233 results on '"Kim, Ji Young"'
Search Results
2. A Rapid Assessment of Sensitivity to Reward Delays and Classwide Token Economy Savings for School-Aged Children.
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Kim, Ji Young, Fienup, Daniel M., Reed, Derek D., and Jahromi, Laudan B.
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DELAY discounting (Psychology) , *PRODUCTION scheduling , *APATHY , *CLASSROOMS , *ACQUISITION of data - Abstract
Delay discounting tasks measure the relation between reinforcer delay and efficacy. The present study established the association between delay discounting and classroom behavior and introduced a brief measure quantifying sensitivity to reward delays for school-aged children. Study 1 reanalyzed data collected by Reed and Martens (J Appl Behav Anal 44(1):1–18, https://doi.org/10.1901/jaba.2011.44-1, 2011) and found that 1-month delay choices predicted student classroom behavior. Study 2 examined the utility of the 1-month delay indifference point in predicting saving and spending behavior of second-grade students using token economies with two different token production schedules. Collectively, results showed (a) the 1-month delay indifference point predicted classroom behavior, (b) children who discounted less and had greater self-regulation, accrued and saved more tokens, and (c) a variable token production schedule better correlated with discounting than a fixed schedule. Implications are discussed regarding utility of a rapid discounting assessment for applied use. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Analysis of Shear Characteristics of Quenchable Boron-Alloyed Steel 22MnB5 During the Hot Mechanical Piercing Process.
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Park, Kye Jeong, Kim, Hye Jin, Kim, Ji Young, Kong, Je Youl, Park, Jea Myoung, Yoon, Seung Chae, and Hyun, Joo Sik
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Hot stamping is a widely adopted technique for manufacturing high-strength vehicle body parts using boron-alloyed steels, such as 22MnB5. This process involves heating the material to 900 ℃ or higher in a furnace, followed by in-die quenching to achieve a strength of over 1.5 GPa. The process includes heating, forming, in-die quenching, and trimming. Laser trimming is the conventional method used for this purpose. However, laser trimming has limitations in terms of productivity and energy cost, and alternative methods have been explored, such as mechanical piercing during the hot stamping process at high temperatures. This study aims to optimize the process parameters, including the piercing temperature, time and clearance between the die-punch, to achieve optimal performance and their mechanical stability. The results show that hot piercing is the feasible method for cutting the boron-alloyed steel parts during the hot stamping process. In this study, the optimal performance is achieved under specific process conditions used for hot mechanical piercing, which is corresponding to differential clearance and mechanical piercing time, respectively. The size and distribution of the burr generated by the shearing process were not significantly affected by the hot mechanical piercing time with lower clearance. However, with the larger clearance, the hot mechanical piercing time significantly affected the size and distribution of the burr. In addition, hydrogen embrittlement becomes more severe as the martensitic phase transformation completes, and the hot mechanical piercing time has the greater influence on the process than the clearance conditions. Therefore, when designing the process for optimal performance of hot mechanical piercing, it is crucial to consider the effects of clearance and time as significant variables and verify their effects. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Age and gender effects on striatal dopamine transporter density and cerebral perfusion in individuals with non-degenerative parkinsonism: a dual-phase 18F-FP-CIT PET study.
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Kim, Ji-Young, Kang, Seo Young, Moon, Byung Seok, Kim, Bom Sahn, Jeong, Jee Hyang, and Yoon, Hai-Jeon
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CAUDATE nucleus , *PERFUSION , *POSITRON emission tomography , *PARKINSONIAN disorders , *PARKINSON'S disease , *DOPAMINE receptors , *DOPAMINE - Abstract
Background: Dual-phase fluorine-18 labeled N-3-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (18F-FP-CIT) positron emission tomography (PET) scans could be used to support disorders like Parkinson's disease (PD). Dopamine transporter (DAT) binding and cerebral perfusion are associated with ageing and gender. We investigated the effects of age and gender on non-degenerative parkinsonism, using automated quantification in striatum: specific binding ratios (SBRs) for DAT binding in delayed phase PET (dCIT) and standardized-uptake-value ratios (SUVRs) for cerebral perfusion in early phase PET (eCIT). We also examined the correlations between SBR and SUVR. Methods: This retrospective study analyzed subjects with dual-phase 18F-FP-CIT PET scans. The eCIT images were acquired immediately post-injection, and dCIT images were taken 120 min later. With Brightonix software, automated quantification of SBRs for dCIT and SUVRs for eCIT were acquired from visually normal scans. The effects of aging and gender were assessed by regressing SBRs and SUVRs on age for both genders. The correlations between SUVRs and SBRs were evaluated. Results: We studied 79 subjects (34 males and 45 females). An age-related reduction in SBRs was observed in the dorsal striatum, ventral striatum, caudate nucleus, and putamen for both genders. SUVRs were found to negatively correlate with age in the dorsal striatum, ventral striatum, caudate nucleus, and putamen for males and in the dorsal striatum and caudate nucleus for females. Positive correlations between SBRs and SUVRs in the dorsal striatum, ventral striatum, caudate nucleus, and putamen for male and in the dorsal striatum, caudate nucleus, and putamen for females. Conclusions: Using quantified values from dual-phase 18F-FP-CIT PET with a single injection, we demonstrate a negative impact of age on SBRs (DAT binding) in the striatum for both genders and SUVRs (cerebral perfusion) in the dorsal striatum and caudate nucleus for both genders and in the ventral striatum and putamen for males. Additionally, we found positive associations between SBR and SUVR values in the dorsal striatum, caudate nucleus, and putamen for both genders and in the ventral striatum for males. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Comparison of Acquisition Criteria Applied to Individual and Sets of Tacts: A Systematic Replication.
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Chang, Hung, Nainani, Tania, and Kim, Ji Young
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- 2024
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6. Simultaneous detection of residues of 34 beta-lactam antibiotics in livestock and fish samples through liquid chromatography-tandem mass spectrometry.
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Park, Sun Young, Kim, Yu Ra, Lim, Su Ji, Kim, Ji Young, Choi, Jang Deok, and Moon, Gui Im
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β-Lactam is one of the widely used veterinary drugs, but simultaneous analytical methods for β-lactam on various animal foods have not been established. In this study, we aimed to detect 34 β-lactam antibiotics simultaneously in livestock samples (beef, pork, chicken, egg, and milk) by liquid chromatography-tandem mass spectrometry (LC–MS/MS). Samples were extracted using phosphate buffer/acetonitrile or water/acetonitrile and then cleaned with 150 mg of C
18 and 900 mg of MgSO4 . The method showed acceptable recovery and repeatability of 66.1–119% and 1.5–26%, respectively. The method was employed to monitor 127 real samples from the domestic market to confirm its applicability, and no β-lactam residues were detected. It was also applied to other matrices (eel, flat fish, and shrimp) and showed acceptable recovery (62.1–120%) and repeatability (1.0–28%). The method is expected to improve the efficiency of monitoring veterinary drug residues in domestic livestock products and fishery foods. [ABSTRACT FROM AUTHOR]- Published
- 2024
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7. Investigation of safety and efficacy of febantel and fenbendazole in fish and exposure assessment.
