Chung-Ang University

This study examines the antimicrobial and antibiofilm effectiveness of baicalin and carvacrol against Salmonella enterica ser. Typhimurium on food contact surfaces and chicken meat. The minimum inhibitory concentrations (MIC) for baicalin and carvacrol were found to be 100 μg/mL and 200 μg/mL, respectively, which aligns with findings from previous studies. The compounds exhibited a concentration-dependent decrease in microbial populations and biofilm formation. When used together, they displayed a remarkable synergistic effect, greatly augmenting their antibacterial activity. The assessment of food quality demonstrated that these treatments have no negative impact on the sensory characteristics of chicken meat. The impact of the structure on biofilms was observed through the use of Field Emission Scanning Electron Microscopy (FE-SEM) and Confocal Laser Scanning Microscopy (CLSM), revealing disrupted biofilm architectures and decreased cell viability. Crucially, RT-PCR analysis revealed a marked downregulation of quorum sensing (luxS), virulence (hilA), and stress response (rpoS) genes, highlighting the multifaceted antimicrobial mechanism of action. This gene-specific suppression suggests a targeted disruption of bacterial communication and virulence pathways, offering insight into the comprehensive antibiofilm strategy. This provides further insight into the molecular mechanisms that contribute to their antibiofilm effects.

Listening to music is a crucial tool for relieving stress and promoting relaxation. However, the limited options available for stress-relief music do not cater to individual preferences, compromising its effectiveness. Traditional methods of curating stress-relief music rely heavily on measuring biological responses, which is time-consuming, expensive, and requires specialized measurement devices. In this paper, a deep learning approach to solve this problem is introduced that explicitly uses convolutional neural networks and provides a more efficient and economical method for generating large datasets of stress-relief music. These datasets are composed of Mel-scaled spectrograms that include essential sound elements (such as frequency, amplitude, and waveform) that can be directly extracted from the music. The trained model demonstrated a test accuracy of 98.7%, and a clinical study indicated that the model-selected music was as effective as researcher-verified music in terms of stress-relieving capacity. This paper underlines the transformative potential of deep learning in addressing the challenge of limited music options for stress relief. More importantly, the proposed method has profound implications for music therapy because it enables a more personalized approach to stress-relief music selection, offering the potential for enhanced emotional well-being.

A metamaterial can be used for fabricating an electromagnetic absorber by tailoring its effective permittivity and permeability. In general, a metamaterial absorber works at a specific resonant frequency, and its absorption frequency does not change after the structure is fabricated. A three-dimensionally (3D)-printed shape memory polymer (SMP) is a potential candidate for overcoming this limitation and realising reconfigurability with its fabrication versatility. In this work, we propose a frequency – and bandwidth-controllable electromagnetic absorber using 3D-printed shape memory meta-wires (SMMWs). Unlike the conventional usage of SMPs with two states, thermally deformable SMMWs have three different modes that are realised by controlling the states of each column. Multi-material additive manufacturing is used to print the SMMW, with an SMP substrate and a high-temperature filament being the materials that are printed. The high absorptivity and frequency – and bandwidth-tuning capability are numerically and experimentally demonstrated for three different modes.

Calcium (Ca2+) deficiency leads to disease symptoms such as blossom-end-rot (BER), resulting in the cessation of apical growth, curling, shoot and flower tip necrosis, and fruit chlorosis in hot peppers (Capsicum annuum L.). Previous reports have stated that an excessive supply of cations like potassium (K+) and magnesium (Mg2+) affects the incidence of BER in plants of the Solanaceae family, such as tomato. In this study, we aimed to investigate the correlation between the contents of three cations and BER symptoms in pepper fruits. We assessed the distribution of three cations (Ca2+, K+, and Mg2+) in three distinct sections (pedicel, proximal half, and distal half) of the pepper fruit in both healthy and BER-defective peppers. We found that the overall amount of Ca2+ was not correlated with BER symptoms in pepper fruits. Instead, a high Ca2+/ K+ ratio in the pedicel of pepper fruit has a correlative impact on BER symptoms in the chili pepper fruit. Therefore, the manifestation of BER symptoms could be associated with the Ca2+/ K+ value and the relative percentage of the calcium-to-potassium ratio in the pedicel of the pepper fruit. Furthermore, we performed a transcriptomic analysis on both BER-resistant and BER-sensitive pepper fruits to gain a more profound understanding of the molecular mechanisms driving BER symptoms in chili peppers. BER-resistant pepper cultivar was shown to deploy defense programs against calcium-deficient stress conditions. We believe that our study provides helpful insights into the importance of the Ca2+/ K+ ratio in preventing physiological diseases, such as BER, in chili pepper cultivation.

