samples are suspended on a thorough 8-μm hole substrate via PMMA transfer method to avoid substrate effects. As a result, the thermal conductivity graphene is significantly reduced from 3000 to 660 W/m K at 320 K with increasing graphene layers and decreasing grain sizes due to the enhanced phonon scattering. The multilayer graphene with fine grain sizes that has the suppressed thermal conductivity can be useful for application in various field, such as thermoelectric material and thermal rectification.

The in-plane thermal conductivity ( k S i G ) of silicon-doped graphene (SiG) was greatly suppressed primarily due to increased phonon scattering associated with the large mass difference of Si from its host C atoms. For SiG as supported on an 8 nm-thick SiO2 substrate, the measured k S i G represents progressive decrease and saturation with the increase of Si dopants concentration, showing more than an order-of-magnitude reduction from that of supported pristine graphene (PG) and nearly two order-of-magnitude reductions when compared with suspended PG at about 2% doping concentration. The enhanced graphene-substrate conformity through thermal annealing in a vacuum additionally lowers k S i G from that of ambient annealing. The substitutional Si dopants tend to suppress the contribution of temperature-sensitive phonons with long mean free paths and weaken the temperature dependence of k S i G . The presence of Si dopants seems to allow for faster attainment of thermal equilibrium between different heat carriers due to the reduced phonon mean free paths. We believe that SiG holds the possibility of exclusively controlling the thermal properties of graphene, since the substitutional dopants do not violently destruct the hexagonal lattice structure of graphene and may possibly have minimal effects on graphene's electrical properties.

We describe recent progress in the development of spectrally tunable micro-engineered notch filters operating in the longwave infrared (LWIR) region from 8 to 12 µm based on using the guided-mode resonance (GMR) effect. The device structure consists of a subwavelength dielectric grating on top of a homogeneous waveguide using high-index dielectric transparent materials, i.e., germanium (Ge) with a refractive index of 4.0 and zinc selenide (ZnSe) with a refractive index of 2.4. We design the filters to reflect the incident broadband light at one (or more) narrow spectral band while fully transmitting the rest of the light. Filters based on one-dimensional (1-D) gratings are polarization-dependent and those based on two-dimensional (2-D) gratings are less polarization-dependent. We designed and characterized both 1-D and 2- D filters. Anti-reflection coatings (ARCs) were applied on the backside of some of the filter substrates to improve transmission over the entire spectral region. We carried out transmission measurements of these filters using two separate experimental setups—an automated tunable room-temperature quantum cascade laser (QCL) system as well as a modified Fourier Transform Infrared (FTIR) spectrometer with normal incidence of light on the sample. We will present filter designs, theoretical simulation, characterization experiments and results.

It is necessary to improve the health of older adults through exercise, but there is no concrete way to implement it or an environment in which they can exercise continuously. Our objective was to confirm the safety and efficacy of information technology (IT) convergence gamification exercise equipment for older adults. We tried to demonstrate equivalence to conventional exercise by comparing the functional improvement.Randomized controlled trial, with 8-week-long IT convergence exercises 3 times a week vs conventional exercise.40 community-dwelling participants aged 60-85 years.Participants were randomly divided into a conventional exercise group (group 1) and an IT convergence exercise group (group 2). Both groups were trained for 8 weeks, and functional assessment was performed before training (pre-evaluation), after training, and after 4 weeks of rest.There were functional improvements in both groups. A comparison of the differences in the functional assessment between pre-evaluation and after 8 weeks of training yielded the following results. In group 1, the mean Five Times Sit to Stand Test-30 seconds was scored as 3.60 ± 2.56 (P.015); Five Times Sit to Stand Test-5 times, -1.75 ± 2.04 s (P.015); Berg Balance Scale, 1.05 ± 1.39 (P.015); Timed Up-and-Go test, -0.64 ± 0.64 s (P.015); and 10-m Walking Test, -0.35 ± 0.47 s (P.015). And in group 2, the mean Five Times Sit to Stand Test-30 seconds (s) was scored as 3.70 ± 2.62 (P.015), Five Times Sit to Stand Test-5 times, -1.65 ± 1.59 s (P.015); Berg Balance Scale, 1.05 ± 1.00 (P.015); Timed Up-and-Go test, -0.93 ± 0.68 s (P.015); 10-m Walking Test, -0.41 ± 0.489 s (P.015); Chair Sit and Reach test, 2.23 ± 3.19 cm (P.015); and Korean version of the Falls Efficacy Scale-International, -1.05 ± 1.43 (P.015).The results of this study suggest that the IT convergence gamification exercise equipment such as balpro110 has exercise effects similar to conventional exercise and also has advantages as an alternative to exercise for older adults in the next generation.

