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An electrochemical immunoassay based on the redox cycling method was presented using vertically paired electrodes (VPEs), which were fabricated using PEDOT:PSS as an electrode material and parylene-C as a dielectric layer.

Switching peptides were designed to bind reversibly to the binding pocket of antibodies (IgG) by interacting with frame regions (FRs). These peptides can be quantitatively released when antigens bind to IgG. As FRs have conserved amino acid sequences, switching peptides can be used as antibodies for different antigens and different source animals. In this study, an electrochemical one-step immunoassay was conducted using switching peptides labeled with ferrocene for the quantitative measurement of analytes. For the effective amperometry of the switching peptides labeled with ferrocene, a pyrolyzed carbon electrode was prepared by pyrolysis of the parylene-C film. The feasibility of the pyrolyzed carbon electrode for the electrochemical one-step immunoassay was determined by analyzing its electrochemical properties, such as its low double-layer capacitance (

In this study, parylene-C films from plasma deposition as well as thermal deposition were pyrolyzed to prepare a carbon electrode for application in electrochemical immunoassays.

As the shelf life of platelets collected from donated blood is very short, approximately 5 days, the determination of bacterial contamination in platelets has become necessary. In this study, rapid analysis of Gram-positive and Gram-negative bacterial contamination in platelet samples was presented without pre-enrichment using pig serum-derived antibodies against the outer membrane proteins (OMP) of Gram-negative bacteria and antibodies against lipoteichoic acid (LTA) on the surface of Gram-positive bacteria. The anti-OMP antibodies against Gram-negative bacteria were isolated using sequential incubation with (1) the modified Gram-negative bacteria ClearColi, which lacks lipopolysaccharide (LPS) on the outer membrane, and (2) the Gram-positive bacteria

A one-step immunoassay was developed for five types of food-poisoning-related bacteria using a switching peptide and antibodies isolated from unimmunized horse serum. The one-step immunoassay involves mixing samples and reagents in a homogeneous solution without any washing steps. In this work, a one-step immunoassay configuration was developed using isolated antibodies labelled with an organic fluorescence quencher and a switching-peptide labelled with a fluorescent dye. The fluorescence-labelled switching-peptide was bound to the antigen-binding site of the isolated antibodies before binding to the bacteria (no fluorescence signal), and the switching-peptide dissociated from the antibodies as soon as they bound to the bacteria (fluorescence signal turns on). By quantifying the generated fluorescence signal, the one-step immunoassay presented here allows microbial detection without any washing step.

Chemiluminescence immunoassays have been widely employed for diagnosing various diseases. However, because of the extremely low intensity chemiluminescence signals, highly sensitive transducers, such as photomultiplier tubes and image sensors with cooling devices, are required to overcome this drawback. In this study, a hypersensitive photosensor was developed based on cesium lead bromide (CsPbBr3) perovskite quantum dots (QDs) with sufficient high sensitivity for chemiluminescence immunoassays. First, CsPbBr3 QDs with a highly uniform size, that is, 5 nm, were synthesized under thermodynamic control to achieve a high size confinement effect. For the fabrication of the photosensor, MoS2 nanoflakes were used as an electron transfer layer and heat-treated at an optimum temperature. Additionally, a parylene-C film was used as a passivation layer to improve the physical stability and sensitivity of the photosensor. In particular, the trap states on the CsPbBr3 QDs were reduced by the passivation layer, and the sensitivity was increased. Finally, a photosensor based on CsPbBr3 QDs was employed in chemiluminescence immunoassays for the detection of human hepatitis B surface antigen, human immunodeficiency virus antibody, and alpha-fetoprotein (AFP, a cancer biomarker). When compared with the conventionally used equipment, the photosensor was determined to be feasible for application in chemiluminescence immunoassays.

In this study, parylene-C films from plasma deposition as well as thermal deposition were pyrolyzed to prepare a carbon electrode for application in electrochemical immunoassays. Plasma deposition could prepare parylene-C in a faster deposition rate and more precise control over the thickness in comparison with the conventional thermal deposition. To analyze the influence of the deposition method, the crystal and electronic structures of the pyrolyzed parylene-C films obtained

Antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein (NP) were purified from pig serum through two steps: (1) isolation of anti-NP IgG antibodies using magnetic beads with immobilized human SARS-CoV-2 NP and (2) filtration of anti-spike protein (SP) IgG antibodies using magnetic beads with immobilized human SARS-CoV SP. The enhanced specificity of the purified antibodies to the NP of SARS-CoV-2 was demonstrated using an immunoassay with anti-NP IgG antibodies after the isolation and filtration steps. The binding constants (Kd) of the purified anti-NP IgG antibodies to the NP of SARS-CoV-2 and the SP of SARS-CoV were estimated using a surface plasmon resonance biosensor (SPR). A competitive assay using the two-step purified anti-NP IgG antibodies from pig serum demonstrated (a) the detection of SARS-CoV-2 in viral fluid and (b) the discrimination of SARS-CoV-2 from SARS-CoV, MERS-CoV, and CoV strain 229E in viral fluids.

