Programmable Threshold Logic Implementations in a Memristor Crossbar Array

In this study, we demonstrate the implementation of programmable threshold logics using a 32 × 32 memristor crossbar array. Thanks to forming-free characteristics obtained by the annealing process, its accurate programming characteristics are presented by a 256-level grayscale image. By simultaneous subtraction between weighted sum and threshold values with a differential pair in an opposite way, 3-input and 4-input Boolean logics are implemented in the crossbar without additional reference bias. Also, we verify a full-adder circuit and analyze its fidelity, depending on the device programming accuracy. Lastly, we successfully implement a 4-bit ripple carry adder in the crossbar and achieve reliable operations by read-based logic operations. Compared to stateful logic driven by device switching, a 4-bit ripple carry adder on a memristor crossbar array can perform more reliably in fewer steps thanks to its read-based parallel logic operation.

YOLOv5 based object detection in reel package X-ray images of semiconductor component

The industrial manufacturing landscape is currently shifting toward the incorporation of technologies based on artificial intelligence (AI). This transition includes an evolution toward smart factory infrastructure, with a specific focus on AI-driven strategies in production and quality control. Specifically, AI-empowered computer vision has emerged as a potent tool that offers a departure from extant rule-based systems and provides enhanced operational efficiency at manufacturing sites. As the manufacturing sector embraces this new paradigm, the impetus to integrate AI-integrated manufacturing is evident. Within this framework, one salient application is AI deep learning-facilitated small-object detection, which is poised to have extensive implications for diverse industrial applications. This study describes an optimized iteration of the YOLOv5 model, which is known for its efficacious single-stage object-detection abilities underpinned by PyTorch. Our proposed "improved model" incorporates an additional layer to the model's canonical three-layer architecture, augmenting accuracy and computational expediency. Empirical evaluations using semiconductor X-ray imagery reveal the model's superior performance metrics. Given the intricate specifications of surface-mount technologies, which are characterized by a plethora of micro-scale components, our model makes a seminal contribution to real-time, in-line production assessments. Quantitative analyses show that our improved model attained a mean average precision of 0.622, surpassing YOLOv5's 0.349, and a marked accuracy enhancement of 0.865, which is a significant improvement on YOLOv5's 0.552. These findings bolster the model's robustness and potential applicability, particularly in discerning objects at reel granularities during real-time inferencing.

The role of grit in inclusive education: a study of motivation and achievement among preservice physical education teachers

Introduction

Grit, a combination of enduring effort and persistent interest, is key to long-term goals. The training of preservice physical education (PE) teachers is vital for child development, emphasizing the need to assess their resilience and commitment. However, research is limited regarding how grit influences motivation and achievement goals in PE. The purpose of this study was to explore how the grit dimensions of preservice PE teachers impact their motivation and achievement goals, which may subsequently shape their future career intentions of becoming PE teachers.

Methods

A total of 279 preservice physical education (PE) teachers (69.5% males; 26.9% PE graduate program) from five South Korean universities participated in the study. They completed validated questionnaires measuring grit, motivation, achievement goal orientations, and career intentions. Descriptive statistics, correlation analysis, and structural equation modeling (SEM) were used to examine variable relationships and test the hypothesis model.

Results

Correlation analysis indicated a spectrum of relationships between facets of grit (perseverance of effort and consistency of interests), motivational parameters, and career intention, with both positive and negative correlations ranging from weak to moderate (r ranging from 0.119 to 0.425, p < 0.05-0.01). SEM confirmed the model's goodness-of-fit (χ2/df = 1.928, RMSEA = 0.058, IFI = 0.92, TLI = 0.91, CFI = 0.92). Path analysis showed that both perseverance of effort and consistency of interests significantly influenced motivational mechanisms (β ranging from -0.34 to 0.57, p < 0.05-0.01), both directly and indirectly, which then notably impacted career intentions (β = 0.10, p < 0.05). Notably, both grit dimensions significantly impacted mastery approach goals (β ranging from 0.49 to 0.56, p < 0.01). Mastery approach goals, in turn, had a substantial impact on intrinsic motivation (β = 0.27, p < 0.01), which subsequently significantly influenced career intentions (β = 0.32, p < 0.01).

Conclusion

The study illuminated the complex relationships between grit dimensions, motivation, achievement goals, and career intentions of future PE teachers. SEM validation confirmed grit's direct and indirect influence on goal orientations and motivation, underscoring the importance of incorporating grit-building strategies alongside mastery approach goals in preservice PE programs to enhance resilience, dedication, and long-term career commitment.

Valley-centre tandem perovskite light-emitting diodes

Perovskite light-emitting diodes (PeLEDs) have emerged as a promising new light source for displays. The development roadmap for commercializing PeLEDs should include a tandem device structure, specifically by stacking a thin nanocrystal PeLED unit and an organic light-emitting diode unit, which can achieve a vivid and efficient tandem display; however, simply combining light-emitting diodes with different characteristics does not guarantee both narrowband emission and high efficiency, as it may cause a broadened electroluminescence spectra and a charge imbalance. Here, by conducting optical simulations of the hybrid tandem (h-tandem) PeLED, we have discovered a crucial optical microcavity structure known as the h-tandem valley, which enables the h-tandem PeLED to emit light with a narrow bandwidth. Specifically, the centre structure of the h-tandem valley (we call it valley-centre tandem) demonstrates near-perfect charge balance and optimal microcavity effects. As a result, the h-tandem PeLED achieves a high external quantum efficiency of 37.0% and high colour purity with a narrow full-width at half-maximum of 27.3 nm (versus 64.5 nm in organic light-emitting diodes) along with a fast on-off response. These findings offer a new strategy to overcome the limitations of nanocrystal-based PeLEDs, providing valuable optical and electrical guidelines for integrating different types of light-emitting device into practical display applications.

Spatiotemporal lake area changes influenced by climate change over 40 years in the Korean Peninsula

Water resources in lakes of the Korean Peninsula play a significant role in society and ecosystems in both South and North Korea. This study characterized spatiotemporal changes in the lake area during the dry season (March-May) in the Korean Peninsula over the last 40 years. The satellite images (Landsat 5-9) were used to derive annual areas of 975 lakes during the dry season from 1984 to 2023. Our analysis indicated that the MNDWI is the optimal remote sensing-based index for delineating lake areas in the Korean Peninsula, with an overall accuracy of 92.3%. Based on the selected index, the total lake areas of the dry seasons have increased from 1070.7 km2 in 1984 to 1659.3 km2 in 2023, mainly due to newly constructed dam reservoirs. While the detailed changes in lake area vary, we found divergent results based on their sizes. The large lakes (> 10 km2) showed their area increased by 0.0473 km2 (0.1%) every year and have more influences from climate change. On the contrary, the small lakes (≤ 10 km2) have area decreases by 0.0006-0.006 km2 (0.15-0.5%) every year and have less influence from climate change. This study shows that the spatiotemporal lake area changes are determined by either climate change or human activity.

Implementation of Convolutional Neural Networks in Memristor Crossbar Arrays with Binary Activation and Weight Quantization

We propose a hardware-friendly architecture of a convolutional neural network using a 32 × 32 memristor crossbar array having an overshoot suppression layer. The gradual switching characteristics in both set and reset operations enable the implementation of a 3-bit multilevel operation in a whole array that can be utilized as 16 kernels. Moreover, a binary activation function mapped to the read voltage and ground is introduced to evaluate the result of training with a boundary of 0.5 and its estimated gradient. Additionally, we adopt a fixed kernel method, where inputs are sequentially applied to a crossbar array with a differential memristor pair scheme, reducing unused cell waste. The binary activation has robust characteristics against device state variations, and a neuron circuit is experimentally demonstrated on a customized breadboard. Thanks to the analogue switching characteristics of the memristor device, the accurate vector-matrix multiplication (VMM) operations can be experimentally demonstrated by combining sequential inputs and the weights obtained through tuning operations in the crossbar array. In addition, the feature images extracted by VMM during the hardware inference operations on 100 test samples are classified, and the classification performance by off-chip training is compared with the software results. Finally, inference results depending on the tolerance are statistically verified through several tuning cycles.

