Highly efficient blue InGaN nanoscale light-emitting diodes.

Indium gallium nitride (InGaN)-based micro-LEDs (µLEDs) are suitable for meeting ever-increasing demands for high-performance displays owing to their high efficiency, brightness and stability1-5. However, µLEDs have a large problem in that the external quantum efficiency (EQE) decreases with the size reduction6-9. Here we demonstrate a blue InGaN/GaN multiple quantum well (MQW) nanorod-LED (nLED) with high EQE. To overcome the size-dependent EQE reduction problem8,9, we studied the interaction between the GaN surface and the sidewall passivation layer through various analyses. Minimizing the point defects created during the passivation process is crucial to manufacturing high-performance nLEDs. Notably, the sol-gel method is advantageous for the passivation because SiO2 nanoparticles are adsorbed on the GaN surface, thereby minimizing its atomic interactions. The fabricated nLEDs showed an EQE of 20.2 ± 0.6%, the highest EQE value ever reported for the LED in the nanoscale. This work opens the way for manufacturing self-emissive nLED displays that can become an enabling technology for next-generation displays.

Exotic Magnetic Anisotropy Near Digitized Dimensional Mott Boundary.

The magnetic anisotropy of low-dimensional Mott systems exhibits unexpected magnetotransport behavior useful for spin-based quantum electronics. Yet, the anisotropy of natural materials is inherently determined by the crystal structure, highly limiting its engineering. The magnetic anisotropy modulation near a digitized dimensional Mott boundary in artificial superlattices composed of a correlated magnetic monolayer SrRuO3 and nonmagnetic SrTiO3 , is demonstrated. The magnetic anisotropy is initially engineered by modulating the interlayer coupling strength between the magnetic monolayers. Interestingly, when the interlayer coupling strength is maximized, a nearly degenerate state is realized, in which the anisotropic magnetotransport is strongly influenced by both the thermal and magnetic energy scales. The results offer a new digitized control for magnetic anisotropy in low-dimensional Mott systems, inspiring promising integration of Mottronics and spintronics.

Impact of COVID-19 on ophthalmic medical access during successive waves: Demographics, disease factors, and wave locations.

BACKGROUND: The coronavirus disease (COVID-19) pandemic significantly impacted medical care, including ophthalmology. This study aimed to identify factors associated with reduced ophthalmic medical access during the pandemic. METHODS: This nationwide population-based cohort study analysed South Korean health insurance claims data from January 2019 to November 2021. Outpatient visits and surgeries for age-related macular degeneration, cataract, diabetic retinopathy, glaucoma, and retinal detachment during the two pandemic waves were compared with those in the non-pandemic period. Poisson regression was used to estimate incidence rate ratios and changes in outpatient visits and surgeries between waves concerning patient age, sex, residential location, and health insurance type. RESULTS: Outpatient visits for five eye diseases decreased in the first wave (0.733-0.985, P < 0.001). In the second wave, only outpatient visits for age-related macular degeneration, cataract, and glaucoma decreased (0.754, 0.878, and 0.874, respectively, all P < 0.001). Age-related macular degeneration, cataract, and glaucoma surgeries were significantly reduced in the first wave (0.829, P < 0.001; 0.836, P < 0.001; 0.904, P = 0.030, respectively). Age-related macular degeneration (0.852) and cataract (0.716) surgeries dropped in the second wave. Women and elderly (>65 years) patients curtailed outpatient visits and surgeries more throughout the pandemic and were less resilient during the second wave. Wave location was also related to outpatient visits and surgeries. CONCLUSIONS: The COVID-19 pandemic decreased outpatient visits and surgeries for eye diseases, with more significant impact on women, older patients, and those residing near wave locations. These findings can inform healthcare policies to minimise future pandemic impacts on healthcare delivery.

Infrared Transparent and Electromagnetic Shielding Correlated Metals via Lattice-Orbital-Charge Coupling.