Oral squamous cell carcinoma (OSCC) frequently invades nearby bone and bone involvement determines the prognosis of patients. Growth factors, stored in the bone matrix and released during bone destruction, are known as key components in the bone-tumor interaction. However, the coordination of growth factor signals and the precise mechanism of bone destruction in oral cancer are still unclear. In the study, we investigated the differential cytokine expression profile of oral cancer cells by TGF-β treatment and the function of altered expression of cytokines on the osteoclast differentiation. We established TGFBR2-knockdown cells using small hairpin RNA. TGF-β was treated to both TGFBR2 expressing and knockdown cells and the culture supernatants were analyzed using a cytokine array kit. We found that the TGF-β inhibited IGFBP3 level and enhanced MMP9 level. We confirmed this regulation of IGFBP3 and MMP9 by TGF-β using ELISA and zymography, respectively. IGFBP3 is known as to modulate the bioavailability of IGF1, which is abundant in the bone microenvironment and regulates osteoclast differentiation. Therefore, we further analyzed the function of IGFBP3 on osteoclastogenesis. Although IGFBP3 increased the viability of murine bone marrow macrophages, the osteoclast differentiation of these cells was blocked by IGFBP3 in a dose-dependent manner. These results revealed a novel pathway for the regulation of osteoclastogenesis by oral cancer cells, which may be a new therapeutic target for osteolysis induced by oral cancer infiltrating into the bone.

One of the key challenges in biology is to understand how individual cells process information and respond to perturbations. However, most of the existing single-cell analysis methods can only provide a glimpse of cell properties at specific time points and are unable to provide cell secretion and protein analysis at single-cell resolution. To address the limits of existing methods and to accelerate discoveries from single-cell studies, we propose and experimentally demonstrate a new sensor based on bound states in the continuum to quantify exosome secretion from a single cell. Our optical sensors demonstrate high-sensitivity refractive index detection. Because of the strong overlap between the medium supporting the mode and the analytes, such an optical cavity has a figure of merit of 677 and sensitivity of 440 nm/RIU. Such results facilitate technological progress for highly conducive optical sensors for different biomedical applications.

Osteoarthritis (OA) is a common joint disease that results from the disintegration of joint cartilage and the underlying bone. Because cartilage and chondrocytes lack the ability to self-regenerate, efforts have been made to utilize stem cells to treat OA. Although various methods have been used to differentiate stem cells into functional chondrocytes, the currently available methods cannot induce stem cells to undergo differentiation into chondrocyte-like cells without inducing characteristics of hypertrophic chondrocytes, which finally lead to cartilage disintegration and calcification. Therefore, an optimized method to differentiate stem cells into chondrocytes that do not display undesired phenotypes is needed. This study focused on differentiating adipose-derived stem cells (ASCs) into functional chondrocytes using a small molecule that regulated the expression of Sox9 as a key factor in cartilage development and then explored its ability to treat OA. We selected ellipticine (ELPC), which induces chondrocyte differentiation of ASCs, using a GFP-Sox9 promoter vector screening system. An in vivo study was performed to confirm the recovery rate of cartilage regeneration with ASC differentiation into chondrocytes by ELPC in a collagenase-induced animal model of OA. Taken together, these data indicate that ellipticine induces ASCs to differentiate into mature chondrocytes without hypertrophic chondrocytes in vitro and in vivo, thus overcoming a problem encountered in previous studies. These results indicate that ELPC is a novel chondrocyte differentiation-inducing drug that shows potential as a cell therapy for OA., Osteoarthritis: Drug-induced stem cell differentiation shows therapeutic promise A novel method of generating healthy cartilage cells from stem cells could repair and regenerate joints and bones damaged by osteoarthritis. The cells that produce and maintain cartilage tissue are known as chondrocytes. Stem cell therapy could potentially re-start cartilage and bone regeneration in patients with osteoarthritis, however scientists have struggled to successfully induce stem cells to differentiate into functioning chondrocytes. A new method developed by Soyeon Lim and Ki-Chul Hwang at the Catholic Kwandong University, Gangneung, South Korea, and co-workers uses a drug called ellipticine to boost the expression of Sox-9, a key protein involved in cartilage development. The researchers found that the ellipticine-based method induced a mature, healthy chondrocyte population in cell cultures and rat models of osteoarthritis. Rats injected with these cells recovered from cartilage damage, suggesting a potential osteoarthritis therapy.

