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Atomically precise signatures of native subsurface As monovacancy defect in GaAs studied by STM imaging and DFT calculations
No full textWe conducted scanning tunneling microscopy (STM) measurements and density functional theory (DFT) calculations to investigate surface arsenic vacancies (V-As) and intrinsic subsurface V-As in GaAs(110), revealing distinct STM features and symmetries depending on their depth from the surface. A surface V-As appears as a symmetric dark contrast at the missing As site with estimated size of similar to 21.8 A(2). In contrast, a second-layer V-As exhibits an asymmetric two-lobe darker contrast, due to relaxation and charge accumulation in the underlying Ga atoms. A third-layer V-As, however, shows a symmetric "butterfly-like" dark contrast, caused by charge accumulation in the lower layers along with charge depletion around the central surface As atom. DFT calculations using the modified Becke-Johnson local density approximation (mbJ-LDA) reveal that V-As in bulk GaAs introduce slightly dispersed, partially-filled gap states near the conduction band, confirming previous theoretical predictions. The above findings show key features to distinguish surface and native subsurface V-As relative to their location from the surface via STM. Moreover, our findings reveal details into the structural, energetic, and electronic properties of V-As in bulk GaAs, which can provide valuable insights into the desired V-As-induced below-band gap excitation in GaAs for terahertz and optoelectronic device applications.TRUEsciescopu
A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
No full textThis paper presents a novel comparator-swapping background offset calibration method for SAR ADCs, addressing the limitations of previous calibration techniques. The proposed method uses three comparators to eliminate reset time and calibrates offset mismatch based on the LSB conversion, leading to rapid offset convergence and reduced dependence on input signal statistics. By alternating the roles of the comparators and eliminating the need for an additional calibration cycle, the method achieves efficient calibration without the overhead of extra reference comparators. A prototype 8-bit SAR ADC implemented in a 28 nm CMOS LPP process demonstrates the effectiveness of the proposed technique, achieving a measured SNDR of 44.3 dB and SFDR of 58.4 dB at 500 MS/s, with a power consumption of 1.13 mW. The ADC occupies only 0.0033 mm2, with a Walden FoM of 16.8 fJ/conversion-step. The results show that the proposed calibration method is competitive with state-of-the-art techniques, offering a highly accurate and efficient solution for background offset mismatch calibration in SAR ADCs.TRUEsciescopu
Comparison among machine learning models for prediction performance of Seebeck coefficient
No full textThe advancement of materials science has been propelled by the integration of computational
methods such as molecular dynamics (MD) and density functional theory (DFT). Recently, machine
learning (ML) has emerged as a promising tool, offering faster and accurate predictions by leveraging
data-driven approaches. This study focuses on applying ML techniques to predict the thermoelectric
properties of materials, particularly the Seebeck coefficient, a critical parameter for evaluating ther-
moelectric efficiency. Utilizing the Ricci ab initio computational database, this research compares the
performance of different ML models, including CGCNN and CraTENet, and explores a novel feature
fusion model that integrates structural and compositional information.
The results demonstrate that CGCNN outperforms CraTENet in predicting the Seebeck coefficient,
benefiting from structural information. However, the proposed fusion model, while robust, exhibits
intermediate performance between the individual models, suggesting that simple feature addition may
not fully leverage the strengths of both architectures. Additionally, multi-task learning approaches for
predicting both Seebeck coefficient and bandgap show slight performance trade-offs but highlight the
potential of simultaneous property prediction. These findings underscore the importance of leverag-
ing domain-specific correlations and advanced feature fusion techniques to optimize thermoelectric
material discovery and design.Maste
Metabolic outcomes in non-alcoholic and alcoholic steatotic liver disease among Korean and American adults