Copper Alloy Design for Preventing Sulfur-Induced Embrittlement in Copper

This study presents an experimental approach to address sulfur-induced embrittlement in copper alloys. Building on recent theoretical insights, we identified specific solute elements, such as silicon and silver, known for their strong binding affinity with vacancies. Through experimental validation, we demonstrated the effectiveness of Si and Ag in preventing sulfur-induced embrittlement in copper, even though they are not typical sulfide formers such as zirconium. Additionally, our findings highlight the advantages of these elements over traditional solutes, such as their high solubility and propensity to accumulate along grain boundaries. This approach may have the potential to be applied to other metals prone to sulfur-induced embrittlement, including nickel, iron, and cobalt, offering broader implications for materials engineering strategies and alloy development.

Effects of hip joint kinematics on the effective pelvis stiffness and hip impact force during simulated sideways falls

Improved understanding is required on how hip fracture risk is influenced by landing configuration. We examined how hip impact dynamics was affected by hip joint kinematics during simulated sideways falls. Twelve young adults (7 males, 5 females) of mean age 23.5 (SD = 1.5) years, participated in pelvis release experiments. Trials were acquired with the hip flexed 15° and 30° for each of three hip rotations: +15° ("external rotation"), 0°, and -15° ("internal rotation"). During falls, force-deformation data of the pelvis were recorded. Outcome variables included the peak hip impact force (Fexperimental) and effective stiffness of the pelvis (k1st, ksecant, and kms) determined with different methods suggested in literature, and predicted hip impact force during a fall from standing height (F1st, Fsecant and Fms). The two-way repeated-measures ANOVA was used to test whether these variables were associated with hip joint angles. The Fexperimental, ksecant and Fsecant were associated with hip rotation (F = 5.587, p = 0.005; F = 9.278, p < 0.0005; F = 5.778, p = 0.004, respectively), and 15 %, 31 % and 17 % smaller in 15° external than internal rotation (848 versus 998 N; 24.6 versus 35.6 kN/m; 2,637 versus 3,170 N, respectively). However, none of the outcome variables were associated with hip flexion (p > 0.05). Furthermore, there were no interactions between the hip rotation and flexion for all outcome variables (p > 0.05). Our results provide insights on hip impact dynamics, which may help improve a hip model to assess hip fracture risk during a fall.

Adsorption of CMIT/MIT on the Model Pulmonary Surfactant Monolayers

Polyhexamethylene guanidine (PHMG) is a guanidine-based chemical that has long been used as an antimicrobial agent. However, recently raised concerns regarding the pulmonary toxicity of PHMG in humans and aquatic organisms have led to research in this area. Along with PHMG, there are concerns about the safety of non-guanidine 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT) in human lungs; however, the safety of such chemicals can be affected by many factors, and it is difficult to rationalize their toxicity. In this study, we investigated the adsorption characteristics of CMIT/ MIT on a model pulmonary surfactant (lung surfactant, LS) using a Langmuir trough attached to a fluorescence microscope. Analysis of the π-A isotherms and lipid raft morphology revealed that CMIT/MIT exhibited minimal adsorption onto the LS monolayer deposited at the air/water interface. Meanwhile, PHMG showed clear signs of adsorption to LS, as manifested by the acceleration of the L o phase growth with increasing surface pressure. Consequently, in the presence of CMIT/MIT, the interfacial properties of the model LS monolayer exhibited significantly fewer changes than PHMG.

Comparison of the Effects of Botulinum Toxin Doses on Nerve Regeneration in Rats with Experimentally Induced Sciatic Nerve Injury

This study was designed to compare the effects of various doses of botulinum neurotoxin A (BoNT/A) on nerve regeneration. Sixty-five six-week-old rats with sciatic nerve injury were randomly allocated to three experimental groups, a control group, and a sham group. The experimental groups received a single session of intraneural BoNT/A (3.5, 7.0, or 14 U/kg) injection immediately after nerve-crushing injury. The control group received normal intraneural saline injections after sciatic nerve injury. At three, six, and nine weeks after nerve damage, immunofluorescence staining, an ELISA, and toluidine blue staining was used to evaluate the regenerated nerves. Serial sciatic functional index analyses and electrophysiological tests were performed every week for nine weeks. A higher expression of GFAP, S100β, GAP43, NF200, BDNF, and NGF was seen in the 3.5 U/kg and 7.0 U/kg BoNT/A groups. The average area and myelin thickness were significantly greater in the 3.5 U/kg and 7.0 U/kg BoNT/A groups. The sciatic functional index and compound muscle action potential amplitudes exhibited similar trends. These findings indicate that the 3.5 U/kg and 7.0 U/kg BoNT/A groups exhibited better nerve regeneration than the 14 U/kg BoNT/A and control group. As the 3.5 U/kg and the 7.0 U/kg BoNT/A groups exhibited no statistical difference, we recommend using 3.5 U/kg BoNT/A for its cost-effectiveness.

Patterns of Reacted Adatoms in Adsorption of Acetonitrile on Si{111}-(7 × 7)

We report on the covalent binding of acetonitrile (CH3CN) on Si{111}-(7 × 7) at ∼300 K studied by scanning tunneling microscopy, thermal desorption spectroscopy, and first-principles theoretical calculations. The site-specific study makes it possible to unravel the site-by-site and step-by-step kinetics. A polarized CH3CN prefers to adsorb on the faulted half more frequently compared to on the unfaulted half. Moreover, a molecular CH3CN adsorbs four-times more preferably on the center adatom-rest atom (CEA-REA) pair than on the corner adatom-rest atom (COA-REA) pair. Such site selectivity, the number ratio of reacted-CEA/reacted-COA, depends on the number of reacted adatoms in the half-unit cell. The site selectivity and the resulting reacted-adatom patterns are understood well by considering a simple model. In this simple model, the molecular adsorption probability changes step-by-step and site-by-site with increasing reacted adatoms. Furthermore, our theoretical calculations are overall consistent with the experimental results. The site-selectivity of the adsorption of CH3CN on Si{111}-(7 × 7) is explained well by the chemical reactivity depending on the local conformation, the local density of states, and the interaction between polarized adsorbates.

Strategies to Extend the Lifetime of Perovskite Downconversion Films for Display Applications

Metal halide perovskite nanocrystals (PeNCs) have outstanding luminescent properties that are suitable for displays that have high color purity and high absorption coefficient; so they are evaluated for application as light emitters for organic light-emitting diodes, light-converters for downconversion displays, and future near-eye augmented reality/virtual reality displays. However, PeNCs are chemically vulnerable to heat, light, and moisture, and these weaknesses must be overcome before devices that use PeNCs can be commercialized. This review examines strategies to overcome the low stability of PeNCs and thereby permit the fabrication of stable downconversion films, and summarizes downconversion-type display applications and future prospects. First, methods to increase the chemical stability of PeNCs are examined. Second, methods to encapsulate PeNC downconversion films to increase their lifetime are reviewed. Third, methods to increase the long-term compatibility of resin with PeNCs, and finally, how to secure stability using fillers added to the resin are summarized. Fourth, the method to manufacture downconversion films and the procedure to evaluate their reliability for commercialization is then described. Finally, the prospects of a downconversion system that exploits the properties of PeNCs and can be employed to fabricate fine pixels for high-resolution displays and for near-eye augmented reality/virtual reality devices are explored.