Background/aim We investigated the clinical role of the molecular targets, APEX1 and Jagged-1, and the Apex1 - Jagged-1 cascade in gastric cancer cells. Materials and methods We used 6 human gastric cancer cell lines (SNU-1, SNU-5, SNU-16, NCI-N87, KATO- III and AGS), and demonstrated the chemosensitivity of APEX1 and Jagged-1 through the MTT assay and immunoblotting. Tumor growth was assayed following cisplatin and 5-FU treatment using a xenograft model injected with KATO-III cells. Moreover, gastric tumor samples from 9 patients, divided in 2 groups according to chemotherapy response, were examined by immunocytochemical (IHC) staining, and protein expression levels were scored. Results Following APEX1 knockdown, the MTT assay revealed that the IC50 of cisplatin and 5-FU in AGS cells was decreased approximately 7% and 15%, respectively, however, their decrease in chemoresistant KATO-III cells was decreased by approximately 21% and 67% for cisplatin and 5-FU, respectively. The tumor volume of KATO-III/sicontrol mice treated with cisplatin and 5-FU was affected less, compared with KATO-III/siAPEX1 mice treated with cisplatin and 5-FU. Also, the expression levels of APEX1, Jagged-1 and CD133, assayed by IHC staining, were higher in the chemorefractory group than in the chemoresponsive group. Conclusion Jagged-1-activated signaling by APEX1 plays a role in advanced gastric cancer.

Singularities of open systems, known as exceptional points (EPs), have been shown to exhibit increased sensitivities, but the observation of EPs has so far been limited to wavelength-scaled systems subject to the diffraction limit. Plasmons, the collective oscillations of free electrons coupled to photons, shrink the wavelength of light to electronic and molecular length scales. We propose a novel approach to EPs based on spatial symmetry breaking and report their observation in plasmonics at room temperature. The plasmonic EPs are based on the hybridization of detuned resonances in multilayered plasmonic structures to reach a critical complex coupling rate between nanoantenna arrays, resulting in the simultaneous coalescence of the resonances and loss rates. Their utility as sensors of anti-immunoglobulin G, the most abundant immunoglobulin isotype in human serum, is evaluated. Our work opens the way to a new class of nanoscale devices, sensors and imagers based on topological polaritonic effects. The hybridized modes of an asymmetric plasmonic dimer show avoided crossing of both the real and imaginary parts. This can lead to plasmonic exceptional points, which are used for biosensing with very high sensitivity.

Oral squamous cell carcinoma (OSCC) frequently invades the maxillary or mandibular bone, and this bone invasion is closely associated with poor prognosis and survival. Here, we show that CCL28 functions as a negative regulator of OSCC bone invasion. CCL28 inhibited invasion and epithelial-mesenchymal transition (EMT), and its inhibition of EMT was characterized by induced E-cadherin expression and reduced nuclear localization of β-catenin in OSCC cells with detectable RUNX3 expression levels. CCL28 signaling via CCR10 increased retinoic acid receptor-β (RARβ) expression by reducing the interaction between RARα and HDAC1. In addition, CCL28 reduced RANKL production in OSCC and osteoblastic cells and blocked RANKL-induced osteoclastogenesis in osteoclast precursors. Intraperitoneally administered CCL28 inhibited tumor growth and osteolysis in mouse calvaria and tibia inoculated with OSCC cells. RARβ expression was also increased in tumor tissues. In patients with OSCC, low CCL28, CCR10, and RARβ expression levels were highly correlated with bone invasion. Patients with OSCC who had higher expression of CCL28, CCR10, or RARβ had significantly better overall survival. These findings suggest that CCL28, CCR10, and RARβ are useful markers for the prediction and treatment of OSCC bone invasion. Furthermore, CCL28 upregulation in OSCC cells or CCL28 treatment can be a therapeutic strategy for OSCC bone invasion.