Generally, a high-temperature postannealing process is required to enhance the photoelectrochemical (PEC) performance of hematite nanorod (NR) photoanodes. However, the thermal annealing time is limited to a short duration as thermal annealing at high temperatures can result in some critical problems, such as conductivity degradation of the fluorine-doped tin oxide film and deformation of the glass substrate. In this study, selective laser processing is introduced for hematite-based PEC cells as an alternative annealing process. The developed laser-induced phase transformation (LIPT) process yields hematite NRs with enhanced optical, chemical, and electrical properties for application in hematite NR-based PEC cells. Owing to its improved properties, the LIPT-processed hematite NR PEC cell exhibits an enhanced water oxidation performance compared to that processed by the conventional annealing process. As the LIPT process is conducted under ambient conditions, it would be an excellent alternative annealing technique for heat-sensitive flexible substrates in the future.

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Based on its outstanding mechanical, thermal, and chemical properties, a Polyimide (PI) is useful in a wide range of applications. Its usage in biomedicine is drawing great attention owing to the recent confirmation of the biocompatibility of various PIs. However, the conventional patterning of a PI, based on photolithographic methods, which is expensive and time-consuming, hampers the rapid advancement of research-oriented fields that require frequent design changes. To resolve this problem, we introduce the method of the monolithic digital patterning of PI up to the quasi-three-dimensional (3D) structures at the microscale resolution by laser-induced jetting of highly porous Laser-induced graphene (LIG) from the PI matrix. Pyrolytic jetting of the LIG is dependent not only on the laser-induced temperature but also on its temporal and spatial gradients. However, the surfaces of the remaining PI can be exceptionally smooth at the optimum laser condition, comparable to the pristine surface at the microscopic level, as confirmed by Raman spectroscopy and Atomic force microscopy (AFM) measurements. On-demand microfluidic channels and multilevel imprinting molds are created in a single step using the proposed method as a proof-of-concept, substantiating its potential application in relevant research.

Among the various techniques for micro patterning of metal oxide nanowire, the resistive micro heater is promising technique due to the merit of localized and selective growth of sensing nanowire. In this study, we introduce a facile maskless fabrication of resistive micro heater using selective laser sintering of silver nanoparticle without using any conventional photolithography or vacuum deposition. By localized hydrothermal synthesis of ZnO nanowire using Joule heating of the resistive micro heater, the digitally patterned resistive micro heater is applied to the ZnO nanowire based micro UV sensor.

Measuring the thermal conductivity kg of supported graphene is inherently complicated due to uncertainties associated with the heat dissipation into the substrate. We innovate the use of an ultra-thin 8-nm SiO2 substrate to alleviate these uncertainties and thus improve the accuracy of optothermal Raman technique to measure kg of supported graphene. As a result, we present an extensive kg database for a wide temperature range from 325 K to 575 K. Furthermore, we have found that the thermal conductivity of supported graphene before annealing is close to that of suspended graphene at 3000 W m−1 K−1, which is attributable to graphene “suspension” lightly on the substrate roughness, and then progressively decreases over repeated thermal annealing. We elaborate on this annealing-induced kg to occur mainly because of the thermally enhanced graphene-substrate conformity and interfacial scattering by probing the Raman spectroscopic characterization of charge carrier density in graphene and the thermal expansion mismatching strain between graphene and substrate. Repeated thermal annealing also expedites the depletion of intercalated impurities to reduce the graphene-substrate separation distance, which acts to further reduces kg, ultimately to its lower bound under vacuum-annealing. Therefore, manipulating the thermo-mechanical affiliation can offer an alternative route to control the in-plane thermal conductivity of supported graphene.