Reconfigurable Manipulation of Oxygen Content on Metal Oxide Surfaces and Applications to Gas Sensing

Oxygen vacancies and adsorbed oxygen species on metal oxide surfaces play important roles in various fields. However, existing methods for manipulating surface oxygen require severe settings and are ineffective for repetitive manipulation. We present a method to manipulate the amount of surface oxygen by modifying the oxygen adsorption energy by electrically controlling the electron concentration of the metal oxide. The surface oxygen control ability of the method is verified using first-principles calculations based on density functional theory (DFT), X-ray photoelectron spectroscopy (XPS), and electrical resistance analysis. The presented method is implemented by fabricating oxide thin film transistors with embedded microheaters. The method can reconfigure the oxygen vacancies on the In2O3, SnO2, and IGZO surfaces so that specific chemisorption dominates. The method can selectively increase oxidizing (e.g., NO and NO) and reducing gas (e.g., H2S, NH3, and CO) reactions by electrically controlling the metal oxide surface to be oxygen vacancy-rich or adsorbed oxygen species-rich. The proposed method is applied to gas sensors and overcomes their existing limitations. The method makes the sensor insensitive to one gas (e.g., H2S) in mixed-gas environments (e.g., NO2+H2S) and provides a linear response (R2 = 0.998) to the target gas (e.g., NO2) concentration within 3 s. We believe that the proposed method is applicable to applications utilizing metal oxide surfaces.

Multifunctionality of Additively Manufactured Kelvin Foam for Electromagnetic Wave Absorption and Load Bearing

Rationally engineered porous structures enable lightweight broadband electromagnetic (EM) wave absorbers for countering radar signals or mitigating EM interference between multiple components. However, the scalability of such structures has been hindered by their limited mechanical properties resulting from low density. Herein, an additively manufactured Kelvin foam-based EM wave absorber (KF-EMA) is reported that exhibits multifunctionality, namely EM wave absorption and light-weighted load-bearing structures with constant relative stiffness made possible using bending-dominated lattice structures. Based on tuning design parameters, such as the backbone structures and constituent materials, the proposed KF-EMA features a multilayered 3D-printed design with geometrically optimized KF structures made of carbon black-based backbone composites. The developed KF-EMA demonstrated an absorbance greater than 90% at frequencies ranging from 5.8 to 18 GHz (average EM wave absorption rates of 95.89% and maximum of 99.1% at 15.8 GHz), while the low-density structures of the absorber (≈200 kg m-3 ) still maintained a compression index between the stiffness and relative density (n = 2) under compression. The design strategy paves the way for using metamaterials as mechanically reinforced EM wave absorbers that enable multifunctionality by optimizing unit-cell parameters through a single and low-density structure.

Overcoming Charge Confinement in Perovskite Nanocrystal Solar Cells

The small nanoparticle size and long-chain ligands in colloidal metal halide perovskite quantum dots (PeQDs) cause charge confinement, which impedes exciton dissociation and carrier extraction in PeQD solar cells, so they have low short-circuit current density Jsc , which impedes further increases in their power conversion efficiency (PCE). Here, a re-assembling process (RP) is developed for perovskite nanocrystalline (PeNC) films made of colloidal perovskite nanocrystals to increase Jsc in PeNC solar cells. The RP of PeNC films increases their crystallite size and eliminates long-chain ligands, and thereby overcomes the charge confinement in PeNC films. These changes facilitate exciton dissociation and increase carrier extraction in PeNC solar cells. By use of this method, the gradient-bandgap PeNC solar cells achieve a Jsc = 19.30 mA cm-2 without compromising the photovoltage, and yield a high PCE of 16.46% with negligible hysteresis and good stability. This work provides a new strategy to process PeNC films and pave the way for high performance PeNC optoelectronic devices.

Inter-Brain Synchrony Pattern Investigation on Triadic Board Game Play-Based Social Interaction: An fNIRS Study

Recent advances in functional neuroimaging techniques, including methodologies such as fNIRS, have enabled the evaluation of inter-brain synchrony (IBS) induced by interpersonal interactions. However, the social interactions assumed in existing dyadic hyperscanning studies do not sufficiently emulate polyadic social interactions in the real world. Therefore, we devised an experimental paradigm that incorporates the Korean folk board game "Yut-nori" to reproduce social interactions that emulate social activities in the real world. We recruited 72 participants aged 25.2 ± 3.9 years (mean ± standard deviation) and divided them into 24 triads to play Yut-nori, following the standard or modified rules. The participants either competed against an opponent (standard rule) or cooperated with an opponent (modified rule) to achieve a goal efficiently. Three different fNIRS devices were employed to record cortical hemodynamic activations in the prefrontal cortex both individually and simultaneously. Wavelet transform coherence (WTC) analyses were performed to assess prefrontal IBS within a frequency range of 0.05-0.2 Hz. Consequently, we observed that cooperative interactions increased prefrontal IBS across overall frequency bands of interest. In addition, we also found that different purposes for cooperation generated different spectral characteristics of IBS depending on the frequency bands. Moreover, IBS in the frontopolar cortex (FPC) reflected the influence of verbal interactions. The findings of our study suggest that future hyperscanning studies should consider polyadic social interactions to reveal the properties of IBS in real-world interactions.

Open Reduction of an Isolated Anterior Nasal Spine Fracture: A Case Report and Review of the Literature

A 14-year-old girl had a midfacial trauma event caused by hitting against an opening door and experienced discomfort and swelling of the columella and upper lip. Physical examination revealed mild tenderness on light palpation without any discomfort with upper lip movement. A computed tomography scan of the maxillofacial bones with three-dimensional reconstruction showed a fracture of the anterior nasal spine with obvious leftward displacement, mild-deviation of the caudal aspect of the nasal septum, and no sign of nasal bone fracture. Open reduction and internal fixation was performed with regard to aesthetic and functional concerns, including nasal septum deviation. The postoperative course was uneventful, and healing proceeded normally without complications. Herein, we emphasize the importance of differential diagnosis of isolated anterior nasal spine fractures in patients with midfacial trauma and clinicians' strategic decision-making in treatment modalities.

Artistic Robotic Arm: Drawing Portraits on Physical Canvas under 80 Seconds

In recent years, the field of robotic portrait drawing has garnered considerable interest, as evidenced by the growing number of researchers focusing on either the speed or quality of the output drawing. However, the pursuit of either speed or quality alone has resulted in a trade-off between the two objectives. Therefore, in this paper, we propose a new approach that combines both objectives by leveraging advanced machine learning techniques and a variable line width Chinese calligraphy pen. Our proposed system emulates the human drawing process, which entails planning the sketch and creating it on the canvas, thus providing a realistic and high-quality output. One of the main challenges in portrait drawing is preserving the facial features, such as the eyes, mouth, nose, and hair, which are crucial for capturing the essence of a person. To overcome this challenge, we employ CycleGAN, a powerful technique that retains important facial details while transferring the visualized sketch onto the canvas. Moreover, we introduce the Drawing Motion Generation and Robot Motion Control Modules to transfer the visualized sketch onto a physical canvas. These modules enable our system to create high-quality portraits within seconds, surpassing existing methods in terms of both time efficiency and detail quality. Our proposed system was evaluated through extensive real-life experiments and showcased at the RoboWorld 2022 exhibition. During the exhibition, our system drew portraits of more than 40 visitors, yielding a survey outcome with a satisfaction rate of 95%. This result indicates the effectiveness of our approach in creating high-quality portraits that are not only visually pleasing but also accurate.