Vascular occlusive disease is a chronic disease with significant morbidity and mortality. Although a variety of therapies and medications have been developed, the likelihood of disease re-emergence is high and this can be life-threatening. Based on a previous screening experiment related to vascular obstructive diseases using 34 types of essential oils, cold-pressed oil (CpO) from Citrus aurantifolia (lime) has been demonstrated to have the best effect for the inhibition of vascular smooth muscle cells (VSMCs) proliferation. The aim of the present study was to evaluate the effect of lime CpO on the pathological changes of VSMCs. To determine this, the effect of lime CpO on VSMC proliferation, a major cause of vascular disease, was investigated. To determine the safe concentration interval for toxicity of CpO during VSMC culture, a dilution of 1x10-5 was determined using Cell Counting Kit-8 assay, which was confirmed to be non-toxic using a lactate dehydrogenase assay. To examine the effect of lime CpO in cellular signaling pathways, changes in phosphorylation of both the PI3K/AKT/mTOR and extracellular signal-regulated MEK/ERK signaling pathways with serum were investigated. Furthermore, lime CpO with FBS also significantly decreased the expression levels of the cell cycle regulators cyclin D1 and proliferating cell nuclear antigen. Additionally, lime CpO with FBS significantly inhibited the sprouting of VSMCs in an ex vivo culture system. These results suggested that lime CpO inhibited the abnormal proliferation of VSMCs and can be developed as a nature-based therapeutic agent for obstructive vascular disease.

Clinical nurses have training needs related to the strategies for infection spread prevention. This study aimed to investigate the levels of importance of and performance in the various areas of care for communicable respiratory infections among clinical nurses and to determine the priority of educational needs. Hospitals in which a baseline survey could be conducted were considered, and nurses working in six hospitals that were designated as COVID-19 care centers in Korea were enrolled. The training needs for the care of patients with communicable respiratory infections were analyzed using Borich’s needs equation, and the locus for focus model. Among participants with prior COVID-19 patient care experience, according to Borich’s equation, the need score was the highest for “initial response to communicable respiratory infection”, followed by “management of aerosol-generating procedures in patients with communicable respiratory infection” and “reporting of patients with communicable respiratory infection and death of patient”. An item rated highly in both Borich’s equation and the locus for focus model among the participants with prior experience was “initial response to communicable respiratory infection”. Among participants without prior relevant experience, according to Borich’s equation, the need score was highest for “management of aerosol-generating procedures in patients with a communicable respiratory infection”, followed by “initial response to communicable respiratory infection” and “reporting of patients with communicable respiratory infection and death of patient”. None of the items were rated high in both Borich’s equation and the locus for focus model among participants without relevant prior experience.

Chemiluminescence immunoassays have been widely employed for diagnosing various diseases. However, because of the extremely low intensity chemiluminescence signals, highly sensitive transducers, such as photomultiplier tubes and image sensors with cooling devices, are required to overcome this drawback. In this study, a hypersensitive photosensor was developed based on cesium lead bromide (CsPbBr

The acute demise of stem cells following transplantation significantly compromises the efficacy of stem cell-based cell therapeutics for infarcted hearts. As the stem cells transplanted into the damaged heart are readily exposed to the hostile environment, it can be assumed that the acute death of the transplanted stem cells is also inflicted by the same environmental cues that caused massive death of the host cardiac cells. Pyroptosis, a highly inflammatory form of programmed cell death, has been added to the list of important cell death mechanisms in the damaged heart. However, unlike the well-established cell death mechanisms such as necrosis or apoptosis, the exact role and significance of pyroptosis in the acute death of transplanted stem cells have not been explored in depth. In the present study, we found that M1 macrophages mediate the pyroptosis in the ischemia/reperfusion (I/R) injured hearts and identified miRNA-762 as an important regulator of interleukin 1β production and subsequent pyroptosis. Delivery of exogenous miRNA-762 prior to transplantation significantly increased the post-transplant survival of stem cells and also significantly ameliorated cardiac fibrosis and heart functions following I/R injury. Our data strongly suggest that suppressing pyroptosis can be an effective adjuvant strategy to enhance the efficacy of stem cell-based therapeutics for diseased hearts.

Highly N-doped SiC was presented as an optimal electrode for electrochemical immunoassays with a far higher sensitivity than chemiluminescence detection. As the first step, the electrochemical properties of highly N-doped SiC, such as the double-layer capacitance (Cdl), rate constant for electron transfer (kapp) and ideal polarizable potential range (electrochemical window) were analyzed and compared with those of Au, Pt, and graphite electrodes. The highly N-doped SiC electrode was used for the quantification of oxidized 3,3′,5,5′-tetramethylbenzidine (TMB) which was widely used as chromogenic substrate for commercialized immunoassay kits. In order to enhance the sensitivity for the quantification of the oxidized TMB the chronoamperometry was applied to avoid the background current of i-V measurement. Finally, the chronoamperometry based on the highly N-doped SiC electrode was applied to commercial immunoassay kits for the medical diagnosis of the human immunodeficiency virus (HIV) and the human hepatitis B surface antigen (hHBsAg). The chronoamperometric measurement based on the highly N-doped SiC electrode was proved to detect at far lower limits in comparison with the conventional optical density measurement as well as the chemiluminescence assay based on luminol as a chemiluminescent probe.