Exploration of the electronics solely composed of bottom-up synthesized nanowires has been largely limited due to the complex multistep integration of diverse nanowires. We report a single-step, selective, direct, and on-demand laser synthesis of a hierarchical heterogeneous nanowire-on-nanowire structure (secondary nanowire on the primary backbone nanowire) without using any conventional photolithography or vacuum deposition. The highly confined temperature rise by laser irradiation on the primary backbone metallic nanowire generates a highly localized nanoscale temperature field and photothermal reaction to selectively grow secondary branch nanowires along the backbone nanowire. As a proof-of-concept for an all-nanowire electronics demonstration, an all-nanowire UV sensor was successfully fabricated without using conventional fabrication processes.

The electrical and mechanical robustness of thin metal film electrodes can be improved by adding an atomically thin interlayer, such as graphene, between the metal and the flexible substrate.

Graphene was regarded as inappropriate material for practical thermoelectric application due to its low thermoelectric conversion efficiency (ZT) from its superlative thermal conductivity and gapless electronic structure. In this study, for the first time, we experimentally investigate the significant thermoelectric conversion efficiency enhancement in graphene by introducing substitutional Si dopants during the CVD growth of single layer graphene. The thermal conductivity of Si-doped graphene (SiG) shows the significant suppression due to the large molecular weight mismatch between host C atoms and Si dopants in the same group V. On the other hand, the Si dopants do not severely suppress the electrical properties compared to thermal conductivity due to the narrow minimum in the electron transmission spectrum of SiG near Fermi Level. The incorporated Si dopants provide the progressive reduction in Seebeck coefficient due to the increased scattering of charge carriers in SiG, but we found nearly 17 times thermoelectric conversion efficiency enhancement (ZT/ZT0) in the suspended graphene when the 2.59% of Si dopants are incorporated, which is much higher than graphene with other dopants for lattice defects. We believe that substitutional Si dopants can provide a promising method to break the limit in the current graphene based thermoelectric materials.

Whole-body vibration training (WBVT) is emerging as an alternative exercise method that be easily performed by older adults. This clinical trial investigates the efficacy of WBVT in improving muscle strength and physical performance before resistance exercise, in comparison to conventional resistance exercise after stretching exercise in older adults. The WBVT group (n = 20) performed WBVT using a vibrating platform (SW-VC15™), followed by strengthening exercises. The control group (n = 20) performed stretching instead of WBVT. Both groups underwent a total of 12 sessions (50 min per session). The primary outcome was isokinetic dynamometer. The secondary outcomes were grip strength, short physical performance battery (SPPB), a 36-Item Short Form Survey (SF-36), and body composition analysis. In all results, only the time effect was significant, and the group effect or time x group effect was not. Both groups showed a significant increase in isokinetic dynamometer. Although there was no significant group effect, the increase in mean peak torque was greater in the WBVT group. The only WBVT group showed significant improvement in SPPB. In SF-36, only the control group showed significant improvements. WBVT can be safely performed by older adults and may be an alternative exercise method to boost the effect of strengthening exercise.

Tolerating timing error due to power supply noise (PSN) in digital circuits can be done with adding voltage margins. Conservative addition of voltage margins leads wastes of power reducing the battery life in Internet of Things (IoT) devices. This paper aims to provide guidelines to avoid over-design due to PSN especially for the low-cost IoT devices. To this end, we first present an accurate time-domain behavioral model of timing slack variation due to PSN accounting for the clock-data compensation. The accuracy of the model is verified against SPICE for complex designs, including AES engine and LEON3 processor. To prove the effectiveness of our model for reducing voltage margin, we utilize our model in standard VLSI design flow for various examples, such as timing slack versus noise frequency analysis, determining optimal value of an on-die capacitor, analyzing the effects of time borrowing technique, and PVT variation simulations. The analysis shows that the model helps reduce pessimism in estimated timing slack.

