Height-renderable morphable tactile display enabled by programmable modulation of local stiffness in photothermally active polymer.

Reconfigurable tactile displays are being used to provide refreshable Braille information; however, the delivered information is currently limited to an alternative of Braille because of difficulties in controlling the deformation height. Herein, we present a photothermally activated polymer-bilayer-based morphable tactile display that can programmably generate tangible three-dimensional topologies with varying textures on a thin film surface. The morphable tactile display was composed of a heterogeneous polymer structure that integrated a stiffness-tunable polymer into a light-absorbing elastomer, near-infra-red light-emitting diode (NIR-LED) array, and small pneumatic chamber. Topological expression was enabled by producing localized out-of-plane deformation that was reversible, height-adjustable, and latchable in response to light-triggered stiffness modulation at each target area under switching of stationary pneumatic pressure. Notably, the tactile display could express a spatial softness map of the latched topology upon re-exposing the target areas to modulated light from the NIR-LED array. We expect the developed tactile display to open a pathway for generating high-dimensional tactile information on electronic devices and enable realistic interaction in augmented and virtual environments.

Extending the Operational Lifetime of Electrochemiluminescence Devices by Installing a Floating Bipolar Electrode.

Electrochemiluminescence (ECL) holds significant promise for the development of cost-effective light-emitting devices because of its simple structure. However, conventional ECL devices (ECLDs) have a major limitation of short operational lifetimes, rendering them impractical for real-world applications. Typically, the luminescence of these devices lasts no longer than a few minutes during operation. In the current study, a novel architecture is provided for ECLDs that addresses this luminescence lifespan issue. The device architecture features an ECL active layer between two coplanar driving electrodes and a third floating bipolar electrode. The inclusion of the floating bipolar electrode enables modulating the electrical-field distribution within the active layer when a bias is applied between the driving electrodes. This, in turn, enables the use of opaque yet electrochemically stable noble metals as the driving electrodes while allowing ECL light to escape through the transparent floating bipolar electrode. A significant extension on operational lifetime is achieved, defined as the time required for the initial luminance (>100 cd m-2) to decrease by 50%, surpassing 1 h. This starkly contrasts the short lifetime (<1 min) attained by ECLDs in a conventional sandwich-type architecture with two transparent electrodes. These results provide simple strategies for developing durable ECL-based light-emitting devices.

Identification of a Target Site for Covalent Inhibition of Protein Phosphohistidine Phosphatase 1.

Despite the recent discovery of numerous phosphohistidine (pHis) sites in mammalian proteomes, the functions of this labile post-translational modification (PTM) mostly remain unknown. Phosphohistidine phosphatase 1 (PHPT1), one of the few known protein pHis phosphatases, regulates important cellular processes, and its genetic knockdown attenuated cancer cell proliferation and a liver fibrosis model. Unfortunately, the lack of PHPT1 inhibitors has limited further understanding and the therapeutic potential of this unique enzyme. We report that PHPT1 can be covalently inhibited by targeting Cys73, a residue that is nonessential for the enzyme activity. We also determined the inhibition kinetics of various small molecule electrophiles as potential warheads against PHPT1. Our results lay a foundation for the development of more potent and specific PHPT1 inhibitors.

Effect of heat treatment with different heat transfer modes on the polymerization of tosylate-doped poly(3,4-ethylenedioxythiophene) films.

In this work, tosylate-doped poly(3,4-ethylenedioxythiophene) (PEDOT:Tos) films are prepared by thermally assisted oxidative polymerization either on a hot plate or in a convection oven. The main difference between these heat treatments is the way heat is transferred (conduction or convection) during polymerization. The surface morphology and structure, doped state, chemical composition, and the changes in the physical and chemical properties of the differently heat-treated films are analyzed using various instrumental methods. The hot plate-treated films exhibit a smooth and dense surface morphology with a low root-mean-square roughness of ~ 5 nm. The films have a quinoid-prevalent thiophene structure with a high electrical conductivity of 575 S/cm. By contrast, the oven-treated films show a rough and porous morphology with a surface roughness ranging from 30 to 80 nm depending on the scanning area, which yields high absorption capacity of more than 90% in the near-infrared range. The oven-treated films show a benzenoid-prevalent structure that provides relatively low electrical conductivity of 244 ± 45 S/cm. As a demonstration of these noticeable changes, PEDOT:Tos films are examined as a photothermal conversion layer to convert light energy to thermal energy, which is converted to electrical energy using a thermoelectric device by covering the films on the device.