Despite being a requisite for modern transparent electronics, few metals have a sufficiently high infrared transmittance due to the free electron response. Here, upon alloying the correlated metal SrVO3 with BaVO3, the medium wavelength infrared transmittance at a wavelength of 4 µm is found to be 50% higher than those for Sn-doped In2O3 (ITO) and La-doped BaSnO3 (BLSO). The room temperature resistivity of the alloy of ∼100 µΩ cm is 1 order of magnitude lower than those of ITO and BLSO, guaranteeing a profound electromagnetic shielding effectiveness of 22-31 dB at 10 GHz in the X-band. Systematic investigations reveal symmetry breaking of VO6 oxygen octahedra in SrVO3 due to the substitution of Sr2+ with larger Ba2+ ions, localization of electrons in the lower energy V-dyz and dzx orbitals, and stronger correlation effects. The lattice-orbital-charge-coupled engineering of the electronic band structure in correlated metals offers a new design strategy to create super-broad-band transparent conductors with an enhanced shielding capability.

Effect of the lumbar stability exercise on the height difference between shoulders and range of motion in older adults.

[Purpose] The purpose of this study was to investigate the effect of the lumbar stability exercise on the range of motion (ROM) and height difference of the shoulder and to provide basic data to prevent musculoskeletal disorders for improvement of the quality of life of older adults. [Participants and Methods] Twenty older adults without musculoskeletal problems were divided into the lumbar stability exercise group and the passive upper arm exercise group and performed exercise for 30 minutes, 3 times a week for 5 weeks. The shoulder flexion, abduction, extension, and height difference between shoulders were measured. A paired t-test was applied for comparative analysis of data before and after exercise in both groups. [Results] In the lumbar stability exercise group, the shoulder flexion, abduction and height difference were significantly different. In the passive upper arm exercise group, the abduction was significantly different. [Conclusion] Since it was proved that the height difference and range of motion of shoulder are improved when the lumbar stability exercise is indirectly carried out without directly doing shoulder exercise, it is suggested that the lumbar stability exercise is strongly recommended for clinical uses to improve functions in older adults.

Improved Monitoring of Wildlife Invasion through Data Augmentation by Extract-Append of a Segmented Entity.

Owing to the continuous increase in the damage to farms due to wild animals' destruction of crops in South Korea, various methods have been proposed to resolve these issues, such as installing electric fences and using warning lamps or ultrasonic waves. Recently, new methods have been attempted by applying deep learning-based object-detection techniques to a robot. However, for effective training of a deep learning-based object-detection model, overfitting or biased training should be avoided; furthermore, a huge number of datasets are required. In particular, establishing a training dataset for specific wild animals requires considerable time and labor. Therefore, this study proposes an Extract-Append data augmentation method where specific objects are extracted from a limited number of images via semantic segmentation and corresponding objects are appended to numerous arbitrary background images. Thus, the study aimed to improve the model's detection performance by generating a rich dataset on wild animals with various background images, particularly images of water deer and wild boar, which are currently causing the most problematic social issues. The comparison between the object detector trained using the proposed Extract-Append technique and that trained using the existing data augmentation techniques showed that the mean Average Precision (mAP) improved by ≥2.2%. Moreover, further improvement in detection performance of the deep learning-based object-detection model can be expected as the proposed technique can solve the issue of the lack of specific data that are difficult to obtain.

Comparison of maximum strength, proprioceptive, dynamic balance, maximum joint angle between two groups classified through the ankle instability instrument.

[Purpose] The purpose of this study is to figure out the information obtainable from ankle instability instrument (AII) survey among various factors related to the ankle instability. [Participants and Methods] This study targeted on 34 participants, divided the participants into stability group and instability group based on AII survey results, and measured the maximum isometric contraction, proprioception, dynamic balance, and maximum joint angles. The independent t-test was used. [Results] The maximum isometric contraction showed significance in the plantar flexion while the proprioceptive sense showed significance in both dorsiflexion and plantar flexion. The dynamic balanced showed significance in the anterior direction while the maximum joint angles showed significance in the dorsiflexion. [Conclusion] According to the results, the participants who were classified as ankle instability patients based on AII survey results involved problems in the maximum isometric contraction, proprioception, dynamic balance, and maximum joint angles.

Dieckol is a natural positive allosteric modulator of GABAA-benzodiazepine receptors and enhances inhibitory synaptic activity in cultured neurons.