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Kim, Min Ji, Kim, Ji Young, Shin, Dong Woo, and Kim, Hyun-Kyung
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- 2024
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8. Simultaneous determination of 31 Sulfonamide residues in various livestock matrices using liquid chromatography-tandem mass spectrometry.
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Kim, Yu Ra, Park, Sunyoung, Kim, Ji Young, Choi, Jang-Duck, and Moon, Gui-Im
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- 2024
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9. Re-evaluation of a microbiological acceptable daily intake for tylosin based on its impact on human intestinal microflora.
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Kim, Min Ji, Kim, Ji Young, Choi, Jang Duck, and Moon, Guiim
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- 2024
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10. Validation of a Method Based on Liquid Chromatography-Tandem Mass Spectrometry for Multiclass Screening and Analysis of 59 Veterinary Drugs in Fishery Foods.
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Park, Sunyoung, Park, Hyunjin, Kim, Ji-Young, Choi, Jang-Deok, Moon, Gui-Im, and Shin, Dong Woo
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Veterinary drugs (VDs) are regulated to prevent their abuse or misuse and protect humans that consume animal-based food products from exposure to VD residues. VD residues are managed according to the maximum residue limits (MRLs) or by prohibiting the use of VDs based on their residual properties and toxicities. However, all VD residues, even those that are not managed by MRLs, in animal-based food products will be regulated for public health improvement. Accordingly, herein, the applicability of an existing multiclass analytical method for the analysis of 59 VDs in fishery foods was validated. Applicability of this method to the analysis of VDs in livestock foods has already been confirmed. In this method, the sample was extracted with water:acetonitrile (1:4, v/v) followed by cooling, concentration, and analysis via liquid chromatography-mass spectrometry. Accuracies and precisions for three fishery foods (namely, flat fish, eel, and shrimp) were 63.7–120% and 1.9–30%, respectively, and a minimum of 63% (44/70) compounds could be quantified. This method is expected to improve the capabilities and efficiencies of monitoring VD residues in animal-based food products and will enhance food safety. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Aspacochioside C from Asparagus cochinchinensis attenuates eumelanin synthesis via inhibition of TRP2 expression.
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Yunmam, Silvia, Lee, Hae Ran, Hong, Seong Min, Kim, Ji-Young, Kang, Tong Ho, Lee, Ai Young, Jang, Dae Sik, and Kim, Sun Yeou
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MELANOGENESIS ,MELANINS ,ASPARAGUS ,PLANT products ,PROTEIN expression ,SAPONINS ,BRACHYDANIO - Abstract
Aspacochioside C (ACC) is a steroidal saponin isolated from Asparagus cochinchinensis. Steroidal saponins, such as pseudoprotodioscin and dioscin, are known to inhibit melanogenesis, but the role of ACC in melanogenesis remains unknown. Due to the toxic effect of the commonly used skin whitening agents like arbutin, kojic acid and α-lipoic acid alternative plant products are recentlybeen studied for their anti-hypergmentation effect. This study explores the role of ACC in melanogenesis in both in vivo and in vitro models. Here, we for the first time demonstrate that ACC attenuated α-MSH- and UVB-induced eumelanin production by inhibiting tyrosinase-related protein (TRP)-2 protein expression in both murine B16F10 and human melanoma MNT1 cells. However, ACC had no significant effect on pheomelanin concentration. ACC also decreased the pigmentation density in zebrafish embryos, which indicates that ACC targets TRP2 and inhibits eumelanin synthesis. Our results demonstrate that ACC inhibits TRP2, thereby attenuating eumelanin synthesis both in in vitro and in vivo zebrafish model. Therefore, ACC can potentially be used as an anti-melanogenic agent for both aesthetic and pharmaceutical purposes. [ABSTRACT FROM AUTHOR]
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- 2023
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12. The added value of SPECT/CT lymphoscintigraphy in the initial assessment of secondary extremity lymphedema patients.
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Yoon, Hai-Jeon, Woo, Kyong-Je, Kim, Ji-Young, Kang, Seo Young, Moon, Byung Seok, and Kim, Bom Sahn
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SINGLE-photon emission computed tomography ,COMPUTED tomography ,LYMPHEDEMA ,RADIONUCLIDE imaging - Abstract
An added value of SPECT/CT over planar lymphoscintigraphy for initial staging in patients with secondary extremity lymphedema was investigated. Furthermore, we developed a hybrid SPECT/CT classification combining dermal backflow (DBF) of SPECT and honeycomb pattern (HP) of CT, correlated it with lymphoscintigraphic staging and clinical severity. Forty-one patients with secondary extremity lymphedema who underwent lymphoscintigraphy with SPECT/CT were included retrospectively. The severity of extremity lymphedema was assessed using CT volumetry. Lymphoscintigraphic findings were evaluated using the Taiwan Lymphoscintigraphy Staging (TLS), and CT-based and SPECT-based quantitative analysis were performed. TLS was performed by planar scintigraphy only and with SPECT/CT, respectively. The SPECT/CT findings were classified into DBF−/HP−, DBF+/HP−, DBF+/HP+, and DBF−/HP+. Based on these findings, patients were categorized into five classes: Class 1 = DBF−HP− entire limb, Class 2 = DBF+/HP− proximal/distal limb without DBF+/HP+ or DBF−/HP+, Class 3 = DBF+/HP+ proximal/distal limb without DBF−/HP+, Class 4 = Mixed DBF+/HP+ and DBF−/HP+ in proximal/distal limb, Class 5 = DBF−/HP+ entire limb. Adding SPECT/CT to planar scintigraphy showed a 15.4% modification rate in lymphoscintigraphic staging. HP volume ratio significantly increased as clinical severity and lymphoscintigraphic staging increased, while DBF volume ratio increased with severity and followed expected patterns according to lymphoscintigraphic staging. Hybrid SPECT/CT lymphoscintigraphic classification showed strong positive correlation with clinical severity and TLS. Our results demonstrated substantial modification of lymphoscintigraphic staging by adding SPECT/CT to a conventional planar scintigraphy. In addition, a hybrid SPECT/CT is expected to provide new indicators reflecting lymphoscintigraphic staging and clinical severity by providing both of functional DBF and anatomical HP information. [ABSTRACT FROM AUTHOR]
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- 2023
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13. Angiotensin receptor blockers, but not angiotensin-converting enzyme inhibitors, inhibit abnormal bone changes in spondyloarthritis.
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Choi, Jin Sun, Kim, Ji-Young, Ahn, Min-Joo, Jang, Hanbit, Song, Seungtaek, Choi, Sung Hoon, Park, Ye-Soo, Jo, Sungsin, Kim, Tae-Hwan, and Shim, Seung Cheol
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- 2023
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14. The clinical effectiveness of fused image of single-photon emission CT and facial CT for the evaluation of degenerative change of mandibular condylar head.