Temperature sensing using junctions between mobile ions and mobile electrons.

Sensing technology is under intense development to enable the Internet of everything and everyone in new and useful ways. Here we demonstrate a method of stretchable and self-powered temperature sensing. The basic sensing element consists of three layers: an electrolyte, a dielectric, and an electrode. The electrolyte/dielectric interface accumulates ions, and the dielectric/electrode interface accumulates electrons (in either excess or deficiency). The ions and electrons at the two interfaces are usually not charge-neutral, and this charge imbalance sets up an ionic cloud in the electrolyte. The design functions as a charged temperature-sensitive capacitor. When temperature changes, the ionic cloud changes thickness, and the electrode changes open-circuit voltage. We demonstrate high sensitivity (∼1 mV/K) and fast response (∼10 ms). Such temperature sensors can be made small, stable, and transparent. Depending on the arrangement of the electrolyte, dielectric, and electrode, we develop four designs for the temperature sensor. In addition, the temperature sensor has good linearity in the range of tens of Kelvin. We further show that the temperature sensors can be integrated into stretchable electronics and soft robots.

Manufacturing Process of Polymeric Microneedle Sensors for Mass Production.

In this work, we present a fabrication process for microneedle sensors made of polylactic acid (PLA), which can be utilized for the electrochemical detection of various biomarkers in interstitial fluid. Microneedles were fabricated by the thermal compression molding of PLA into a laser machined polytetrafluoroethylene (PTFE) mold. Sensor fabrication was completed by forming working, counter, and reference electrodes on each sensor surface by Au sputtering through a stencil mask, followed by laser dicing to separate individual sensors from the substrate. The devised series of processes was designed to be suitable for mass production, where multiple microneedle sensors can be produced at once on a 4-inch wafer. The operational stability of the fabricated sensors was confirmed by linear sweep voltammetry and cyclic voltammetry at the range of working potentials of various biochemical molecules in interstitial fluid.

Paper-Based Ionic Thermocouples for Inexpensive and High-Precision Measurement of Temperature.

Accurate and yet cost-effective temperature measurements are required in various sectors of academia and industry. Thermocouples (TCs) are most widely used for temperature measurements; however, their low temperature sensitivity and high thermal conductivity should be improved to ensure the reliable measurement of output voltage for small temperature differences. To address this, a paper-based ionic thermocouple (P-iTC) presented here utilizes a pair of paper strips soaked with the electrolytes of potassium ferri-/ferrocyanide and iron (II/III) chloride redox couples, which are used as p- and n-type elements, respectively. The fabricated P-iTC provides 70× higher temperature sensitivity (α, 2.8 mV/K) and 30× lower thermal conductivity (k, 0.8 W/m K) than those of commercial K-type TCs, thereby yielding a remarkably high α/k ratio of 3.5 mV m/W. Reliable sensing performance is measured during three weeks of operation, which indicates that the P-iTC should be stable in long-term operation. To demonstrate the practicality of the P-iTC, a 3 × 3 planar array of P-iTCs is fabricated to monitor the temperature profile of a surface in contact with heat sources. Using pencil-drawn graphite electrodes on paper, a highly cost-effective P-iTC with the material cost of ∼0.5 cents per device is also fabricated, which is successfully used to monitor cold chain temperatures while retaining its excellent temperature-sensing performance.

High-Molecular-Weight Electroactive Polymer Additives for Simultaneous Enhancement of Photovoltaic Efficiency and Mechanical Robustness in High-Performance Polymer Solar Cells.

