229 results on '"Seulgi Lee"'
Search Results
102. Ultra-small ZnS quantum dots embedded in N-doped carbon matrix for high-performance Li-ion battery anode
- Author
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Seulgi Lee, Sungjin Kim, Jihyeon Gim, Muhammad Hilmy Alfaruqi, Seokhun Kim, Vinod Mathew, Balaji Sambandam, JangYeon Hwang, and Jaekook Kim
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Mechanics of Materials ,Mechanical Engineering ,Ceramics and Composites ,Industrial and Manufacturing Engineering - Published
- 2022
103. A Study on the Effects of Local Resident’s Social-Cultural Influence and Environmental Impact on Festival Satisfaction and Local Pride : In case of the 3rd Suseong Lake Festival
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Dong-Jin Kim and Seulgi Lee
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Cultural influence ,Pride ,media_common.quotation_subject ,General Engineering ,General Earth and Planetary Sciences ,Environmental impact assessment ,Sociology ,Socioeconomics ,General Environmental Science ,media_common - Published
- 2018
104. Antidepressant Effects of Vaccinium bracteatum via Protection Against Hydrogen Peroxide-Induced Oxidative Stress and Apoptosis
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Young Ran Kim, Ara Jo, Jawon Shin, Dool-Ri Oh, Eun-Jin Choi, Seulgi Lee, Chul Yung Choi, Yu-Jin Kim, Jaeyong Kim, and Huwon Kang
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0301 basic medicine ,Programmed cell death ,biology ,Chemistry ,Cytochrome c ,General Medicine ,Pharmacology ,medicine.disease_cause ,Malondialdehyde ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Complementary and alternative medicine ,Catalase ,Apoptosis ,biology.protein ,medicine ,Monoamine oxidase A ,Serotonin transporter ,Oxidative stress - Abstract
The present study evaluates the anti-oxidative stress activity of Vaccinium bracteatum Thunb. fruit extract (VBFW) to identify the mechanisms responsible for its antidepressant-like effects. To evaluate the antidepressant and anti-oxidant effects of VBFW, malondialdehyde (MDA), serotonin transporter (SERT), and monoamine oxidase A (MAO-A) levels were measured in a mouse model of chronic restraint stress (CRS). The underlying mechanisms preventing oxidative stress and neuronal apoptosis were investigated using in vitro models of hydrogen peroxide (H2O[Formula: see text]-induced neuronal damage. The results showed that VBFW treatment (200[Formula: see text]mg/kg) significantly reduced MDA, SERT, and MAO-A levels in the prefrontal cortex of CRS mice. Furthermore, VBFW (30[Formula: see text][Formula: see text]g/mL) exhibited protective effects against H2O2-induced cell death via inhibition of the H2O2-induced increase in Bax and decrease in Bcl-2 levels within the mitochondria of SH-SY5Y cells. Furthermore, VBFW (10 and 30[Formula: see text][Formula: see text]g/mL) exerted protective effects against H2O2-induced cell death through inhibition of key mitochondria-associated apoptotic proteins such as cytochrome c, caspase-3 and PARP. Additionally, VBFW (10 and 30[Formula: see text][Formula: see text]g/mL) could improve the activity of anti-oxidant enzymes (such as SOD and catalase) in H2O2-treated SH-SY5Y cells. These results suggest that the antidepressant and anti-oxidant effects of VBFW might be mediated by the regulation of SERT and MAO-A, and possibly associated with regulation of oxidative stress-induced apoptosis.
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- 2018
105. Comparison of Anti-oxidative Activity in a Single Serving Size of the Commercial Coffees and Teas
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Gune-Hee Jo, Seulgi Lee, Taehun Kim, Sun Hye Bing, Jin Woo Seo, Eui-Ra Kwon, Jong Im Kim, Joon Sig Choi, and Jae-Myean Lee
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chemistry.chemical_classification ,Reactive oxygen species ,Antioxidant ,biology ,medicine.medical_treatment ,food and beverages ,Peppermint tea ,biology.organism_classification ,Ascorbic acid ,medicine.disease_cause ,Polygonatum odoratum ,chemistry.chemical_compound ,chemistry ,Polyphenol ,medicine ,Food science ,Caffeine ,Oxidative stress - Abstract
The aim of this work was to study the comparison of anti-oxidative activity in a single serving size of commercial coffees and teas. Commercial regular coffees and teas, including, brand regular coffees (BCA, BCB, BCC, BCD, and BCE), green tea (GTA, GTB, GTC, and GTD), black tea (BTA, BTB, and BTC), pu-erh tea (PTA, PTB, and PTC), chamomile tea (CTA, CTB, and CTC), peppermint tea (PA, PB, and PC), polygonatum odoratum tea (POTA, POTB, and POTC), and jujube tea (JTA, JTB, and JTC) were assayed for the levels of ascorbic acid, caffeine, total content of polyphenols and flavonoids, and ability to scavenge free radicals, using two in vitro antioxidant assays. The scavenging abilities of BCA and BCC were 664.91 ± 48.87 mg ascorbic acid equivalent/serving size and 624.36 ± 16.18 mg ascorbic acid equivalent/serving size, respectively. The four beverage samples (BCA, BCC, GTD, and BTA) significantly reduced the production of reactive oxygen species (ROS) and intracellular oxidative stress induced by H2O2. These results suggest that the beverages possess significant radical scavenging ability, which may be due to the presence of antioxidants. Furthermore, the significant reducing level of ROS evidences the potential antioxidant effects of these beverages in human cells.
- Published
- 2017
106. Ultrasmooth Organic Films Via Efficient Aggregation Suppression by a Low-Vacuum Physical Vapor Deposition
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Jin Ho Lee, Hee Cheul Choi, Soyoung Kim, Youngkwan Yoon, and Seulgi Lee
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Technology ,Materials science ,Diffusion ,Nucleation ,vapor deposition ,Substrate (electronics) ,Chemical vapor deposition ,Article ,Adsorption ,organic films ,aggregation suppression ,cooling rate ,Deposition (phase transition) ,General Materials Science ,Thin film ,Microscopy ,QC120-168.85 ,QH201-278.5 ,Engineering (General). Civil engineering (General) ,TK1-9971 ,Descriptive and experimental mechanics ,Chemical engineering ,Physical vapor deposition ,Electrical engineering. Electronics. Nuclear engineering ,TA1-2040 - Abstract
Organic thin films with smooth surfaces are mandated for high-performance organic electronic devices. Abrupt nucleation and aggregation during film formation are two main factors that forbid smooth surfaces. Here, we report a simple fast cooling (FC) adapted physical vapor deposition (FCPVD) method to produce ultrasmooth organic thin films through effectively suppressing the aggregation of adsorbed molecules. We have found that thermal energy control is essential for the spread of molecules on a substrate by diffusion and it prohibits the unwanted nucleation of adsorbed molecules. FCPVD is employed for cooling the horizontal tube-type organic vapor deposition setup to effectively remove thermal energy applied to adsorbed molecules on a substrate. The organic thin films prepared using the FCPVD method have remarkably ultrasmooth surfaces with less than 0.4 nm root mean square (RMS) roughness on various substrates, even in a low vacuum, which is highly comparable to the ones prepared using conventional high-vacuum deposition methods. Our results provide a deeper understanding of the role of thermal energy employed to substrates during organic film growth using the PVD process and pave the way for cost-effective and high-performance organic devices.
- Published
- 2021
107. Inositol pyrophosphates as multifaceted metabolites in the regulation of mammalian signaling networks
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Seung Eun Park, Seyun Kim, Seulgi Lee, and Seung Ju Park
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0301 basic medicine ,lcsh:R5-920 ,Cell signaling ,PPIP5K ,biology ,Chemistry ,Saccharomyces cerevisiae ,Metabolism ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,IP6K ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,lcsh:Biology (General) ,Biochemistry ,inositol pyrophosphate ,cell signaling ,Phosphorylation ,Animal Science and Zoology ,Inositol ,lcsh:Medicine (General) ,lcsh:QH301-705.5 - Abstract
Inositol pyrophosphates (PP-IPs) such as 5-diphosphoinositol pentakisphosphate (5-IP7) are inositol metabolites with high-energy phosphoanhydride bonds. The formation of PP-IPs is catalyzed by two groups of enzymes, the IP6 kinases and the PPIP5 kinases, which both phosphorylate inositol hexakisphosphate (IP6). In mammals, PP-IPs are implicated in diverse biological phenomena including cellular growth, vesicular trafficking, apoptosis, and metabolic homeostasis. Mechanistically, all the diverse actions of PP-IPs proceed in one of two ways: the PP-IPs modulate the activity of their target proteins either through allosteric binding or protein pyrophosphorylation. In this review, we highlight recent advances in our understanding of the pleiotropic functions of the mammalian PP-IPs and the metabolic enzymes that produce them. We also discuss some future challenges in the exploration of areas where PP-IPs play important but unknown roles in physiology and disease.