Phlorotannin supplement (PS) is a natural hypnotic substrate that modulates γ-aminobutyric acid type A (GABAA)-benzodiazepine (BZD) receptors. However, there is a lack of functional data assessing the role of individual components of PS, such as Dieckol, as allosteric activators of GABAA receptors (GABAAR). Using the whole cell patch clamp technique, we demonstrated that PS functionally enhanced the activity of GABAA-BZD receptors in a heterologous system and in primary cultured neurons. Application of diazepam (DZP) or Dieckol (1) increased GABAAR-mediated inward current in HEK293T cells containing the α1 subunit in a dose-dependent manner, (2) which was blocked by co-treatment with the selective benzodiazepine site antagonist, flumazenil (FLZ); it also (3) increased the amplitude of GABAA-BZD receptors in primary cultured neurons, which was blocked by FLZ and (4) attenuated spontaneous activity in cultured neurons. These results indicate that PS and Dieckol act as positive allosteric activators of GABAA-BZD receptors, which might be the underlying mechanism of the sedative-hypnotic effect of PS. To our knowledge, this is the first study to directly link Dieckol-induced GABAAR activation via the BZD site binding and suppression of spontaneous neuronal activity in vitro.

Comparison of maximum strength, proprioceptive, dynamic balance, maximum joint angle of stability and instability ankle by Cumberland Ankle Instability Tool.

[Purpose] The purpose of this study was to investigate the factors of ankle instability by using Cumberland ankle instability tool (CAIT), which have been frequently used as ankle instability tools. The participants were divided into the normal ankle group and the instability ankle group. Maximum strength, proprioception, dynamic balance and maximum rage of joint motion were compared in order to find out factors of instability in the questionnaires. [Participants and Methods] A total of 44 participants were classified into the control (CON) group and the chronic ankle instability (CAI) group according to questionnaire types. Muscle strength, proprioception, dynamic balance and maximum joint angle were measured. The independent t-test was used. [Results] In the case of maximum ankle strength, it showed significance in CON group and CAI group ankle dorsiflexion and plantarflexion. In proprioception, it showed significance in CON group and CAI group. In dynamic balance, it showed significance in anterior (ANT) direction of the CON group and CAI group. Maximum joint angle produced significance in dorsiflexion of CON group and CAI group. [Conclusion] Information on maximum strength, proprioception, dynamic balance of anterior direction, and maximum joint angle of dorsiflexion is available through questionnaire CAIT.

Differences of quadriceps activity during inline lunge by using FMS assessment.

[Purpose] This study assessed the exercise capacity of healthy adults while performing the inline lunge exercise by using Functional Movement Screen (FMS). Compared the difference in muscle activity of the quadriceps according to the exercise capacity. [Participants and Methods] Thirty two healthy participants (12 males, 20 females) participated in this study. The surface electromyography (sEMG) was used to measure the electrical activities for the vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL) of quadriceps. [Results] Both groups had significant difference when sitting up and getting up during the inline lunge. In scores 3 group, vastus medialis showed higher muscle activity than vastus lateralis. On contrary, in scores 2 group, vastus lateralis had higher muscle activity than vastus medialis. [Conclusion] Therefore, this study suggests that inline lunge can help to strengthen the quadriceps effectively by showing the difference of quadriceps activity according to exercise capacity.

The molecular mechanism of synaptic activity-induced astrocytic volume transient.

