Effects of Sensing Tactile Arrays, Shear Force, and Proprioception of Robot on Texture Recognition.

In robotics, tactile perception is important for fine control using robot grippers and hands. To effectively incorporate tactile perception in robots, it is essential to understand how humans use mechanoreceptors and proprioceptors to perceive texture. Thus, our study aimed to investigate the impact of tactile sensor arrays, shear force, and the positional information of the robot's end effector on its ability to recognize texture. A deep learning network was employed to classify tactile data from 24 different textures that were explored by a robot. The input values of the deep learning network were modified based on variations in the number of channels of the tactile signal, the arrangement of the tactile sensor, the presence or absence of shear force, and the positional information of the robot. By comparing the accuracy of texture recognition, our analysis revealed that tactile sensor arrays more accurately recognized the texture compared to a single tactile sensor. The utilization of shear force and positional information of the robot resulted in an improved accuracy of texture recognition when using a single tactile sensor. Furthermore, an equal number of sensors placed in a vertical arrangement led to a more accurate distinction of textures during exploration when compared to sensors placed in a horizontal arrangement. The results of this study indicate that the implementation of a tactile sensor array should be prioritized over a single sensor for enhanced accuracy in tactile sensing, and the use of integrated data should be considered for single tactile sensing.

Prevalence of feet and ankle arthritis and their impact on clinical indices in patients with rheumatoid arthritis: a cross-sectional study.

BACKGROUND: We aimed to evaluate the prevalence of foot and/or ankle arthritis (FAA) and its impact on clinical indices in patients with rheumatoid arthritis (RA). METHODS: This cross-sectional study used data from the Korean College of Rheumatology Biologics & Targeted therapy registry to observe clinical outcomes of patients undergoing biologics therapy and conventional therapy. FAA was defined as ≥1 tender or swollen joint in the ankle and/or 1st-5th metatarsophalangeal (MTP) joints. Disease Activity Score 28 (DAS28), Routine Assessment of Patient Index Data 3 (RAPID3), Simplified Disease Activity Index (SDAI), and Clinical Disease Activity Index (CDAI) were assessed. RESULTS: Among 2046 patients, 598 had FAA. The ankle joint was the most commonly involved joint in FAA (tender joint, 71.4%; swollen joint, 59.5%), followed by the third and second MTP joints. Patients with FAA showed higher DAS28, RAPID3, SDAI, and CDAI scores. FAA presence was significantly associated with non-remission as per DAS28-ESR (odds ratio, 3.4; 95% confidence interval, 2.0-5.8), DAS28-CRP (3.6, 2.4-5.3), SDAI (6.3, 2.8-14.6), CDAI (7.6, 2.4-24.3), and RAPID3 (5.6, 2.7-11.5) indices on adjusting for age, sex, disease duration, presence of rheumatoid factor, presence of anti-cyclic citrullinated peptide antibody, lung disease, use of methotrexate, and previous use of biological disease-modifying anti-rheumatic drugs. Patients with FAA were less likely to achieve remission of SDAI (n = 6, 1.0%) and CDAI (n = 3, 0.5%) than that of DAS28-ESR (n = 21, 3.5%), DAS28-CRP (n = 38, 6.4%), and RAPID3 (n = 12, 2.0%). CONCLUSIONS: FAA represents a severe disease activity and is an independent risk factor for non-remission in patients with RA.

Strong optical coupling between mutually orthogonal plasmon oscillations in a silver nanosphere-nanowire joined system.

A top-to-bottom joined system consisting of a silver nanowire and nanospheres was fabricated by embedding silver nanospheres on a glass or silicon substrate on which 3-aminothiophenol as an analyte molecule was adsorbed, and then placing silver nanowires on the substrate to make gap sites between a nanowire and nanospheres. In the far-field Raman measurements, the sphere under the wire exhibited more than 60 times higher Raman enhancement than isolated spheres. The surface enhanced Raman scattering (SERS) spectra obtained by the 647.1 nm excitation showed highly polarized feature, exhibiting ca. 4 times higher SERS intensity for the electric field parallel to the wire axis than that perpendicular to the wire axis while those by the 514.5 nm excitation showed non-polarized feature against the incident electric field direction. The polarized feature by the 647.1 nm excitation is explained in terms of optical coupling in a vertical direction to the substrate plane, between the silver nanosphere and the longitudinal surface plasmon mode of the nanowire. The longitudinal plasmon of the nanowire functions as an antenna of the incident radiation field in this type of coupled plasmon mode, to yield the confined field. Near-field two-photon excitation imaging measurements as well as numerical calculations of the localized electric field around the system support this idea and indicate that the coupling between the surface plasmon of silver nanospheres and the longitudinal mode of silver nanowires is site-selective.

