Kyung Hee University
  • Seoul, South Korea
Recent publications
Pancreatic cancer is one of the deadliest diseases with a poor prognosis and a five-survival rate. The STAT3 pathway is hyperactivated which contributes to the sustained proliferative signals in pancreatic cancer cells. We have isolated kaempferide (KF), an O-methylated flavonol, from the green propolis of Mimosa tenuiflora and examined its effect on two forms of cell death namely, apoptosis and paraptosis. KF significantly increased the cleavage of caspase-3 and PARP. It also downmodulated the expression of Alix (an intracellular inhibitor of paraptosis) and increased the expression of CHOP and ATF4 (transcription factors that promote paraptosis) indicating that KF promotes apoptosis as well as paraptosis. KF also increased intracellular reactive oxygen species (ROS) suggesting the perturbance of the redox state. N-acetylcysteine reverted the apoptosis- and paraptosis-inducing effects of KF. Some ROS inducers are known to suppress the STAT3 pathway and investigation revealed that KF downmodulates STAT3 and its upstream kinases (JAK1, JAK2, and Src). Additionally, KF also elevated the expression of SHP-1, a tyrosine phosphatase which is involved in the negative modulation of the STAT3 pathway. Knockdown of SHP-1 prevented KF-driven STAT3 inhibition. Altogether, KF has been identified as a promoter of apoptosis and paraptosis in pancreatic cancer cells through the elevation of ROS generation and SHP-1 expression.
The construction industry's digital transformation is lagging despite accelerated digital technology development necessitating business adaptation. While individual digital technologies have received some focus, comprehensive evaluations and recommendations concerning digital transformation remain scarce. Maturity assessment models comprehensively evaluate an organization's state, but construction enterprises have lacked emphasis on assessing digital transformation maturity. This study aims to develop a framework evaluating construction enterprises' digital transformation maturity degree. The framework comprises a digital transformation maturity assessment model facilitating expert individual assessments and an assessment method based on the optimized fairness-aware collective opinion generation paradigm generating collective assessments. The model explores digital transformation's influencing factors to construct a hierarchical model with dimensions, indicators, and levels. The paradigm reduces expert subjectivity and fairness concern's influence, improving collective assessment accuracy. Under this paradigm, Bayesian best-worst method determines indicator weights and a bi-objective optimization model aggregates expert opinions. We apply the framework to China State Construction Engineering Corporation's 3rd Bureau, verifying feasibility and validity, analyzing results and providing suggestions.
Aim Among numerous constituents of Panax ginseng , a constituent named Ginsenoside Rb1 (G‐Rb1) has been studied to diminish inflammation associated with diseases. This study investigated the anti‐inflammatory properties of G‐Rb1 on human dental pulp cells (hDPCs) exposed to lipopolysaccharide (LPS) and aimed to determine the underlying molecular mechanisms. Methodology The KEGG pathway analysis was performed after RNA sequencing in G‐Rb1‐ and LPS‐treated hDPCs. Reverse‐transcription polymerase chain reaction (RT–PCR) and western blot analysis were used for the assessment of cell adhesion molecules and inflammatory cytokines. Statistical analysis was performed with one‐way ANOVA and the Student–Newman–Keuls test. Results G‐Rb1 did not exhibit any cytotoxicity within the range of concentrations tested. However, it affected the levels of TNF‐α, IL‐6 and IL‐8, as these showed reduced levels with exposure to LPS. Additionally, less mRNA and protein expressions of vascular cell adhesion molecule‐1 (VCAM‐1) and intercellular adhesion molecule‐1 (ICAM‐1) were shown. With the presence of G‐Rb1, decreased levels of PI3K/Akt, phosphorylated IκBα and p65 were also observed. Furthermore, phosphorylated ERK and JNK by LPS were diminished within 15, 30 and 60 min of G‐Rb1 exposure; however, the expression of non‐phosphorylated ERK and JNK remained unchanged. Conclusions G‐Rb1 suppressed the LPS‐induced increase of cell adhesion molecules and inflammatory cytokines, while also inhibiting PI3K/Akt, phosphorylation of NF–κB transcription factors, ERK and JNK of MAPK signalling in hDPCs.