KEY POINTS: Neuronal activity causes astrocytic volume change via K+ uptake through TREK-1 containing two-pore domain potassium channels. The volume transient is terminated by Cl- efflux through the Ca2+ -activated anion channel BEST1. The source of the Ca2+ required to open BEST1 appears to be the stretch-activated TRPA1 channel. Intense neuronal activity is synaptically coupled with a physical change in astrocytes via volume transients. ABSTRACT: The brain volume changes dynamically and transiently upon intense neuronal activity through a tight regulation of ion concentrations and water movement across the plasma membrane of astrocytes. We have recently demonstrated that an intense neuronal activity and subsequent astrocytic AQP4-dependent volume transient are critical for synaptic plasticity and memory. We have also pharmacologically demonstrated a functional coupling between synaptic activity and the astrocytic volume transient. However, the precise molecular mechanisms of how intense neuronal activity and the astrocytic volume transient are coupled remain unclear. Here we utilized an intrinsic optical signal imaging technique combined with fluorescence imaging using ion sensitive dyes and molecular probes and electrophysiology to investigate the detailed molecular mechanisms in genetically modified mice. We report that a brief synaptic activity induced by a train stimulation (20 Hz, 1 s) causes a prolonged astrocytic volume transient (80 s) via K+ uptake through TREK-1 containing two-pore domain potassium (K2P) channels, but not Kir4.1 or NKCC1. This volume change is terminated by Cl- efflux through the Ca2+ -activated anion channel BEST1, but not the volume-regulated anion channel TTYH. The source of the Ca2+ required to open BEST1 appears to be the stretch-activated TRPA1 channel in astrocytes, but not IP3 R2. In summary, our study identifies several important astrocytic ion channels (AQP4, TREK-1, BEST1, TRPA1) as the key molecules leading to the neuronal activity-dependent volume transient in astrocytes. Our findings reveal new molecular and cellular mechanisms for the synaptic coupling of intense neuronal activity with a physical change in astrocytes via volume transients.

Phase Instability amid Dimensional Crossover in Artificial Oxide Crystal.

Artificial crystals synthesized by atomic-scale epitaxy provide the ability to control the dimensions of the quantum phases and associated phase transitions via precise thickness modulation. In particular, the reduction in dimensionality via quantized control of atomic layers is a powerful approach to revealing hidden electronic and magnetic phases. Here, we demonstrate a dimensionality-controlled and induced metal-insulator transition (MIT) in atomically designed superlattices by synthesizing a genuine two-dimensional (2D) SrRuO_{3} crystal with highly suppressed charge transfer. The tendency to ferromagnetically align the spins in an SrRuO_{3} layer diminishes in 2D as the interlayer exchange interaction vanishes, accompanying the 2D localization of electrons. Furthermore, electronic and magnetic instabilities in the two SrRuO_{3} unit cell layers induce a thermally driven MIT along with a metamagnetic transition.

Dicaffeoylquinic acids alleviate memory loss via reduction of oxidative stress in stress-hormone-induced depressive mice.

Chronic stress can lead to depression due to elevated levels of stress hormones such as glucocorticoid. This is accompanied by an increase in reactive oxygen species (ROS) levels in the brain, which can cause dendritic spine loss and atrophy in neurons, followed by memory loss. Dicaffeoylquinic acids (diCQAs) are naturally occurring polyphenolic antioxidant compounds in Arctium lappa extracts (AL). The effects of natural derivatives of cafferoylqunic acid on stress hormone-induced depressive behavior and their underlying mechanisms are uncertain. In the current study, we showed that diCQAs reduced depressive behaviors including memory loss in corticosterone (CORT) treated mice. The mechanism of anti-depressants of diCQAs is likely through reduction of ROS production by inhibiting the activity of monoamine oxidase (MAO) type A and B in neurons and astrocytes. Among diCQAs, 3,4- and 3,5-diCQA significantly inhibited the activity of MAO enzymes followed by the reduction of ROS in neurons and astrocytes and also protected neuronal atrophy and synaptic transmission against stress hormone. These results suggest that 3,4- and 3,5-diCQAs effectively reduced depressive symptoms and inhibited ROS production to alleviate memory loss in stress hormone-induced depressive mice and hence, which provide some potential natural antidepressants.

Interleukin-6 as a Potential Predictor of Neurologic Outcomes in Cardiac Arrest Survivors Who Underwent Target Temperature Management.