Daily changes in spatial accessibility to ICU beds and their relationship with the case-fatality ratio of COVID-19 in the state of Texas, USA

During the COVID-19 pandemic, many patients could not receive timely healthcare services due to limited availability and access to healthcare resources and services. Previous studies found that access to intensive care unit (ICU) beds saves lives, but they overlooked the temporal dynamics in the availability of healthcare resources and COVID-19 cases. To fill this gap, our study investigated daily changes in ICU bed accessibility with an enhanced two-step floating catchment area (E2SFCA) method in the state of Texas. Along with the increased temporal granularity of measurements, we uncovered two phenomena: 1) aggravated spatial inequality of access during the pandemic, and 2) the retrospective relationship between insufficient ICU bed accessibility and the high case-fatality ratio of COVID-19 in rural areas. Our findings suggest that those locations should be supplemented with additional healthcare resources to save lives in future pandemic scenarios.

Distinct Effects of Methamphetamine Isomers on Limbic Norepinephrine and Dopamine Transmission in the Rat Brain

Methamphetamine (METH) is a psychostimulant that primarily exerts its effects on the catecholamine (dopamine (DA) and norepinephrine (NE)) systems, which are implicated in drug addiction. METH exists as two distinct enantiomers, dextrorotatory (d) and levorotatory (l). In contrast to d-METH, the major component of illicit METH used to induce states of euphoria and alertness, l-METH is available without prescription as a nasal decongestant and has been highlighted as a potential agonist replacement therapy to treat stimulant use disorder. However, little is known regarding l-METH's effects on central catecholamine transmission and behavior. In this study, we used fast-scan cyclic voltammetry to elucidate how METH isomers impact NE and DA transmission in two limbic structures, the ventral bed nucleus of the stria terminalis (vBNST) and nucleus accumbens (NAc), respectively, of anesthetized rats. In addition, the dose-dependent effects of METH isomers on locomotion were characterized. d-METH (0.5, 2.0, 5.0 mg/kg) enhanced both electrically evoked vBNST-NE and NAc-DA concentrations and locomotion. Alternatively, l-METH increased electrically evoked NE concentration with minimal effects on DA regulation (release and clearance) and locomotion at lower doses (0.5 and 2.0 mg/kg). Furthermore, a high dose (5.0 mg/kg) of d-METH but not l-METH elevated baseline NE and DA concentrations. These results suggest mechanistic differences between NE and DA regulation by the METH isomers. Moreover, l-METH's asymmetric regulation of NE relative to DA may have distinct implications in behaviors and addiction, which will set the neurochemical framework for future studies examining l-METH as a potential treatment for stimulant use disorders.

Ultrafast PEDOT:PSS/H2 SO4 Electrical Double Layer Capacitors: Comparison with Polyaniline Pseudocapacitors

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is one of the most widely studied conductive polymers, owing to its excellent electrical, optical, and mechanical properties, with various applications such as organic electrochemical transistors, electrochromics, and flexible/stretchable supercapacitors. The charging mechanism of PEDOT:PSS supercapacitors has been traditionally believed to be faradaic, which involves the transfer of charge across the electrode/electrolyte interface. In the present work, however, robust experimental evidence suggests that the PEDOT:PSS supercapacitors mainly store and deliver charge nonfaradaically. The various electrochemical properties of PEDOT:PSS electrical double layer capacitors (EDLCs) are clearly distinguishable from those of polyaniline (PANI) pseudocapacitors, which store charge faradaically. Owing to the nonfaradaic mechanism, the frequency response of PEDOT:PSS supercapacitors is comparable to that of state-of-the-art ultrafast EDLCs with carbon-based electrodes, making them suitable for high-frequency applications such as 60 Hz AC line filtering. This result is of great importance for the fundamental understanding of the charging mechanism of mixed ionic-electronic conducting polymers, such as PEDOT:PSS, and is expected to contribute to the development of various electrochemical devices based on this type of material.

Validation of the Korean self-administered computerized versions of the kiddie schedule for affective disorders and schizophrenia for school-age children (KSADS-COMP)

The purpose of the present study was to examine the validity of the Korean version of the parent and youth self-administered versions of the KSADS-COMP (The Kiddie Schedule for Affective Disorders and Schizophrenia for school-age children). To assess the criterion validity of the KSADS-COMP, diagnoses made by the selfadministered KSADS-COMP were compared to the gold-standard diagnoses made by the child-adolescent psychiatrists in 41 participants (mean age=14.93 ± 2.16 years, female=41.46 %). Gwet's first order agreement coefficient (AC1) concordance ratings showed moderate to good range. The present study shows promising validity of the Korean self-administered versions of the KSADS-COMP in Korean youths.

Factors Affecting Stress and Mental Health During the COVID-19 Pandemic

OBJECTIVE

This study examined the factors influencing the mental health and stress of individuals during the coronavirus disease-2019 (COVID-19) pandemic.

METHODS

A total of 600 participants were enrolled in this anonymous questionnaire survey that included questions on their demographic profiles and experiences related to the COVID-19 pandemic. The COVID-19 Stress Scale for Korean People (CSSK), Warwick- Edinburgh Mental Wellbeing Scale, Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, Insomnia Severity Index, and Multidimensional Scale of Perceived Social Support were used. Data were analyzed using multiple regression to identify the factors affecting the total CSSK scores and the scores of each of the three CSSK subscales.

RESULTS

Multiple regression analyses revealed that the severity of insomnia, sex, degree of income decline, occupation, religion, education level, marital status, residential status, level of social support, and degree of depression and anxiety had significant relationships with COVID-19-related stress.

CONCLUSION

We identified factors affecting stress and mental health in the general population during the COVID-19 pandemic. Our findings may be helpful in providing an individualized approach to managing the mental health of the public. We expect that the results of this study will be used to screen high-risk individuals vulnerable to stress and to establish policies related to the public health crisis.

Ultra-bright, efficient and stable perovskite light-emitting diodes

Metal halide perovskites are attracting a lot of attention as next-generation light-emitting materials owing to their excellent emission properties, with narrow band emission^1-4. However, perovskite light-emitting diodes (PeLEDs), irrespective of their material type (polycrystals or nanocrystals), have not realized high luminance, high efficiency and long lifetime simultaneously, as they are influenced by intrinsic limitations related to the trade-off of properties between charge transport and confinement in each type of perovskite material^5-8. Here, we report an ultra-bright, efficient and stable PeLED made of core/shell perovskite nanocrystals with a size of approximately 10 nm, obtained using a simple in situ reaction of benzylphosphonic acid (BPA) additive with three-dimensional (3D) polycrystalline perovskite films, without separate synthesis processes. During the reaction, large 3D crystals are split into nanocrystals and the BPA surrounds the nanocrystals, achieving strong carrier confinement. The BPA shell passivates the undercoordinated lead atoms by forming covalent bonds, and thereby greatly reduces the trap density while maintaining good charge-transport properties for the 3D perovskites. We demonstrate simultaneously efficient, bright and stable PeLEDs that have a maximum brightness of approximately 470,000 cd m^-2, maximum external quantum efficiency of 28.9% (average = 25.2 ± 1.6% over 40 devices), maximum current efficiency of 151 cd A^-1 and half-lifetime of 520 h at 1,000 cd m^-2 (estimated half-lifetime >30,000 h at 100 cd m^-2). Our work sheds light on the possibility that PeLEDs can be commercialized in the future display industry.