Recent studies have shown that several upstream signaling elements of apoptosis and necroptosis are closely associated with acute injury in the heart. In our study, we observed that miR-105 was notably dysregulated in rat hearts with myocardial infarction (MI). Thus, the purpose of this study was to test the hypothesis that miR-105 participates in the regulation of RIP3/p-MLKL- and BNIP3-dependent necroptosis/apoptosis in H9c2 cells and MI rat hearts. Our results show that the RIP3/p-MLKL necroptotic pathway and BNIP3-dependent apoptosis signaling are enhanced in H9c2 cells under hypoxic conditions, whereas, compared with these pathways in the controls, those in miR-105-treated H9c2 cells are suppressed. Mechanistically, we identified miR-105 as the miRNA directly suppressing the expression of RIP3 and BNIP3, two important mediators involved in cell necroptosis and apoptosis. Furthermore, MI rat hearts injected with miR-105 had decreased infarct sizes, indicating that miR-105 is among three miRNAs that function simultaneously to suppress necroptotic/apoptotic cell death pathways and to inhibit MI-induced cardiomyocyte cell death at multiple levels. Taken together, miR-105 may constitute a new therapeutic strategy for cardioprotection in ischemic heart disease. Keywords: apoptosis, ischemic heart, microRNA-105, necroptosis, programmed cell death

A capacitive biosensor based on vertically paired electrodes with controlled parasitic capacitance is presented to improve the sensitivity of capacitive measurement. The vertically paired electrodes were fabricated with a parylene film as a dielectric layer, with the distance between the electrodes less than hundreds of nanometer. The problem of parasitic capacitance owing to the electrode configuration was analyzed according to the superposed area of the electrode. In this work, two kinds of vertically paired electrodes were fabricated to control the parasitic capacitance—square-type and circular-type electrodes with different superimposed areas of 21.8 (100%) and 9.3 (42%) mm2 and the same electrode area of 9.4 × 10−5 mm2, respectively. The effect of superimposed area of the vertically paired electrodes on capacitive measurement was analyzed using the electrodes. The sensitivity of capacitive measurement was observed to increase with a decrease in superimposed electrode area and frequency. Further, the effect of parasitic capacitance was estimated by computer simulation of the sensitivity of impedance and capacitive measurement when 10% change in RS or CS occurred. The results showed that adsorption of proteins could be sensitively measured when the parasitic capacitance decreased. Finally, the effect of superimposed area of the vertically paired electrodes was measured from the interaction between antigens (human serum albumin, HSA) and immobilized antibodies (anti-HSA antibodies).

We present our latest work and investigation of exceptional point in plasmonic nanostructures. We show that the non-Hermitian singularity can be effectively deployed in small scale sensors and pave the path for engineering metamaterials with novel properties.

Neurodegenerative disease is a brain disorder caused by the loss of structure and function of neurons that lowers the quality of human life. Apart from the limited potential for endogenous regeneration, stem cell-based therapies hold considerable promise for maintaining homeostatic tissue regeneration and enhancing plasticity. Despite many studies, there remains insufficient evidence for stem cell tracing and its correlation with endogenous neural cells in brain tissue with three-dimensional structures. Recent advancements in tissue optical clearing techniques have been developed to overcome the existing shortcomings of cross-sectional tissue analysis in thick and complex tissues. This review focuses on recent progress of stem cell treatments to improve neurodegenerative disease, and introduces tissue optical clearing techniques that can implement a three-dimensional image as a proof of concept. This review provides a more comprehensive understanding of stem cell tracing that will play an important role in evaluating therapeutic efficacy and cellular interrelationship for regeneration in neurodegenerative diseases.

Vertically paired electrodes (VPEs) with multiple electrode pairs were developed for the enhancement of capacitive measurements by optimizing the electrode gap and number of electrode pairs. The electrode was fabricated using a conductive polymer layer of PEDOT:PSS instead of Ag and Pt metal electrodes to increase the VPE fabrication yield because the PEDOT:PSS layer could be effectively etched using a reactive dry etching process. In this study, sensitivity enhancement was realized by decreasing the electrode gap and increasing the number of VPE electrode pairs. Such an increase in sensitivity according to the electrode gap and the number of electrode pairs was estimated using a model analyte for an immunoassay. Additionally, a computer simulation was performed using VPEs with different electrode gaps and numbers of VPE electrode pairs. Finally, VPEs with multiple electrode pairs were applied for SARS-CoV-2 nucleoprotein (NP) detection. The capacitive biosensor based on the VPE with immobilized anti-SARS-CoV-2 NP was applied for the specific detection of SARS-CoV-2 in viral cultures. Using viral cultures of SARS-CoV-2, SARS-CoV, MERS-CoV, and CoV-strain 229E, the limit of detection (LOD) was estimated to satisfy the cutoff value (dilution factor of 1/800) for the medical diagnosis of COVID-19, and the assay results from the capacitive biosensor were compared with commercial rapid kit based on a lateral flow immunoassay.