This study investigates the factors influencing users’ intentions to identify false content on short-video platforms, focusing on the role of digital literacy within the framework of the Theory of Planned Behavior (TPB). A structural equation model is employed to examine the relationships among digital literacy, perceived risk, subjective norms, perceived behavioral control, identification attitude, and the intention to identify false content. The analysis reveals that digital literacy significantly impacts subjective norms, perceived behavioral control, identification intention, and perceived risk. Perceived risk positively influences subjective norms, perceived behavioral control, and identification attitude. However, identification attitude does not significantly affect identification intention. The study also explores the mediating roles of perceived risk and perceived behavioral control in the relationship between digital literacy and the intention to identify false content. The findings highlight the importance of enhancing digital literacy and risk awareness among users to combat the spread of false content on short-video platforms. This research contributes to the literature by extending the TPB framework to include digital literacy and perceived risk in the context of false content identification, offering valuable insights for platform managers, policymakers, and educators in promoting a more trustworthy online environment.

Purpose This study aimed to develop a smartphone mobile application-based supportive return to work (RTW) program for cancer survivors and evaluate its effects on their RTW, fatigue, stress, and quality of working life. This program was developed through a comprehensive process involving literature review, interviews with cancer survivors, and consultations with experts. Methods A non-equivalent control group pre- and post-test design was used, with 41 participants assigned to the experimental (n = 18) and control (n = 23) groups based on recruitment timing. The experimental group received a 6-week smartphone mobile application-based supportive RTW program comprising “Counseling and Education” and “Self-Management.” Participants completed assessments of decent RTW, fatigue, stress, and quality of working life at baseline and 6 months later. The experimental group completed an additional post-program completion survey. Results During the 6-week program, no experimental group participants dropped out. The program’s impact on decent RTW remains unclear. Fatigue (F = 2.52, p = 0.095) and quality of working life (F = 0.86, p = 0.434) did not show statistically significant differences. However, there was a significant reduction in stress (F = 4.59, p = 0.017). Conclusion The smartphone application-based RTW program, focusing on self-management and counseling, effectively reduced participants’ stress levels. To further evaluate the effectiveness of the program, a more diverse range of interventions and ongoing programs should be implemented. Implications for Cancer Survivors This study underscores the importance of tailored digital interventions to support the RTW of cancer survivors. The use of mobile smartphone applications allows temporal and spatial flexibility in program participation. Interventions involving various activities should be implemented to ensure ongoing participation.

Purpose Dyslipidemia is a major health issue worldwide. There is growing interest in understanding the potential role of kimchi consumption on serum lipid profiles. However, there are limited epidemiological studies available on this topic. Therefore, this study aims to investigate the association between kimchi intake and serum lipid profiles. Methods We conducted an epidemiological study on participants (aged 40–69 years old) selected from the Health Examinees (HEXA) cohort study (n = 61,761). Four types of kimchi, including Baechu kimchi (cabbage kimchi), Kkakdugi (radish kimchi), Nabak kimchi/Dongchimi (a type of water kimchi made with fermented vegetables), and other kimchi, were assessed by a 106-food item semi-quantitative validated food frequency questionnaire (FFQ). Each kimchi intake is the average value calculated from the FFQ of the baseline and follow-up surveys. Fasting blood data were obtained at baseline and follow-up visits. Linear regression was used to examine the relationship between the intake of kimchi and the change in serum lipid profiles. Results The mean years between the baseline survey and a follow-up survey was 4.97 years. In this study, compared to the lowest category (< 1 serving/day), Baechu kimchi intake (2− < 3 servings/day) had more negative correlations with the change in values of total cholesterol (β: −1.600, 95% confidence interval [CI, −2.744, −0.456]), triglycerides (β: −3.372, 95% CI [−5.414, −1.330]), and low-density lipoprotein cholesterol (β: −1.155, 95% CI [−2.214, −0.095]) in women. In men, Baechu kimchi intake (2− < 3 servings/day) had a more positive correlation associated with the changes in values of high-density lipoprotein cholesterol (β: 0.049, 95% CI [0.031, 0.907]) compared to the lowest intake category (< 1 serving/day). Conclusions Among Korean adults, consumption of kimchi, particularly Baechu kimchi, was found to be associated with improvements in serum lipid profiles. Further studies are required to conduct additional interventions to confirm the association between kimchi and serum lipid profiles.