Immunopathologic Role of Eosinophils in Eosinophilic Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a diverse chronic inflammatory disease of the sinonasal mucosa. CRS manifests itself in a variety of clinical and immunologic patterns. The histological hallmark of eosinophilic CRS (ECRS) is eosinophil infiltration. ECRS is associated with severe disease severity, increased comorbidity, and a higher recurrence rate, as well as thick mucus production. Eosinophils play an important role in these ECRS clinical characteristics. Eosinophils are multipotential effector cells that contribute to host defense against nonphagocytable pathogens, as well as allergic and nonallergic inflammatory diseases. Eosinophils interact with Staphylococcus aureus, Staphylococcal enterotoxin B, and fungi, all of which were found in the tissue of CRS patients. These interactions activate Th2 immune responses in the sinonasal mucosa and exacerbate local inflammation. Activated eosinophils were discovered not only in the tissue but also in the sinonasal cavity secretion. Eosinophil extracellular traps (EETs) are extracellular microbes trapping and killing structures found in the secretions of CRS patients with intact granule protein and filamentous chromatic structures. At the same time, EET has a negative effect by causing an epithelial barrier defect. Eosinophils also influence the local tissue microenvironment by exchanging signals with other immune cells and structural cells. As a result, eosinophils are multifaceted leukocytes that contribute to various physiologic and pathologic processes of the upper respiratory mucosal immune system. The goal of this review is to summarize recent research on the immunopathologic properties and immunologic role of eosinophils in CRS.

Blunted atrial reverse remodeling a year after catheter ablation for atrial fibrillation and their long-term rhythm outcome

Background

Although active rhythm control by atrial fibrillation (AF) catheter ablation (AFCA) reduces left atrial (LA) dimension, blunted atrial reverse remodeling can be observed in patients with significant atrial myopathy. We explored the characteristics and long-term outcomes of AF patients who showed blunted atrial reverse remodeling despite no AF recurrence within a year after AFCA.

Methods

Among a total of 2,756 patients with AFCA, we included 1,685 patients (74.8% male, 60.2±10.1 years old, 54.5% paroxysmal AF) who underwent both baseline and 1-year follow-up echocardiogram, baseline LA&gt;40mm, and did not recur within a year. We divided them into tertile groups (T1–T3) based on one-year percent change of LA dimension after propensity matching for age, sex, AF type, and baseline LA dimension. We also investigated the patients' genetic characteristics with blunted LA reverse remodeling (T1) using a genome-wide association study (GWAS).

Results

Patients with blunted LA reverse remodeling (T1, n=424) were independently associated with body mass index (OR 1.082 [1.010–1.160], p=0.025), LA peak pressure (OR 1.010 [1.002–1.019], p=0.019), LA wall thickness (OR 0.448 [0.252–0.789], p=0.006), LA voltage (OR 0.651 [0.463–0.907], p=0.012), and pericardial fat volume (OR 1.004 [1.001–1.008], p=0.014). Throughout 65.9±37.4 months of follow-up, the incidence of AF recurrence a year after the procedure was significantly higher in the T1 group than in T2 or T3 groups (Log-rank p&lt;0.001). Among 894 patients with GWAS, ATXN1, XPO7, KRR1_PHLDA1, ZFHX3, and their polygenic risk score were associated with blunted LA reverse remodeling.

Conclusions

Patients with blunted LA reverse remodeling after AFCA were independently associated with low LA voltage, thin wall thickness, high LA pressure, and fat volume, and have a genetic background. Long-term clinical recurrence a year after AFCA was higher in this patient group with suspicious atrial myopathy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and WelfareNational Research Foundation of Korea

Interfacial Delamination at Multilayer Thin Films in Semiconductor Devices

With the evolution of semiconducting industries, thermomechanical failure induced in a multilayered structure with a high aspect ratio during manufacturing and operation has become one of the critical reliability issues. In this work, the effect of thermomechanical stress on the failure of multilayered thin films on Si substrates was studied using analytical calculations and various thermomechanical tests. The residual stress induced during material processing was calculated based on plate bending theory. The calculations enabled the prediction of the weakest region of failure in the thin films. To verify our prediction, additional thermomechanical stress was applied to induce cracking and interfacial delamination by various tests. We assumed that, when accumulated thermomechanical-residual and externally applied mechanical stress becomes larger than a critical value the thin-film cracking or interfacial delamination will occur. The test results agreed well with the prediction based on the analytical calculation in that the film with maximum tensile residual stress is the most vulnerable to failure. These results will provide useful analytical and experimental prediction tools for the failure of multilayered thin films in the device design stage.

An Examination of the Stochastic Distribution of Spatial Accessibility to Intensive Care Unit Beds during the COVID-19 Pandemic: A Case Study of the Greater Houston Area of Texas

Sufficient and reliable health care access is necessary for people to be able to maintain good health. Hence, investigating the uncertainty embedded in the temporal changes of inputs would be beneficial for understanding their impact on spatial accessibility. However, previous studies are limited to implementing only the uncertainty of mobility, while health care resource availability is a significant concern during the coronavirus disease (COVID-19) pandemic. Our study examined the stochastic distribution of spatial accessibility under the uncertainties underlying the availability of intensive care unit (ICU) beds and ease of mobility in the Greater Houston area of Texas. Based on the randomized supply and mobility from their historical changes, we employed Monte Carlo simulation to measure ICU bed accessibility with an enhanced two-step floating catchment area (E2SFCA) method. We then conducted hierarchical clustering to classify regions of adequate (sufficient and reliable) accessibility and inadequate (insufficient and unreliable) accessibility. Lastly, we investigated the relationship between the accessibility measures and the case fatality ratio of COVID-19. As result, locations of sufficient access also had reliable accessibility; downtown and outer counties, respectively, had adequate and inadequate accessibility. We also raised the possibility that inadequate health care accessibility may cause higher COVID-19 fatality ratios.

Intrinsic variation effect in memristive neural network with weight quantization

To analyze the effect of the intrinsic variations of the memristor device on the neuromorphic system, we fabricated 32 × 32 Al₂O₃/TiO_x-based memristor crossbar array and implemented 3 bit multilevel conductance as weight quantization by utilizing the switching characteristics to minimize the performance degradation of the neural network. The tuning operation for 8 weight levels was confirmed with a tolerance of ±4μA (±40μS). The endurance and retention characteristics were also verified, and the random telegraph noise (RTN) characteristics were measured according to the weight range to evaluate the internal stochastic variation effect. Subsequently, a memristive neural network was constructed by off-chip training with differential memristor pairs for the Modified National Institute of Standards and Technology (MNIST) handwritten dataset. The pre-trained weights were quantized, and the classification accuracy was evaluated by applying the intrinsic variations to each quantized weight. The intrinsic variations were applied using the measured weight inaccuracy given by the tuning tolerance, RTN characteristics, and the fault device yield. We believe these results should be considered when the pre-trained weights are transferred to a memristive neural network by off-chip training.

Investigation and direct observation of sidewall leakage current of InGaN-Based green micro-light-emitting diodes

Electrical and optical characteristics of InGaN-based green micro-light-emitting diodes (µLEDs) with different active areas are investigated; results are as follows. Reverse and forward leakage currents of µLED increase as emission area is reduced owing to the non-radiative recombination process at the sidewall defects; this is more prominent in smaller µLED because of larger surface-to-volume ratio. Leakage currents of µLEDs deteriorate the carrier injection to light-emitting quantum wells, thereby degrading their external quantum efficiency. Reverse leakage current originate primarily from sidewall edges of the smallest device. Therefore, aggressive suppression of sidewall defects of µLEDs is essential for low-power and downscaled µLEDs.