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Jeon, Seung-Hwan, Lim, Seung-Weon, Jung, Ki-Hyun, Jeon, Jae-Yun, Kim, Sang-Yoon, Kim, Ji-Young, Choi, Yoon-Young, and Hwang, Kyung-Gyun
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SINGLE-photon emission computed tomography ,MANDIBULAR condyle - Abstract
Background: The primary objective of this study was to assess the clinical effectiveness of fused images obtained from single-photon emission computed tomography (SPECT) and facial computed tomography (CT) for evaluating degenerative changes in the mandibular condylar head. This assessment was accomplished by comparing the Technetium-99 m methylene diphosphonate (
99m Tc-MDP) uptake ratio with the results of clinical and radiographic findings. Methods: The study included 17 patients (3 males and 14 females) with suspected osteoarthritis of the mandibular condyle, totaling 34 temporomandibular joints (TMJs). Based on clinical and radiographic examinations, the TMJs were categorized into four groups: normal (group N), internal derangement (group ID), osteoarthritis (group OA), and osteoarthritis sequelae (group OAseq ). For each patient, bone SPECT and facial CT scans were registered and reconstructed to create fused SPECT/CT images. The99m Tc-MDP uptake levels in the TMJs were statistically compared among the four groups. Results: The99m Tc-MDP uptake ratio showed a gradual increase in the order of the following: group N, group OAseq , group ID, and group OA. There was a significant difference observed among groups (p = 0.003), mainly driven by the disparity between group OA and both group N (p < 0.001) and group OAseq (p = 0.048). Conclusion: Fused SPECT/CT image can be an effective tool for evaluating degenerative changes in the mandibular condylar head. The technique demonstrated the ability to differentiate between normal TMJs and those with internal derangement, osteoarthritis, or osteoarthritis sequelae. This approach holds promise as a valuable method in clinical assessments of TMJ degeneration. [ABSTRACT FROM AUTHOR]- Published
- 2023
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15. Inhibition of the NLRP3 Inflammasome Activation/Assembly through the Activation of the PI3K Pathway by Naloxone Protects Neural Stem Cells from Ischemic Condition.
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Kim, Ji Young, Hwang, Mina, Choi, Na-Young, and Koh, Seong-Ho
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Naloxone is a well-known opioid antagonist and has been suggested to have neuroprotective effects in cerebral ischemia. We investigated whether naloxone exhibits anti-inflammatory and neuroprotective effects in neural stem cells (NSCs) injured by oxygen-glucose deprivation (OGD), whether it affects the NOD-like receptor protein 3 (NLRP3) inflammasome activation/assembly, and whether the role of the phosphatidylinositol 3-kinase (PI3K) pathway is important in the control of NLRP3 inflammasome activation/assembly by naloxone. Primary cultured NSCs were subjected to OGD and treated with different concentrations of naloxone. Cell viability, proliferation, and the intracellular signaling proteins associated with the PI3K pathway and NLRP3 inflammasome activation/assembly were evaluated in OGD-injured NSCs. OGD significantly reduced survival, proliferation, and migration and increased apoptosis of NSCs. However, treatment with naloxone significantly restored survival, proliferation, and migration and decreased apoptosis of NSCs. Moreover, OGD markedly increased NLRP3 inflammasome activation/assembly and cleaved caspase-1 and interleukin-1β levels in NSCs, but naloxone significantly attenuated these effects. These neuroprotective and anti-inflammatory effects of naloxone were eliminated when cells were treated with PI3K inhibitors. Our results suggest that NLRP3 inflammasome is a potential therapeutic target and that naloxone reduces ischemic injury in NSCs by inhibiting NLRP3 inflammasome activation/assembly mediated by the activation of the PI3K signaling pathway. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Barcoded multiple displacement amplification for high coverage sequencing in spatial genomics.
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Kim, Jinhyun, Kim, Sungsik, Yeom, Huiran, Song, Seo Woo, Shin, Kyoungseob, Bae, Sangwook, Ryu, Han Suk, Kim, Ji Young, Choi, Ahyoun, Lee, Sumin, Ryu, Taehoon, Choi, Yeongjae, Kim, Hamin, Kim, Okju, Jung, Yushin, Kim, Namphil, Han, Wonshik, Lee, Han-Byoel, Lee, Amos C., and Kwon, Sunghoon
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SINGLE nucleotide polymorphisms ,GENOMICS ,TRIPLE-negative breast cancer ,DNA analysis ,NUCLEOTIDE sequencing - Abstract
Determining mutational landscapes in a spatial context is essential for understanding genetically heterogeneous cell microniches. Current approaches, such as Multiple Displacement Amplification (MDA), offer high genome coverage but limited multiplexing, which hinders large-scale spatial genomic studies. Here, we introduce barcoded MDA (bMDA), a technique that achieves high-coverage genomic analysis of low-input DNA while enhancing the multiplexing capabilities. By incorporating cell barcodes during MDA, bMDA streamlines library preparation in one pot, thereby overcoming a key bottleneck in spatial genomics. We apply bMDA to the integrative spatial analysis of triple-negative breast cancer tissues by examining copy number alterations, single nucleotide variations, structural variations, and kataegis signatures for each spatial microniche. This enables the assessment of subclonal evolutionary relationships within a spatial context. Therefore, bMDA has emerged as a scalable technology with the potential to advance the field of spatial genomics significantly. Spatial genomics offers insights into cellular interactions within tissues. Here, the authors develop barcoded multiple displacement amplification, achieving high-coverage sequencing to map complex genomic variations within cellular landscapes. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Comparison of the cytotoxicity of bisphenol A and its analogs on human placental BeWo cells.
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Kim, Mi Jin, Jo, Ah-Ra, Kim, Ji-Young, An, Mi-Jin, Shin, Geun-Seup, Lee, Hyun-Min, Kim, Jinho, Park, Jinhong, Kim, Chul-Hong, and Kim, Jung-Woong
- Abstract
Background: Bisphenol A (BPA) and its alternatives (BPF, BPS) are widely used in daily consumer products, which commonly expose humans to these chemicals. Bisphenols (BPs) are endocrine-disrupting chemicals widely present in the environment and can accumulate in the entire food chain by circulating in the ecosystem. In humans, BPs intake leads to accumulation in the human body and causes many chronic diseases, including endocrine disruption, immunotoxicity, and cancer. Objective: Although several studies have demonstrated the negative effect of BPA and its alternatives, studies have yet to be determined whether bisphenols can affect human trophoblast cells. Thus, this study aimed to analyze the toxic effect of BPs on the human trophoblast cell line BeWo. Results: We investigated the cytotoxic effect of BPs on human trophoblast cells. The cytotoxicity was measured by the MTS assay and flow cytometric analysis that representing the cell viability, cell proliferation, cell cycle progression and apoptotic cell death. BPs had no effect on BeWo cell viability at concentrations below 100 mM, and did not cause significant changes in cell proliferation and apoptosis. However, BPA and BPS altered cell cycle progression and checkpoint regulator expression. Conclusion: BPs did not affect cell viability and proliferation. However, BPS altered the G
0 /G1 and G2 /M phases of the trophoblast BeWo cells by increasing cyclin B1 expression. [ABSTRACT FROM AUTHOR]- Published
- 2023
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18. β‐arrestin 2 negatively regulates lung cancer progression by inhibiting the TRAF6 signaling axis for NF-κB activation and autophagy induced by TLR3 and TLR4.