Cellulose was successfully extracted from green algae ( Ulva ohnoi ) by chemical treatments. The contents of holocellulose and α‐cellulose significantly increased from 37.6% and 3.3% to 82.5% and 63.3%, respectively, after whole extraction treatments. The extracted cellulose (EC) was mixed to polyvinyl alcohol (PVA) to prepare EC/PVA composite films with polyethylene glycol (PEG) or glycerol (GLY) as a plasticizer. The EC/3%PVA composite film showed the highest tensile strength of 54.42 MPa because of the high PVA content. Adding GLY steeply increased the elongation of the EC/3%PVA film from 3.12% to 126.76%, but adding PEG slightly decreased to 2.63%. The EC/1%PVA/PEG composite film showed the highest visible light transmittance of 84.47%, while the addition of zinc oxide nanoparticles (ZnO‐NPs) significantly improved UV‐blocking properties. In addition, the incorporation of ZnO‐NPs on the EC/PVA‐based composite films showed excellent antibacterial activity against six Gram‐positive and Gram‐negative bacteria.
Color indicator films incorporating aronia extract powder (AEP) and biopolymers like agar, carrageenan, and cellulose nanofiber (CNF) were developed to monitor kimchi freshness. AEP-containing films showed strong UV-barrier properties, and reduced light transmittance by 99.12 % for agar, 98.86 % for carrageenan, and 98.67 % for CNF-based films. All AEP-films exhibited high sensitivity to pH changes and vapor exposure to ammonia and acetic acid. Color change notably influenced by the polymer type, particularly evident with ammonia vapor exposure, especially in the AEP/carrageenan film. The chemical structure and thermal stability of the biopolymers remained unchanged after AEP-addition. Tensile strength increased by 24.2 % for AEP/CNF but decreased by 19.4 % for AEP/agar and 24.3 % for AEP/carrageenan films. AEP-containing films displayed strong antioxidant activity, with 99 % free radical scavenging in ABTS and ~ 80 % in DPPH assays. Alkalized AEP-indicator films were more effective in detecting color changes during kimchi packaging tests. Among the labels, alkalized AEP/agar film showed the most obvious color change from green-gray (fresh kimchi, pH 5.5, acidity 0.48 %) to pale brown (optimal fermentation, pH 4.6, acidity 0.70 %), and pale violet-brown (over-fermented, pH 3.80, acidity 1.35 %). Alkalized AEP-indicator films offer promising real-time detection of packed fermented foods like kimchi.
Lattice strain effects on the piezoelectric properties of crystalline ferroelectrics have been extensively studied for decades; however, the strain dependence of the piezoelectric properties at nano-level has yet to be investigated. Herein, a new overview of the super-strain of nanoporous polycrystalline ferroelectrics is reported for the first time using a nanoengineered barium calcium zirconium titanate composition (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCZT). Atomic-level investigations show that the controlled pore wall thickness contributes to highly strained lattice structures that also retain the crystal size at the optimal value (<30 nm), which is the primary contributor to high piezoelectricity. The strain field derived from geometric phase analysis at the atomic level and aberration-corrected high-resolution scanning transmission electron microscopy (STEM) yields of over 30% clearly show theoretical agreement with high piezoelectric properties. The uniqueness of this work is the simplicity of the synthesis; moreover the piezoresponse d33 becomes giant, at around 7500 pm V⁻¹. This response is an order of magnitude greater than that of lead zirconate titanate (PZT), which is known to be the most successful ferroelectric over the past 50 years. This concept utilizing nanoporous BCZT will be highly useful for a promising high-density electrolyte-free dielectric capacitor and generator for energy harvesting in the future.
Cable monitoring is essential for the prevention of machine malfunctions as machines are operated dynamically. Traditional methods of cable monitoring, conducted through portable or fixed devices, possess the inherent limitations in real‐time damage detection and precise location identification. Herein, a self‐powered, smart cable monitoring system is proposed, utilizing a triboelectric nanogenerator (TENG) as a sensor for the cable and an electric field energy harvester (EFEH) as a power source of the system. Also, the generated electrical outputs from the EFEH are theoretically and experimentally investigated according to the EFEH‐layer numbers, and the optimal number of EFEH‐layers is determined, generating an average electrical power of 2.04 mW. Through hybridization of TENG and EFEH, a synergistic effect is confirmed, resulting in a remarkable 155% enhancement in electrical energy. Consequently, the proposed system is endowed with self‐powered wireless communication capabilities. Additionally, employing a pre‐trained long short‐term memory‐based model, the system can predict the remaining lifespan of the cable with an accuracy rate of 93.7%. Considering these results, the proposed system demonstrates significant potential for industrial cable monitoring applications in the near future.