Exploiting the full advantages of colloidal perovskite nanocrystals for large-area efficient light-emitting diodes

Cost-effective, high-throughput industrial applications of metal halide perovskites in large-area displays are hampered by the fundamental difficulty of controlling the process of polycrystalline film formation from precursors, which results in the random growth of crystals, leading to non-uniform large grains and thus low electroluminescence efficiency in large-area perovskite light-emitting diodes (PeLEDs). Here we report that highly efficient large-area PeLEDs with high uniformity can be realized through the use of colloidal perovskite nanocrystals (PNCs), decoupling the crystallization of perovskites from film formation. PNCs were precrystallized and surrounded by organic ligands, and thus they were not affected by the film formation process, in which a simple modified bar-coating method facilitated the evaporation of residual solvent to provide uniform large-area films. PeLEDs incorporating the uniform bar-coated PNC films achieved an external quantum efficiency (EQE) of 23.26% for a pixel size of 4 mm² and an EQE of 22.5% for a large pixel area of 102 mm² with high reproducibility. This method provides a promising approach towards the development of large-scale industrial displays and solid-state lighting using perovskite emitters.

Phase-Transitional Ionogel-Based Supercapacitors for a Selective Operation

As the demand for energy storage devices increases, the importance of electrolytes for supercapacitors (SCs) is further emphasized. However, since ions in electrolytes are always in an active state, it is difficult to store energy for a long time due to ion diffusion. Here, we have synthesized a phase-transitional ionogel and fabricated an SC based on the ionogel. The 1-ethyl-3-methylimidazolium nitrate ([EMIM]+[NO3]-) ionogel changes its phase from crystal to amorphous when the temperature was elevated above its phase transition temperature (∼44 °C). When the temperature is elevated from 25 to 45 °C, the resistivity of the gel is decreased from 2318.4 kΩ·cm to 43.2 Ω·cm. At the same time, the capacitance is boosted from 0.02 to 37.35 F g-1, and this change was repeatable. Furthermore, the SC exhibits an energy density of 7.77 Wh kg-1 with a power density of 4000 W kg-1 at 45 °C and shows a stable capacitance retention of 87.5% after 3000 cycles of test. The phase transition can switch the SCs from "operating mode" to "storage mode" when the temperature drops. A degree of self-discharge is greatly suppressed in the storage mode, storing 89.51% of charges after 24 h in self-discharge tests.

Highly Selective and Low-Power Carbon Monoxide Gas Sensor Based on the Chain Reaction of Oxygen and Carbon Monoxide to WO3

Carbon monoxide (CO) poisoning can easily occur in industrial and domestic settings, causing headaches, loss of consciousness, or death from overexposure. Commercially available CO gas sensors consume high power (typically 38 mW), whereas low-power gas sensors using nanostructured materials with catalysts lack reliability and uniformity. A low-power (1.8 mW @ 392 °C), sensitive, selective, reliable, and practical CO gas sensor is presented. The sensor adopts floated WO₃ film as a sensing material to utilize the unique reaction of lattice oxide of WO₃ with CO gas. The sensor locally modulates the electron concentration in the WO₃ film, allowing O₂ and CO gases to react primarily in different sensing areas. Electrons generated by the CO gas reaction can be consumed for O₂ gas adsorption in a remote area, and this promotes the additional reaction of CO gas, boosting sensitivity and selectivity. The proposed sensor exhibits a 39.5 times higher response than the conventional resistor-type gas sensor fabricated on the same wafer. As a proof of concept, sensors with In₂O₃ film are fabricated, and the proposed sensor platform shows no advantage in detecting CO gas. Fabrication of the proposed sensor is reproducible and inexpensive due to conventional silicon-based processes, making it attractive for practical applications.

Peptidomimetic Wet-Adhesive PEGtides with Synergistic and Multimodal Hydrogen Bonding

The remarkable underwater adhesion of mussel foot proteins has long been an inspiration in the design of peptidomimetic materials. Although the synergistic wet adhesion of catechol and lysine has been recently highlighted, the critical role of the polymeric backbone has remained largely underexplored. Here, we present a peptidomimetic approach using poly(ethylene glycol) (PEG) as a platform to evaluate the synergistic compositional relation between the key amino acid residues (i.e., DOPA and lysine), as well as the role of the polyether backbone in interfacial adhesive interactions. A series of PEG-based peptides (PEGtides) were synthesized using functional epoxide monomers corresponding to catechol and lysine via anionic ring-opening polymerization. Using a surface force apparatus, highly synergistic surface interactions among these PEGtides with respect to the relative compositional ratio were revealed. Furthermore, the critical role of the catechol-amine synergy and diverse hydrogen bonding within the PEGtides in the superior adhesive interactions was verified by molecular dynamics simulations. Our study sheds light on the design of peptidomimetic polymers with reduced complexity within the framework of a polyether backbone.

Prussian Blue Nanolayer-Embedded Separator for Selective Segregation of Nickel Dissolution in High Nickel Cathodes

Transition metal layered oxides (LiNi_xCo_yMn_1-x-yO₂, NCM) have been considered as one of the most promising cathodes for lithium-ion batteries used in long-mileage electric vehicles and energy storage systems. Despite its potential interest, dissolved transition metal (TM) ions toward anode sides can catalyze parasitic reactions such as electrolytic decomposition and dendritic Li growth, ultimately leading to catastrophic safety hazards. In this study, we demonstrate that Prussian Blue (PB) nanoparticles anchored to a commercial PE separator significantly reduce cell resistance and effectively suppress TM crossover during cycling, even under harsh conditions that accelerate Ni dissolution. Therefore, using a PB-coated separator in a harsh condition to intentionally dissolve Ni²⁺ ions at a high cutoff potential of 4.6 V, NCM||graphite full cells maintain 50.8% of their initial capacity at the 150th cycle. Scalable production of PB-coated separator through the facile synthetic methods can help establish a new research direction for the design of high-energy-density batteries.

Distinct limbic dopamine regulation across olfactory‐tubercle subregions through integration of in vivo fast‐scan cyclic voltammetry and optogenetics

The olfactory tubercle (OT), an important component of the ventral striatum and limbic system, is involved in multi-sensory integration of reward-related information in the brain. However, its functional roles are often overshadowed by the neighboring nucleus accumbens. Increasing evidence has highlighted that dense dopamine (DA) innervation of the OT from the ventral tegmental area (VTA) is implicated in encoding reward, natural reinforcers, and motivated behaviors. Recent studies have further suggested that OT subregions may have distinct roles in these processes due to their heterogeneous DA transmission. Currently, very little is known about regulation (release and clearance) of extracellular DA across OT subregions due to its limited anatomical accessibility and proximity to other DA-rich brain regions, making it difficult to isolate VTA-DA signaling in the OT with conventional methods. Herein, we characterized heterogeneous VTA-DA regulation in the medial (m) and lateral (l) OT in "wild-type," urethane-anesthetized rats by integrating in vivo fast-scan cyclic voltammetry with cell-type specific optogenetics to stimulate VTA-DA neurons. Channelrhodopsin-2 was selectively expressed in the VTA-DA neurons of wild-type rats and optical stimulating parameters were optimized to determine VTA-DA transmission across the OT. Our anatomical, neurochemical, and pharmacological results show that VTA-DA regulation in the mOT is less dependent on DA transporters and has greater DA transmission than the lOT. These findings establish the OT as a unique, compartmentalized structure and will aid in future behavioral characterization of the roles of VTA-DA signaling in the OT subregions in reward, drug addiction, and encoding behavioral outputs necessary for survival.