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Kim, Ji Young, Shin, Ji Hye, Kim, Mi-Jeong, Kang, Yeeun, Lee, Ji Su, Son, Juhee, Jeong, Soo-Kyung, Kim, Daesik, Kim, Duk-Hwan, Chun, Eunyoung, and Lee, Ki-Young
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- 2023
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19. Establishment of analysis method for the quantification of residues of halquinol and its metabolites in livestock and fishery products using liquid chromatography–tandem mass spectrometry.
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Lee, Tae Ho, Park, Sun Young, Kim, Ji Young, Choi, Jang-Duck, and Moon, Guiim
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- 2023
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20. Ebastine impairs metastatic spread in triple-negative breast cancer by targeting focal adhesion kinase.
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Seo, Juyeon, Park, Minsu, Ko, Dongmi, Kim, Seongjae, Park, Jung Min, Park, Soeun, Nam, Kee Dal, Farrand, Lee, Yang, Jinsol, Seok, Chaok, Jung, Eunsun, Kim, Yoon-Jae, Kim, Ji Young, and Seo, Jae Hong
- Abstract
We sought to investigate the utility of ebastine (EBA), a second-generation antihistamine with potent anti-metastatic properties, in the context of breast cancer stem cell (BCSC)-suppression in triple-negative breast cancer (TNBC). EBA binds to the tyrosine kinase domain of focal adhesion kinase (FAK), blocking phosphorylation at the Y397 and Y576/577 residues. FAK-mediated JAK2/STAT3 and MEK/ERK signaling was attenuated after EBA challenge in vitro and in vivo. EBA treatment induced apoptosis and a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f, suggesting that EBA targets BCSC-like cell populations while reducing tumor bulk. EBA administration significantly impeded BCSC-enriched tumor burden, angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Our findings suggest that EBA may represent an effective therapeutic for the simultaneous targeting of JAK2/STAT3 and MEK/ERK for the treatment of molecularly heterogeneous TNBC with divergent profiles. Further investigation of EBA as an anti-metastatic agent for the treatment of TNBC is warranted. [ABSTRACT FROM AUTHOR]
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- 2023
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21. c-Jun N-terminal kinase 1 (JNK1) phosphorylates OTX2 transcription factor that regulates early retinal development.
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An, Mi-Jin, Lee, Hyun-Min, Kim, Chul-Hong, Shin, Geun-Seup, Jo, Ah-Ra, Kim, Ji-Young, Kim, Mi Jin, Kim, Jinho, Park, Jinhong, Hwangbo, Yujeong, Kim, Jeongkyu, and Kim, Jung-Woong
- Abstract
Background: The transcription factor orthodenticle homeobox 2 (OTX2) has critical functions in brain and eye development, and its mutations in humans are related to retinal diseases, such as ocular coloboma and microphthalmia. However, the regulatory mechanisms of OTX2 are poorly identified. Objective: The identification of JNK1 as an OTX2 regulatory protein through the protein interaction and phosphorylation. Methods: To identify the binding partner of OTX2, we performed co-immunoprecipitation and detected with a pooled antibody that targeted effective kinases. The protein interaction between JNK1 and OTX2 was identified with the co-immunoprecipitation and immunocytochemistry. In vivo and in vitro kinase assay of JNK1 was performed to detect the phosphorylation of OTX2 by JNK1. Results: JNK1 directly interacted with OTX2 through the transactivation domain at the c-terminal region. The protein–protein interaction and co-localization between JNK1 and OTX2 were further validated in the developing P0 mouse retina. In addition, we confirmed that the inactivation of JNK1 K55N mutant significantly reduced the JNK1-mediated phosphorylation of OTX2 by performing an immune complex protein kinase assay. Conclusion: c-Jun N-terminal kinase 1 (JNK1) phosphorylates OTX2 transcription factor through the protein–protein interaction. [ABSTRACT FROM AUTHOR]
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- 2023
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22. Photonically active bowtie nanoassemblies with chirality continuum.
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Kumar, Prashant, Vo, Thi, Cha, Minjeong, Visheratina, Anastasia, Kim, Ji-Young, Xu, Wenqian, Schwartz, Jonathan, Simon, Alexander, Katz, Daniel, Nicu, Valentin Paul, Marino, Emanuele, Choi, Won Jin, Veksler, Michael, Chen, Si, Murray, Christopher, Hovden, Robert, Glotzer, Sharon, and Kotov, Nicholas A.
- Abstract
Chirality is a geometrical property described by continuous mathematical functions1–5. However, in chemical disciplines, chirality is often treated as a binary left or right characteristic of molecules rather than a continuity of chiral shapes. Although they are theoretically possible, a family of stable chemical structures with similar shapes and progressively tuneable chirality is yet unknown. Here we show that nanostructured microparticles with an anisotropic bowtie shape display chirality continuum and can be made with widely tuneable twist angle, pitch, width, thickness and length. The self-limited assembly of the bowties enables high synthetic reproducibility, size monodispersity and computational predictability of their geometries for different assembly conditions6. The bowtie nanoassemblies show several strong circular dichroism peaks originating from absorptive and scattering phenomena. Unlike classical chiral molecules, these particles show a continuum of chirality measures2 that correlate exponentially with the spectral positions of the circular dichroism peaks. Bowtie particles with variable polarization rotation were used to print photonically active metasurfaces with spectrally tuneable positive or negative polarization signatures for light detection and ranging (LIDAR) devices.Self-limited assembly of 'imperfect' chiral nanoparticles enables formation of bowtie-shaped microparticles with size monodispersity and continuously variable chirality to be used for printing photonically active metasurfaces. [ABSTRACT FROM AUTHOR]
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- 2023
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23. Enhanced Hydrogen Delayed Fracture of 1.5 GPa Hot Stamping Steel Sheet with Sheared Surface by Double Punching Method.
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Kim, Ji-Young, Yoon, Seung-Chae, Kim, Hye-Jin, and Lee, Myoung-Gyu
- Abstract
A cold trimming technology reduces the process time and product cost compared to the common laser trimming method in hot stamping process. However, high stress concentration during the cold trimming can lead to quality defects such as premature cracking. Moreover, the defects may cause critical delayed fracture under hydrogen environment. In this study, experimental and numerical investigation are provided to understand the effect of cold trimming method on the surface quality and hydrogen induced delayed fracture of a hot stamped high strength steel. Specimens with different clearances, tool geometries, and process conditions are considered along with different trimming methods. The new trimming processes are the process division and double punching methods, which are suggested to overcome the drawback of the conventional single punching method. The experiments show that the sheared surface profile is mainly dependent on the trimming clearance, while the hydrogen embrittlement (or its resultant delayed fracture) is dominantly affected by the stress state of the trimmed surface. Especially, significant improvement in the hydrogen delayed fracture of hot stamped steel can be achieved by introducing the double punch method. This study suggests that the double punching can be a potential trimming method as an alternative to the laser trimming by reducing the cost and process time in producing the hot stamped automotive parts. [ABSTRACT FROM AUTHOR]
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- 2023
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24. Chiral assemblies of pinwheel superlattices on substrates.