This research focused on the relationships among 34 major airports in China, analyzing how these relationships are influenced by spatial dependence and heterogeneity. Using a spatial econometric model, it found that passenger traffic in China’s airports displays a mutually driven aggregation effect. Furthermore, the study revealed that the airport relationship changes from complementarity to competition as the geographic distance between them decreases. The study also classified the main airports in China into three hierarchical levels and found significant complementarity and competition among those within the hub-and-spoke network structure. Specifically, this study identified a complementary relationship among regional trunk and local branch airports, as-well-as significant competition among hub airports. Crucially, the study suggests that the absence of a hub airport weakens the collaborative interactions between different types of airports, emphasizing the critical importance of hub airports for the connectivity and operational efficiency of China’s airport network.

Surveillance video analysis using automated AI-based techniques is a prominent research field with real-world applications. Several techniques aiming at recognizing activities, behaviour, and violent actions are present in literature. Real-world data analysis for violence detection is still a major challenge due to the limited datasets available for training with complex scenarios and varied scaling of objects performing different activities. In this paper, we present a novel deep learning model considering specially designed frame encoders for spatial feature extraction that are generalized towards many challenges, such as light conditions and indoor and outdoor scenarios. Furthermore, the spatial features in the stacked form are analyzed using a temporal deep learning model to observe and learn the temporal patterns dependencies by considering past and future information while predicting the violent or normal class. In the literature, violence is considered a binary classification of either fight or no fight. Different from these techniques, we present a multi-class classification of violent activities considering different types of human violence, such as assault, shooting, etc. The data for multi-class violence classification is extracted from the famous real-world anomaly detection UCF-crime dataset, where only six human-involved types of anomalies are considered for preparing training and testing sets. We report 41.1%, 48.85% accuracy for 16 and 8 frames in a single sequence. This data shows that more research is demanded to increase the robustness of deep models in violence detection. Finally, the proposed results against recent methods over violence detection datasets are marginally better, indicating the effectiveness of the proposed feature extraction and temporal learning mechanism.

The activation of the angiopoietin (Angpt)-Tie system is linked to endothelial dysfunction during sepsis. Bacterial quorum-sensing molecules function as pathogen-associated molecular patterns. However, their impact on the endothelium and the Angpt-Tie system remains unclear. Therefore, this study investigated whether treatment with N-3-oxododecanoyl homoserine lactone (3OC12-HSL), a quorum-sensing molecule derived from Pseudomonas aeruginosa, impaired endothelial function in human umbilical vein endothelial cells. 3OC12-HSL treatment impaired tube formation even at sublethal concentrations, and immunocytochemistry analysis revealed that it seemed to reduce vascular endothelial-cadherin expression at the cell−cell interface. Upon assessing the mRNA expression patterns of genes associated with the Angpt-Tie axis, the expressions of Angpt2, Forkhead box protein O1, Tie1, and vascular endothelial growth factor 2 were found to be upregulated in the 3OC12-HSL-treated cells. Moreover, western blot analysis revealed that 3OC12-HSL treatment increased Angpt2 expression. A co-immunoprecipitation assay was conducted to assess the effect of 3OC12-HSL on the IQ motif containing GTPase activating protein 1 (IQGAP1) and Rac1 complex and the interaction between these proteins was consistently maintained regardless of 3OC12-HSL treatment. Next, recombinant human (rh)-Angpt1 was added to assess whether it modulated the effects of 3OC12-HSL treatment. rh-Angpt1 addition increased cellular viability, improved endothelial function, and reversed the overall patterns of mRNA and protein expression in endothelial cells treated with 3OC12-HSL. Additionally, it was related to the increased expression of phospho-Akt and the IQGAP1 and Rac1 complex. Collectively, our findings indicated that 3OC12-HSL from Pseudomonas aeruginosa can impair endothelial integrity via the activation of the Angpt-Tie axis, which appeared to be reversed by rh-Angpt1 treatment.

Which kinds of grievances garner support from the public on online platforms? Focusing on national online petitioning, one of the forms of direct democracy in contemporary politics, we examine the content and characteristics of petitions that succeeded in attracting public attention and support. Using our comprehensive data on online petitions that were submitted to the executive office between 2017 and 2022 in South Korea, our analysis yields three important findings. First, a mix of post-materialist topics such as human rights and gender equality and materialist topics such as safety and environment turn out to be salient among petitions that meet the signature threshold. Second, online petitions the contents of which reveal either moral emotions or Confucian attitudes are more likely to gain public support compared to others. Third, keywords that are related to moral claims asking for the apprehension of perpetrators on behalf of victims, such as ‘victim,’ ‘perpetrator,’ ‘kid,’ and ‘punishment,’ appear most frequently inside the petitions that cross the signature threshold. Such findings provide implications for understanding both the potentials and limitations of national online petitioning in contemporary democracies.