Nitric oxide (NO) promotes angiogenesis via various mechanisms; however, the effective transmission of NO in ischemic diseases is unclear. Herein, we tested whether NO-releasing nanofibers modulate therapeutic angiogenesis in an animal hindlimb ischemia model. Male wild-type C57BL/6 mice with surgically-induced hindlimb ischemia were treated with NO-releasing 3-methylaminopropyltrimethoxysilane (MAP3)–derived or control (i.e., non-NO-releasing) nanofibers, by applying them to the wound for 20 min, three times every two days. The amount of NO from the nanofiber into tissues was assessed by NO fluorometric assay. The activity of cGMP-dependent protein kinase (PKG) was determined by western blot analysis. Perfusion ratios were measured 2, 4, and 14 days after inducing ischemia using laser doppler imaging. On day 4, Immunohistochemistry (IHC) with F4/80 and gelatin zymography were performed. IHC with CD31 was performed on day 14. To determine the angiogenic potential of NO-releasing nanofibers, aorta-ring explants were treated with MAP3 or control fiber for 20 min, and the sprout lengths were examined after 6 days. As per either LDPI (Laser doppler perfusion image) ratio or CD31 capillary density measurement, angiogenesis in the ischemic hindlimb was improved in the MAP3 nanofiber group; further, the total nitrate/nitrite concentration in the adduct muscle increased. The number of macrophage infiltrations and matrix metalloproteinase-9 (MMP-9) activity decreased. Vasodilator-stimulated phosphoprotein (VASP), one of the major substrates for PKG, increased phosphorylation in the MAP3 group. MAP3 nanofiber or NO donor SNAP (s-nitroso-n-acetyl penicillamine)-treated aortic explants showed enhanced sprouting in an ex vivo aortic ring assay, which was partially abrogated by KT5823, a potent inhibitor of PKG. These findings suggest that the novel NO-releasing nanofiber, MAP3 activates PKG and promotes therapeutic angiogenesis in response to hindlimb ischemia.
The transfer of sperm cells to the egg cell during pollen germination and pollen tube (PT) growth is an essential process for successful reproduction in higher plants. In this process, proper cell wall assembly and remodeling is important for the normal growth of PTs. The functions of members of the Beta(β)-Expansin (EXPB) family, which encode proteins that loosen cell walls, remain poorly understood. Here, we performed a meta-expression analysis of all OsEXPBs sourced from anatomical samples comprising 22 tissues and/or organs. We identified five pollen-preferred OsEXPBs (i.e., OsEXPB1a, OsEXPB1b, OsEXPB9, OsEXPB10, and OsEXPB13). We also identified gene duplication events that specifically involved pollen-preferred OsEXPBs. Subcellular localization of the OsEXPB proteins was found to match well with their roles as cell wall loosening factors, and these were also visible when in transit through the secretory pathway. Further functional characterization of OsEXPBs using a gene editing system for all five targets after removing probable redundancy revealed that a quintuple expb1a;1b;9;10;13 mutant was sterile due to defects in PT elongation. Taken together, the results of our study suggest that the role of five pollen-preferred OsEXPBs that share common expression patterns is important for normal PT growth in rice.
Disclosure of intimate personal stories is an essential part of many marketplace conversations. In four experiments, this research investigates whether a social media influencer’s sharing of sensitive self-disclosure (i.e., personal information involving risk and vulnerability) can either enhance or diminish their persuasive impact. In Study 1, we find that the impact of sensitive self-disclosure on persuasion is contingent on the expected types of influencer-audience relationships (communal vs. exchange). An influencer’s sensitive self-disclosure enhances persuasion when the expected influencer-audience relationship is communal, characterized by emotional connection and mutual care. In exchange relationships, where the audience expects a more information-oriented approach, sensitive self-disclosure diminishes the influencer’s persuasive impact. Study 2 demonstrates that these effects are mediated by trust in communal relationships and by perceived violations of relationship norms in exchange relationships. Studies 3 and 4 identify the boundary conditions for these effects. Study 3 shows that extremely sensitive self-disclosure, which triggers a norm violation, reduces persuasion in a communal relationship. Study 4 reveals that solicited sensitive self-disclosure, which triggers conflicting norms, increases persuasion in an exchange relationship. This research widens the scope of persuasion literature by incorporating sensitive self-disclosure as a novel framework for understanding online influencer-audience persuasion.