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Zhou, Shan, Li, Jiahui, Lu, Jun, Liu, Haihua, Kim, Ji-Young, Kim, Ahyoung, Yao, Lehan, Liu, Chang, Qian, Chang, Hood, Zachary D., Lin, Xiaoying, Chen, Wenxiang, Gage, Thomas E., Arslan, Ilke, Travesset, Alex, Sun, Kai, Kotov, Nicholas A., and Chen, Qian
- Abstract
The unique topology and physics of chiral superlattices make their self-assembly from nanoparticles highly sought after yet challenging in regard to (meta)materials1–3. Here we show that tetrahedral gold nanoparticles can transform from a perovskite-like, low-density phase with corner-to-corner connections into pinwheel assemblies with corner-to-edge connections and denser packing. Whereas corner-sharing assemblies are achiral, pinwheel superlattices become strongly mirror asymmetric on solid substrates as demonstrated by chirality measures. Liquid-phase transmission electron microscopy and computational models show that van der Waals and electrostatic interactions between nanoparticles control thermodynamic equilibrium. Variable corner-to-edge connections among tetrahedra enable fine-tuning of chirality. The domains of the bilayer superlattices show strong chiroptical activity as identified by photon-induced near-field electron microscopy and finite-difference time-domain simulations. The simplicity and versatility of substrate-supported chiral superlattices facilitate the manufacture of metastructured coatings with unusual optical, mechanical and electronic characteristics.Chiroptically active pinwheel assemblies on substrates are formed by tetrahedral gold nanoparticles from the effective ‘compression’ of a perovskite-like, low-density phase, thereby enabling the manufacture of metastructured coatings with special chiroptical characteristics as identified by photon-induced near-field electron microscopy and chirality measures. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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25. Toward damage-tolerant bulk metallic glasses: Fracture behavior and brittle–ductile transition.
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Ryu, Wook Ha, Kim, Ji Young, and Park, Eun Soo
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- 2022
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26. Enhanced metabolic flux of methylerythritol phosphate (MEP) pathway by overexpression of Ginkgo biloba 1-Hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate Reductase 1 (GbHDR1) gene in poplar.
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Kang, Min-Kyoung, Kim, Ji-Young, Choi, Young-Im, Hu, Lujie, Yang, Chaodong, Jin, Zhehao, Park, Yun Ji, Kim, Soo-Un, and Kim, Sang-Min
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- 2022
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27. Spatial epitranscriptomics reveals A-to-I editome specific to cancer stem cell microniches.
- Author
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Lee, Amos C., Lee, Yongju, Choi, Ahyoun, Lee, Han-Byoel, Shin, Kyoungseob, Lee, Hyunho, Kim, Ji Young, Ryu, Han Suk, Kim, Hoe Suk, Ryu, Seung Yeon, Lee, Sangeun, Cheun, Jong-Ho, Yoo, Duck Kyun, Lee, Sumin, Choi, Hansol, Ryu, Taehoon, Yeom, Huiran, Kim, Namphil, Noh, Jinsung, and Lee, Yonghee
- Subjects
TRIPLE-negative breast cancer ,ALTERNATIVE RNA splicing ,TUMOR microenvironment ,CANCER stem cells ,B cells ,RNA editing ,T cells - Abstract
Epitranscriptomic features, such as single-base RNA editing, are sources of transcript diversity in cancer, but little is understood in terms of their spatial context in the tumour microenvironment. Here, we introduce spatial-histopathological examination-linked epitranscriptomics converged to transcriptomics with sequencing (Select-seq), which isolates regions of interest from immunofluorescence-stained tissue and obtains transcriptomic and epitranscriptomic data. With Select-seq, we analyse the cancer stem cell-like microniches in relation to the tumour microenvironment of triple-negative breast cancer patients. We identify alternative splice variants, perform complementarity-determining region analysis of infiltrating T cells and B cells, and assess adenosine-to-inosine base editing in tumour tissue sections. Especially, in triple-negative breast cancer microniches, adenosine-to-inosine editome specific to different microniche groups is identified. The spatial context of epitranscriptomic features in the tumour microenvironment remains poorly understood. Here, a method for transcriptomic and epitranscriptomic analysis of immunofluorescence-stained tissue, Select-seq, is applied to stem cell-like microniches in triple negative breast cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
28. Chiral phonons in microcrystals and nanofibrils of biomolecules.
- Author
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Choi, Won Jin, Yano, Keiichi, Cha, Minjeong, Colombari, Felippe M., Kim, Ji-Young, Wang, Yichun, Lee, Sang Hyun, Sun, Kai, Kruger, John M., de Moura, André F., and Kotov, Nicholas A.
- Abstract
Chiral phonons are concerted mirror-symmetric movements of atomic groups connected by covalent and intermolecular bonds. Such lattice vibrations in crystals of biomolecules should be highly specific to their short- and long-range organizations, but their chiroptical signatures and structure–property relationships remain uncertain. Here we show that terahertz chiroptical spectroscopy enables the registration and attribution of chiral phonons for microscale and nanoscale crystals of amino acids and peptides. Theoretical analysis and computer simulations indicate that sharp mirror-symmetric bands observed for left- and right-handed enantiomers originate from the collective vibrations of biomolecules interconnected by hydrogen bonds into helical chains. The sensitivity of chiral phonons to minute structural changes can be used to identify physical and chemical differences in seemingly identical formulations of dipeptides used in health supplements. The generality of these findings is demonstrated by chiral phonons observed for amyloid nanofibrils of insulin. Their spectral signatures and polarization rotation strongly depend on their maturation stage, which opens a new door for medical applications of terahertz photonics. Chiral phonons—long-range lattice vibrations with rotational motion of atoms—are observed by terahertz chiroptical spectroscopy in biocrystals. Terahertz circular dichroism peaks between 0.2 and 2.0 THz clearly identify the chirality of these phonons in various microcrystalline and nanofibrils of biomolecules. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. USP15 negatively regulates lung cancer progression through the TRAF6-BECN1 signaling axis for autophagy induction.
- Author
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Kim, Mi-Jeong, Min, Yoon, Jeong, Soo-Kyung, Son, Juhee, Kim, Ji Young, Lee, Ji Su, Kim, Duk-Hwan, Lee, Joo Sang, Chun, Eunyoung, and Lee, Ki-Young
- Published
- 2022
- Full Text
- View/download PDF
30. Biomarker LEPRE1 induces pelitinib-specific drug responsiveness by regulating ABCG2 expression and tumor transition states in human leukemia and lung cancer.
- Author
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Lee, A-Ram, Lee, Sunho, Shin, Jee Yoon, Kim, Ji-Young, Moon, Kyoung-Sik, and Jung, Joungsun
- Subjects
LUNG cancer ,PROTEIN kinase B ,ACUTE myeloid leukemia ,BIOMARKERS ,LEUKEMIA ,CADHERINS - Abstract
Biomarkers for treatment sensitivity or drug resistance used in precision medicine include prognostic and predictive molecules, critical factors in selecting appropriate treatment protocols and improving survival rates. However, identification of accurate biomarkers remain challenging due to the high risk of false-positive findings and lack of functional validation results for each biomarker. Here, we discovered a mechanical correlation between leucine proline-enriched proteoglycan 1 (LEPRE1) and pelitinib drug sensitivity using in silico statistical methods and confirmed the correlation in acute myeloid leukemia (AML) and A549 lung cancer cells. We determined that high LEPRE1 levels induce protein kinase B activation, overexpression of ATP-binding cassette superfamily G member 2 (ABCG2) and E-cadherin, and cell colonization, resulting in a cancer stem cell-like phenotype. Sensitivity to pelitinib increases in LEPRE1-overexpressing cells due to the reversing effect of ABCG2 upregulation. LEPRE1 silencing induces pelitinib resistance and promotes epithelial-to-mesenchymal transition through actin rearrangement via a series of Src/ERK/cofilin cascades. The in silico results identified a mechanistic relationship between LEPRE1 and pelitinib drug sensitivity, confirmed in two cancer types. This study demonstrates the potential of LEPRE1 as a biomarker in cancer through in-silico prediction and in vitro experiments supporting the clinical development of personalized medicine strategies based on bioinformatics findings. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Physical activity levels, exercise preferences, and exercise barriers in Korean children and adolescents after cancer treatment.