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- 2017
108. Amphiphilic Peptide Nanorods Based on Oligo-Phenylalanine as a Biocompatible Drug Carrier
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Seulgi Lee, Kyoung-Seok Ryu, Joon Sig Choi, and Su Jeong Song
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Curcumin ,Phenylalanine ,Biomedical Engineering ,Pharmaceutical Science ,Antineoplastic Agents ,Apoptosis ,Biocompatible Materials ,Bioengineering ,Peptide ,02 engineering and technology ,010402 general chemistry ,Hemolysis ,01 natural sciences ,Surface-Active Agents ,chemistry.chemical_compound ,Cell Line, Tumor ,Neoplasms ,Amphiphile ,Animals ,Humans ,Cytotoxicity ,Zebrafish ,Histidine ,Essential amino acid ,Pharmacology ,chemistry.chemical_classification ,Drug Carriers ,Nanotubes ,Chemistry ,Organic Chemistry ,Nile red ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Biochemistry ,Biophysics ,0210 nano-technology ,Drug carrier ,Oligopeptides ,HeLa Cells ,Biotechnology - Abstract
Peptide nanostructure has been widely explored for drug-delivery systems in recent studies. Peptides possess comparatively lower cytotoxicity and are more efficient than polymeric carriers. Here, we propose a peptide nanorod system, composed of an amphiphilic oligo-peptide RH3F8 (Arg–His3–Phe8), as a drug-delivery carrier. Arginine is an essential amino acid in typical cell-penetration peptides, and histidine induces endo- and lysosomal escape because of its proton sponge effect. Phenylalanine is introduced to provide rich hydrophobicity for stable self-assembly and drug encapsulation. The self-assembled structure of RH3F8 showed nanorod-shaped morphology, positive surface charge, and retained formation in water for 35 days. RH3F8, labeled with Nile Red, showed high cellar uptake and accumulation in both cytoplasm and nucleus. The RH3F8 nanorods demonstrated negligible cytotoxicity, as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and hemolys...
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- 2017
109. Patient Navigator Facilitated Text Messaging Intervention Improves Linkage to care in Viral Hepatitis B: A Pilot Study
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Soonsik Kim, Joseph McMenamin, Soyoung Yoon, Seulgi Lee, and Chul S. Hyun
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Linkage (software) ,Patient Navigator ,020205 medical informatics ,business.industry ,Viral hepatitis b ,02 engineering and technology ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,Intervention (counseling) ,0202 electrical engineering, electronic engineering, information engineering ,Text messaging ,Medicine ,030212 general & internal medicine ,Medical emergency ,business - Published
- 2017
110. Evaluation of an Improved U.S. Food and Drug Administration Method for the Detection of Cyclospora cayetanensis in Produce Using Real-Time PCR
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Seulgi Lee, Helen R. Murphy, and Alexandre J. da Silva
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0301 basic medicine ,Dna template ,030231 tropical medicine ,030106 microbiology ,Food Contamination ,Improved method ,Real-Time Polymerase Chain Reaction ,Microbiology ,Cyclospora cayetanensis ,Food and drug administration ,03 medical and health sciences ,0302 clinical medicine ,TaqMan ,Animals ,Humans ,Cyclosporiasis ,biology ,United States Food and Drug Administration ,Oocysts ,Amplicon ,biology.organism_classification ,Virology ,United States ,Cyclospora ,Real-time polymerase chain reaction ,Nested polymerase chain reaction ,Food Science - Abstract
Cyclospora cayetanensis is a protozoan parasite that causes human diarrheal disease associated with the consumption of fresh produce or water contaminated with C. cayetanensis oocysts. In the United States, foodborne outbreaks of cyclosporiasis have been linked to various types of imported fresh produce, including cilantro and raspberries. An improved method was developed for identification of C. cayetanensis in produce at the U.S. Food and Drug Administration. The method relies on a 0.1% Alconox produce wash solution for efficient recovery of oocysts, a commercial kit for DNA template preparation, and an optimized TaqMan real-time PCR assay with an internal amplification control for molecular detection of the parasite. A single laboratory validation study was performed to assess the method's performance and compare the optimized TaqMan real-time PCR assay and a reference nested PCR assay by examining 128 samples. The samples consisted of 25 g of cilantro or 50 g of raspberries seeded with 0, 5, 10, or 200 C. cayetanensis oocysts. Detection rates for cilantro seeded with 5 and 10 oocysts were 50.0 and 87.5%, respectively, with the real-time PCR assay and 43.7 and 94.8%, respectively, with the nested PCR assay. Detection rates for raspberries seeded with 5 and 10 oocysts were 25.0 and 75.0%, respectively, with the real-time PCR assay and 18.8 and 68.8%, respectively, with the nested PCR assay. All unseeded samples were negative, and all samples seeded with 200 oocysts were positive. Detection rates using the two PCR methods were statistically similar, but the real-time PCR assay is less laborious and less prone to amplicon contamination and allows monitoring of amplification and analysis of results, making it more attractive to diagnostic testing laboratories. The improved sample preparation steps and the TaqMan real-time PCR assay provide a robust, streamlined, and rapid analytical procedure for surveillance, outbreak response, and regulatory testing of foods for detection of C. cayetanensis.
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- 2017
111. Knowledge, Awareness, and Prevention of Hepatitis B Virus Infection Among Korean American Parents
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Joseph McMenamin, William R. Ventura, Seulgi Lee, and Sarah Hyun
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Gerontology ,Parents ,Adult ,Male ,medicine.medical_specialty ,Korean Americans ,Health Knowledge, Attitudes, Practice ,Epidemiology ,media_common.quotation_subject ,New York ,Health literacy ,Chronic hepatitis B ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Risk Factors ,Republic of Korea ,medicine ,Humans ,Mass Screening ,Hepatitis B Vaccines ,030212 general & internal medicine ,Young adult ,Children ,media_common ,Aged ,Hepatitis ,Aged, 80 and over ,Original Paper ,Asian ,business.industry ,Public health ,Public Health, Environmental and Occupational Health ,Hepatitis B ,Middle Aged ,medicine.disease ,Vaccination ,Health education ,Socioeconomic Factors ,Family medicine ,030211 gastroenterology & hepatology ,Female ,business ,Seriousness - Abstract
Hepatitis B (HB) affects 240 million people around the world, and children and young adults make up a large proportion of the infected population. Approximately 1 million people die from HB each year. Despite the seriousness of HB and its complications, many are poorly linked to clinical care. A lack of health literacy may be a critical barrier hindering access to HB care for adults as well as children in these populations. We, therefore, performed a survey to assess the level of knowledge of HB among Korean American parents. The survey was conducted on 521 Korean American adults who attended community-based HB awareness campaigns held at various locations throughout the metropolitan New York area between January 2015 and November 2016. Of these, 296 parents, who had children between ages 1 and 30, were identified. All participants were asked a series of questions regarding various aspects of HB and were evaluated on the basis of their awareness on each subject. A separate questionnaire was also employed to obtain demographic characteristics of the participants. The study revealed a significant deficit of knowledge of HB in most aspects the survey evaluated. Although the majority of the participants knew that HB is a liver disease, and many of them had been screened for HB, they had a poor understanding of vaccination, screening, their own HB status, modes of HBV transmission, and the consequences and treatment of HB. The participants also had a low level of awareness of their own children’s HB status. This study demonstrates a low level of knowledge of HB among Korean American parents electing to attend a hepatitis education program. In addition, many parents are not aware of their children’s screening and immune (or non-immune) status. The lack of health literacy may contribute to poor health access in HB care, not only in adults but also in children. This suggests an urgent need for education on HB in Korean American parents as well as in young children.
- Published
- 2017
112. Apoptin Gene Delivery by the Functionalized Polyamidoamine Dendrimer Derivatives Induces Cell Death of U87-MG Glioblastoma Cells
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Jin Han, Seulgi Lee, Yoonhee Bae, Joon Sig Choi, Kyung Soo Ko, and Hyangshuk Rhim
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0301 basic medicine ,Dendrimers ,Pharmaceutical Science ,Apoptosis ,Gene delivery ,Biology ,Arginine ,Transfection ,Flow cytometry ,03 medical and health sciences ,Cell Line, Tumor ,Glioma ,medicine ,Humans ,Histidine ,Viability assay ,Cytotoxicity ,Cells, Cultured ,medicine.diagnostic_test ,Brain Neoplasms ,Lysine ,DNA ,Genetic Therapy ,Cell cycle ,medicine.disease ,Molecular biology ,030104 developmental biology ,Capsid Proteins ,Glioblastoma - Abstract
Malignant glioma is the most common and aggressive form of primary brain tumor in adults. In this study, we describe the efficacy of nonviral gene delivery carriers, histidine- and arginine- or histidine- and lysine-grafted polyamidoamine (PAMAM) dendrimers (PAMAM-H-R and PAMAM-H-K), in delivering a therapeutic and a tumor-selective killer gene, apoptin, using human glioma cells (U87-MG) and newborn human dermal fibroblast cells. We analyzed transfection efficiency using luciferase and a plasmid DNA encoding for enhanced green fluorescent protein and assessed cell viability in both cells. The results show that transfection efficiency of PAMAM-H-R and PAMAM-H-K was greatly increased compared with that of native PAMAM. Moreover, among PAMAM derivatives, cytotoxicity of PAMAM-H-K was very low. We treated both cells with complexes of PAMAM-H-R or PAMAM-H-K and apoptin and analyzed their cellular uptake by flow cytometry and localization by confocal microscopy. Furthermore, cell cycle distribution, caspase 3 activity assay, and JC-1 analysis showed cell death induced by apoptin in U87-MG cells. The present study demonstrates that a PAMAM-H-R/apoptin complex is an effective gene carrier system in glioma cell culture.