The effects of knee ligament load using simulated hip abductor and hamstring muscle strengthening during cutting maneuver.

BACKGROUND: This study aimed to analyze knee ligament of load and joint moment to simulate the strengthening of the hip abductor and hamstring muscles using musculoskeletal modeling, thereby contributing to decrease of knee ligament load. METHODS: Forty participants (age: 21.85 ± 1.90 years; height: 1.76 ± 0.06 m; body mass: 68.5 ± 7.06 kg) were instructed to run at 4.5 ± 0.2 m/s from a 5 m distance posterior to the force plate, land their feet on the force plate, and perform the cutting maneuver on the left. In the musculoskeletal modeling, the hip abductor and hamstring muscles were targeted to construct a model with a 30% increase in the contraction force of the hip abductor, hamstring, and both 2 muscles. The variables were the ligament force and knee joint moment. One-way repeated measure ANOVA and Bonferroni test were used to compare the abductor/hamstring, abductor, hamstring and control models. RESULTS: There were significant differences in anterior bundle of the anterior cruciate ligament (ACL) (P = .001), inferior bundle of the superficial layer of the medial collateral ligament (MCL) (P = .016), and posterior bundle of the superficial layer of the MCL (P = .022) force. The post hoc showed that the hamstring model had lower anterior bundle of the ACL and inferior bundle of the superficial layer of the MCL than the abductor/hamstring and abductor models (P < .05) and lower posterior bundle of the superficial layer of the MCL than the abductor and control models (P < .05). There was a significant difference in the adduction (P = .028) and internal rotation moments (P = .014). The post hoc showed that both moments were lower in the hamstring model than in the other models (P < .05). CONCLUSIONS: The hamstring strengthening may contribute significantly to preventing ACL or MCL injury by reducing knee ligament load.

Experience of operating a medical humanities course at one medical school during the COVID-19: a retrospective study.

BACKGROUND: This study summarizes the experience of operating a 'Medical Humanities' course, which was taught remotely to maintain activities and discussions at medical schools in Daegu, Korea during the sudden and unexpected coronavirus disease 2019 (COVID-19). METHODS: The subjects of this study were 73 first- and 79 second-grade medical students who took the medical humanities (1) and (2) courses among first- and second-grade students of Yeungnam University College of Medicine in 2020. Of the 152 students who agreed to the online survey, 123 completed the survey. Self-, environmental, and program evaluations were conducted on the study subjects, and differences according to grade and gender were analyzed. RESULTS: As a result of the study, a significant difference between self-evaluation and environmental evaluation was confirmed. Self-evaluation was determined to be higher in the first grade than in the second grade. The environmental evaluation showed that male students were more satisfied than female students and students generally had difficulties in the classroom environment. Of the applications used in class, the highest satisfaction was observed with KakaoTalk (Kakao Corp.) and Zoom (Zoom Video Communications Inc.). At the end of COVID-19, the students preferred online classes. CONCLUSION: If the learning environment for online classes is well prepared and systematic provisions are made, such as class operations that are suitable for the subject, effective education and learning can be achieved by taking advantage of both face-to-face and online classes.

Base effects on fabrication of silver nanoparticles embedded silica nanocomposite for surface-enhanced Raman scattering (SERS).

In this paper, we studied on the effect of organic bases in the case of ethylene glycol based fabrication of silver nanoparticles embedded silica nanocomposite (Ag SNC) without heating. Considering their chemical structures, butylamine (BA), ethanolamine (EA), triethanolamine (TEA), tributylamine (TBA), octylamine (OA) and Jeffamine 500 (JA) were used as an organic base. In addition, the effect of the concentrations of AgNO3 and organic bases on the formation of Ag SNC was also examined. In conformity with the characteristics of Ag SNC, SERS signal intensity of benzenethiol on Ag SNC was measured. As a result, the SERS signal intensity of Ag SNCs was strongly dependent on the reaction conditions. Furthermore, when reacted under the best reaction condition with concentrations of AgNO3 and OA, 3 mM and 5 mM, respectively, a large-scale production of Ag SNC was possible under the mild conditions.

Transmittance Control of a Water-Repellent-Coated Layer on a Tensioned Web in a Roll-to-Roll Slot-Die Coating System.