The development of small-molecule acceptors (SMAs) has significantly enhanced the power conversion efficiency (PCE) of polymer solar cells (PSCs); however, the inferior mechanical properties of SMA-based PSCs often limit their long-term stability and application in wearable power generators. Herein, we demonstrate a simple and effective strategy for enhancing the mechanical robustness and PCE of PSCs by incorporating a high-molecular-weight (MW) polymer acceptor (P A, P(NDI2OD-T2)). The addition of 10-20 wt % P A leads to a more than 4-fold increase in the mechanical ductility of the SMA-based PSCs in terms of the crack onset strain (COS). At the same time, the incorporation of P A into the active layer improves the charge transport and recombination properties, increasing the PCE of the PSC from 14.6 to 15.4%. The added P As act as tie molecules, providing mechanical and electrical bridges between adjacent domains of SMAs. Thus, for the first time, we produce highly efficient and mechanically robust PSCs with a 15% PCE and 10% COS at the same time, thereby demonstrating their great potential as stretchable or wearable power generators. To understand the origin of the dual enhancements realized by P A, we investigate the influence of the P A content on electrical, structural, and morphological properties of the PSCs.

Immuno-enhancement effects of Korean Red Ginseng in healthy adults: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Most clinical studies of immune responses activated by Korean Red Ginseng (KRG) have been conducted exclusively in patients. However, there is still a lack of clinical research on immune-boosting benefits of KRG for healthy persons. This study aims to confirm how KRG boosts the immune system of healthy subjects. METHODS: A total of 100 healthy adult subjects were randomly divided into two groups that took either a 2 g KRG tablet or a placebo per day for 8 weeks. The primary efficacy evaluation variables included changes in T cells, B cells, and white blood cells (WBCs) before and after eight weeks of KRG ingestion. Cytokines (TNF-α, INF-γ, IL-2 and IL-4), WBC differential count, and incidence of colds were measured in the secondary efficacy evaluation variables. Safety evaluation variables were used to identify changes in laboratory test results that incorporated adverse reactions, vital signs, hematological tests, blood chemistry tests, and urinalysis. RESULTS: Compared to the placebo group, the KRG intake group showed a significant increase in the number of T cells (CD3) and its subtypes (CD4 and CD8), B cells, and the WBC count before and after eight weeks of the intake. There were no clinically significant adverse reactions or other notable results in the safety evaluation factors observed. CONCLUSION: This study has proven through its eight-week intake test and subsequent analysis that KRG boosts the immune system through an increase in T cells, B cells, and WBCs, and that it is safe according to the study's safety evaluation.

A Light-Driven Vibrotactile Actuator with a Polymer Bimorph Film for Localized Haptic Rendering.

A vibrotactile actuator driven by light energy is developed to produce dynamic stimulations for haptic rendering on a thin-film structure. The actuator is constructed by adopting a thermal bimorph membrane structure of poly(3,4-ethylenedioxythiophene) doped with p-toluenesulfonate (PEDOT-Tos) coated onto a polyethylene terephthalate (PET) film. Upon irradiation of near-infrared (NIR) light, the light energy absorbed at the PEDOT-Tos layer is converted into thermoelastic bending deformation due to the mismatch in coefficient of thermal expansion between PEDOT-Tos and PET. Since the light-induced deformation is reversible, spatially localized, and rapidly controllable with designed light signals, the proposed actuator can produce vibrotactile stimulation over 10 dB at arbitrary areas in the human-sensitive frequency range from 125 to 300 Hz using a low input power of ∼2.6 mW mm-2, as compared with a complex electrical circuit and high input power needed to achieve such actuation performance. Together with its simple structure based on light-driven actuation, the advent of this actuator could open up new ways to achieve substantial advances in rendering textures at a flexible touch interface.

Efficacy and Safety of Electroacupuncture for Insomnia Disorder: A Multicenter, Randomized, Assessor-Blinded, Controlled Trial.