Unprecedented land cover and land use (LCLU) changes can significantly alter the interactions between the land and atmosphere through biogeophysical processes, potentially changing the monsoon systems. Therefore, it is necessary to quantify the LCLU changes and the impacts on the climate in the East Asian monsoon (EAM) region, where significant human‐induced LCLU changes have occurred. This study quantified the LCLU transitions with fractional maps produced using the recently developed categorical LCLU maps from 1982 to 2015. In the five sub‐regions, identified as having undergone significant LCLU transitions, the relationships of the transitions with 2 m temperature were investigated using the ERA5‐Land reanalysis data. The quantified LCLU transitions revealed that, in northeastern China, the dominant trend was forests and grasslands changing into croplands. Moreover, in the marginal areas of Inner Mongolia, the transitions of grasslands to croplands and forests were evident. Croplands were mainly converted to forests in the Sichuan region. In particular, in the Sichuan region, the temperature increased by more than 0.04°C as the forests increased by 1%. In the marginal areas of Inner Mongolia, a 1% decrease in grasslands and a 1% increase in forests, respectively, were associated with a temperature rise of more than 0.03 and 0.04°C. The detected LCLU transitions affect the regional warming as demonstrated by correlation, regression and Granger‐causality analyses and the related biogeophysical processes. Thus, the identified LCLU transitions can change the regional climate and potentially affect the monsoon systems by changing the contrast in heat between land and ocean. This empirical research will not only provide insight into possible changes to climate by LCLU transitions in the EAM region, but it will also yield practical information for implementing land cover policies while considering the geographical characteristics of the region.
Previous studies have proposed alopecia areata (AA) as a potential outcome of COVID-19 infection among autoimmune diseases, yet the findings might be inconclusive and difficult to generalize due to limited sample sizes and evidence levels. Thus, we aimed to investigate in detail the long-term risk of AA following SARS-CoV-2 infection based on large, binational, general population-based cohort studies. Our study investigated the long-term AA risk after SARS-CoV-2 infection by analyzing bi-national, claim-based cohorts in South Korea and Japan: a Korean nationwide cohort (K-COV-N cohort; discovery cohort; total n = 10 027 506) and a Japanese claims-based cohort (JMDC cohort; validation cohort; total n = 12 218 680). AA was identified based on the international classification of diseases 10th revision code (L63) requiring at least three claims within 1 year. After exposure-driven propensity score matching, SARS-CoV-2 infection was associated with an increased risk of incident AA (aHR, 1.66; 95% CI, 1.38–1.99). This increased risk was observed and persisted for up to 6 months. A similar pattern was observed in the validation cohort. As modifiable factors, severe COVID-19 increased the risk of AA, whereas receiving two or more doses of the COVID-19 vaccine before infection decreased the risk of AA. Through a bi-national cohort study in South Korea and Japan, SARS-CoV-2 infection was associated with an elevated risk for incident AA in the aspect of long COVID.
Background Suicide is the second-leading cause of death among adolescents and is associated with clusters of suicides. Despite numerous studies on this preventable cause of death, the focus has primarily been on single nations and traditional statistical methods. Objective This study aims to develop a predictive model for adolescent suicidal thinking using multinational data sets and machine learning (ML). Methods We used data from the Korea Youth Risk Behavior Web-based Survey with 566,875 adolescents aged between 13 and 18 years and conducted external validation using the Youth Risk Behavior Survey with 103,874 adolescents and Norway’s University National General Survey with 19,574 adolescents. Several tree-based ML models were developed, and feature importance and Shapley additive explanations values were analyzed to identify risk factors for adolescent suicidal thinking. Results When trained on the Korea Youth Risk Behavior Web-based Survey data from South Korea with a 95% CI, the XGBoost model reported an area under the receiver operating characteristic (AUROC) curve of 90.06% (95% CI 89.97-90.16), displaying superior performance compared to other models. For external validation using the Youth Risk Behavior Survey data from the United States and the University National General Survey from Norway, the XGBoost model achieved AUROCs of 83.09% and 81.27%, respectively. Across all data sets, XGBoost consistently outperformed the other models with the highest AUROC score, and was selected as the optimal model. In terms of predictors of suicidal thinking, feelings of sadness and despair were the most influential, accounting for 57.4% of the impact, followed by stress status at 19.8%. This was followed by age (5.7%), household income (4%), academic achievement (3.4%), sex (2.1%), and others, which contributed less than 2% each. Conclusions This study used ML by integrating diverse data sets from 3 countries to address adolescent suicide. The findings highlight the important role of emotional health indicators in predicting suicidal thinking among adolescents. Specifically, sadness and despair were identified as the most significant predictors, followed by stressful conditions and age. These findings emphasize the critical need for early diagnosis and prevention of mental health issues during adolescence.