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- 2017
113. Effect of changes in head postures during use of laptops on muscle activity of the neck and trunk
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Yijung Chung, Seulgi Lee, and Yeseb Lee
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medicine.diagnostic_test ,business.industry ,05 social sciences ,Anatomy ,Electromyography ,Trunk ,Neck muscles ,03 medical and health sciences ,0302 clinical medicine ,Head (vessel) ,Medicine ,0501 psychology and cognitive sciences ,Muscle activity ,business ,050107 human factors ,030217 neurology & neurosurgery - Published
- 2017
114. A study of the authenticity of traditional cultural products: focus on Korean, Chinese, and Japanese consumers
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Heeju Chae, Eunju Ko, Seulgi Lee, and Chieko Minami
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Consumption (economics) ,Ethnocentrism ,05 social sciences ,Advertising ,Commercialization ,Purchasing ,Focus (linguistics) ,0502 economics and business ,Cultural goods ,050211 marketing ,Sociology ,Marketing ,China ,050203 business & management - Abstract
Countries’ specific traditional cultures are becoming popular subjects for commercialization. The research discussed here focuses on “traditional cultural products” (TCPs) and investigates consumer attitudes and behaviors with respect to cultural aspects. Consumer attitudes and the purposes of consumption within the commercialization of traditional cultures encircling cultural authenticity are scrutinized. Results show that while the personal factor of consumers’ open-mindedness toward other cultures positively influences their attitudes toward TCPs, the ethnocentrism and familiarity of the culture have negative effects. This analysis of the purchasing purpose model of culture products among three countries – Korea, China, and Japan – shows that positive attitudes toward the aesthetic elements are crucial in raising the will to consume traditional cultural goods. Moreover, Korean and Chinese consumers have significantly considered the cultural/historical authenticity of goods whereas Japanese cons...
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- 2017
115. Clinical characteristics and associated factors of canal switch in benign paroxysmal positional vertigo
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Geonho Lee, Seong-Jun Choi, Bong Jik Kim, Hee-Sung Park, Jin Woong Choi, and Seulgi Lee
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Adult ,Male ,medicine.medical_specialty ,Benign paroxysmal positional vertigo ,Multivariate analysis ,Demographics ,Gastroenterology ,Lateral canal ,Patient Positioning ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,otorhinolaryngologic diseases ,Medicine ,Humans ,Benign Paroxysmal Positional Vertigo ,Physical Therapy Modalities ,Aged ,business.industry ,General Neuroscience ,Middle Aged ,medicine.disease ,Sensory Systems ,Semicircular Canals ,Otorhinolaryngology ,Etiology ,Female ,sense organs ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
BACKGROUND Canal switch benign paroxysmal positional vertigo (CS-BPPV) is a transition of BPPV involving one canal to another canal during or after canalith repositioning procedures (CRP). OBJECTIVE To investigate the clinical characteristics of CS-BPPV and its associated factors. METHODS The data of 2,303 patients with BPPV involving the lateral canal (LC) or posterior canal (PC) were retrospectively analyzed. Demographics, etiologies, and various clinical parameters related to CRP were compared between patients with and without CS-BPPV. RESULTS Sixty-eight (2.95%) patients exhibited CS-BPPV. For patients with CS-BPPV from the PC to the LC, as well as those with CS-BPPV from the LC to the PC, the CRP number for the original canal in CS-BPPV was significantly greater than in non-CS-BPPV (P = 0.002). More CRP cycles were required to treat CS-BPPV than non-CS-BPPV involving the same canal. Multivariate analysis showed that CS-BPPV from the LC to the PC was significantly associated with multiple CRP cycles and use of the Gufoni maneuver (P = 0.038 and P
- Published
- 2019
116. Long term outcome of a community-based hepatitis B awareness campaign: eight-year follow-up on linkage to care (LTC) in HBV infected individuals
- Author
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Joseph McMenamin, Chul S. Hyun, Okhyun Ko, and Seulgi Lee
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Health Knowledge, Attitudes, Practice ,Hepatitis B virus ,Korean Americans ,030106 microbiology ,Population ,Emigrants and Immigrants ,medicine.disease_cause ,Chronic hepatitis B ,Health Services Accessibility ,lcsh:Infectious and parasitic diseases ,03 medical and health sciences ,0302 clinical medicine ,Hepatitis B, Chronic ,Linkage-to-care ,Community hepatitis B campaign ,Health care ,medicine ,Prevalence ,Humans ,Mass Screening ,lcsh:RC109-216 ,030212 general & internal medicine ,education ,Aged ,Hepatitis ,education.field_of_study ,Health disparity ,Insurance, Health ,Asian ,New Jersey ,business.industry ,Hepatitis B ,Middle Aged ,medicine.disease ,Health equity ,Infectious Diseases ,Family medicine ,Cohort ,Health education ,Female ,business ,Follow-Up Studies ,Research Article - Abstract
Background Chronic hepatitis B (CHB) is a major cause of liver-related morbidity and mortality. High HBV prevalence in immigrants and ethnic minorities and numerous barriers to healthcare access are associated with serious health disparities in the United States. Reportedly, self-awareness of HBV infection is low, suggesting a greater need for effective screening and education. Further, low levels of linkage to care (LTC) (completion of a first doctor’s visit after the diagnosis of chronic HBV infection) may be responsible for the lack of engagement over the continuum of care and for needed services. Methods Demographics and survey data were obtained from 97 Korean American adults chronically infected with HBV, initially identified through a series of community screening events in northern New Jersey between Dec. 2009 and June 2015. Eight year follow-up on these HBV-infected individuals was obtained to determine their access to care, and thus the efficacy of a campaign to improve LTC. The participants’ self-awareness of HBV infection and other factors for LTC were also evaluated. Results Of a total of 97 HBV-infected participants (age range 30 to 79), 74 were aware of their infections at screening. The remaining 23 had been unaware of their infections until screening. Eight years after the campaign, some 66 of these 97 individuals accessed care (LTC rate 68%). Health insurance status, presence or absence of symptoms and level of knowledge of CHB were among the most significant factors in LTC. Conclusion A community-based hepatitis B screening and education campaign can be instrumental in prompting HBV infected individuals to access care, as demonstrated in the cumulative increase in LTC in our cohort. Despite many years of awareness of HBV infection, many are not accessing care owing to a lack of health insurance, suggesting a pressing need for advocacy and health education to improve access to affordable coverage in the Asian American population. Community efforts and strategies similar to the ones employed in the current study may serve as a model to improve the engagement of HBV-infected individuals in high risk immigrant populations.
- Published
- 2019
117. Supplementary Information from Facile synthesis of reduced graphene oxide by modified Hummer's method as anode material for Li-, Na- and K-ion secondary batteries
- Author
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Jeonggeun Jo, Seulgi Lee, Jihyeon Gim, Jinju Song, Sungjin Kim, Mathew, Vinod, Alfaruqi, Muhammad Hilmy, Seokhun Kim, Jinsub Lim, and Jaekook Kim
- Abstract
CV profile
- Published
- 2019
- Full Text
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118. Study of Natural Language Processing for Collecting Cyber Threat Intelligence Using SyntaxNet
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Junhyung Park, Minseok Kim, Seulgi Lee, MoonSeog Jun, Nak Hyun Kim, Hyeisun Cho, and Byungik Kim
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Computer science ,business.industry ,computer.software_genre ,Security token ,Domain (software engineering) ,Indicator of compromise ,Resource (project management) ,Code (cryptography) ,Malware ,Artificial intelligence ,business ,computer ,Natural language processing ,Test data ,Vulnerability (computing) - Abstract
The importance of cyberattack analysis has increased for responding quickly and effectively to cyber threats, which are becoming more intelligent. Analyzing cyberattacks requires examining the resources (malicious code, IP, domain, vulnerability, etc.) used in the cyberattack, similarity between the resources, attack technique, attack target, and activity time. It is also necessary to collect the data to be used in the analysis of a cyberattack. The formatted data shared through a specific format can be collected according to that format. However, it is difficult to collect the data when the cyberattack analyst generates the analysis result in unformatted data in the form of a report. As a way to solve this problem, this paper proposes the technique of using natural language processing technology to collect the Indicator of Compromise (IoC) in the form of a report. We have outlined the technologies and designed the processing procedure needed to extract resource data (IoC) abused in cyberattacks and the attack techniques (TTPs) included in the report based on the natural language processing model (SyntaxNet) disclosed as open source by Google. Extracting 345,364 token data based on 190 malware(and cyberattack) analysis reports and testing of them by dividing them into learning and test data in the ratio of about 9:1 resulted in extraction of IoC data at an average f1-score of 76%.
- Published
- 2019
119. Multifractality of fine bubbles in turbulence due to lift
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Seulgi Lee, Gihun Shim, Changhoon Lee, and Itzhak Fouxon
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Fluid Flow and Transfer Processes ,Physics ,Turbulence ,Computational Mechanics ,Equations of motion ,Mechanics ,01 natural sciences ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,Lift (force) ,Modeling and Simulation ,0103 physical sciences ,Quantitative Biology::Populations and Evolution ,010306 general physics ,Cluster analysis - Abstract
An equation of motion is derived for isolated bubbles in turbulence, an equation similar to that governing phytoplankton. Simulations show the clustering of bubbles in vertical columns.
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- 2018
120. Super-contrast-enhanced darkfield imaging of nano objects through null ellipsometry
- Author
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Jungchul Lee, Seongkeun Cho, Hyungu Kim, Seulgi Lee, Joo Won-Don, Janghwi Lee, Sangwoo Bae, Taehyun Kim, and Akinori Ohkubo
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Materials science ,Null (radio) ,business.industry ,Magnification ,Polarizer ,01 natural sciences ,Noise (electronics) ,Atomic and Molecular Physics, and Optics ,law.invention ,Photodiode ,010309 optics ,Optics ,law ,Ellipsometry ,0103 physical sciences ,Wafer ,010306 general physics ,business ,Nanoscopic scale - Abstract
We rediscover the null ellipsometry principle for an outstanding image-contrast enhancement method for darkfield imaging. Simply by adding polarizers, compensators, and a photodiode sensor to a conventional darkfield imaging system and applying the null principle, Si nano-cylinder structures as small as D20 nm (H20 nm) on non-patterned wafer, and gap defects as small as 14.6 nm and bridge defects as small as 21.9 nm on 40 nm line and 40 nm space patterns (H40 nm), which are invisible in conventional darkfield imaging, can be distinguished from scattered noise. To the best of our knowledge, no method has been successful for identifying such small non-metal (silicon) nanoscale objects with such low magnification (×20) optics.