BACKGROUND: Serum interleukin-6 (IL-6) is a cytokine released in response to an inflammatory stimulus or tissue injury. IL-6 levels are known to increase in patients with brain injury. OBJECTIVE: We investigated the neurologic outcomes associated with serum IL-6 levels in out-of-hospital cardiac arrest (OHCA) survivors who underwent target temperature management (TTM). METHODS: This was a prospective single-center observational study from October 2018 to November 2019 in a cohort of 45 patients. Serum inflammatory markers (IL-6, C-reactive protein, white blood cells) were determined in samples obtained immediately and at 24, 48, and 72 h after the return of spontaneous circulation (ROSC). Poor neurologic outcome, defined as Cerebral Performance Category 3-5 at 3 months after cardiac arrest, was the primary outcome. RESULTS: Among 45 patients enrolled in this study, 25 (55.6%) patients showed a poor neurologic outcome. IL-6 levels were significantly higher in the poor neurologic outcome group immediately (IL-60) after ROSC. The area under the curve (AUC) value of IL-60 was the highest among those of serum IL-6, CRP, and WBC at each time point. The IL-6 levels for predicting poor neurologic outcome had a sensitivity of 75.0%, with 80% specificity at IL-60. The AUC of IL-60 was 0.810 (95% confidence interval 0.664-0.913), with a cutoff value of 346.7 pg mL-1. CONCLUSIONS: Serum IL-6 level immediately after ROSC was a highly specific and sensitive marker for the 3-month poor neurologic outcome, and may be a useful early predictive marker of neurologic outcome in OHCA survivors treated with TTM.

Effect of abdominal drawing-in maneuver with prone hip extension on muscle activation of posterior oblique sling in normal adults.

[Purpose] There have been many studies on ipsilateral erector spinae in regard of prone hip extension (PHE). However, mediating methods have been focusing on the reinforcement of gluteus. Hereupon, this study is intended to identify how an increase of abdominal drawing-in maneuver influences on posterior oblique sling (POS) and suggest a mediating method to effectively reinforce them. [Participants and Methods] This study has been conducted on normal male (10) and female (10), and participants were asked to prove PHE exercise and abdominal drawing-in maneuver prone hip extension exercise (ADIM PHE). Surface electromyography (EMG) was recorded from the contralateral latissimus dorsi, ipsilateral erector spinae, ipsilateral gluteus maximus, and ipsilateral biceps femoris. A pared t-test was used to compare muscle activity POS. [Results] EMG activity of the contralateral latissimus dorsi, ipsilateral gluteus maximus was significantly greater performed ADIM PHE than PHE. As for ipsilateral erector spinae muscle, ipsilateral biceps femoris activation was lower in ADIM PHE than PHE. [Conclusion] According to the results of this study, abdominal drawing-in maneuver seems to be an important factor that influences on muscular activation of POS.

Atomic Observation of Filling Vacancies in Monolayer Transition Metal Sulfides by Chemically Sourced Sulfur Atoms.

Chemical treatment using bis(trifluoromethane) sulfonimide (TFSI) was shown to be particularly effective for increasing the photoluminescence (PL) of monolayer (1L) MoS2, suggesting a convenient method for overcoming the intrinsically low quantum yield of this material. However, the underlying atomic mechanism of the PL enhancement has remained elusive. Here, we report the microscopic origin of the defect healing observed in TFSI-treated 1L-MoS2 through a correlative combination of optical characterization and atomic-scale scanning transmission electron microscopy, which showed that most of the sulfur vacancies were directly repaired by the extrinsic sulfur atoms produced from the dissociation of TFSI, concurrently resulting in a significant PL enhancement. Density functional theory calculations confirmed that the reactive sulfur dioxide molecules that dissociated from TFSI can be reduced to sulfur and oxygen gas at the vacancy site to form strongly bound S-Mo. Our results reveal how defect-mediated nonradiative recombination can be effectively eliminated by a simple chemical treatment method, thereby advancing the practical applications of monolayer semiconductors.

Influence of muscle activation of posterior oblique sling from changes in activation of gluteus maximus from exercise of prone hip extension of normal adult male and female.

[Purpose] There have been many study ipsilateral erector spinae in regard of prone hip extension (PHE). However, mediating methods have been focusing on the reinforcement of gluteus. Hereupon, this study is intended to identify how an increase of gluteus maximus influences on posterior oblique sling (POS) and suggest a mediating method to effectively reinforce them. This study shows the seclective POS strength exercise. [Participants and Methods] This study has been conducted on normal male (13) and female (13), and participants were asked to proceed PHE exercise and prone hip extension with hip abduction with knee flexion (PHEAKF). Surface electromyography (EMG) was recorded from the contralateral latissimus dorsi, contralateral erector spinae, ipsilateral erector spinae, ipsilateral gluteus maximus, and ipsilateral biceps femoris. A paried t-test was used to compare muscle activity POS. [Results] EMG activity of the contralateral latissimus dorsi, ipsilateral erector spinae, and ipsilateral gluteus maximus was significantly greater performed PHEAKF than PHE. As for ipsilateral biceps femoris, muscle activation was lower in PHEAKF than PHE. [Conclusions] According to the results of this study, increase in muscular activation from the direction of muscular fiber and posterior oblique sling seems to be an important factor that influencontralateral crector spinae on muscular activation of POS.