Solar cells are important alternatives to fossil fuels for energy generation in today's world, where the demand for alternative, renewable sources of energy is increasing. However, solar cells, which are installed outdoors, are susceptible to pollution by environmental factors. A solution to overcome this limitation involves coating solar cell surfaces with functional coatings. In this study, we propose a transmittance control method for a tensioned web in a roll-to-roll, transparent, water-repellent film coating. First, we analyzed the effects of process conditions on the transmittance and contact angle of the transparent water-repellent film during roll-to-roll slot-die coating. It was confirmed that the tension was the most dominant factor, followed by the coating gap. Through the tension control, the transmittance was changed by 3.27%, and the contact angle of the DI water was changed by 17.7°. In addition, it was confirmed that the transmittance was changed by 0.8% and the contact angle of DI water by 3.9° via the coating gap control. Based on these results, a transmittance prediction model was developed according to the tension and coating gap, and was then verified experimentally. Finally, a water-repellent film with a high transmittance of 89.77% was obtained using this model.

Multifunctional silver-embedded magnetic nanoparticles as SERS nanoprobes and their applications.

In this study, surface-enhanced Raman spectroscopy (SERS)-encoded magnetic nanoparticles (NPs) are prepared and utilized as a multifunctional tagging material for cancer-cell targeting and separation. First, silver-embedded magnetic NPs are prepared, composed of an 18-nm magnetic core and a 16-nm-thick silica shell with silver NPs formed on the surface. After simple aromatic compounds are adsorbed on the silver-embedded magnetic NPs, they are coated with silica to provide them with chemical and physical stability. The resulting silica-encapsulated magnetic NPs (M-SERS dots) produce strong SERS signals and have magnetic properties. In a model application as a tagging material, the M-SERS dots are successfully utilized for targeting breast-cancer cells (SKBR3) and floating leukemia cells (SP2/O). The targeted cancer cells can be easily separated from the untargeted cells using an external magnetic field. The separated targeted cancer cells exhibit a Raman signal originating from the M-SERS dots. This system proves to be an efficient tool for separating targeted cells. Additionally, the magnetic-field-induced hot spots, which can provide a 1000-times-stronger SERS intensity due to aggregation of the NPs, are studied.

Numerical Modeling of Ink Widening and Coating Gap in Roll-to-Roll Slot-Die Coating of Solid Oxide Fuel Cell Electrolytic Layer.

Slot-die coatings are advantageous when used for coating large-area flexible devices; in particular, the coating width can be controlled and simultaneous multi-layer coatings can be processed. To date, the effects of ink widening and the coating gap on the coating thickness have only been considered in a few studies. To this end, we developed two mathematical models to accurately estimate the coating width and thickness that consider these two effects. We used root mean square deviation (RMSD) to experimentally verify the developed method. When the coating gap was increased, the coating width increased and the coating thickness decreased. Experimental results showed that the estimated performances of the coating width and thickness models were as high as 98.46% and 95.8%, respectively. We think that the developed models can be useful for determining the coating conditions according to the ink properties to coat a functional layer with user-defined widths and thicknesses in both lab- and industrial-scale roll-to-roll slot-die coating processes.

Macroscopic single-walled-carbon-nanotube fiber self-assembled by dip-coating method.

Pure macroscopic single-walled-carbon-nanotube (SWNT) fibers are fabricated by using a dip-coating method without any additive or additional electrical equipment or complex apparatus. The present method only utilizes microfluidics, which includes capillary condensation, capillary flow, and surface tension, and results in the self-assembly and self-alignment of SWNT colloids.

Fluorine geochemistry in bedrock groundwater of South Korea.

High fluoride concentrations (median=4.4 mg/L) in deep bedrock groundwater of South Korea prevent the usage of it as a drinking water source. The hydrogeochemistry of deep thermal groundwaters (N=377) in diverse bedrocks has been studied in order to evaluate the geologic and geochemical controls on fluoride concentrations in groundwater. The groundwater samples were clustered geologically, and the average and median concentrations of fluoride were compared by the Mann-Whitney U test. The order of median fluoride concentration with respect to geology is as follows: metamorphic rocks> or =granitoids > or =complex rock>>volcanic rocks> or =sedimentary rocks. This result indicates that the geological source of fluoride in groundwater is related to the mineral composition of metamorphic rocks and granitoids. With respect to groundwater chemistry, the fluoride concentration was highest in Na-HCO3 type groundwater and lowest in Ca-HCO3 type groundwater. Ionic relationships also imply that the geochemical behavior of fluoride in groundwater is related to the geochemical process releasing Na and removing Ca ions. The thermodynamic relationship between the activities of Ca and F indicates that fluoride concentration is controlled by the equilibrium of fluorite (CaF2). In other words, the upper limits of fluoride concentration are determined by the Ca ion; i.e., Ca concentrations play a crucial role in fluoride behavior in deep thermal groundwater. The result of this study suggests that the high fluoride in groundwater originates from geological sources and fluoride can be removed by fluorite precipitation when high Ca concentration is maintained. This provides a basis for a proper management plan to develop the deep thermal groundwater and for treatment of high fluoride groundwater frequently found in South Korea.