Previous studies have reported that Hedyotis diffusa Willdenow extract shows various biological activities on cerebropathia, such as neuroprotection and short-term memory enhancement. However, there has been a lack of studies on the inhibitory activity on neurodegenerative diseases such as Alzheimer’s disease (AD) through enzyme assays of H. diffusa. Therefore, H. diffusa extract and fractions were evaluated for their inhibitory effects through assays of enzymes related to AD, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and β-site amyloid precursor protein cleaving enzyme 1 (BACE1), and on the formation of advanced glycation end-product (AGE). In this study, ten bioactive compounds, including nine iridoid glycosides 1–9 and one flavonol glycoside 10, were isolated from the ethyl acetate and n-butanol fractions of H. diffusa using a bioassay-guided approach. Compound 10 was the strongest inhibitor of cholinesterase, BACE1, and the formation of AGEs of all isolated compounds, while compound 5 had the lowest inhibitory activity. Compounds 3, 6, and 9 exhibited better inhibitory activity than other compounds on AChE, and two pairs of diastereomeric iridoid glycoside structures (compounds 4, 8, and 6, 7) showed higher inhibitory activity than others on BChE. In the BACE1 inhibitory assay, compounds 1–3 were good inhibitors, and compound 10 showed higher inhibitory activity than quercetin, the positive control. Moreover, compounds 1 and 3 were stronger inhibitors of the formation of AGE than aminoguanidine (AMG), the positive control. In conclusion, this study is significant since it demonstrated that the potential inhibitory activity of H. diffusa on enzymes related to AD and showed the potential use for further study as a natural medicine for AD treatment on the basis of the bioactive components isolated from H. diffusa.

Robot learning by demonstration is a research paradigm that can play an important role in expanding areas where robots can be applied. An easy method to get a policy to reproduce the demonstrated behavior is to learn a model that maps directly from demonstrations to action. This is referred to as behavioral cloning (BC). In this paper, a novel robotic BC method for directly imitating a policy from trajectories generated by performing a task is proposed. The proposed method not only allows a user to obtain a demonstrated trajectory for performing a task by manipulating the robot, but also automatically generates a trajectory by having the robot perform the task on behalf of the user. Experiment results showed that the proposed method can effectively learn to make accurate behavior prediction for robot manipulators.

Recently, reinforcement learning utilizing deep learning, called deep reinforcement learning, is being developed for discontinuous action space. It is shown that deep reinforcement learning has higher playing skills than those of human in the video game as Atari. The development of deep reinforcement learning for discontinuous action space, has been extended to the continuous action space as robot control area. The area of control deals with issues closely related to real world environment. However, deep reinforcement learning has limitations to solve control problems in the real world due to numerous trial-and-error based training. To address the limitations of learning in the real world, virtual world environments are used to emulate control problem in real world. In this paper, to solve a complex robot manipulation task, the learning robot manipulation based modular reward shaping is proposed. Since it is difficult to solve the complex task using only single primitive manipulation skill with a reward, it is required to combine various primitive manipulation skills with various rewards. In simulation results, it is shown that the combination of the reward functions affects to the robot manipulation performance.

Advances in deep reinforcement learning enabled cost-efficient training of control policy of physical robot actions from robot simulators. Learning control policy in a simulated environment is cost-efficient over learning in a real environment. Reward engineering is one of the key components to train efficient control policy. For tasks with long horizons such as navigation and manipulation, a sparse reward is providing limited information. The robot simulator for a physical engine of physical robot manipulation has made it easy for researchers in the field of deep reinforcement learning to simulate complicated robot manipulation environments. In this paper, A robot manipulation simulator and a deep RL framework are utilized for implement a training control policy by utilizing previous experiences. For implementation, Recent innovation Hindsight Experience Replay (HER) algorithms with previous experiences to calculate dense rewards from a sparse reward is leveraged . Proposed implementation showed an approach to investigate the reward engineering method to formulate dense reward in robot manipulator tasks.

This paper provides an experimental study of reinforcement learning on IoT devices using distilled knowledge, whose a teacher with a well-trained model transfers to a student with a new model to be trained. The experimental results show that the distilled knowledge is effective to a new model training on IoT devices.