Purpose In clinical practice, most patients with hepatocellular carcinoma require subsequent treatments for remaining, progressing, or recurring tumors. We investigated all-treatment array and outcomes in an HCC cohort from initial diagnosis to death. Methods We enrolled 1687 consecutive patients with HCC who underwent initial diagnosis and treatment at the National Cancer Center, Korea, from January 2004 to December 2009. Results In total, 1357 patients (80.4%) showed RPRTs during median 20.4-month follow-up. Initial transplantation resulted in the least rate (32.3%) of RPRTs. Median treatment frequency was 3.0 times (range 1–20) and 382 patients (27.3%) received treatments ≥6 times. The median treatment frequency was different based on four factors (p

Many new functional materials have been studied for efficient production and storage of energy. Many new materials such as sodium-based and sulfide-based materials have been proposed for energy storage, but research on Li batteries is still dominant. Due to the influence of environmental concerns regarding nuclear energy, interest in and research on fusion power are steadily increasing. For the commercialization of nuclear fusion, a design standard based on a considerable level of physical analysis and modeling is proposed. Nevertheless, limitations of existing materials in nuclear fusion environments limit practical applications. Tritium propagation material for continuous fusion reaction is one of the core materials, and therefore research on this material is being carried out intermittently. The key material for Li-based energy storage and tritium generation is the functional material Li-M-O. In this review, a structural description of functional Li-M-O system materials and technical trends for its applications are introduced.

Inspired by steel-wire reinforced concrete, which is a strong building material, a novel nanocomposite of a nanowire reinforced nanoparticle matrix film was developed for flexible and transparent electrode applications. The transparent electrode made in this study exhibits superior mechanical characteristics under tensile as well as compressive bending, in comparison to conventional sintered metal nanoparticle based metallic grids.

Background Virtual reality (VR)-based rehabilitation is considered a beneficial therapeutic option for stroke rehabilitation. This pilot study assessed the clinical feasibility of a newly developed VR-based planar motion exercise apparatus (Rapael Smart Board™ [SB]; Neofect Inc., Yong-in, Korea) for the upper extremities as an intervention and assessment tool. Methods This single-blinded, randomized, controlled trial included 26 stroke survivors. Patients were randomized to the intervention group (SB group) or control (CON) group. During one session, patients in the SB group completed 30 min of intervention using the SB and an additional 30 min of standard occupational therapy; however, those in the CON group completed the same amount of conventional occupational therapy. The primary outcome was the change in the Fugl–Meyer assessment (FMA) score, and the secondary outcomes were changes in the Wolf motor function test (WMFT) score, active range of motion (AROM) of the proximal upper extremities, modified Barthel index (MBI), and Stroke Impact Scale (SIS) score. A within-group analysis was performed using the Wilcoxon signed-rank test, and a between-group analysis was performed using a repeated measures analysis of covariance. Additionally, correlations between SB assessment data and clinical scale scores were analyzed by repeated measures correlation. Assessments were performed three times (baseline, immediately after intervention, and 1 month after intervention). Results All functional outcome measures (FMA, WMFT, and MBI) showed significant improvements (p p = 0.038). Some parameters of the SB assessment, such as the explored area ratio, mean reaching distance, and smoothness, were significantly associated with clinical upper limb functional measurements with moderate correlation coefficients. Conclusions The SB was available for improving upper limb function and health-related quality of life and useful for assessing upper limb ability in stroke survivors. Trial registration The study was registered with the clinical research information service (CRIS) (KCT0003783, registered 15 April 2019; retrospectively registered).