PURPOSE: To evaluate the efficacy and safety of electroacupuncture in treating insomnia. PATIENTS AND METHODS: In a multicenter, randomized, assessor-blinded, controlled trial, 150 patients with DSM-5-diagnosed insomnia with Insomnia Severity Index (ISI) scores ≥ 15 were randomly assigned to three different groups that underwent 10 sessions of electroacupuncture, sham-electroacupuncture, or usual care for 4 weeks from October 2015 to June 2016 at four Korean medicine hospitals, Republic of Korea. The primary outcome included the ISI score at Week 4; the secondary outcomes included evaluations of Pittsburgh Sleep Quality Index (PSQI), sleep diary, Hospital Anxiety and Depression Scale (HADS), EuroQoL five dimension (EQ-5D), Patient Global Impression of Change (PGIC), and salivary melatonin and cortisol levels. Assessments were performed at baseline (Week 0) and at Weeks 2, 4, 8, and 12. RESULTS: Compared with the usual care group, electroacupuncture group showed a greater improvement in ISI, PSQI, sleep diary-derived variables and HADS and EQ-5D scores at Week 4. The effects mostly persisted until Week 12. There were no significant differences between electroacupuncture and sham-electroacupuncture groups at Week 4 in all outcome measures, except sleep diary-derived sleep efficiency. However, the ISI score showed a significant difference between these groups at Weeks 8 and 12. Treatment success as per PGIC was significantly and borderline higher for electroacupuncture compared with usual care and sham-electroacupuncture, respectively. No significant changes in salivary melatonin and cortisol levels before and after treatment were observed in all groups. No serious adverse events were reported. Blinding was maintained in the sham-electroacupuncture group. CONCLUSION: Ten sessions of electroacupuncture can improve the sleep quality of patients with insomnia without serious adverse effects. Thus, it can be recommended as an effective, safe, and well-tolerated intervention.

Low-Voltage Reversible Electroadhesion of Ionoelastomer Junctions.

Electroadhesion provides a simple route to rapidly and reversibly control adhesion using applied electric potentials, offering promise for a variety of applications including haptics and robotics. Current electroadhesives, however, suffer from key limitations associated with the use of high operating voltages (>kV) and corresponding failure due to dielectric breakdown. Here, a new type of electroadhesion based on heterojunctions between iono-elastomer of opposite polarity is demonstrated, which can be operated at potentials as low as ≈1 V. The large electric field developed across the molecular-scale ionic double layer (IDL) when the junction is placed under reverse bias allows for strong adhesion at low voltages. In contrast, under forward bias, the electric field across the IDL is destroyed, substantially lowering the adhesion in a reversible fashion. These ionoelastomer electroadhesives are highly efficient with respect to the force capacity per electrostatic capacitive energy and are robust to defects or damage that typically lead to catastrophic failure of conventional dielectric electroadhesives. The findings provide new fundamental insight into low-voltage electroadhesion and broaden its possible applications.

Thermocells for Hybrid Photovoltaic/Thermal Systems.

The photovoltaic conversion efficiency of solar cells is highly temperature dependent and decreases with increasing temperature. Therefore, the thermal management of solar cells is crucial for the efficient utilization of solar energy. We fabricate a hybrid photovoltaic/thermocell (PV/T) module by integrating a thermocell directly into the back of a solar panel and explore the feasibility of the module for its practical implementation. The proposed PV/T hybrid not only performs the cooling of the solar cells but also produces an additional power output by converting the heat stored in the solar cell into useful electric energy through the thermocell. Under illumination with an air mass of 1.5 G, the conversion efficiency of the solar cell can improve from 13.2% to 15% by cooling the solar cell from 61 °C to 34 °C and simultaneously obtaining an additional power of 3.53 µW/cm2 from the thermocell. The advantages of the PV/T module presented in this work, such as the additional power generation from the thermocell as well as the simultaneous cooling of the solar cells and its convenient installation, can lead to the module's importance in practical and large-scale deployment.

Ionoelastomer junctions between polymer networks of fixed anions and cations.

Soft ionic conductors have enabled stretchable and transparent devices, but liquids in such devices tend to leak and evaporate. In this study, we demonstrate diodes and transistors using liquid-free ionoelastomers, in which either anions or cations are fixed to an elastomer network and the other ionic species are mobile. The junction of the two ionoelastomers of opposite polarity yields an ionic double layer, which is capable of rectifying and switching ionic currents without electrochemical reactions. The entropically driven depletion of mobile ions creates a junction of tough adhesion, and the stretchability of the junction enables electromechanical transduction.