- Author
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Kim, Ji Young, Yoo, Samuel, Yeon, Su Jin, Min, Ji Hee, Kim, Dong-il, Lee, Ji Won, Han, Jung Woo, Lyu, Chuhl Joo, and Jeon, Justin Y.
- Subjects
- *
PHYSICAL activity , *CHILDHOOD cancer , *CANCER treatment , *BRAIN tumors - Abstract
Purpose: The purpose of the current study was to explore physical activity (PA) levels, exercise preferences, and perceived barriers to PA in childhood cancer survivors. Methods: This cross-sectional study surveyed 120 childhood cancer survivors aged 8–18 years from the pediatric oncology center in South Korea between March and August 2017. The modified Exercise & Quality of Life questionnaire, Korea Youth Risk Behavior Web-based Survey, and Godin Leisure-Time Questionnaire were used to assess PA levels, preferences, and exercise barriers. Results: Among 120 participants (72 boys, 48 girls) whose average age at the time of the survey was 14.57 ± 3.00 years and the average age at diagnosis was 8.22 years, the three most common diagnoses were acute leukemia (43.3%), brain tumor (13.3%), and malignant lymphoma (10.8%). Only 16 participants (5%) met the PA recommendations for children (at least 60 min of moderate PA per day). The most preferred sporting activities included soccer, basketball, strengthening exercises, badminton, dance, and taekwondo. They generally had positive attitudes toward exercise, and more than 63% of participants intended to exercise the following month. The five most prevalent perceived barriers to exercise were lack of time, poor health, reluctance to sweat, lack of exercise skills, and no exercise partners. Conclusions: While most childhood cancer survivors did not meet the PA recommendation, most of them agreed that exercise was beneficial, and they intended to participate in the exercise. Exercise and PA programs should be tailored to the personal health and preferences of childhood cancer survivors. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
32. Third-harmonic Mie scattering from semiconductor nanohelices.
- Author
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Ohnoutek, Lukas, Kim, Ji-Young, Lu, Jun, Olohan, Ben J., Răsădean, Dora M., Dan Pantoș, G., Kotov, Nicholas A., and Valev, Ventsislav K.
- Abstract
Chiroptical spectroscopies provide structural analyses of molecules and nanoparticles but they require sample volumes that are incompatible with generating large chemical libraries. New optical tools are needed to characterize chirality for the ultrasmall (<1 µl) volumes required in the high-throughput synthetic and analytical stations for chiral compounds. Here we show experimentally a novel photonic effect that enables such capabilities—third-harmonic Mie scattering optical activity—observed from suspensions of CdTe nanostructured helices in volumes <<1 µl. Third-harmonic Mie scattering was recorded on illuminating CdTe helices with 1,065, 1,095 and 1,125 nm laser beams and the intensity was around ten-times higher in the forward direction than sideways. The third-harmonic ellipticity was as high as 3° and we attribute this effect to the interference of chiral and achiral effective nonlinear susceptibility tensor components. Third-harmonic Mie scattering on semiconductor helices opens a path for rapid high-throughput chiroptical characterization of sample volumes as small as 10
−5 µl. Third-harmonic Mie scattering optical activity from suspensions of semiconductor (CdTe) nanostructured helices is observed, opening ways for chiroptical characterization of semiconductor and other chiral non-metallic particles in volumes potentially of the order of 10–17 m3 . [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
33. Stable Zn Metal Anodes with Limited Zn-Doping in MgF2 Interphase for Fast and Uniformly Ionic Flux.
- Author
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Kim, Ji Young, Liu, Guicheng, Ardhi, Ryanda Enggar Anugrah, Park, Jihun, Kim, Hansung, and Lee, Joong Kee
- Subjects
- *
HYDROGEN evolution reactions , *ANODES , *METALS , *INTERFACIAL resistance , *ZINC alloys - Abstract
Highlights: A limitedly Zn-doped MgF2 passivation layer consisting of a porous pure MgF2- and gradient Zn-doped MgF2-regions was developed for stable Zn metal anodes with excellent reversibility to 8000 cycles at 10.0 mA cm−2. The MgF2 region facilitates facile de-solvation of Zn ions and effective hydrogen evolution reaction suppression. The Zn-doped MgF2 region enhances transfer kinetics and homogeneous deposition of Zn ions by interfacial polarization between Zn dopant and MgF2 matrix, and high concentration of the Zn dopant as fine nuclei. The practical applications of aqueous Zn metal batteries are currently restricted by the inherent drawbacks of Zn such as the hydrogen evolution reaction, sluggish kinetics, and dendrite formation. To address these problems, herein, a limitedly Zn-doped MgF2 interphase comprising an upper region of pure, porous MgF2 and a lower region of gradient Zn-doped MgF2 is achieved via radio frequency sputtering technique. The porous MgF2 region is a polar insulator whose high corrosion resistance facilitates the de-solvation of the solvated Zn ions and suppression of hydrogen evolution, resulting in Zn metal electrodes with a low interfacial resistance. The Zn-doped MgF2 region facilitates fast transfer kinetics and homogeneous deposition of Zn ions owing to the interfacial polarization between the Zn dopant and MgF2 matrix, and the high concentration of the Zn dopant on the surface of the metal substrate as fine nuclei. Consequently, a symmetric cell incorporating the proposed Zn metal exhibits low overpotentials of ~ 27.2 and ~ 99.7 mV without Zn dendrites over 250 to 8000 cycles at current densities of 1.0 and 10.0 mA cm−2, respectively. The developed Zn/MnO2 full cell exhibits superior capacity retentions of 97.5% and 84.0% with average Coulombic efficiencies of 99.96% after 1000 and 3000 cycles, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Enantiomer-dependent immunological response to chiral nanoparticles.