Developing an autonomous indoor mobile robot navigation system from scratch is very difficult and it takes a long time. It requires a series of complex tasks such as handling given sensor inputs, calculating all the information needed for autonomous navigation, and controlling actuators required for movement. In this paper, an autonomous navigation system for indoor mobile robots is introduced mainly based on open source provided by the robot operating system. The presented system is capable of autonomously navigating an unstructured indoor environment avoiding collision with static or dynamic objects. To this end, the system consists of three main modules: mapping, localization, and planning. The mapping module builds a global map for an unknown environment by means of a simultaneous localization and mapping algorithm based on laser scanner data. The localization module estimates the mobile robot’s pose within the prebuilt map by way of an adaptive Monte Carlo localization approach. The planning module builds a local cost map for collision avoidance, generates collision-free trajectories to reach a goal pose based on the cost map, and produces control commands to follow the trajectories. The presented system has been tested not only in simulation environments built in the Gazebo simulator but also in real environments utilizing the Jackal mobile robot, to validate its performance for autonomous navigation including collision avoidance.

Today, a paradigm in the manufacturing industry has been shifted from mass production to small and custom production. To adapt to today’s industrial expectations, this paper presents position-based visual servoing of multiple robotic manipulators. The presented visual servoing consists of two modules: task planning and motion planning. The task planning module manipulates each robotic arm not to collide with each other by distributing a task to them in a systematic manner. The motion planning module employs the MoveIt framework to solve inverse kinematics for each robotic arm so that it moves each end-effector’s pose to the desired pose to complete the task. In addition, the module controls a robotic hand to grasp or release a target object. The presented visual servoing has been tested and verified in the Gazebo simulator.

Applying deep learning to symbolic planning is not straightforward because they differently internalize knowledge. One represents knowledge numerically while the other does symbolically. Hybrid methods that take strengths from both techniques will deliver better performance on automated planning. This paper presents a method to improve the performance of symbolic planning by applying LSTM recurrent networks to inferring the guidance knowledge for search tree node expansion. The networks learn sequential patterns across previous node expansions and generalizes the learned knowledge to predict promising actions and their probability scores at the present expansion step. The prediction consists with node cost estimation for heuristic search. A simple experiment vindicates the method of this research.

This paper addresses a continual lifelong learning problem that learns incremental multiple tasks in real-world environments. We overview and summarize representative approaches and categorization of the state-of-the-art in continual learning. Comparable scenarios, benchmark datasets, and baseline approaches for different continual scenarios introduced in this paper. We suggested a comparison of the differences and similarities with other machine learning methods. We also report real-world applications, especially robots and healthcare fields. We summarize current states and suggest future direction of continual learning problems.

Herein, we present switching-peptides for a one-step immunoassay, without the need for additional antibody treatment or washing steps to detect antigen–antibody interactions. Fluorescently labeled switching-peptides were dissociated from the immobilized antibody soon after the antigens were bound to the binding pockets. In this study, four different parts of the antibody (IgG) frame regions were chemically synthesized, and these peptides were bound to immobilized antibodies as switching-peptides. We presented the design principle of switching-peptides and used Pymol software, based on the changes in thermodynamic parameters, to study the interaction between antibodies and switching-peptides. The binding properties of switching-peptides were analyzed based on Forster resonance energy transfer between switching-peptides as well as between switching-peptides and antibodies (IgGs) isolated from different animals. The binding constants of the four switching-peptides to antibodies were estimated to be in the range of 1.48–3.29 μM. Finally, the feasibility of using switching-peptides for the quantitative one-step immunoassay was demonstrated by human hepatitis B surface antigen (hHBsAg) detection and statistical comparison of the assay results with those of conventional ELISA. The limit of detection for HBsAg was determined to be 56 ng/mL, and the dynamic range was estimated to be 136 ng/mL–33 μg/mL. These results demonstrate the feasibility of the one-step immunoassay for HBsAg.

This paper proposes a system design for automation in multi-agent-based manufacturing systems to conduct a given complex task automatically by controlling multiple robotic manipulators in a systematic manner. To this end, the proposed system is designed with three-module configurations: environmental perception, task planning, and motion planning. The environmental perception module utilizes a vision sensor to recognize all objects placed on the workspace and extract their unique ID, size, and pose. The task planning module divides a given task into primitive skill levels and distributes each primitive skill to the associated robotic manipulator with the relevant object information in a systematic manner for robotic manipulators not to collide with each other. The motion planning module determines the motion of a robotic arm and a robotic hand by solving inverse kinematics for the robotic arm and by opening or closing two fingers. The proposed system has been tested and verified in real robot environments through a complex task "peg in hole" that requires at least two robotic manipulators.