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- 2018
121. Improved lithium storage in Fe2O3 nano-particles over nano-rods morphology
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Alok Kumar Rai, Satendra Pal Singh, Sungjin Kim, Jay Singh, Jaekook Kim, and Seulgi Lee
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Materials science ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Anode ,chemistry ,Chemical engineering ,Electrode ,Hydrothermal synthesis ,Particle ,General Materials Science ,Lithium ,0210 nano-technology - Abstract
Fe2O3 nano-particles and nano-rods were synthesized by hydrothermal synthesis method under different reaction conditions and then applied as anode materials for Lithium ion batteries. Microstructural analysis confirmed these two shapes and structures for Fe2O3 samples. It was noticed that the electrochemical performance of Fe2O3 is highly influenced by its particle morphology. Unexpectedly, Fe2O3 nano-particles exhibit excellent electrochemical performances as compared to nano-rods morphology, which may be due to the least micro strain, high stability of nano-particles structure, small agglomerations, etc. It is believed that the nano-particles structure provides extra reaction sites to accommodate large Li-ions, shorten the Li-ion diffusion paths to improve the electronic conductivity and offers large electrolyte/electrode contact area for fast electrochemical reactions. In contrast, the nano-rods morphology could not hold its structural integrity during the lithiation/de-lithiation reactions and collapsed only after certain number of cycles giving rise to poor electrochemical performances, as confirmed by post cycling ex-situ studies. More precisely, Fe2O3 nano-particles electrode delivered the excellent reversible capacity of 1125 mAh g−1 and 1007 mAh g−1 at 1C and 4C after 100 and 80 cycles, respectively, while Fe2O3 nano-rods exhibit only 113.5 mAh g−1 at 1C and 326.7 mAh g−1 at 4C.
- Published
- 2021
122. Fabrication of 1D mesoporous NiO nano-rods as high capacity and long-life anode material for lithium ion batteries
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Satendra Pal Singh, Sungjin Kim, Alok Kumar Rai, Jay Singh, Jaekook Kim, and Seulgi Lee
- Subjects
Materials science ,Mechanical Engineering ,Non-blocking I/O ,Metals and Alloys ,Oxide ,Nanoparticle ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Anode ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Mechanics of Materials ,Electrode ,Materials Chemistry ,0210 nano-technology ,Mesoporous material - Abstract
In the present work, one–dimensional porous NiO nano-rods as an anode material were synthesized using facile hydrothermal synthesis method to improve the electrochemical performance for LIBs application. The NiO nano-rods were typically several hundred nanometers in length, which are composed by loosely stacked nanoparticles. It is believed that the obtained architecture with mesoporous structure can ensure rapid electrons/ions transfer, penetration of the electrolyte to the electrode surfaces and buffer the volume expansion of NiO during charge/discharge processes. When evaluated as anode material, the NiO nano-rods exhibit excellent rate performance and long-life cycling performance with high reversibility. The porous NiO nano-rods exhibit a capacity of 1029.3 mA h g−1 at 1C up to 100 cycles and even retains a reversible capacity of 548.4 mA h g−1 at 4C after 80 cycles. Thus, it is believed that the current strategy can be applicable to improve the electrochemical performances of various metal oxide electrodes in rechargeable secondary battery.
- Published
- 2021
123. Effect of Rheum undulatum Linne extract and Glycyrriza uralensis Fischer extract against arachidonic acid and iron-induced oxidative stress in HepG2 cell and CCl4-induced liver injury in mice
- Author
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Hyeong Sik Lee, Eun Hye Lee, Su Youn Baek, Kwang-Youn Kim, Sang-Chan Kim, Seulgi Lee, and Young Woo Kim
- Subjects
0301 basic medicine ,Liver injury ,biology ,Chemistry ,Rheum undulatum ,biology.organism_classification ,medicine.disease_cause ,medicine.disease ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Biochemistry ,030220 oncology & carcinogenesis ,Hepg2 cells ,medicine ,Arachidonic acid ,Oxidative stress - Published
- 2016
124. Enzyme-responsive destabilization of stabilized plasmid-lipid nanoparticles as an efficient gene delivery
- Author
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Yan Lee, Seulgi Lee, Joon Sig Choi, and Su Jeong Song
- Subjects
Cell Survival ,Pharmaceutical Science ,02 engineering and technology ,Gene delivery ,010402 general chemistry ,01 natural sciences ,Cathepsin B ,Polyethylene Glycols ,Fatty Acids, Monounsaturated ,PEG ratio ,Humans ,Cationic liposome ,Liposome ,Chemistry ,Phosphatidylethanolamines ,Gene Transfer Techniques ,technology, industry, and agriculture ,DNA ,Transfection ,021001 nanoscience & nanotechnology ,Controlled release ,0104 chemical sciences ,Quaternary Ammonium Compounds ,HEK293 Cells ,Biochemistry ,PEGylation ,Biophysics ,Nanoparticles ,lipids (amino acids, peptides, and proteins) ,0210 nano-technology ,Oligopeptides ,Linker ,Plasmids - Abstract
Stabilized plasmid-lipid particles (SPLPs) have been developed to overcome the low stability issue of cationic liposomes, however, SPLPs that are too stable result in unsatisfactory transfection efficiency. In this article, we prepared enzyme-responsive SPLPs (eSPLPs) composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and mPEG-GLFG-K-(C16)2, a PEG lipid with an enzymatically-cleavable linker (glycine-phenylalanine-leucine-glycine, GFLG). eSPLPs were successfully prepared with plasmid DNA (pDNA) encapsulation efficiency of over 80%, using the detergent dialysis method. The PEG shell stabilized eSPLPs and maintained a hydrodynamic diameter of around 200nm. Although typical SPLPs were relatively intact in endosomal condition, the PEG shell of eSPLPs was cleaved following the degradation of the GFLG linker by cathepsin B in the endosome. Then, eSPLPs collapsed and induced endosomal disruption triggering the controlled release of the encapsulated pDNA into cytoplasm. Owing to the enzyme-responsive destabilization, eSPLPs showed a 10 to 100-fold higher transfection efficiency than control SPLPs, which was confirmed using luciferase assay. These results suggest that eSPLPs might be promising candidates for practical use as gene delivery systems, with both stability and high transfection efficiency for future in vivo applications.
- Published
- 2016
125. IPMK: A versatile regulator of nuclear signaling events
- Author
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Jiyoon Beon, Seulgi Lee, Jina Park, Eun-Ha Kim, and Seyun Kim
- Subjects
0301 basic medicine ,Cancer Research ,Transcription, Genetic ,Regulator ,Biology ,medicine.disease_cause ,Bioinformatics ,Epigenesis, Genetic ,Inositol polyphosphate multikinase ,Phosphatidylinositol 3-Kinases ,03 medical and health sciences ,chemistry.chemical_compound ,Phosphatidylinositol Phosphates ,Transcription (biology) ,Intestinal Neoplasms ,Genetics ,medicine ,Animals ,Humans ,Inositol ,Epigenetics ,Phosphatidylinositol ,Molecular Biology ,Cell Nucleus ,Mutation ,Carcinoma ,Epithelial Cells ,Cell biology ,Phosphotransferases (Alcohol Group Acceptor) ,030104 developmental biology ,chemistry ,Second messenger system ,Molecular Medicine ,Signal Transduction - Abstract
Inositol-derived metabolites (e.g., phosphoinositides and inositol polyphosphates) are key second messengers that are essential for controlling a wide range of cellular events. Inositol polyphosphate multikinase (IPMK) exhibits complex catalytic activities that eventually yield water-soluble inositol polyphosphates (e.g., IP4 and IP5) and lipid-bound phosphatidylinositol 3,4,5-trisphosphate. A series of recent studies have suggested that IPMK may be a multifunctional regulator in the nucleus of mammalian cells. In this review, we highlight the novel modes of action of IPMK in transcriptional and epigenetic regulation, and discuss its roles in physiology and disease.