Objective. Studies regarding the combination of ultrasound and transcutaneous electrical nerve stimulation (TENS) are rarely reported. In this study, we aimed to elucidate the efficacy and safety of a stimulator using low-intensity pulsed ultrasound (LIPUS) combined with TENS in patients with painful knee osteoarthritis (OA). We evaluated the effectiveness of this therapy against pain, physical function, and cartilage regeneration. Moreover, we aim to prove the superiority of the effects of LIPUS combined with TENS therapy compared with only TENS therapy.Methods. Of the 40 included patients, aged 45–85 years with painful knee OA, 20 patients received only TENS therapy and 20 patients received LIPUS combined with TENS therapy for 8 weeks (a total of more than 80 treatment sessions). We evaluated visual analogue scale (VAS), Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, MOS 36-Item Short-Form Health Survey (SF-36), and femoral articular cartilage (FAC) thickness. The evaluation was performed at three visits: visit 1 (V1, pretreatment, within 28 days after screening), visit 2 (V2, posttreatment period 1, ±3 days after treatment), and visit 3 (V3, posttreatment period 2, 21 ± 3 days after treatment).Results. We expected that LIPUS combined with TENS therapy would be superior to only TENS therapy. However, there was no significant difference between the two therapies. In the within-group comparison, both treatments (only TENS therapy and LIPUS with TENS therapy) demonstrated statistical differences from baseline values for pain and physical function outcomes. FAC thickness showed no significant differences after treatment in both groups.Conclusion. The effects of a stimulator using LIPUS with TENS on pain relief and functional improvement were not superior to the only TENS therapy. Cartilage regeneration, which was expected as an additional benefit of LIPUS, was also not significantly evident. Therefore, further investigation is warranted to determine whether the combination therapy is beneficial. This trial is registered withKCT0003883.

We present principles of leaky-mode photonic lattices explaining key properties enabling potential device applications. The one-dimensional grating-type canonical model is rich in properties and conceptually transparent encompassing all essential attributes applicable to two-dimensional metasurfaces and periodic photonic slabs. We address the operative physical mechanisms grounded in lateral leaky Bloch mode resonance emphasizing the significant influence imparted by the periodicity and the waveguide characteristics of the lattice. The effects discussed are not explainable in terms of local Fabry-Perot or Mie resonances. In particular, herein, we summarize the band dynamics of the leaky stopband revealing principal Bragg diffraction processes responsible for band-gap size and band closure conditions. We review Bloch wave vector control of spectral characteristics in terms of distinct evanescent diffraction channels driving designated Bloch modes in the lattice.

Selective laser sintering of metal nanoparticle ink is an attractive technology for the creation of metal layers at the microscale without any vacuum deposition process, yet its application to elastomer substrates has remained a highly challenging task. To address this issue, we introduced the shear-assisted laser transfer of metal nanoparticle ink by utilizing the difference in thermal expansion coefficients between the elastomer and the target metal electrode. The laser was focused and scanned across the absorbing metal nanoparticle ink layer that was in conformal contact with the elastomer with a high thermal expansion coefficient. The resultant shear stress at the interface assists the selective transfer of the sintered metal nanoparticle layer. We expect that the proposed method can be a competent fabrication route for a transparent conductor on elastomer substrates.

Lateropulsion after stroke is defined as a postural bias toward the paretic side and push away from the non-paretic side. New rehabilitation techniques and programs should be designed to attenuate lateropulsion and improve functions of balance and gait.This study aimed to determine the effects of whole-body tilting postural training (WTPT) using a Spine Balance 3D on lateropulsion and postural control as compared with general postural training (GPT). Postural training was performed and involved a whole-body tilt apparatus that enables postural training in the tilted position, in multiple directions.This was a pragmatic, single-blind, randomized controlled trial conducted between June 2018 and May 2019. We randomly allocated 30 patients with subacute stroke and lateropulsion based on the Scale of Contraversive Pushing (SCP score0) to experimental (n=15) and control (n=15) groups. The experimental group received WTPT with a whole-body tilt apparatus, and the control group GPT. WTPT was performed with the Spine Balance 3D and GPT with postural training commonly applied in the clinic. All participants received treatment for 30min/session, 2 times/day, 5 days/week for 3 weeks. The primary outcome measure was lateropulsion assessed with the Burke Lateropulsion Scale (BLS). Secondary outcome measures were postural control ability, activities of daily living, Postural Assessment Scale for Stroke (PASS) score, Berg Balance Scale (BBS) score, Korea-modified Barthel index (K-MBI), and Fugl-Meyer Motor Assessment-Lower Extremity (FMA-L) score.For the primary outcome, after training, BLS scores were decreased more for the experimental than control group (Δ=-5.8 vs. Δ=-4.2, P=0.002). For secondary outcomes, scores were improved more for the experimental than control group: PASS (Δ=13.8 vs. Δ=8.5, P0.001), BBS (Δ=20.1 vs. Δ=11.1, P=0.001), K-MBI (Δ=27.0 vs. Δ=20.1, P=0.005), and FMA-L (Δ=10.2 vs. Δ=6.3, P=0.002).WTPT is a potentially effective therapeutic intervention for lateropulsion recovery in patients with subacute stroke. It may be useful for improving postural control and activities of daily living.