Patients with oral squamous cell carcinoma (OSCC) bone invasion are surgically treated with bone resection, which results in severe physical and psychological damage. Here, we investigated the potential of fractalkine (CX3CL1), which is regulated by transforming growth factor (TGF-β), as a novel biomarker for correct prediction and early detection of OSCC-associated bone invasion. TGF-β knockdown and treatment with a TGF-β-neutralizing antibody decreased the level of fractalkine in the culture media of HSC-2 and YD10B OSCC cells. Treatment with a fractalkine-neutralizing antibody reduced TGF-β-stimulated invasion by HSC-2 and YD10B cells. Fractalkine treatment increased the viability, invasion, and uPA secretion of both OSCC cell lines. Furthermore, OSCC cell bone invasion was assessed following subcutaneous inoculation of wild-type or TGF-β knockdown OSCC cells in mouse calvaria. TGF-β knockdown prevented erosive bone invasion, reduced the number of osteoclasts at the tumor-bone interface, and downregulated fractalkine expression in mouse tumor tissues. Our results indicate that the production of fractalkine is stimulated by TGF-β and mediates TGF-β-induced cell invasion in several OSCC cell lines showing an erosive pattern of bone invasion. Fractalkine may be a useful predictive marker and therapeutic target for OSCC-induced bone destruction.

In this work phospholipid quantification was carried out using an enzymatic assay based on cyclic voltammetry of the condensation product of N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline sodium salt (DAOS) and 4-aminoantipyrine (4-AP) with a graphite electrode. For the optimization of electrochemical measurement for the product, electrochemical properties such as the electrochemical window, double layer capacitance (Cdl) and electron transfer rate (kapp) were analyzed for a graphite-electrode and Au-electrode. The phospholipid enzymatic assay based the on electrochemical measurement using the graphite electrode was applied to the diagnosis of sepsis for sera from healthy volunteers (n = 16), patients with systemic inflammatory response syndrome (SIRS, n = 16) and severe sepsis patients (n = 24). Finally, the phospholipid quantification results from the electrochemical measurement were statistically compared with the conventional method based on optical density measurement.

Planar structured interfaces, also known as metasurfaces, are continuously attracting interest owing to their ability to manipulate fundamental attributes of light, including angular momentum, phase, or polarization. However, chromatic aberration, limiting broadband operation, has remained a challenge for metasurfaces-based optical components and imagers. The limitation stems from the intrinsic dispersion of existing materials and design principles. Here we report and experimentally demonstrate polarization-independent fishnet-achromatic-metalenses with measured average efficiencies over 70% in the continuous band from the visible (640 nm) to the infrared (1200 nm). Results of the scalable platform are enabling for applications requiring broad bandwidth and high efficiency including energy harvesting, virtual reality and information processing devices, or medical imaging., Here the authors demonstrate all-dielectric fishnet-achromatic-metalenses from the visible to the near-infrared region. This metalens performs efficiently independent of polarization over about an octave from 640 nm to 1200 nm.

We have demonstrated the first plasmonic exceptional points (EPs) at subwavelength scale. The plasmonic EPs are based on the hybridization of detuned resonances in multilayered plasmonic crystals to reach a critical complex coupling rate between nanoantennas arrays, and, exhibit the dispersion of exceptional points around the non-Hermitian singularity and enhanced nanosensing was observed. The ability to drive plasmons to EPs lays the foundation to explore topological physics at small scales and to novel sensors and optoelectronic devices based on topological polaritonic effects

The present study translated the Vocal Tract Discomfort Scale (VTDS) into Korean (K-VTDS) and evaluated its reliability and validity.This was a prospective study.The VTDS was first translated into Korean and validated. One hundred and fifty-nine patients with voice disorders were divided into three different diagnostic groups (functional, structural, and neurologic voice disorder) and 131 vocally healthy adults were also included. All participants completed the K-VTDS and the Korean version of the Voice Handicap Index (K-VHI) and Korean versions of the Voice-Related Quality of Life (K-VRQOL). The internal consistency of the K-VTDS was analyzed through Cronbach's α coefficient. The VTDS score differences related to the diagnostic groups were assessed with t test and analysis of variance. We assessed the correlation between the K-VTDS, the K-VHI, and the K-VRQOL using Pearson's correlation analysis.High internal consistency and the test-retest reliability of the K-VTDS were found. The voice disorder group had significantly higher K-VTDS scores for the subscales and total scores than those in the healthy group (P0.001). The K-VTDS scores for the subscale of frequency and total scores were highest in the functional voice disorder group. We found a significant difference in frequency and total score of the K-VTDS between the functional voice disorder group and the structural voice disorder group (P0.05). We observed a strong positive correlation among the scores for the subscales of frequency and severity, and total scores in the K-VTDS. The K-VTDS showed moderate correlation with the K-VHI and the K-VRQOL.The K-VTDS is a reliable and valid instrument for voice assessment for voice disorders in Korean-speaking patients.