Complete mitochondrial genome of Lycodes tanakae (Perciformes: Zoarcidae).

The complete mitochondrial genome of Lycodes tanakae was sequenced for the first time from its muscle tissue using the next-generation sequencing method. Its mitochondrial genome was 16,594 base pairs in length, containing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and one control region. Its overall A, C, G, and T contents were 25.6%, 30.6%, 18.7%, and 25.2%, respectively. Its, A + T content (50.8%) was slightly higher than its G + C content (49.2%). A phylogenetic tree was built using 10 belonging to the order Perciformes and two species belonging to the order Scorpaeniformes.

Complete mitochondrial genome of Parupeneus barberinus (Perciformes, Mullidae): mitogenome characterization and phylogenetic analysis.

Parupeneus barberinus is a tropical/subtropical reef-dwelling marine fish belonging to the family Mullidae. Herein, we report the first sequencing and assembly of the complete mitochondrial genome of P. barberinus. The complete mitochondrial genome is 16,560 bp long and has the typical vertebrate mitochondrial gene arrangement, consisting of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and a control region. Phylogenetic analysis using mitochondrial genomes of 18 species showed that P. barberinus is clustered with P. multifasciatus and P. chrysopleuron and rooted with other Mullidae species. This mitochondrial genome provides potentially important resources for addressing taxonomic issues and studying molecular evolution.

Complete mitochondrial genome of Hemilepidotus gilberti (Scorpaeniformes: Cottidae).

The complete mitochondrial genome of gilbert's irish lord (Hemilepidotus gilberti), a fish belonging to family Cottidae, was sequenced for the first time. This complete mitochondrial genome was 16,907 nucleotides in length, consisting of 38 mitochondrial genes (13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a control region). The order of these genes was similar to that of other teleosts. The overall A, C, G, and T nucleotide contents in mitogenome were 26.8%, 30.4%, 17.0%, and 25.8%, respectively. The A + T content (52.6%) was higher than the G + C content (47.4%). NJ phylogenetic analysis was performed for 10 related species within the family of Cottidae along with, two fish species belonging to another family (Sebastidae).

Exploration of replicative senescence-associated genes in human dermal fibroblasts by cDNA microarray technology.

The aging process is known to be regulated by specific genes in various organisms, including yeast, the nematode C. elegans, fruitflies and mice. To explore the novel genes involved in aging process, we applied cDNA microarray technology to a replicative senescence model of human dermal fibroblasts (HDF). Eighty-four genes, including inflammatory genes, cell cycle regulatory genes, cytoskeletal genes, and metabolic genes were found to show more than two fold expressional differences in young and old fibroblasts. Furthermore, 31 genes were confirmed to be up- or down-regulated during replicative senescence by semi-quantitative RT-PCR. The overexpressions of several genes including CD36, putative lymphocyte G0/G1 switch gene (G0S2), tumor protein D52-like 1 (TPD52L1), chemokine (C-X-C motif) ligand 6, myxovirus resistant gene 1 (MX1), and the down-regulation of the immunoglobulin superfamily containing leucine-rich repeat (ISLR), neurotrimin, insulin-like growth factor 2 associated protein (IGF2A), and apoptosis-related RNA binding protein (NAPOR3) were newly identified. These results suggest that fibroblasts show the deregulation of various cellular processes, such as inflammatory response, mitosis, cell adhesion, transport, signal transduction, and metabolism during replicative senescence.

Identification of amyloid beta-peptide responsive genes by cDNA microarray technology: involvement of RTP801 in amyloid beta-peptide toxicity.