No full textBackground: This study investigated the prevalence and causal relationships of chronic metabolic diseases (diabetes, hypertension, and dyslipidemia) with steatotic liver disease (SLD), specifically metabolically associated alcoholic liver disease (MetALD). Methods: We conducted a comprehensive analysis using cross-sectional data from the KNHANES from 2011 to 2021 and the NHANES from 1999 to 2020. Longitudinal data from 2001 to 2014 from the KoGES were used. Participants were categorized into the metabolic dysfunction-associated SLD(MASLD), MetALD, and ALD groups based on their hepatic steatosis index (HSI), including liver profiles, body composition, and diabetes, and alcohol consumption. Multivariable, including age and smoking status, logistic and Cox regression analyses were performed to assess the prevalence and incidence of chronic diseases. Results: In both the KNHANES and NHANES cohorts, an increased HSI was significantly associated with a higher prevalence of chronic metabolic diseases. Longitudinal data from the KoGES cohort showed that MASLD and MetALD were significant predictors of chronic metabolic disease in both men and women. MetALD showed a higher hazard ratio for the development of chronic metabolic diseases than MASLD in Cox regression analysis. Conclusions: This study highlighted the intertwined nature of SLD and metabolic health, with an emphasis on the role of MetALD. The significant association between MetALD and chronic metabolic diseases underscores the need for integrated management strategies that address both liver health and metabolic risk factors. © The Author(s) 2025.TRUEsciescopu
Higher Circulating Resistin Levels Linked to Increased Sarcopenia Risk in Older Adults
No full textContext Experimental evidence indicates that resistin, an adipokine, negatively impacts muscle metabolism by hindering myogenesis.Objective To explore resistin's potential as a biomarker of muscle health in humans by examining the relationship between circulating resistin levels and sarcopenia in older adults.Design and Setting A case-control study conducted in a geriatric clinical unit.Participants The study included 247 individuals aged 65 and older who underwent comprehensive geriatric evaluations.Main Outcome Measures Sarcopenia was defined based on Asian-specific thresholds, with serum resistin concentrations measured using an ELISA.Results After adjusting for sex, age, fat mass, smoking, osteoarthritis, and diabetes, participants with sarcopenia, low muscle mass, and weak muscle strength exhibited at least 27.0% higher circulating resistin concentrations than controls (P = .002-.003). Elevated serum resistin levels were inversely associated with skeletal muscle mass, gait speed, and the short physical performance battery score and positively associated with the time to complete 5 chair stands (P = .019-.048). Higher serum resistin levels were linked to an increased risk of sarcopenia, low muscle mass, and weak muscle strength (all P = .005). Finally, participants in the highest resistin quartile had at least 3 times higher odds of having adverse muscle outcomes compared to those in the lowest quartile (P = .007-.029).Conclusion This study set out to establish a link between blood resistin levels and sarcopenia, suggesting that circulating resistin may serve as a potential biomarker reflecting poor muscle health in humans.FALSEsciescopu
RSCF: Relation-Semantics Consistent Filter for Entity Embedding of Knowledge Graph
No full textIn knowledge graph embedding, leveraging relation specific entity transformation has markedly enhanced performance. However, the consistency of embedding differences before and after transformation remains unaddressed, risking the loss of valuable inductive bias inherent in the embeddings. This inconsistency stems from two problems. First, transformation representations are specified for relations in a disconnected manner, allowing dissimilar transformations and corresponding entity embeddings for similar relations. Second, a generalized plug-in approach as a SFBR (Semantic Filter Based on Relations) disrupts this consistency through excessive concentration of entity embeddings under entity-based regularization, generating indistinguishable score distributions among relations. In this paper, we introduce a plug-in KGE method, Relation-Semantics Consistent Filter (RSCF). Its entity transformation has three features for enhancing semantic consistency: 1) shared affine transformation of relation embeddings across all relations, 2) rooted entity transformation that adds an entity embedding to its change represented by the transformed vector, and 3) normalization of the change to prevent scale reduction. To amplify the advantages of consistency that preserve semantics on embeddings, RSCF adds relation transformation and prediction modules for enhancing the semantics. In knowledge graph completion tasks with distance-based and tensor decomposition models, RSCF significantly outperforms state-of-the-art KGE methods, showing robustness across all relations and their frequencies
A Vertically‐Stacked Optoelectronic Sensor for Localized Hemodynamics Monitoring
No full textAbstractOptoelectronic sensors are widely used as they monitor important biosignals in real‐time, many times in non‐invasive ways by making use of the degree of light absorption through live tissues. In many of the applications, the optoelectronic sensors in a small form factor with attachable or insertable forms enable understanding the critically important biological states and mechanisms, including localized activities in very complex biological environments, such as in the brain. In this report, an optoelectronic sensor is presented, built by vertically integrating two different micro light emitting diodes (microLEDs) next to a photodetector with a predetermined interoptode distance in attachable or insertable forms. Both of the optical simulations and experimental results validate the designs and capabilities of the approach, by demonstrating the sensors on a human finger, around femoral vessels in a mouse model, and in mouse brains to monitor optogenetically‐induced localized hemodynamics.TRUEsciescopu