Determination of Urinary Caffeine Metabolites as Biomarkers for Drug Metabolic Enzyme Activities.

Caffeine is commonly taken via the daily dietary consumption of caffeine-containing foods. The absorbed caffeine is metabolized to yield various metabolites by drug-metabolizing enzymes, and measuring the levels of each caffeine metabolite can provide useful information for evaluating the phenotypes of those enzymes. In this study, the urinary concentrations of caffeine and its 13 metabolites were determined, and the phenotypes of drug metabolic enzymes were investigated based on the caffeine metabolite ratios. Human urine samples were pretreated using solid phase extraction, and caffeine and its metabolites were analyzed using liquid chromatography-tandem mass spectrometry. Based on the urinary caffeine metabolite concentrations, the caffeine metabolite ratios were calculated for six human subjects at specified time points after caffeine intake. Variations in urinary metabolite levels among individuals and time points were reported. In addition, the resultant enzyme activities showed different patterns, depending on the metabolite ratio equations applied. However, some data presented a constant metabolite ratio range, irrespective of time points, even at pre-dose. This suggests the possibility of urinary caffeine metabolite analysis for routine clinical examination. These findings show that urinary caffeine and the metabolite analysis would be useful in evaluating metabolic phenotypes for personalized medicine.

Lithium-oxygen batteries with triplex Li+-selective solid membranes.

A lithium-oxygen battery based on a triplex-Li+-selective solid membrane (LSSM) is proposed. An inorganic LSSM with a triplex (porous/dense/porous) structure is prepared via tape-casting. The cell exhibits promising rate-capability and reversibility during cycling. The triplex-LSSM architecture may allow cell designs to be scaled up for use in large systems.

Toll-like receptor 2 promotes neurogenesis from the dentate gyrus after photothrombotic cerebral ischemia in mice.

The subgranular zone (SGZ) of hippocampal dentate gyrus (HDG) is a primary site of adult neurogenesis. Toll-like receptors (TLRs), are involved in neural system development of Drosophila and innate immune response of mammals. TLR2 is expressed abundantly in neurogenic niches such as adult mammalian hippocampus. It regulates adult hippocampal neurogenesis. However, the role of TLR2 in adult neurogenesis is not well studied in global or focal cerebral ischemia. Therefore, this study aimed to investigate the role of TLR2 in adult neurogenesis after photochemically induced cerebral ischemia. At 7 days after photothrombotic ischemic injury, the number of bromodeoxyuridine (BrdU)-positive cells was increased in both TLR2 knock-out (KO) mice and wild-type (WT) mice. However, the increment rate of BrdU-positive cells was lower in TLR2 KO mice compared to that in WT mice. The number of doublecortin (DCX) and neuronal nuclei (NeuN)-positive cells in HDG was decreased after photothrombotic ischemia in TLR2 KO mice compared to that in WT mice. The survival rate of cells in HDG was decreased in TLR2 KO mice compared to that in WT mice. In contrast, the number of cleaved-caspase 3 (apoptotic marker) and the number of GFAP (glia marker)/BrdU double-positive cells in TLR2 KO mice were higher than that in WT mice. These results suggest that TLR2 can promote adult neurogenesis from neural stem cell of hippocampal dentate gyrus through increasing proliferation, differentiation, and survival from neural stem cells after ischemic injury of the brain.

Agrimonia eupatoria L. (Agrimony) Extract Alters Liver Health in Subjects with Elevated Alanine Transaminase Levels: A Controlled, Randomized, and Double-Blind Trial.