Amyloid beta-peptide (Abeta), a causative molecule in the pathogenesis of Alzheimer's disease and the main component of senile plaques, is known to be neurotoxic in vitro and in vivo. The mechanisms involved in this Ab-mediated neurotoxicity are not fully understood, although there is evidence to suggest the involvement of oxidative stress, alterations in calcium homeostasis, and/or of CDK activators. Many studies have suggested that Ab may exert its toxic effect via the activation of transcription factors. Therefore, we investigated Ab- responsive genes in human neuroblastoma CHP134 cells using 3.1K human DNA microarrays. Among the several genes overexpressed or repressed by Ab, RTP801, Hi95/sestrin 2, and stanniocalcin 2 were confirmed to be Ab-mediated overexpression in the cells by semiquantitative RT-PCR. Transient expression of the sense RTP801 gene in CHP134 cells increased sensitivity to Abeta cytotoxicity and the expression of the antisense RTP801 gene protected the cells from the Abeta toxicity. These results suggest that RTP801 might play important roles in Abeta toxicity and the pathogenesis of Alzheimer's disease.

Overexpression of mitochondrial thioredoxin reductase and peroxiredoxin III in hepatocellular carcinomas.

Thioredoxin reductase 2 (TrxR2), thioredoxin II (Trx II) and peroxiredoxin III (Prx III) are specifically localized in mitochondria and believed to play important roles in the regulation of cellular redox status by serving as a primary line of defense against H2O2 produced during respiration. Substantial evidence indicates that the alteration of cellular redox status is a critical factor involved in cell growth and death and results in tumorigenesis. We therefore investigated the expression of TrxR2 and Prx III in 58 paraffin-embedded hepatocellular carcinoma tissues by immunohistochemistry. The labeling indices of TrxR2 and Prx III were significantly higher in tumor tissues than in the corresponding adjacent normal tissues. In 39 (67.2%) out of 58 samples, the levels of TrxR2 expression were higher in tumor tissues than in corresponding adjacent normal tissues, while 11 samples (19.0%) showed lower expression in tumor tissues. Prx III expression was increased in tumor tissues of 23 samples (39.7%) compared to adjacent normal tissues and were decreased in 18 samples (31.0%). These results suggest that alterations in cellular redox status by enhanced expression of TrxR2 and/or Prx III might be associated with the formation and development of hepatocellular carcinomas.

Outcomes of open versus closed treatment in the management of mandibular subcondylar fractures.

OBJECTIVES: To compare the clinical and radiological outcomes after closed reduction (CR) and open reduction and internal fixation (ORIF) in the management of subcondylar fractures. MATERIALS AND METHODS: Forty-eight patients presenting with subcondylar fracture between January 2010 and March 2013 were evaluated retrospectively. Fifteen patients were treated with CR and 33 patients with ORIF. The clinical and radiologic parameters were evaluated during follow-up (mean, 7.06 months; range, 3 to 36 months). RESULTS: In the CR group, no patients had any problems with regard to the clinical parameters. The average period of maxillomandibular fixation (MMF) was 5.47 days. The preoperative average tangential angulation of the fractured fragment was 3.67°, and loss of ramus height was 2.44 mm. In the ORIF group, no clinical problems were observed, and the average period of MMF was 6.33 days. The preoperative average tangential angulation of the subcondylar fragment was 8.66°, and loss of ramus height was 3.61 mm. CONCLUSION: CR provided satisfactory clinical results, though ORIF provided more accurate reduction of the fractured fragment. So there is no distinct displacement of fractured fragment, CR should be selected than ORIF because of no need for surgery.

Comparison of resorbable plates and titanium plates for fixation stability of combined mandibular symphysis and angle fractures.

OBJECTIVES: We compared resorbable plates with titanium plates for treatment of combined mandibular angle and symphyseal fractures. MATERIALS AND METHODS: Patients with mandibular angle and symphysis fractures were divided into two groups. The control (T) group received titanium plates while the experimental (R) group received resorbable plates. All procedures were carried out under general anesthesia using standard surgical techniques. We compared the frequency of wound dehiscence, development of infection, malocclusion, malunion, screw breakage, and any other technical difficulties between the two groups. RESULTS: Thirteen patients were included in the R group, where 39 resorbable plates were applied. The T group consisted of 16 patients who received 48 titanium plates. The mean age in the R and T groups was 28.29 and 24.23 years, respectively. Primary healing of the fractured mandible was obtained in all patients in both groups. Postoperative complications were minor and transient. Moreover, there were no significant differences in the rates of various complications between the two groups. Breakage of 3 screws during the perioperative period was seen in the R group, while no screws or plates were broken in the T group. CONCLUSION: Resorbable plates can be used to stabilize combined mandibular angle and symphysis fractures.

Encoding peptide sequences with surface-enhanced Raman spectroscopic nanoparticles.

Peptides synthesized on microbeads were encoded by chemically and physically adsorbing surface-enhanced Raman spectroscopic nanoparticles (SERS dots) on the microbead surface during the synthesis, which could be easily and rapidly decoded by Raman spectroscopy.