Inter-Brain Synchrony Levels According to Task Execution Modes and Difficulty Levels: an fNIRS/GSR Study

Hyperscanning is a brain imaging technique that measures brain synchrony caused by social interactions. Recent research on hyperscanning has revealed substantial inter-brain synchrony (IBS), but little is known about the link between IBS and mental workload. To study this link, we conducted an experiment consisting of button-pressing tasks of three different difficulty levels for the cooperation and competition modes with 56 participants aged 23.7±3.8 years (mean±standard deviation). We attempted to observe IBS using functional near-infrared spectroscopy (fNIRS) and galvanic skin response (GSR) to assess the activities of the human autonomic nervous system. We found that the IBS levels increased in a frequency band of 0.075-0.15 Hz, which was unrelated to the task repetition frequency in the cooperation mode according to the task difficulty level. Significant relative inter-brain synchrony (RIBS) increases were observed in three and 10 channels out of 15 for the hard tasks compared to the normal and easy tasks, respectively. We observed that the average GSR values increased with increasing task difficulty levels for the competition mode only. Thus, our results suggest that the IBS revealed by fNIRS and GSR is not related to the hemodynamic changes induced by mental workload, simple behavioral synchrony such as button-pressing timing, or autonomic nervous system activity. IBS is thus explicitly caused by social interactions such as cooperation.

Size compatibility and concentration dependent supramolecular host-guest interactions at interfaces

The quantification of supramolecular host-guest interactions is important for finely modulating supramolecular systems. Previously, most host-guest interactions quantified using force spectroscopic techniques have been reported in force units. However, accurately evaluating the adhesion energies of host-guest pairs remains challenging. Herein, using a surface forces apparatus, we directly quantify the interaction energies between cyclodextrin (CD)-modified surfaces and ditopic adamantane (DAd) molecules in water as a function of the DAd concentration and the CD cavity size. The adhesion energy of the β-CD-DAd complex drastically increased with increasing DAd concentration and reached saturation. Moreover, the molecular adhesion energy of a single host-guest inclusion complex was evaluated to be ~9.51 kBT. This approach has potential for quantifying fundamental information toward furthering the understanding of supramolecular chemistry and its applications, such as molecular actuators, underwater adhesives, and biosensors, which require precise tuning of specific host-guest interactions.

Mussel-Inspired Multiloop Polyethers for Antifouling Surfaces

Despite the widespread use of polymers for antifouling coatings, the effect of the polymeric topology on the antifouling property has been largely underexplored. Unlike conventional brush polymers, a loop conformation often leads to strong steric stabilization of surfaces and antifouling and lubricating behavior owing to the large excluded volume and reduced chain ends. Herein, we present highly antifouling multiloop polyethers functionalized with a mussel-inspired catechol moiety with varying loop dimensions. Specifically, a series of polyethers with varying catechol contents were synthesized via anionic ring-opening polymerization by using triethylene glycol glycidyl ether (TEG) and catechol-acetonide glycidyl ether (CAG) to afford poly(TEG-co-CAG)_n. The versatile adsorption and antifouling effects of multiloop polyethers were evaluated using atomic force microscopy and a quartz crystal microbalance with dissipation. Furthermore, the crucial role of the loop dimension in the antifouling properties was analyzed via a surface force apparatus and a cell attachment assay. This study provides a new platform for the development of versatile antifouling polymers with varying topologies.

Importance of Interfacial Structures in the Catalytic Effect of Transition Metals on Diamond Growth

Here, using ab initio calculations, we investigated the interaction between transition metals (M) and diamond C(111) surfaces. As a physical parameter describing the catalytic effect of a transition metal on diamond growth, we considered interfacial energy difference, ΔE int, between 1 × 1 and 2 × 1 models of M/C(111). The results showed that the transition-metal elements in the middle of the periodic table (groups 4-10) favor a 1 × 1 M/C(111) structure with diamond bulk-like interfaces, while the elements at the sides of the periodic table (groups 3, 11, and 12) favor a 2 × 1 M/C(111) structure with the 2 × 1 Pandey chain structure of C(111) underneath M. In addition, calculations of MC carbide formation for early transition metals (groups 3-6) showed that they have a tendency to form MC rather than M/C(111), which explains their low efficiency as catalysts for diamond growth. Further analysis suggests that ΔE int could serve as another parameter (catalytic descriptor) for describing catalytic diamond growth in addition to the conventional parameter of the melting temperature of M.

Differential Surface Capping Effects on the Applications of Simple Amino-Acid-Capped ZnS:Mn Nanoparticles

Water-dispersible ZnS:Mn nanoparticles (NPs) were prepared by capping their surface with simple structured amino acids: l-alanine (Ala), l-glycine (Gly), and l-valine (Val) molecules, which have very similar structures except for the terminal organic functional groups. The detailed characterization works for the prepared colloidal NPs were performed using various spectroscopic methods. In particular, the NPs commonly showed UV/visible absorption peaks around 325 nm and PL emission peaks around 590 nm, corresponding to the wavelength of orange color light. In this study, these amino-acid-capped NPs were applied as optical photosensors in the detection of specific divalent transition metal cations in the same conditions. Consequently, all three NPs showed exclusive fluorescence quenching effects upon the addition of Cu (II) metal ions, whereas their quenching efficiencies were quite different to each other. These experimental results indicated that the Gly-ZnS:Mn NPs (k = 4.09 × 10⁵ M⁻¹) can be the most effective optical photosensor for the detection of Cu²⁺ ions in water among the three NPs in the same conditions. This study showed that the steric effect of the capping ligand can be one of the key factors affecting the sensor activities of the ZnS:Mn NPs.

Distinct dose-dependent effects of methamphetamine on real-time dopamine transmission in the rat nucleus accumbens and behaviors

Methamphetamine (METH) is a potent psychostimulant that exerts many of its physiological and psychomotor effects by increasing extracellular dopamine (DA) concentrations in limbic brain regions. While several studies have focused on how potent, neurotoxic doses of METH augment or attenuate DA transmission, the acute effects of lower and behaviorally activating doses of METH on modulating DA regulation (release and clearance) through DA D2 autoreceptors and transporters remain to be elucidated. In this study, we investigated how systemic administration of escalating, subneurotoxic doses of METH (0.5-5 mg/kg, IP) alter extracellular DA regulation in the nucleus accumbens (NAc), in both anesthetized and awake-behaving rats through the use of in vivo fast-scan cyclic voltammetry. Pharmacological, electrochemical, and behavioral evidence show that lower doses (≤2.0 mg/kg, IP) of METH enhance extracellular phasic DA concentrations and locomotion as well as stereotypies. In contrast, higher doses (≥5.0 mg/kg) further increase both phasic and baseline DA concentrations and stereotypies but decrease horizontal locomotion. Importantly, our results suggest that acute METH-induced enhancement of extracellular DA concentrations dose dependently activates D2 autoreceptors. Therefore, these different METH dose-dependent effects on mesolimbic DA transmission may distinctly impact METH-induced behavioral changes. This study provides valuable insights regarding how low METH doses alter DA transmission and paves the way for future clinical studies on the reinforcing effects of METH.

Upper facial surgery: simultaneous hairline-lowering surgery during endoscopic forehead lifting

Background Endoscopic forehead lifting is one of the most common procedures in the field of upper facial surgery. The upper third of the face determines the facial expression and plays a key role in the appearance of facial youth. After the forehead, a high hairline is one of the most important features of the upper third of the face contributing to age identification. The combined evaluation of these two features should be a basic premise of upper facial surgery.Methods The authors present a surgical sequence in which endoscopic forehead lifting and lowering of the high hairline by means of a scalp flap advancement are carried out during the same operation. The incision line is located along the hairline. After the scalp and forehead flap are moved, they are fixed using the bone tunnel fixation method.Results In total, 194 patients were treated with endoscopic forehead lifting and simultaneous hairline lowering between August 2018 and July 2020. On average, the patients’ hairlines were 18 mm lower and their eyebrows were 5 mm higher. No patients had serious complications.Conclusions Endoscopic forehead lifting and simultaneous hairline lowering surgery make it possible to address the entire upper third of the face in a single facial rejuvenation operation.