Objective To investigate the efficacy of electromechanically-assisted rehabilitation of upper limb function in post-stroke patients. Design Randomized controlled trial. Subjects Forty-eight stroke patients. Methods Patients were randomly assigned to control and experimental groups. The control group underwent occupational therapy training with conventional methods. The experimental group underwent electromechanically-assisted training using an end effector robot (Camillo®). Interventions were provided for 30 min per day, 5 days a week, for 4 weeks. Primary outcome was change in Fugl-Meyer Assessment (FMA) before and after training. Secondary outcomes were changes in hand function, upper limb strength, spasticity, mental status and quality of life. Results Mean improvement in FMA was 1.17 (standard deviation (SD) 4.18) in the control group and 2.52 (SD 5.48) in the experimental group. Although FMA in the experimental group improved significantly after training, the improvement in FMA did not differ significantly between groups. Among the secondary outcomes, the Motricity Index (MI) improved significantly after training in the experimental group, and the change in MI between groups was statistically significant. Conclusion Electromechanically-assisted rehabilitation using Camillo® was not more effective than conventional occupation therapy for upper arm function. LAY ABSTRACT Electromechanically-assisted upper limb training is effective for stroke patients who need spontaneous exercise, because it provides highly precise and unlimited repetitive upper limb movements. In hemiplegic patients after stroke, upper limb function is important for daily life movements and working ability. The end effector robot, Camillo®, is an electromechanicallyassisted upper limb training device that trains overall upper limb movement by inducing simultaneous motion of the shoulder, elbow and hand. This study evaluated the effect of rehabilitation using Camillo® by comparing it with conventional upper limb rehabilitation. In conclusion, electromechanically-assisted rehabilitation with Camillo® was not more effective than conventional occupational therapy for upper limb function.

Laser has long been used for material processing, and its applications to nanomaterials for their direct synthesis, positioning and processing are currently active fields of study. The main mechanism of typical laser processes is photothermal reaction by a focused laser that remotely generates confined temperature field at a desired position with high controllability. The laser-induced elevated temperature enables direct synthesis of nanomaterials in both gas and liquid environment as well as photophysical processing of nanomaterials through melting or vaporization, represented by laser sintering and ablation processes, in spatially selective manners. On the other hand, recent advances in laser process further incorporates not only different optical responses such as optical forces and photochemical reactions for more advanced manipulation of nanomaterials, but also the interaction between electromagnetic waves, nanostructures and underlying substrates to facilitate novel processing those cannot be achieved by any other means including laser nanowelding for percolation network and laser thinning for two dimensional nanomaterials. At the same time, the shortcomings of laser process in nanomaterial processing such as limited resolution and low throughput are tackled through introducing different optical schemes together with the integration with other systems. In this review, we summarize the development and current status of digital selective laser methods for nanomaterials in broad aspects that cover from nanomaterial synthesis to its processing.