Major depressive disorder (MDD) is associated with T cell activation, but no studies have examined the combined effects of T cell activation and deficits in T regulatory (Treg) cells on the severity of acute phase MDD. Using flow cytometry, we determined the percentage and median fluorescence intensity of CD69, CD71, CD40L, and HLADR-bearing CD3+, CD4+, and CD8+ cells, and cannabinoid type 1 receptor (CB1), CD152 and GARP (glycoprotein A repetitions predominant)-bearing CD25+ FoxP3 T regulatory (Treg) cells in 30 MDD patients and 20 healthy controls in unstimulated and stimulated (anti-CD3/CD28) conditions. Based on cytokine levels, we assessed M1 macrophage, T helper (Th)-1 cell, immune-inflammatory response system (IRS), T cell growth, and neurotoxicity immune profiles. We found that the immune profiles (including IRS and neurotoxicity) were significantly predicted by decreased numbers of CD152 or GARP-bearing CD25+ FoxP3 cells or CD152 and GARP expression in combination with increases in activated T cells (especially CD8+ CD40L+ percentage and expression). MDD patients showed significantly increased numbers of CD3+ CD71+, CD3+ CD40L+, CD4+ CD71+, CD4+ CD40L+, CD4+ HLADR+, and CD8+ HLADR+ T cells, increased CD3+ CD71+, CD4+ CD71+ and CD4+ HLADR+ expression, and lowered CD25+ FoxP3 expression and CD25+ FoxP+ CB1+ numbers as compared with controls. The Hamilton Depression Rating Scale score was strongly predicted (between 30 and 40% of its variance) by a lower number of CB1 or GARP-bearing Treg cells and one or more activated T cell subtypes (especially CD8+ CD40L+). In conclusion, increased T helper and cytotoxic cell activation along with decreased Treg homeostatic defenses are important parts of MDD that lead to enhanced immune responses and, as a result, neuroimmunotoxicity.
We designed and synthesized two blue fluorescent dopants, N1,N7-bis(4-(tert-butyl)-2,6-dimethylphenyl)-9-isopropyl-5,5-dimethyl-N1,N7-diphenyl-4,5,6a1,11a1-tetrahydro-3H-benzo[cd]pyrene-1,7-diamine (DMP-BP) and N1,N7-bis(dibenzo[b,d]furan-4-yl)-9-isopropyl-N1,N7-bis(4-isopropylphenyl)-5,5-dimethyl-4,5-dihydro-3H-benzo[cd]pyrene-1,7-diamine (DBF-BP), by introducing alkylated N-phenylaniline and alkylated dibenzo[b,d]furan-amine as side groups, based on the pyrene chromophore, 3H-benzo[cd]pyrene (BP) core. When used as dopants in OLED devices, both DMP-BP and DBF-BP exhibited device performances with current efficiencies of over 9 cd A⁻¹ and full width at half maximum (FWHM) values of less than 44 nm. Both materials achieved an excellent device lifetime with LT95 values exceeding 200 hours. Particularly, the DBF-BP device demonstrated a maximum external quantum efficiency of 8.03% and an EL spectrum with a narrow FWHM of 42 nm. The LT95 lifetime of the DBF-BP device was 207 hours, corresponding to an outstanding device lifetime of over 12 000 hours when extrapolated to LT50.
Light‐emitting transistors (LETs) are a remarkable, emerging class of electronic devices that combine the switching function of field‐effect transistors (FETs) and the light‐emitting function of light‐emitting diodes (LEDs). In order to achieve efficient light emission, effective electron and hole injection from source and drain electrodes is necessary. Various strategies have been introduced to accomplish this, such as incorporating asymmetric electrodes or charge injection layers during device fabrication. These approaches have inevitably introduced complexity in the device fabrication process. Herein, light‐emitting electrochemical transistors (LECTs) are demonstrated that combine principles of electrochemistry and optoelectronics to achieve multi‐functionality in a simple device architecture. Hybrid polyelectrolytes, poly(9‐vinylcarbazolesulfonate)‐ lithium and copper (II) salts (PVK‐Li and PVK‐Cu) incorporating Li⁺ ion and Cu²⁺ ions are added at variable concentrations to the organic emitting layer of LECTs to effect electrochemical p‐type doping. This electrochemical doping approach yielded improvements in electrical and optical performances including mobilities, brightnesses, and external quantum efficiency of the LECTs. The dynamics of how charges including ions, electrons, and holes move and interact are discussed in the device to facilitate emissive charge carrier recombination and light emission. This investigation provides valuable insights into the realms of both electrochemistry and optoelectronics.
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5,562 members
Ayaz Anwar
  • Department of Applied Chemistry
Taegoo Terry Kim
  • Department of Global Eminence
Nam Minh Nguyen
  • School of Medicine
Ashwini Kumar Arya
  • Department of Electronic Engineering
Sang Hyuk Im
  • Department of Chemical Engineering(Graduate)
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Seoul, South Korea