Quantum-confinement effect on the linewidth broadening of metal halide perovskite-based quantum dots

The linewidth broadening caused by various physicochemical effects does limit the well-known advantage of ultrahigh color purity of metal halide perovskites (MHPs) for use in next-generation light-emitting diodes (LEDs). We have theoretically examined the quantum- and dielectric-confinement effects of a quantum dot (QD) on the degree of photoluminescence linewidth broadening. It is predicted that the linewidth (Δλ_QC) is mainly contributed by the two opposing effects: (i) the linewidth broadening due to the repulsive kinetic energy of confined excitons (ΔλQCKE) and (ii) the overall linewidth narrowing caused by the attractive Coulomb interaction (ΔλQCCoul). It is shown that the relative contribution essentially remains at a constant value and is evaluated asΔλQCCoul/ΔλQCKE=0.42, which is independent of the QD size and the chemical nature of semiconducting emitter. We have computed Δλ_QCfor various QD sizes of the prototypical MHP emitter, MAPbBr₃, where MA denotes a methylammonium (CH₃NH₃) organic cation. The calculated results show that the linewidth broadening due to the quantum confinement (Δλ_QC) increases rapidly beginning at the QD radius approximately equal to 6.5 nm but Δλ_QCis less than 2 nm even atR= 1.5 nm. Thus, Δλ_QCis much narrower than the linewidth caused by the exciton-LO phonon Fröhlich coupling (∼23.4 nm) which is known as the predominant mechanism of linewidth broadening in hybrid MHPs. Thus, the linewidth broadening due to the quantum confinement (Δλ_QC) is not a risk factor in the realization of MHP-based ultrahigh-quality next-generation LEDs.

Anterior resection syndrome: a randomized clinical trial of a 5-HT3 receptor antagonist (ramosetron) in male patients with rectal cancer

BACKGROUND

No effective treatment exists for anterior resection syndrome (ARS) following sphincter-saving surgery for rectal cancer. This RCT assessed the safety and efficacy of a 5-HT3 receptor antagonist, ramosetron, for ARS.

METHODS

A single-centre, randomized, controlled, open-label, parallel group trial was conducted. Male patients with ARS 1 month after rectal cancer surgery or ileostomy reversal were enrolled and randomly assigned (1 : 1) to 5 μg of ramosetron (Irribow®) daily or conservative treatment for 4 weeks. Low ARS (LARS) score was calculated after randomization and 4 weeks after treatment. The study was designed as a superiority test with a primary endpoint of the proportion of patients with major LARS between the groups. Primary outcome analysis was based on the modified intention-to-treat population. Safety was assessed by monitoring adverse events during the study.

RESULTS

: A total of 100 patients were randomized to the ramosetron (49 patients) or conservative treatment group (51 patients). Two patients were excluded, and 48 and 50 patients were analysed in the ramosetron and control groups, respectively. The proportion of major LARS after 4 weeks was 58 per cent (28 of 48 patients) in the ramosetron group versus 82 per cent (41 of 50 patients) in the control group, with a difference of 23.7 per cent (95 per cent c.i. 5.58 to 39.98, P = 0.011). There were minor adverse events in five patients, which were hard stool, frequent stool or anal pain. These were not different between the two groups. There were no serious adverse events.

CONCLUSION

: Ramosetron could be safe and feasible for male patients with ARS.

TRIAL REGISTRATION NUMBER

NCT02869984 (http://www.clinicaltrials.gov).

Gas sensing materials roadmap

Gas sensor technology is widely utilized in various areas ranging from home security, environment and air pollution, to industrial production. It also hold great promise in non-invasive exhaled breath detection and an essential device in future internet of things. The past decade has witnessed giant advance in both fundamental research and industrial development of gas sensors, yet current efforts are being explored to achieve better selectivity, higher sensitivity and lower power consumption. The sensing layer in gas sensors have attracted dominant attention in the past research. In addition to the conventional metal oxide semiconductors, emerging nanocomposites and graphene-like two-dimensional materials also have drawn considerable research interest. This inspires us to organize this comprehensive 2020 gas sensing materials roadmap to discuss the current status, state-of-the-art progress, and present and future challenges in various materials that is potentially useful for gas sensors.

Tailoring the Structure of Low-Dimensional Halide Perovskite through a Room Temperature Solution Process: Role of Ligands

In this study, halide perovskite nanocrystals are synthesized by controlling the ligand length and amount, and investigated the effects on the change in the ligand length and amount on the shape, size, crystal structure, and optical properties of the perovskite nanocrystals. The results reveal the tendency and respective effects of amine and acid ligands on perovskite nanocrystals. The amine ligands bind directly to the perovskite nanocrystals. Consequently, the amine ligands with longer chains interfere with the aggregation of the initially formed nanocrystals, thus limiting the size of the halide perovskite nanocrystals. Similar to the amine ligands, the acid ligands directly bond with the perovskite nanocrystals; however, they are also indirectly distributed around the nanocrystals, thus affecting their structure and dispersion. Consequently, the acid ligands affect the assembly of the initially formed nanocrystals, which determine the shape and crystal structure of the nanocrystals. It is believed that the report will provide useful insight on the synthesis of halide perovskites for application in optoelectronic devices.

Sex differences in mapping and rhythm outcomes of a repeat atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

The risk of procedure-related complications and rhythm outcomes differ between men and women after atrial fibrillation catheter ablation (AFCA). We evaluated whether consistent sex differences existed in mapping and rhythm outcomes in repeat ablation procedures.

Methods

Among 3,282 patients in the registry, we analysed 443 consecutive patients (24.6% female, 58.5 ± 10.3 years old, 61.5% paroxysmal AF) who underwent a second AFCA. We compared the clinical factors, mapping, left atrial (LA) pressure, complications, and long-term clinical recurrences after propensity score matching.

Results

The LA volume index (43.1 ± 18.6 vs. 35.8 ± 11.6 ml/m2, p &lt; 0.001) was higher, but LA dimension (40.0 ± 6.8 vs. 41.6 ± 6.3mm, p = 0.018), LA voltage (0.94 ± 0.55 vs. 1.20 ± 0.68 mV, p = 0.002), and pericardial fat volume (89.5 ± 43.1 vs. 122.1 ± 53.9 cm3, p &lt; 0.001) lower in women with a repeat ablation than in their male counterparts. The pulmonary vein (PV) reconnections were lower (58.7% vs. 74.9%, p = 0.001), but the proportion of extra-PV triggers (27.5% vs. 17.0%, p = 0.026) and elevated LA pulse pressures (79.7% vs. 63.7%, p = 0.019) was significantly higher in women than men. There was no significant sex difference in the procedure-related complication rate (4.6% vs. 4.2%, p = 0.791). During a 31(8∼60) month median follow-up, clinical recurrences were significantly higher in women after both the de novo procedure (log rank p = 0.039, antiarrhythmic drug [AAD]-free log rank p &lt; 0.001) and second procedure (log rank p = 0.006, AAD-free log rank p = 0.093). A female sex (HR 1.51 [1.06-2.15], p = 0.023), non-paroxysmal AF (HR 1.78 [1.30-2.34], p &lt; 0.010), and extra-PV triggers (HR 1.88 [1.28-2.75], p = 0.001) were independently associated with clinical recurrences after repeat procedures.

Conclusions

During the repeat AFCA procedures, PV reconnections were lower in women than men, and the existence of extra-PV triggers and an LA pressure elevation was more significant, which resulted in poor rhythm outcomes.