- Published
- 2016
126. Oral Presentation V
- Author
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Cheong Soo Park, Jong Ju Jeong, Jandee Lee, Woong Youn Chung, SeulGi Lee, Min Jhi Kim, Jung Bum Choi, Eun Jeong Ban, Cho Rok Lee, Sang-Wook Kang, Kee-Hyun Nam, and Tae Hyung Kim
- Subjects
Presentation ,medicine.medical_specialty ,business.industry ,Endocrinology, Diabetes and Metabolism ,media_common.quotation_subject ,General surgery ,Medicine ,Radiology, Nuclear Medicine and imaging ,Surgery ,business ,media_common - Abstract
BACKGROUND AND AIMS Some recent guidelines recommend unilateral thyroidectomy for low-risk differentiated thyroid cancer (DTC) sized > 1 and < 4 cm. The present study was designed to evaluate the proper extent of thyroidectomy for patients who have DTC sized > 1 and < 4 cm. METHODS From April 1967 to December 2011, a total of 16,065 DTC patients underwent thyroidectomy at Yonsei University Hospital. Among them, 5,427 (33.7%) patients were classified as having DTC > 1 and < 4 cm and were enrolled in this study. Clinicopathologic features and prognostic results (disease-free and disease-specific survival rates) were analyzed by retrospective medical chart review. The mean follow-up duration was 57.3 ± 58.1 months. RESULTS In the subtypes of tumors, papillary thyroid carcinoma (PTC) was the most common cancer (96.9%) and follicular and poorly differentiated carcinoma comprised 2.7 and 0.1% respectively. The mean tumor size was 1.84 ± 0.74 cm. Patients had extrathyroidal extension (69.3%), multiplicity (35.0%), bilaterality (26.3%), central lymph node metastasis (35.8%), and lateral neck node metastases (20.2%). Of a total of 5,427 patients, 4,353 (80.2%) underwent total thyroidectomy and 1,043 (19.2%) patients underwent less- than-total thyroidectomy. The recurrence rates in total thyroidectomic and less-than-total thyroidectomic groups were 3.9 and 10.0% respectively. The less-than-total thyroidectomic group showed lower disease-free survival (DFS) rate (p= 0.039) and higher disease-specific survival (DSS) (p = 0.035) rate compared with the total thyroidectomic group. In multivariate analysis for DFS, tumor size, N stage, and the extent of thyroidectomy were independent risk factors. In multivariate analysis for DSS, age, gender, tumor size, and N and M stage were independent risk factors. CONCLUSION In patients with tumor size > 1 and ≤ 4 cm, total thyroidectomy was beneficial in reducing recurrence. However, our study confirmed that risk factors for DSS were not the extent of thyroidectomy but traditional prognostic factors, such as older age, male sex, large tumor size, lymph node metastasis, and distant metastasis.
- Published
- 2016
127. Reduced Graphene Oxide By Modified Hummer’s Method Under Appropriate Drying Temperatures As Anode Material for Rechargeable Li, Na and K Batteries
- Author
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Jaekook Kim, Muhammad Hilmy Alfaruqi, Seulgi Lee, Indeok Lee, and Seokhun Kim
- Subjects
chemistry.chemical_compound ,Materials science ,Chemical engineering ,chemistry ,Graphene ,law ,Oxide ,Anode ,law.invention - Abstract
We have successfully synthesized Reduced graphene oxide (rGO) sheets by modified Hummer’s method without additional reducing procedures, such as chemical and thermal treatment, by using appropriate drying temperatures under ambient atmosphere. The rGO sample dried at the optimum temperature of 250 has the most increased specific surface area and porosity as evidenced by SEM and BET analysis, leading to improved lithium-ion, sodium-ion and potassium-ion storage properties. We confirmed the use of a moderate drying temperature led to electrodes’ enhanced cyclability and good electrochemical performance at high current densities. The dimensions of the sheets ranged from nanometers to micrometres and these were entangled with each other to form aggregates. These morphological features of rGO facilitates the movement of guest ions larger than Li-ions, however there were slight instability during repeated cycling. To improve the electrochemical properties, we adopted simple chemical strategies using surfactant/solvent-assisted ultrasonication or mechanical or thermal methods. Our results will be useful for improving the full cell characteristics, and especially for preventing potential drop in sodium-ion batteries and potassium-ion batteries, which are expected to replace the lithium-ion battery system.
- Published
- 2020
128. Potassium Inserted V2O5.xH2o Nanorods As a High-Performance Cathode Materials for Cost Effective Aqueous Rechargeable Zinc-Ion Batteries
- Author
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Muhammad Hilmy Alfaruqi, Seokhun Kim, Sunhyeon Park, Saiful Islam, Sohyun Park, JunJi Piao, Jaekook Kim, and Seulgi Lee
- Subjects
Materials science ,Aqueous solution ,chemistry ,law ,Potassium ,Zinc ion ,Inorganic chemistry ,chemistry.chemical_element ,Nanorod ,Cathode ,law.invention - Abstract
Research attention in aqueous rechargeable zinc-ion batteries (ARZIBs) is growing immensely because of their low-cost and eco-friendly cell components. However, its challenging to find new cathode materials towards practical application of ARZIBs. In this contribution, ground-breaking work on the potassium-pillared V2O5.nH2O (K0.5V2O5.nH2O) nanorod with exposed layer structure as high-performance cathode for ARZIB is presented. The storage mechanism of the K0.5V2O5.nH2O cathode in ARZIB is systematically elucidated using a combined of in situ synchrotron X-ray diffraction, ex situ synchrotron X-ray absorption spectroscopy, ex situ TEM analyses, and first-principle calculations. The K0.5V2O5. nH2O cathode displays a notable discharge capacity of 439 mAh g−1 at a current density of 50 mA g−1. Furthermore, it recovers 96% of the capacity after 1500 cycles at 8000 mA g−1. Impressively, the Zn/K0.5V2O5.nH2O battery offers a specific energy of 121 Wh kg−1 at a high specific power of 6480 W kg−1. The superior performance of the cathode is attributed to its unique exposed layer structure with high surface energy, high conductivity, and low migration barrier. The zinc (Zn) insertion pathway into K0.5V2O5.nH2O was studied using density function theory (DFT). This study provides an insight for designing high-performance cathode materials for ARZIBs and other electrochemical systems.
- Published
- 2020
129. Preperation of Br-Doped Li4Ti5O12 Anode and Its Electrochemical Performance in Li-Ion Battery
- Author
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JunJi Piao, Saiful Islam, Jaekook Kim, Seulgi Lee, and Seokhun Kim
- Subjects
Battery (electricity) ,Materials science ,Inorganic chemistry ,Doping ,Electrochemistry ,Anode ,Ion - Abstract
In this work, we studied about Br-doped Li4Ti5O12-xBrx (“x”= 0, 0.1, 0.3, 0.5 and 0.7) anode materials, which were synthesized by a conventional solid-state reaction using precursors of Li2CO3, TiO2 and LiBr, and we found that their electrochemical properties were related to the doping behavior Most of the Br ions are situated on the surfaces/interfaces of agglomerated particles rather than in the bulk lattice after quantitative instrumental analysis. This lead to the formation of Narrow conduction paths of electron and Li-ion on their surfaces/interfaces. The presence of these narrow surface electrical conduits increased the rate-capability of the LTOBr samples during charging/discharging process. Highly Br-doped sample (LTOBr0.7) showed a slight reduction in capacity. The LTOBr0.5 sample, by the mean time, showed the highest capacity of 125 mAh/g at 1C compared to 115 mAh/g for pure LTO. This was explained with the formation of fine precipitations (Br-containing second phase) on the surfaces of the LTO particles due to high Br addition. The formation of fine precipitations (Br-containing second phase) on the surfaces of the LTO particles due to high Br addition could be the explanation of this.
- Published
- 2020
130. Hierarchically nanorod structured Na2Ti6O13/Na2Ti3O7 nanocomposite as a superior anode for high-performance sodium ion battery
- Author
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Sakshee Chandel, Jaekook Kim, Satendra Pal Singh, Seulgi Lee, Sungjin Kim, Seunggyeong Lee, and Alok Kumar Rai
- Subjects
Morphology (linguistics) ,Nanocomposite ,Chemistry ,General Chemical Engineering ,Sodium-ion battery ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Anode ,Chemical engineering ,Phase (matter) ,Nanorod ,0210 nano-technology - Abstract
In this work, the nanorod structured Na2Ti6O13/Na2Ti3O7 nanocomposite anode is synthesized via facile solvothermal method for sodium ion battery application. The Lebail refinement analysis was performed to obtain the phase fractions ratio of Na2Ti6O13 and Na2Ti3O7 in the nanocomposite sample. It was found to be ~82% and ~ 18% for Na2Ti6O13 and Na2Ti3O7 phases, respectively. The microstructure analysis confirmed the nanorods morphology of the nanocomposite sample, which are self-assembled in hierarchal manner and exhibits the flower-like morphology at high magnifications. The obtained morphology demonstrates remarkable electrochemical performances such as superior cycling stability of 182 mAh g−1 at 100 mA g−1 after 165 cycles and high rate capability of 161 mAh g−1 at 500 mA g−1 over 100 cycles, which can be ascribed to the excellent synergetic effect between Na2Ti6O13 and Na2Ti3O7 phases that could effectively nullify the drawbacks of individual phases and thereby act as complementary to each other advantages.
- Published
- 2020
131. High-voltage cathode materials by combustion-based preparative approaches for Li-ion batteries application
- Author
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Jinju Song, Sunhyeon Park, Balaji Sambandam, Jaekook Kim, Seulgi Lee, Seokhun Kim, Vinod Mathew, Jun Lee, Sohyun Park, and Sungjin Kim
- Subjects
Range (particle radiation) ,Renewable Energy, Sustainability and the Environment ,Scale (chemistry) ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Nanotechnology ,High voltage ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Combustion ,01 natural sciences ,Energy storage ,0104 chemical sciences ,Nanomaterials ,chemistry ,Scalability ,Lithium ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Energy storage devices remain critical to meet the increasing demands of the modern society. Rechargeable lithium ion batteries (LIBs) are a crucial finding in this century to compensate the energy demand in the present day. As device performance is intimately correlated with the material properties, production of functional energy storage nanomaterials endowed with exceptional physico-chemical properties in view of their particle-size confinement has become critically significant. Low- or moderate-temperature synthetic strategies that are versatile, easily scalable, and efficiently produce size-tuned and efficient materials are essential. In the recent past, combustion-based synthetic process has emerged as one of the promising strategies for developing customized energy storage nanomaterials due to rapid synthesis and ease of preparations in a large scale, etc. In the present review, the advancements in the design and chemistry of these strategies in developing a wide range of high voltage cathode materials for LIBs have been discussed. Among the various combustion techniques, this study will focus mainly on solution combustion, sol-gel based combustion and polyol-based pyro-synthesis. The versatility of these processes to provide tailored particle morphologies and particle sizes at the nanoscale and their effects on the material performance in various applications, particularly in energy storage, is also discussed.