- Author
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Xu, Liguang, Wang, Xiuxiu, Wang, Weiwei, Sun, Maozhong, Choi, Won Jin, Kim, Ji-Young, Hao, Changlong, Li, Si, Qu, Aihua, Lu, Meiru, Wu, Xiaoling, Colombari, Felippe M., Gomes, Weverson R., Blanco, Asdrubal L., de Moura, Andre F., Guo, Xiao, Kuang, Hua, Kotov, Nicholas A., and Xu, Chuanlai
- Abstract
Chirality is a unifying structural metric of biological and abiological forms of matter. Over the past decade, considerable clarity has been achieved in understanding the chemistry and physics of chiral inorganic nanoparticles1–4; however, little is known about their effects on complex biochemical networks5,6. Intermolecular interactions of biological molecules and inorganic nanoparticles show some commonalities7–9, but these structures differ in scale, in geometry and in the dynamics of chiral shapes, which can both impede and strengthen their mirror-asymmetric complexes. Here we show that achiral and left- and right-handed gold biomimetic nanoparticles show different in vitro and in vivo immune responses. We use irradiation with circularly polarized light (CPL) to synthesize nanoparticles with controllable nanometre-scale chirality and optical anisotropy factors (g-factors) of up to 0.4. We find that binding of nanoparticles to two proteins from the family of adhesion G-protein-coupled receptors (AGPCRs)—namely cluster-of-differentiation 97 (CD97) and epidermal-growth-factor-like-module receptor 1 (EMR1)—results in the opening of mechanosensitive potassium-efflux channels, the production of immune signalling complexes known as inflammasomes, and the maturation of mouse bone-marrow-derived dendritic cells. Both in vivo and in vitro immune responses depend monotonically on the g-factors of the nanoparticles, indicating that nanoscale chirality can be used to regulate the maturation of immune cells. Finally, left-handed nanoparticles show substantially higher (1,258-fold) efficiency compared with their right-handed counterparts as adjuvants for vaccination against the H9N2 influenza virus, opening a path to the use of nanoscale chirality in immunology.Nanoparticles with different chiralities have different in vitro and in vivo effects on the immune system, suggesting new ways of creating vaccine adjuvants. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Multifactorial engineering of biomimetic membranes for batteries with multiple high-performance parameters.
- Author
-
Wang, Mingqiang, Emre, Ahmet E., Kim, Ji-Young, Huang, Yiting, Liu, Li, Cecen, Volkan, Huang, Yudong, and Kotov, Nicholas A.
- Subjects
LITHIUM sulfur batteries ,LITHIUM ions ,MECHANICAL engineering ,THERMAL properties ,HIGH temperatures ,DIFFUSION ,BIOMIMETIC materials - Abstract
Lithium–sulfur (Li–S) batteries have a high specific capacity, but lithium polysulfide (LPS) diffusion and lithium dendrite growth drastically reduce their cycle life. High discharge rates also necessitate their resilience to high temperature. Here we show that biomimetic self-assembled membranes from aramid nanofibers (ANFs) address these challenges. Replicating the fibrous structure of cartilage, multifactorial engineering of ion-selective mechanical, and thermal properties becomes possible. LPS adsorption on ANF surface creates a layer of negative charge on nanoscale pores blocking LPS transport. The batteries using cartilage-like bioinspired ANF membranes exhibited a close-to-theoretical-maximum capacity of 1268 mAh g
−1 , up to 3500+ cycle life, and up to 3C discharge rates. Essential for safety, the high thermal resilience of ANFs enables operation at temperatures up to 80 °C. The simplicity of synthesis and recyclability of ANFs open the door for engineering high-performance materials for numerous energy technologies. Lithium–sulfur batteries have a high specific capacity, but lithium polysulfide diffusion (LPS) and dendrite growth reduce their cycle life. Here, the authors show a biomimetic aramid nanofiber membrane for effectively suppressing LPS diffusion as well as lithium dendrites while allowing lithium ions to be transported. The membranes resists performance degradation at high temperatures and can be produced at scale by Kevlar recycling. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
36. Effects of diesel exhaust particles and urban particles on brain endothelial cells.
- Author
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Kim, Ji Young, Hong, Seonmi, Bolormaa, Ochirpurev, Seo, Je Hoon, Eom, Sang-Yong, Kim, Yong-Dae, and Kim, Heon
- Published
- 2022
- Full Text
- View/download PDF
37. Amino acid deprivation induces AKT activation by inducing GCN2/ATF4/REDD1 axis.
- Author
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Jin, Hyeon-Ok, Hong, Sung-Eun, Kim, Ji-Young, Jang, Se-Kyeong, and Park, In-Chul
- Published
- 2021
- Full Text
- View/download PDF
38. The C-terminal HSP90 inhibitor NCT-58 kills trastuzumab-resistant breast cancer stem-like cells.
- Author
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Park, Soeun, Kim, Yoon-Jae, Park, Jung Min, Park, Minsu, Nam, Kee Dal, Farrand, Lee, Nguyen, Cong-Truong, La, Minh Thanh, Ann, Jihyae, Lee, Jeewoo, Kim, Ji Young, and Seo, Jae Hong
- Published
- 2021
- Full Text
- View/download PDF
39. Multiplicative functions additive on polygonal numbers.
- Author
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Kim, Byungchan, Kim, Ji Young, Lee, Chong Gyu, and Park, Poo-Sung
- Subjects
- *
POLYGONAL numbers , *ADDITIVE functions , *UNIQUENESS (Mathematics) - Abstract
We prove that the set P (H , resp.) of all positive pentagonal (hexagonal, resp.) numbers is an additive uniqueness set for the collection of multiplicative functions; if a multiplicative function f satisfies the equation f (a + b) = f (a) + f (b) for all a , b ∈ P (H , resp.), then f is the identity function. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
40. The cytotoxic effects of bisphenol A alternatives in human lung fibroblast MRC5 cells.
- Author
-
Kim, Ji-Young, Shin, Geun-Seup, Kim, Chul-Hong, Kim, Mi Jin, An, Mi-Jin, Lee, Hyun-Min, and Kim, Jung-Woong
- Abstract
Background: Endocrine-disrupting compounds (EDCs) disrupt homeostasis via the dysregulation of hormone synthesis and metabolism. Bisphenol A (BPA) is widely used in consumer products, such as thermal receipts, water bottles, and baby bottles. However, BPA is also an EDC that acts as an estrogen agonist, and human exposure to BPA can lead to estrogenic effects. Consequently, manufacturers have started investigating the properties and effects of alternatives to BPA, molecules such as bisphenol F (BPF) and bisphenol S (BPS). Objective: Although multiple studies have demonstrated the adverse effect of bisphenols, it remains unknown whether bisphenols affect human lung fibroblast cells. In this study, we investigated the cytotoxic effects of BPA, BPF, and BPS on the MRC5 human lung fibroblast cell line. Results: We examined and compared the effects of BPA and its alternatives on cell proliferation, cell cycle progression, and apoptosis. Conclusion: Brief exposures to low concentrations of BPA, BPF, and BPS had no effects on cell viability, cell cycle progression, or apoptosis among MRC5 human lung fibroblast cells. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
41. 1-Universal binary and ternary Hermitian lattices over imaginary quadratic fields.