Standardized Citrus unshiu peel extract ameliorates dexamethasone-induced neurotoxicity and depressive-like behaviors in mice.

Dried Citrus unshiu peel, also known as Chinpi, have been commonly used as a traditional medicine to improve for allergy, inflammation and hepatopathy. Many previously studies have reported that citrus flavonoids show neuroprotective activities. However, the antidepressant-related effects of C. unshiu peels have not been well characterized. Here, the antidepressant-like effects of standardized C. unshiu peel extract (SCP) were evaluated in in vivo and in vitro depression models induced by dexamethasone (DEX), a synthetic glucocorticoid. Male ICR mice (9-week-old) were injected the DEX (40 mg/kg) and were orally given SCP daily (30, 100, and 300 mg/kg) for 14 consecutive days. The depressive-like behaviors were determined by use of open filed test (OFT), sucrose preference test (SPT), tail suspension test (TST), and forced swim test (FST). We show that treatment with SCP significantly alleviated DEX-induced depressive-like behaviors and reduced neurotoxicity in a concentration dependent manner in SH-SY5Y cells. Additionally, repeated DEX injection markedly decreased brain derived neurotrophic factor (BDNF) level, tropomyosin receptor kinase B (TrkB), and cyclic AMP-response element-binding protein (CREB), while SCP treatment improved these levels in the cerebral cortex and hippocampus regions. Our findings suggest that SCP exhibits significant antidepressant-like effects in the DEX-induced depressive animal model, and this activity may be mediated by preventing corticosterone-induced neurotoxicity.

Atomistic study of the alloying behavior of crystalline SnSe1-xSx.

Recently, layered chalcogenide alloys (LCAs) have been extensively investigated for use in various practical applications by selectively controlling the amount of foreign components. However, the alloying behavior of layered chalcogenides has been rarely explored at the atomistic level. Here, we study the microstructural evolution of SnSe1-xSx alloys on the atomic scale by combining scanning tunneling microscopy (STM) measurements with first-principles density functional theory (DFT) calculations. STM topographic images suggest that S atoms substituted in SnSe1-xSx are not randomly distributed, but tend to form local SnS clusters. The degree of S atom alloying was quantitatively estimated to be about 60% from STM images, indicating that homo-atoms (S-S) are a preferred arrangement over hetero-atoms (S-Se). Our DFT calculations further confirmed that the mixing energy of random SnSe1-xSx alloys showed positive behavior over the whole S composition range considered. This result suggests that SnSe1-xSx has a tendency toward local phase segregation into SnSe and SnS rather than random alloys. We expect our atomistic study on the alloying behavior to provide important insight for fabricating optimal SnSe1-xSx alloys with high thermoelectric properties.

Stabilization of graphene nanopore.

Graphene is an ultrathin, impervious membrane. The controlled introduction of nanoscale pores in graphene would lead to applications that involve water purification, chemical separation, and DNA sequencing. However, graphene nanopores are unstable against filling by carbon adatoms. Here, using aberration-corrected scanning transmission electron microscopy and density-functional calculations, we report that Si atoms stabilize graphene nanopores by bridging the dangling bonds around the perimeter of the hole. Si-passivated pores remain intact even under intense electron beam irradiation, and they were observed several months after the sample fabrication, demonstrating that these structures are intrinsically robust and stable against carbon filling. Theoretical calculations reveal the underlying mechanism for this stabilization effect: Si atoms bond strongly to the graphene edge, and their preference for tetrahedral coordination forces C adatoms to form dendrites sticking out of the graphene plane, instead of filling the nanopore. Our results provide a novel way to develop stable nanopores, which is a major step toward reliable graphene-based molecular translocation devices.