- Published
- 2020
132. Cathepsin B-Responsive Liposomes for Controlled Anticancer Drug Delivery in Hep G2 Cells
- Author
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Tai Hwan Ha, Seulgi Lee, Su Jeong Song, Jeil Lee, and Joon Sig Choi
- Subjects
GLFG peptide ,cathepsin B ,lcsh:RS1-441 ,Pharmaceutical Science ,02 engineering and technology ,Pharmacology ,Article ,Cathepsin B ,lcsh:Pharmacy and materia medica ,03 medical and health sciences ,medicine ,Doxorubicin ,Cytotoxicity ,030304 developmental biology ,0303 health sciences ,Liposome ,Chemistry ,technology, industry, and agriculture ,021001 nanoscience & nanotechnology ,In vitro ,Hep G2 ,drug delivery ,liposome ,Drug delivery ,Cancer cell ,lipids (amino acids, peptides, and proteins) ,0210 nano-technology ,medicine.drug - Abstract
In recent decades, several types of anticancer drugs that inhibit cancer cell growth and cause cell death have been developed for chemotherapeutic application. However, these agents are usually associated with side effects resulting from nonspecific delivery, which may induce cytotoxicity in healthy cells. To reduce the nonspecific delivery issue, nanoparticles have been successfully used for the delivery of anticancer drugs to specific target sites. In this study, a functional polymeric lipid, PEG-GLFG-K(C16)2 (PEG-GLFG, polyethylene glycol-Gly-Leu-Phe-Gly-Lys(C16)2), was synthesized to enable controlled anticancer drug delivery using cathepsin B enzyme-responsive liposomes. The liposomes composed of PEG-GLFG/DOTAP (1,2-dioleoyl-3-trimethylammonium-propane (chloride salt))/DPPC (dipalmitoylphosphatidylcholine)/cholesterol were prepared and characterized at various ratios. The GLFG liposomes formed were stable liposomes and were degraded when acted upon by cathepsin B enzyme. Doxorubicin (Dox) loaded GLFG liposomes (GLFG/Dox) were observed to exert an effective anticancer effect on Hep G2 cells in vitro and inhibit cancer cell proliferation in a zebrafish model.
- Published
- 2020
133. Inositol Pyrophosphates: Signaling Molecules with Pleiotropic Actions in Mammals
- Author
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Hyoungjoon Ahn, Min Gyu Kim, Seulgi Lee, and Seyun Kim
- Subjects
Cell signaling ,PPIP5K ,Inositol Phosphates ,Allosteric regulation ,Pharmaceutical Science ,Review ,Energy homeostasis ,Analytical Chemistry ,lcsh:QD241-441 ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,lcsh:Organic chemistry ,Biosynthesis ,Drug Discovery ,Animals ,Humans ,cell signaling ,Inositol ,Phosphorylation ,Physical and Theoretical Chemistry ,030304 developmental biology ,0303 health sciences ,Phosphotransferases (Phosphate Group Acceptor) ,physiologic functions ,Kinase ,Organic Chemistry ,Phosphate ,Cell biology ,IP6K ,chemistry ,inositol pyrophosphate ,Chemistry (miscellaneous) ,signaling molecules ,Molecular Medicine ,030217 neurology & neurosurgery ,Function (biology) ,Signal Transduction - Abstract
Inositol pyrophosphates (PP-IPs) such as 5-diphosphoinositol pentakisphosphate (5-IP7) are inositol metabolites containing high-energy phosphoanhydride bonds. Biosynthesis of PP-IPs is mediated by IP6 kinases (IP6Ks) and PPIP5 kinases (PPIP5Ks), which transfer phosphate to inositol hexakisphosphate (IP6). Pleiotropic actions of PP-IPs are involved in many key biological processes, including growth, vesicular remodeling, and energy homeostasis. PP-IPs function to regulate their target proteins through allosteric interactions or protein pyrophosphorylation. This review summarizes the current understanding of how PP-IPs control mammalian cellular signaling networks in physiology and disease.
- Published
- 2020
134. Chloroquine Treatment Suppresses Mucosal Inflammation in a Mouse Model of Eosinophilic Chronic Rhinosinusitis
- Author
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Yong Min Kim, Ki Sang Rha, Mi Ra Choi, Seulgi Lee, Soo Kyoung Park, Jun Xu, and Sun Hee Yeon
- Subjects
Pulmonary and Respiratory Medicine ,sinusitis ,Immunology ,models, animal ,Mucous membrane of nose ,Immunoglobulin G ,Proinflammatory cytokine ,03 medical and health sciences ,rhinitis ,0302 clinical medicine ,therapeutics ,medicine ,Immunology and Allergy ,030223 otorhinolaryngology ,B-cell activating factor ,Dexamethasone ,nasal polyps ,biology ,business.industry ,Interleukin ,Chloroquine ,Toll-like receptor 9 ,interferons ,Real-time polymerase chain reaction ,030228 respiratory system ,biology.protein ,Original Article ,Tumor necrosis factor alpha ,business ,medicine.drug - Abstract
Purpose The Toll-like receptor 9 (TLR9) signaling pathway is involved in the pathogenesis of chronic rhinosinusitis (CRS) with nasal polyposis. The aim of this study was to assess the therapeutic potential of the TLR9 pathway inhibitor chloroquine in CRS mice. Methods The expression of type I interferons (IFNs) in human CRS tissues was evaluated using quantitative polymerase chain reaction (qPCR), western blotting, and immunofluorescence. Mice were divided into 4 treatment groups: the control, nasal polyp (NP), chloroquine treatment (NP + Chlq), and dexamethasone treatment (NP + Dexa) groups. The effects of chloroquine on polyp formation and mucosal inflammation were examined by hematoxylin and eosin staining. The expression levels of type I IFN, B-cell activating factor (BAFF), TLR9, high mobility group box 1 (HMGB1), and proinflammatory cytokine expression levels were assessed using qPCR, western blot, or enzyme-linked immunosorbent assay. Results IFN-α and IFN-β mRNA levels were significantly higher in patients with eosinophilic NPs (EPs) than in healthy individuals or non-EP patients. The polyp score, epithelial thickness, mucosal thickness, and the number of eosinophils in nasal mucosa were significantly higher in the NP group compared with the control, NP + Chlq, and NP + Dexa groups. NP + Chlq or NP + Dexa significantly suppressed the induction of type I IFN and BAFF expression in the NP group; these treatments also significantly suppressed the induction of TLR9, HMGB1, interferon regulatory factors, interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and Th cytokine expression in the NP group. The secreted levels of anti-dsDNA Immunoglobulin G (IgG) were significantly higher in the NP group than in the control, NP + Chlq, and NP + Dexa groups. There were significant positive correlations between BAFF and mRNA levels of IFN-α/β/the protein levels of anti-dsDNA IgG. Conclusions Chloroquine may be used for the treatment of patients with eosinophilic CRS.
- Published
- 2020
135. Inhibition of MMP-2 and MMP-9 activities by solvent-partitioned Sargassum horneri extracts
- Author
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Chang-Suk Kong, Fatih Karadeniz, Seulgi Lee, Jung Hwan Oh, and Jung-Ae Kim
- Subjects
0301 basic medicine ,Gelatin Zymography ,Brown algae ,Context (language use) ,Aquatic Science ,Matrix metalloproteinase ,Oceanography ,Biochemistry ,lcsh:Aquaculture. Fisheries. Angling ,03 medical and health sciences ,0302 clinical medicine ,TIMP ,Molecular Biology ,lcsh:SH1-691 ,chemistry.chemical_classification ,MMP ,Sargassum horneri ,Blot ,030104 developmental biology ,Enzyme ,chemistry ,Animal ecology ,030220 oncology & carcinogenesis ,HT1080 - Abstract
Background Matrix metalloproteinases (MMPs) are linked with several complications such as metastasis of cancer progression, oxidative stress, and hepatic fibrosis. Brown seaweeds are being extensively studied for their bioactive molecule content against cancer progression. In this context, Sargassum horneri was reported to possess various bioactivities including antiviral, antimicrobial, and anti-inflammatory partly due to its phenolic compound content. Methods In this study, potential of S. horneri was evaluated through anti-MMP effect in HT1080 fibrosarcoma cells. S. horneri crude extract was fractionated with organic solvents, namely, water (H2O), n-buthanol (n-BuOH), 85% aqueous methanol (85% aq. MeOH), and n-hexane. The non-toxicity of fraction samples (Sargassum horneri solvent-partitioned extracts (SHEs)) was confirmed by cell-viability assay. SHEs were tested for their ability to inhibit MMP enzymatic activity through gelatin digestion evaluation and cell migration assay. Expressions of MMP-2 and MMP-9 and tissue inhibitors of MMP (TIMPs) were evaluated by reverse transcription and Western blotting. Results All fractions inhibited the enzymatic activities of MMP-2 and MMP-9 according to gelatin zymography. Except H2O fraction, fractions hindered the cell migration significantly. All tested fractions suppressed both mRNA and protein levels of MMP-2, MMP-9, TIMP-1, and TIMP-2. Conclusion Overall, current results suggested that S. horneri has potential to be a good source for anti-MMP agents, and further investigations are underway for better understanding of the action mechanism and isolation and elucidation of the bioactive molecules.