Hydrothermal growth of zinc oxide (ZnO) nanowire (NW) enables a facile synthesis of versatile 1D nanostructure, but the conventional bulk heating procedure is assessed to be unsuitable for microsensor application in terms of selectivity and power consumption. In this study, we introduce selective electro-thermal growth of ZnO NW on photolithographically patterned electrode in the liquid environment. By applying constant current to the targeted electrode, densely packed ZnO NWs are successfully synthesized only at the desired electrode with very small power consumption. It is also confirmed that the electro — thermally grown ZnO NW network connecting two distinct electrode can be utilized as photosensitive channel, proving that this process as well as the resultant ZnO NW has a high potential for microsensor applications.

The long-wave infrared (LWIR) spectral region spanning ∼ 8 − 12 µ m is useful for many scientific and industrial applications. As traditional multilayer film components are not straightforwardly realized at these bands, we provide design, fabrication, and testing of polarization independent bandstop filters based on the guided-mode resonance (GMR) effect. Focusing on the zero-contrast grating architecture, we successfully fabricate prototype filters in the Ge-on-ZnSe materials system. Applying mask-based photolithography and dry etching, photoresist patterns form the desired Ge grating structures. The resulting devices exhibit clean transmittance nulls and acceptably high sidebands. Moreover, we verify polarization independent notch filtering by assembling two identical GMR filters with gratings oriented orthogonally. This approach to realize effective GMR elements will be useful for various fields including photonic and optoelectronic devices operating in the LWIR region.

Selective laser sintering of metal nanoparticle ink is a low-temperature and non-vacuum technique developed for the fabrication of patterned metal layer on arbitrary substrates, but its application to a metal layer composed of large metal area with small voids is very much limited due to the increase in scanning time proportional to the metal pattern density. For the facile manufacturing of such metal layer, we introduce micropatterning of metal nanoparticle ink based on laser-induced thermocapillary flow as a complementary process to the previous selective laser sintering process for metal nanoparticle ink. By harnessing the shear flow of the solvent at large temperature gradient, the metal nanoparticles are selectively pushed away from the scanning path to create metal nanoparticle free trenches. These trenches are confirmed to be stable even after the complete process owing to the presence of the accompanying ridges as well as the bump created along the scanning path. As a representative example of a metal layer with large metal area and small voids, dark-field photomask with Alphabetic letters are firstly created by the proposed method and it is then demonstrated that the corresponding letters can be successfully reproduced on the screen by an achromatic lens.

In this Letter, we report the development of a continuously tunable color filter based on a self-assembled isotropically stretchable microbead monolayer. Spreading equidistantly upon the application of lateral strain, the isotropically stretchable monolayer serves as a dynamic diffraction grating whose diffraction angle can be mechanically modulated. Combined with a simple spatial filtering scheme, the spectra of the filtered light are solely controlled by external strain (up to 32% radial strain) to cover a broad visible spectrum. Through a finite-difference time-domain far-field diffraction simulation, we validate the working principle of the proposed color filter. The proposed continuously tunable color filter is expected to open original applications in next-generation display field.

The grain size of CVD (Chemical Vapor Deposition) graphene was controlled by changing the precursor gas flow rates, operation temperature, and chamber pressure. Graphene of average grain sizes of 4.1 &micro, m, 2.2 &micro, m, and 0.5 &micro, m was synthesized in high quality and full coverage. The possibility to tailor the thermoelectric conversion characteristics of graphene has been exhibited by examining the grain size effect on the three elementary thermal and electrical properties of &sigma, S, and k. Electrical conductivity (&sigma, ) and Seebeck coefficients (S) were measured in a vacuum for supported graphene on SiO2/Si FET (Field Effect Transistor) substrates so that the charge carrier density could be changed by applying a gate voltage (VG). Mobility (&micro, ) values of 529, 459, and 314 cm2/V&middot, s for holes and 1042, 745, and 490 cm2/V&middot, s for electrons for the three grain sizes of 4.1 &micro, m, respectively, were obtained from the slopes of the measured &sigma, vs. VG graphs. The power factor (PF), the electrical portion of the thermoelectric figure of merit (ZT), decreased by about one half as the grain size was decreased, while the thermal conductivity (k) decreased by one quarter for the same grain decrease. Finally, the resulting ZT increased more than two times when the grain size was reduced from 4.1 &micro, m to 0.5 &micro, m.