CuCap: Comparative Analysis of Customized Captioning between North American and South Korean d/Deaf and Hard-of-Hearing Users
No full textAffective and prosodic captions convey not only what a speaker says, but also how they say it - louder words may appear thicker, quieter ones thinner; angry in red, calm in blue. These captions can improve access, satisfaction, and engagement for d/Deaf and Hard-of-Hearing (dhh) users. While prior work has explored their design space, it has focused largely on dhh participants in North America, limiting generalizability beyond English and Latin-based scripts. To uncover the role of culture and language, we ran an exploratory study with 49 dhh participants from North America and South Korea using CuCap, a tool that allowed them to personalize which speech features were displayed, and how. While emotion visualization was a universally favored choice, confirming prior findings, prosody preferences varied across cultures, reflecting linguistic and hearing factors. These findings point to the need for flexible captioning systems that account for cultural, linguistic, and individual differences. © 2025 Copyright held by the owner/author(s)
Emotional and sensory ratings of vibration Tactons in the lab and crowdsourced settings
No full textVibrotactile actuators in consumer devices present new opportunities to crowdsource subjective ratings of tactile icons (i.e., Tactons). Yet, little is known about the effects of user demographics, hardware form factors, and study environments on subjective ratings. Also, the feasibility of crowdsourcing emotional and sensory ratings remains underexplored. To address this gap, we investigated valence, arousal, and roughness ratings by controlling for the Tacton design approach, biological sex, form factor, and study environment. Study 1 investigated the effects of two biological sexes and three smartphone models on the ratings from 36 participants in a controlled laboratory setting using two sets of 24 Tactons (48 in total) created using different design approaches. Strong correlations (mean Pearson's r=0.86) existed in all ratings across biological sexes regardless of Tacton sets, while valence ratings showed moderate or low correspondence across smartphone models depending on Tacton set. In Study 2, we crowdsourced the Tacton ratings with 36 new participants to explore the impact of an uncontrolled setting on the results. We identified a subset of parameters, such as duration, that were influenced by the settings, where demographics and form factors varied. Also, arousal and roughness ratings demonstrated strong correspondences with 85% and 77% of statistically equivalent Tactons between the lab and crowdsourced settings, but valence ratings showed moderate to strong correlations depending on Tacton design approaches. Based on these findings, we offer guidelines for Tacton design in uncontrolled settings and for crowdsourcing emotional and sensory ratings. © 2025 Elsevier LtdFALSEsciessciscopu
Low Serum 25-Hydroxyvitamin D as a Risk Factor for Frailty in Community-Dwelling Older Men: A Korean Nationwide Study
No full textBackground: Despite the critical role of vitamin D in various biological processes, its impact on frailty—a condition closely linkedto biological age—remains inconclusive. This study aimed to explore the association between serum 25-hydroxyvitamin D (25[OH]D) levels and frailty status in older Korean adults, utilizing a comprehensive frailty index (FI) and a nationally representative dataset.
Methods: This cross-sectional study included 6,589 participants aged ≥65 years from the Korea National Health and Nutrition Examination Survey (2008–2012). Frailty was assessed using a deficit accumulation FI based on 38 physical, cognitive, psychological,and social items.
Results: After adjusting for potential confounders, frail men showed 6.8% lower serum 25(OH)D concentrations compared to nonfrail controls (P=0.007). Men in the lowest serum 25(OH)D quartile (≤39.3 nmol/L) exhibited a 5.3% higher FI (P=0.047) and1.71-fold increased odds of frailty (P=0.005), compared to those in the highest quartile (>63.3 nmol/L). Similarly, men with vitaminD deficiency (<30 nmol/L) exhibited a 9.6% higher FI compared to those with sufficient vitamin D levels (≥50 nmol/L; P=0.004).
However, no significant association between serum 25(OH)D concentration and frailty was observed in women across any analysis.
Conclusion: These findings suggest that low serum 25(OH)D concentrations are a potential risk factor for frailty, particularly in men.
Further research is warranted to determine whether vitamin D supplementation in such high-risk older adults could help mitigate frailtyTRUEsciescopuskc