- Published
- 2018
136. Usability of the Thera-Band® to improve foot drop in stroke survivors
- Author
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JungHee Park, DongGeon Lee, MinKyung Jin, GyuDong Song, Seung-Hoo Lee, YoHan Jo, SoungKyun Hong, SunHae Song, SeulGi Lee, SeungHyeon Pyo, GyuChang Lee, and SunHye Jung
- Subjects
Male ,030506 rehabilitation ,Foot drop ,medicine.medical_specialty ,medicine.medical_treatment ,Foot Orthoses ,Physical Therapy, Sports Therapy and Rehabilitation ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,medicine ,Humans ,Stroke survivor ,Gait ,Rehabilitation ,business.industry ,Foot ,Stroke Rehabilitation ,Usability ,Middle Aged ,medicine.anatomical_structure ,Gait analysis ,Female ,Neurology (clinical) ,medicine.symptom ,Ankle ,0305 other medical science ,business ,Cadence ,human activities ,030217 neurology & neurosurgery - Abstract
Stroke survivors show "foot drop", dragging their toes on the ground in the swing phase of gait. Ineffective ankle dorsiflexion may result in an abnormal gait pattern.The purpose of this study was to investigate the effect of ankle Thera-Band® use on gait patterns in stroke survivors.Gait data were collected in eight subjects who had had strokes using gait analysis system, both with and without the Thera-Band®. The following dependent variables of gait parameters were analyzed: velocity, cadence, step length, stride length, single support time, and double support time.There were significant improvements in gait velocity, cadence, stride length, and double support time in those who used the Thera-Band® compared to those who did not (p 0.05). However, there were no significant differences in step length or single support time (p 0.05).The results show that ankle Thera-Band® use may have a positive effect in improving gait parameters by increasing the ankle stability in stroke survivors with foot drop. Its usefulness in the rehabilitation of foot drop in stroke survivors needs to be further investigated.
- Published
- 2018
137. Managing Cyber Threat Intelligence in a Graph Database: Methods of Analyzing Intrusion Sets, Threat Actors, and Campaigns
- Author
-
Nak Hyun Kim, Hyeisun Cho, Junhyung Park, Seulgi Lee, and Byungik Kim
- Subjects
Intrusion ,Graph database ,Order (exchange) ,Computer science ,Effective method ,Malware ,Cyber threat intelligence ,computer.software_genre ,Computer security ,computer ,Protocol (object-oriented programming) ,Meaning (linguistics) - Abstract
Efforts to cope jointly with the ever-increasing number of breach incidents have resulted in the establishment of the standard format and protocol and given birth to many consultative groups. In addition, various channels that distribute Cyber Threat Intelligence information free of charge have emerged, and studies on utilizing such channels have spread. As the market for sharing information professionally is expanding, the need to manage the shared information in various ways in order to achieve better result has arisen. This paper proposes a standardized management structure and method based on the standardized format and a meaning and standard of Cyber Threat Intelligence that can be shared outside when loading OSINT information collected from various channels into the graph database. This paper also proposes a method of supporting the detection provided by existing security equipment with the information saved in the graph database and an effective method of analysis. Lastly, the paper discusses the advantages that can be expected from saving cyber threat information in the graph database developed using information collected from the outside.
- Published
- 2018
138. The Lives of Refugee Children: A Korean Example
- Author
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Emily Seulgi Lee and Shin Ji Kang
- Subjects
Refugee ,Political science ,Criminology - Published
- 2018
139. Design of a Cyber Threat Information Collection System for Cyber Attack Correlation
- Author
-
Nak Hyun Kim, MoonSeog Jun, Hyeisun Cho, Byun-Ik Kim, and Seulgi Lee
- Subjects
Computer science ,media_common.quotation_subject ,Virtualization ,computer.software_genre ,Computer security ,Domain (software engineering) ,Open data ,Open-source intelligence ,Server ,Cyber-attack ,Malware ,Function (engineering) ,computer ,media_common - Abstract
Nowadays, the number of cyber threats is increasing continuously, and attack techniques are becoming increasingly advanced and intelligent. One important thing that should be noted with regard to this situation is the marked increase in similar cyber incidents which use the same IP, domain, and malicious code for one cyberattack. Therefore, it is essential to understand the correlation between cyberattacks that occur due to the re-use of the same attack infrastructure (IP, domain, malicious code, etc.) for different cyberattacks, in order to detect and respond promptly to similar cyberattacks. To understand the correlation between cyberattacks, it is necessary to collect the related data concerning the procedures and techniques of cyberattacks. This paper proposes the design details of the cyber threat information collection system according to such needs. The proposed system performs the function of collecting the attack infrastructure data (IoCs) exploited for the cyberattack from various open data sources (OSINT, Open Source INTelligence), and uses the collected data as an input value to collect more data recursively. The relationship of the collected data can also be collected, saved, and managed, so that the data can be used to analyze the collection of cyberattacks. The proposed system uses a virtualization structure and distributed processing technology to collect data stably from various collection channels.
- Published
- 2018
140. Method of Quantification of Cyber Threat Based on Indicator of Compromise
- Author
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Hyeisun Cho, Seulgi Lee, Byungik Kim, Junhyung Park, and Nak Hyun Kim
- Subjects
Indicator of compromise ,Computer science ,business.industry ,Error analysis ,Response level ,Blacklisting ,Malware ,The Internet ,Computer security ,computer.software_genre ,business ,computer ,Cyber threats - Abstract
As a large quantity of new and varied attacks occur in Korea, it is difficult to analyze and respond to them with limited security experts and existing equipment. This paper proposes a method of analyzing the threat of Indicator of Compromise (IoC) used for cyber incidents and calculating it as a quantitative value in order to check the analysis priority of cyber incidents that occur in large quantities. Using this method, a large quantity of cyber incidents can be efficiently responded to by checking the quantification of cyber threat objectively to quickly determine the response level of the cyber incident and actively analyze cyber incidents with high threat levels.
- Published
- 2018
141. A Study on a Cyber Threat Intelligence Analysis (CTI) Platform for the Proactive Detection of Cyber Attacks Based on Automated Analysis
- Author
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Byung Ik Kim, Seulgi Lee, Junhyung Park, Nak Hyun Kim, and Hyeisun Cho
- Subjects
Computer science ,Information and Communications Technology ,Malware ,Cyber threat intelligence ,computer.software_genre ,Computer security ,computer ,Phase (combat) ,Blocking (computing) - Abstract
This paper proposes an automated cyberattack analysis platform that is designed to analyze and respond to cyberattacks, which are becoming ever more intelligent and advanced. The ICT information generated during previous cyberattacks will be collected to analyze cyberattacks automatically, and the relationship between the collected information, level of re-exploitation, and similar ICT information among cyberattacks will be automatically analyzed. If the values that are currently being monitored are entered into the developed platform, the most similar cyberattacks in the past and the current phase of attacks will be provided to the analyst. In addition, a system capable of blocking attacks in advance before damages are caused could be developed by providing response/analysis guideline information on the potential future attack inflow.
- Published
- 2018
142. Chronic Pain Patients’ Gaze Patterns toward Pain-Related Information: Comparison between Pictorial and Linguistic Stimuli
- Author
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Lee, Jieun, primary, Beom, Jaewon, additional, Choi, Seoyun, additional, Wachholtz, Seulgi Lee Amy, additional, and Lee, Jang-Han, additional
- Published
- 2019
- Full Text
- View/download PDF
143. Effect of Age on the Voice Onset Time of Korean Stops in VCV contexts
- Author
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Seulgi Lee and Young-Mee Lee
- Subjects
medicine.medical_specialty ,Speech and language impairment ,Aspirated consonant ,Place of articulation ,Voice-onset time ,medicine ,Dependent measure ,Phonation ,Audiology ,Psychology - Abstract
This study investigated the effects of the age of Korean speakers, place of articulation, and phonation types on voice onset time (VOT) of stops. Twenty-five preschoolers, 25 schoolers, and 25 adults who had no history of speech and language impairment produced plosives in /VCV/ words in isolation. A three-way () mixed design was used with the age of speakers (preschoolers, schoolers, adults) as a between-subject factor, the place of articulation (bilabials, alveolars, velars) and phonation types (plain, tense, aspirated consonants) as a within-subject factor. The dependent measure was the VOT values. Results revealed that three main effects were statistically significant. Preschoolers exhibited longer VOTs than adults (p alvelars > bilabials) (all p tense > plain) (all p
- Published
- 2015
144. Shift control of a dry-type two-speed dual-clutch transmission for an electric vehicle
- Author
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Kyungha Kim, Hanho Son, Jongyun Park, Seulgi Lee, Hyun-Chul Kim, and Sungwha Hong
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Stall torque ,Engineering ,business.product_category ,business.industry ,Mechanical Engineering ,Aerospace Engineering ,Automotive engineering ,Dual (category theory) ,Quality (physics) ,Direct torque control ,Transmission (telecommunications) ,Control theory ,Electric vehicle ,Torque sensor ,Clutch ,business - Abstract
In this paper, a shift control algorithm to improve the shift quality was proposed for an electric vehicle with a dry-type two-speed dual-clutch transmission. To analyse the shift characteristics of the target electric vehicle, dynamic models for the two-speed dual-clutch transmission and the drivetrain were developed. Based on the dynamic models, dynamic equations for the transient shift states were derived, and a shift performance simulator was constructed. From analysis of the transient shift state, it was found that the fluctuations in the driveshaft torque, which cause the shift quality to deteriorate, occurred as a result of the inertia torque. Based on the analytical results, a control algorithm was proposed using traction motor torque control as well as shift actuator stroke control. For traction motor control, a compensation torque was applied during the inertia phase. In that phase, actuator stroke control was performed by considering the torque margin and the kissing point during the torque phase instead of the existing map-based control. To evaluate the performance of the proposed control algorithm, a test bench for the target electric vehicle was developed. From the experimental results, it was found that the variations in the driveshaft torque and in the jerk were reduced by the proposed control algorithm, which thereby provides an improved shift quality.