Agrimonia eupatoria L. has been shown to protect against liver injury due to its lipid lowering and antioxidant activities. The aim of this research was to evaluate the effect of A. eupatoria L. aqueous extract (AEE) on 80 subjects with elevated alanine transaminase (ALT) levels in a randomized, double-blind, placebo-controlled, 8-week study. This trial was conducted between January 2013 and July 2013 at the Oriental Medical Hospital (Jecheon) of Semyung University. The trial included subjects aged 20 years or older who were diagnosed with mildly to moderately elevated ALT levels (between 45 and 135 IU/L). Subjects received two capsules of placebo or AEE twice a day for 8 weeks. Adverse events were recorded. Eighty subjects were randomized to placebo or AEE groups who had similar baseline characteristics. During the 8 weeks of treatment, 11 subjects were excluded from the analysis for protocol violation or consent withdrawal; efficacy of treatment was, therefore, evaluated in 69 subjects (placebo = 35, AEE = 34). The AEE group showed a significant reduction in ALT and serum triglyceride (TG) at 8 weeks compared with the placebo group (ALT P = .044, TG P = .020). Significant group and time interactions were found in ALT (P = .038), aspartate aminotransferase (P = .040), and TG (P = .010). Alkaline phosphatase, total bilirubin, and gamma-glutamyl transferase levels were not different between the two groups. There were no reported severe adverse events during this study, and total protein, albumin, blood urea nitrogen, creatine, and total cholesterol levels were normal in both groups. AEE consumption was safe and generally well tolerated without severe adverse events.

One-step fermentative production of aromatic polyesters from glucose by metabolically engineered Escherichia coli strains.

Aromatic polyesters are widely used plastics currently produced from petroleum. Here we engineer Escherichia coli strains for the production of aromatic polyesters from glucose by one-step fermentation. When the Clostridium difficile isocaprenoyl-CoA:2-hydroxyisocaproate CoA-transferase (HadA) and evolved polyhydroxyalkanoate (PHA) synthase genes are overexpressed in a D-phenyllactate-producing strain, poly(52.3 mol% 3-hydroxybutyrate (3HB)-co-47.7 mol% D-phenyllactate) can be produced from glucose and sodium 3HB. Also, various poly(3HB-co-D-phenyllactate) polymers having 11.0, 15.8, 20.0, 70.8, and 84.5 mol% of D-phenyllactate are produced from glucose as a sole carbon source by additional expression of Ralstonia eutropha ß-ketothiolase (phaA) and reductase (phaB) genes. Fed-batch culture of this engineered strain produces 13.9 g l-1 of poly(61.9 mol% 3HB-co-38.1 mol% D-phenyllactate). Furthermore, different aromatic polyesters containing D-mandelate and D-3-hydroxy-3-phenylpropionate are produced from glucose when feeding the corresponding monomers. The engineered bacterial system will be useful for one-step fermentative production of aromatic polyesters from renewable resources.

Electroacupuncture for insomnia disorder: study protocol for a randomized controlled trial.

BACKGROUND: Insomnia is a common sleep disorder that affects many adults either transiently or chronically. The societal cost of insomnia is on the rise, while long-term use of current drug treatments can involve adverse effects. Recently, electroacupuncture (EA) has been used to treat various conditions including insomnia. The objective of this study is to provide scientific evidence for the effect and safety of using EA to treat insomnia. METHODS/DESIGN: In this multicentre, assessor-blind, three-arm, parallel-design, randomised controlled trial, 150 participants will be assigned to the EA group, the sham EA (SEA) group, or the usual care group. The EA and SEA groups will receive the specific treatments 2-3 times a week for 4 weeks, for a total of 10 sessions, whereas the usual care group will not receive EA and will continue with usual care during the same time period. The primary outcome measure will be changes in the Insomnia Severity Index 5 weeks after randomisation. The secondary outcomes will include the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale, a sleep diary, the EuroQoL-5 dimension questionnaire, the levels of melatonin and cortisol, and the Patient Global Impression of Change. Safety will be assessed at each visit. DISCUSSION: The results of this multicentre randomised controlled trial will contribute to provide rigorous clinical evidence for the effects and safety of EA for insomnia disorder. TRIAL REGISTRATION: Korean Clinical Trial Registry, CRIS, KCT0001685 . Registered on 2 November 2015 (retrospectively registered). Date of enrolment of the first participant to the trial 13 October 2015.