We address the adaptive fixed-time containment (FxTC) control problem of a class of uncertain multi-input multi-output nonlinear multiagent systems using event-triggered inter-agent communication under a directed network. Our primary contribution is to develop multi-leader estimation and dynamic event-triggering strategies to ensure practical fixed-time convergence in a distributed containment control framework. First, an event-triggered mechanism that uses distributed containment errors in the dynamic threshold is introduced to reduce needless data transmissions among agents according to decreasing errors. Subsequently, a multi-leader-estimation-based command-filtered backstepping strategy is established to design a distributed adaptive FxTC controller using only neighbors’ output information. Using the fixed-time stability theory, we show that all closed-loop signals are bounded and all followers can be steered to the convex hull spanned by the leaders within a fixed time, regardless of the initial state conditions. Finally, two simulation examples containing robotic manipulators demonstrate the merits of the suggested control strategy.

Glucosinolates (GSLs) are defensive secondary metabolites produced by Brassicaceae species in response to abiotic and biotic stresses. The biosynthesis of GSL compounds and the expression of GSL-related genes are highly modulated by endogenous signals (i.e., circadian clocks) and environmental cues, such as temperature, light, and pathogens. However, the detailed mechanism by which light signaling influences GSL metabolism remains poorly understood. In this study, we found that a light-signaling factor, ELONGATED HYPOCOTYL 5 (HY5), was involved in the regulation of GSL content under light conditions in Arabidopsis (Arabidopsis thaliana). In hy5-215 mutants, the transcript levels of GSL pathway genes were substantially upregulated compared with those in wild-type plants. The content of GSL compounds was also substantially increased in hy5-215 mutants, whereas 35S::HY5-GFP/hy5-215 transgenic lines exhibited comparable levels of GSL-related transcripts and GSL content to those in WT plants. HY5 physically interacts with HISTONE DEACETYLASE9 (HDA9) and binds to the proximal promoter region of MYB29 and IMD1 to suppress aliphatic GSL biosynthetic processes. These results demonstrate that HY5 suppresses GSL accumulation during the daytime, thus properly modulating GSL content daily in Arabidopsis plants.

In this study, a new and facile process was developed for the preparation of composite catalysts based on tungsten oxide (WO3) by batch reactor routes. The structures, morphologies, compositions, and characteristics of synthesized materials were investigated and confirmed. Using batch reactor processes, WO3 nanorods (WO3 NR), heterostructures of WS2/WO3 nanobricks (WS2/WO3 NB), and WS2/WO3 nanorods (WS2/WO3 NR) were successfully prepared. The prepared materials were then employed for hydrogen evolution reaction (HER) to investigate their catalytic performance. The results indicated that the electrocatalytic activities of WS2/WO3 NR are significantly improved compared to those of WO3 NR and WS2/WO3 NB. This improvement could be attributed to the formation of heterostructure between WS2 and WO3 elements in highly uniform materials, which could create the synergistic effect and further improve the catalytic activities of the catalyst. The data shows that the Tafel slope of WS2/WO3 NR (82.7 mV dec⁻¹) is significantly lower than that of WO3 NR (112.5 mV dec⁻¹) and WS2/WO3 NB (195.5 mV dec⁻¹). Furthermore, the resistance of WS2/WO3 NR (397.7 Ω) is markedly decreased compared to those of WO3 NR (1816 Ω) and WS2/WO3 NB (3597 Ω). The results indicate that WS2/WO3 NR could be a great catalyst for electrochemical applications.

Triboelectric nanogenerators (TENGs) are promising energy-harvesting devices that generate electricity from mechanical energy. However, the electrical outputs of typical TENGs are limited because of the fundamental mechanism by which TENGs require a certain amount of space for contact-separation motion. Therefore, we developed an origami-based vertical/fluttering hybrid TENG (OVFH-TENG), which is the innovative structure that can generate electricity from both vertical movement and wind flow which is generated by vertical movement. It consists of a vertical TENG and a fluttering TENG where vertical TENGs can generate electricity and wind flow from mechanical input and the fluttering TENGs can generate electricity from the wind flow which is generated by its own operation process. Thus, OVFH-TENG can effectively harvest energy from vertical contact and fluttering motions with a single input. The optimized OVFH-TENG generated a 34.7% higher output than the general contact-separation TENG. Finally, the OVFH-TENG was able to light 180 LEDs, which was not possible with a general contact-separation TENG.