- Published
- 2015
145. Understanding Luxury Disposition
- Author
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Miah Lee, K.W. Kim, Seulgi Lee, and Eunju Ko
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Marketing ,Relation (database) ,Customer value ,Fashion industry ,Conceptual foundation ,The Conceptual Framework ,Cognition ,Advertising ,Luxury goods ,Disposition ,Business ,Applied Psychology - Abstract
This article aims to provide a conceptual foundation for luxury disposition behavior in relation to luxury customer value and switching costs. The results of a study involving 398 luxury consumers in South Korea demonstrate the distinct typologies of luxury customer values and switching costs in cognitive (financial) and emotional (relational) dimensions as well as luxury disposition behavior as four different types. In addition, the conceptual framework on luxury disposition behavior reveals how luxury customers recognize customer value of luxury goods in perceiving switching costs upon disposition, which leads to different choices in disposition behavior. Theoretical and managerial implications are discussed for marketers or retailers in luxury fashion industry.
- Published
- 2015
146. Preimplant Hearing Threshold: An Important Predictor of Hearing Preservation in Cochlear Implantation With Lateral Wall Electrodes.
- Author
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Geonho Lee, Seulgi Lee, Jee-Hye Chung, Jin Woong Choi, Lee, Geonho, Lee, Seulgi, Chung, Jee-Hye, and Choi, Jin Woong
- Published
- 2021
- Full Text
- View/download PDF
147. Posterior Tympanotomy Versus Subtotal Petrosectomy: A Comparison of Complications in Cochlear Implantation.
- Author
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Seulgi Lee, Jong Bin Lee, Jee-Hye Chung, Jin Woong Choi, Lee, Seulgi, Lee, Jong Bin, Chung, Jee-Hye, and Choi, Jin Woong
- Published
- 2021
- Full Text
- View/download PDF
148. High Ambient Temperature Represses Anthocyanin Biosynthesis through Degradation of HY5
- Author
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Seulgi Lee, Eunkyoo Oh, Thom Thi Nguyen, Jungmook Kim, Inyup Paik, Geonhee Hwang, Jia Ying Zhu, and Sara Kim
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0106 biological sciences ,0301 basic medicine ,Osmotic shock ,Mutant ,Flavonoid ,Arabidopsis ,Plant Science ,lcsh:Plant culture ,01 natural sciences ,high temperature stress ,anthocyanin ,03 medical and health sciences ,chemistry.chemical_compound ,Pigment ,Arabidopsis thaliana ,flavonoid ,lcsh:SB1-1110 ,Original Research ,chemistry.chemical_classification ,biology ,fungi ,food and beverages ,biology.organism_classification ,Ubiquitin ligase ,carbohydrates (lipids) ,030104 developmental biology ,chemistry ,Biochemistry ,Anthocyanin ,visual_art ,visual_art.visual_art_medium ,biology.protein ,gene expression ,010606 plant biology & botany ,HY5 - Abstract
Anthocyanins are flavonoid compounds that protect plant tissues from many environmental stresses including high light irradiance, freezing temperatures, and pathogen infection. Regulation of anthocyanin biosynthesis is intimately associated with environmental changes to enhance plant survival under stressful environmental conditions. Various factors, such as UV, visible light, cold, osmotic stress, and pathogen infection, can induce anthocyanin biosynthesis. In contrast, high temperatures are known to reduce anthocyanin accumulation in many plant species, even drastically in the skin of fruits such as grape berries and apples. However, the mechanisms by which high temperatures regulate anthocyanin biosynthesis in Arabidopsis thaliana remain largely unknown. Here, we show that high ambient temperatures repress anthocyanin biosynthesis through the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) and the positive regulator of anthocyanin biosynthesis ELONGATED HYPOCOTYL5 (HY5). We show that an increase in ambient temperature decreases expression of genes required in both the early and late steps of the anthocyanin biosynthesis pathway in Arabidopsis seedlings. As a result, seedlings grown at a high temperature (28°C) accumulate less anthocyanin pigment than those grown at a low temperature (17°C). We further show that high temperature induces the degradation of the HY5 protein in a COP1 activity-dependent manner. In agreement with this finding, anthocyanin biosynthesis and accumulation do not respond to ambient temperature changes in cop1 and hy5 mutant plants. The degradation of HY5 derepresses the expression of MYBL2, which partially mediates the high temperature repression of anthocyanin biosynthesis. Overall, our study demonstrates that high ambient temperatures repress anthocyanin biosynthesis through a COP1-HY5 signaling module.
- Published
- 2017
149. Anti-Melanogenic Effects of Flavonoid Glycosides from Limonium tetragonum (Thunb.) Bullock via Inhibition of Tyrosinase and Tyrosinase-Related Proteins
- Author
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Chang-Suk Kong, Fatih Karadeniz, Seulgi Lee, and Youngwan Seo
- Subjects
0301 basic medicine ,melanogenesis ,Limonium tetragonum ,Tyrosinase ,Melanoma, Experimental ,Pharmaceutical Science ,Down-Regulation ,Gene Expression ,Biology ,Article ,cell culture ,chemical analysis ,colour cosmetics ,Analytical Chemistry ,lcsh:QD241-441 ,Melanin ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Plumbaginaceae ,lcsh:Organic chemistry ,Downregulation and upregulation ,Cell Line, Tumor ,Drug Discovery ,Animals ,Glycosides ,Physical and Theoretical Chemistry ,chemistry.chemical_classification ,Flavonoids ,Melanins ,Monophenol Monooxygenase ,Organic Chemistry ,Glycoside ,Biological activity ,Intramolecular Oxidoreductases ,030104 developmental biology ,chemistry ,Biochemistry ,Chemistry (miscellaneous) ,Cell culture ,030220 oncology & carcinogenesis ,Molecular Medicine ,Myricetin ,Quercetin ,Oxidoreductases - Abstract
Overproduction and stimulation of tyrosinase result in increased melanogenesis of which several skin disorders such as freckles, spots, and hyperpigmentation appear as complications. Limonium tetragonum is a halophyte well-known for its antioxidative properties. This study investigated the anti-melanogenic effects of solvent-partitioned L. tetragonum extracts (LTEs) and its bioactive constituents, two isolated flavonoid glycosides. Current study followed a set of experiments on B16-F10 mouse melanoma cell model with a focus on tyrosinase activity and production. The anti-melanogenic capacity of LTEs was confirmed by their tyrosinase inhibitory effects, prevention of DOPA oxidation, and suppression of melanin production. The inhibition of tyrosinase and DOPA oxidation by LTEs was suggested to be related with the downregulation of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2, verified with mRNA and protein expression levels. Among all tested LTEs, 85% aq. MeOH and n-BuOH were found to be the most active fractions which later yielded the two known compounds, myricetin 3-galactoside and quercetin 3-O-β-galactopyronaside. The anti-melanogenic potential of the compounds were confirmed by their tyrosinase inhibitory effects. These results suggested that L. tetragonum may serve as a potential source of bioactive substances with effective anti-melanogenesis properties.
- Published
- 2017
150. Polyamidoamine (PAMAM) Dendrimers Modified with Cathepsin-B Cleavable Oligopeptides for Enhanced Gene Delivery
- Author
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Su Jeong Song, Tai Hwan Ha, Seulgi Lee, Sang Jae Son, and Joon Sig Choi
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Materials science ,Polymers and Plastics ,Genetic enhancement ,cathepsin B ,arginine ,02 engineering and technology ,Gene delivery ,010402 general chemistry ,01 natural sciences ,gene delivery ,polyplex ,poly(amidoamine) dendrimer ,GFLG peptide ,histidine ,Article ,Cathepsin B ,HeLa ,lcsh:QD241-441 ,lcsh:Organic chemistry ,Cytotoxicity ,Cathepsin ,biology ,General Chemistry ,Transfection ,021001 nanoscience & nanotechnology ,biology.organism_classification ,0104 chemical sciences ,Biochemistry ,Nanocarriers ,0210 nano-technology - Abstract
Because of the complex mechanisms mediating cancer onset, prognosis, and metastatic behavior, different therapeutic approaches targeting these mechanisms have been investigated. Recent advancements in nanocarrier-based drug and gene delivery methods have encouraged scientific groups to investigate various novel therapeutic techniques. In this study, a poly(amidoamine) (PAMAM) polymer-based gene carrier containing the cathepsin B-enzyme sensitive sequence (glycine-phenylalanine-leucine-glycine, GFLG) was evaluated to determine transfection efficiency. Following the GFLG sequence, the surface of PAMAM generation 4 (G4) was conjugated with histidine (H) and arginine (R) for improved endosomal escape and cellular uptake, respectively. The successful synthesis of G4-GLFG-H-R was confirmed by H-1-nuclear magnetic resonance spectroscopy. The polyplex composed of G4-GLFG-H-R and pDNA was simulated by the enzyme cathepsin B and induced endosomal escape of pDNA, which was confirmed by gel electrophoresis. Compared with the G4 control, enzyme-sensitive G4-GLFG-H-R showed higher transfection efficiency and lower cytotoxicity in HeLa cells. These results demonstrated that G4-GLFG-H-R may be a highly potent and efficient carrier for gene therapy applications.
- Published
- 2017
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