- Author
-
Kim, Byeong Moon and Kim, Ji Young
- Abstract
A positive definite Hermitian lattice is said to be 1-universal if it represents all positive definite unary Hermitian lattices, including both free and non-free Hermitian lattices. This paper is more concerned with the representations of unary non-free Hermitian lattices by Hermitian lattices. We estimate the minimal rank u m 1 of 1-universal Hermitian lattices and we classify all 1-universal binary and ternary Hermitian lattices over imaginary quadratic fields Q (- m) for all positive square-free integers m. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
42. Visual interpretation of [18F]Florbetaben PET supported by deep learning–based estimation of amyloid burden.
- Author
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Kim, Ji-Young, Oh, Dongkyu, Sung, Kiyoung, Choi, Hongyoon, Paeng, Jin Chul, Cheon, Gi Jeong, Kang, Keon Wook, Lee, Dong Young, and Lee, Dong Soo
- Subjects
- *
POSITRON emission tomography , *AMYLOID , *DEEP learning , *INSTRUCTIONAL systems - Abstract
Purpose: Amyloid PET which has been widely used for noninvasive assessment of cortical amyloid burden is visually interpreted in the clinical setting. As a fast and easy-to-use visual interpretation support system, we analyze whether the deep learning–based end-to-end estimation of amyloid burden improves inter-reader agreement as well as the confidence of the visual reading. Methods: A total of 121 clinical routines [18F]Florbetaben PET images were collected for the randomized blind-reader study. The amyloid PET images were visually interpreted by three experts independently blind to other information. The readers qualitatively interpreted images without quantification at the first reading session. After more than 2-week interval, the readers additionally interpreted images with the quantification results provided by the deep learning system. The qualitative assessment was based on a 3-point BAPL score (1: no amyloid load, 2: minor amyloid load, and 3: significant amyloid load). The confidence score for each session was evaluated by a 3-point score (0: ambiguous, 1: probably, and 2: definite to decide). Results: Inter-reader agreements for the visual reading based on a 3-point scale (BAPL score) calculated by Fleiss kappa coefficients were 0.46 and 0.76 for the visual reading without and with the deep learning system, respectively. For the two reading sessions, the confidence score of visual reading was improved at the visual reading session with the output (1.27 ± 0.078 for visual reading-only session vs. 1.66 ± 0.63 for a visual reading session with the deep learning system). Conclusion: Our results highlight the impact of deep learning–based one-step amyloid burden estimation system on inter-reader agreement and confidence of reading when applied to clinical routine amyloid PET reading. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
43. Telmisartan Inhibits the NLRP3 Inflammasome by Activating the PI3K Pathway in Neural Stem Cells Injured by Oxygen-Glucose Deprivation.
- Author
-
Kwon, Hyuk Sung, Ha, Jungsoon, Kim, Ji Young, Park, Hyun-Hee, Lee, Eun-Hye, Choi, Hojin, Lee, Kyu-Yong, Lee, Young Joo, and Koh, Seong-Ho
- Abstract
Angiotensin II receptor blockers (ARBs) have been shown to exert neuroprotective effects by suppressing inflammatory and apoptotic responses. In the present study, the effects of the ARB telmisartan on the NLRP3 inflammasome induced by oxygen-glucose deprivation (OGD) in neural stem cells (NSCs) were investigated, as well as their possible association with the activation of the PI3K pathway. Cultured NSCs were treated with different concentrations of telmisartan and subjected to various durations of OGD. Cell counting, lactate dehydrogenase, bromodeoxyuridine, and colony-forming unit assays were performed to measure cell viability and proliferation. In addition, the activity of intracellular signaling pathways associated with the PI3K pathway and NLRP3 inflammasome was evaluated. Telmisartan alone did not affect NSCs up to a concentration of 10 μM under normal conditions but showed toxicity at a concentration of 100 μM. Moreover, OGD reduced the viability of NSCs in a time-dependent manner. Nevertheless, treatment with telmisartan increased the viability and proliferation of OGD-injured NSCs. Furthermore, telmisartan promoted the expression of survival-related proteins and mRNA while inhibiting the expression of death-related proteins induced by OGD. In particular, telmisartan attenuated OGD-dependent expression of the NLRP3 inflammasome and its related signaling proteins. These beneficial effects of telmisartan were blocked by a PI3K inhibitor. Together, these results indicate that telmisartan attenuated the activation of the NLRP3 inflammasome by triggering the PI3K pathway, thereby contributing to neuroprotection. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Hydrophilic Modification of a Polyurethane Surface Using Grafted 2,4,6-Tris(dimethylaminomethyl) Phenol.
- Author
-
Chung, Yong-Chan, Kim, Ji Young, Park, Ji Eun, and Chun, Byoung Chul
- Abstract
2,4,6-Tris(dimethylaminomethyl) phenol (TDMP) was used as a grafted functional group to modify the hydrophilicity of polyurethane (PU) and to enhance the mechanical properties and low-temperature flexibility of PU. The grafted TDMP after conversion to the ionic form notably enhanced the hydrophilicity of PU, as confirmed by the water contact angle, water swelling, and water vapor permeability results. The light crosslinking that occurred during the grafting step increased the crosslink density and solution viscosity but did not disturb the solvation of PU. The melting of the soft segment was not affected by the grafted TDMP, but the crystallization of the soft segment was significantly reduced. The breaking tensile stress and shape recovery capability were notably enhanced, but the breaking tensile strain and shape retention capability were not impaired. In addition, the grafted TDMP notably improved the flexibility of PU at very low temperature compared with that of plain PU and control series PU. Overall, it is worth grafting TDMP onto PU considering the simple preparation method, the novelty of the modification mechanism, the notable enhancement in hydrophilicity, and the potential applications in fiber and biomedical fields. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. Human pluripotent stem-cell-derived alveolar organoids for modeling pulmonary fibrosis and drug testing.
- Author
-
Kim, Jung-Hyun, An, Geun Ho, Kim, Ji-Young, Rasaei, Roya, Kim, Woo Jin, Jin, Xiong, Woo, Dong-Hun, Han, Choongseong, Yang, Se-Ran, Kim, Jong-Hoon, and Hong, Seok-Ho
- Published
- 2021
- Full Text
- View/download PDF
46. Genetic evidence for sex-biased dispersal and cryptic diversity in the greater horseshoe bat, Rhinolophus ferrumequinum.
- Author
-
Jang, Ji Eun, Byeon, Seo Yeon, Kim, Hye Ri, Kim, Ji Young, Myeong, Hyeon Ho, and Lee, Hyuk Je
- Subjects
HORSESHOE bats ,ANIMAL sexual behavior ,NUCLEAR DNA ,MITOCHONDRIAL DNA ,SPECIES diversity ,ANIMAL offspring sex ratio ,CHLOROPLAST DNA - Abstract
Dispersal plays an important role in the ecological and evolutionary processes of natural populations. Mating behavior (or mating system) is a critical factor shaping dispersal patterns and extents in social mammals, sometimes driving the evolution of sex-biased dispersal. Using molecular markers with contrasting modes of inheritance (mitochondrial DNA and nuclear microsatellites), we determined the population genetic structure and evolutionary history of the great horseshoe bat, Rhinolophus ferrumequinum inhabiting eleven national parks of South Korea, being known as a biodiversity hotspot. Despite apparent matrilineal structure observed over space, there was weak nuclear geographic structure, suggesting female philopatry with male-biased dispersal. The analyses indicated the signal of nonrandom mating (i.e. inbreeding), which is at least partly due to female's sedentary lifestyle. The large-scale phylogenetic analysis revealed unexpected deep divergence among three distinct clades (Southwest China, East China, and Northeast Asia including South Korea), suggesting these may possibly represent cryptic species complex in R. ferrumequinum. Our findings of sex differences in dispersal in R. ferrumequinum inform conservation managements to enhance the population connectivity among the national parks through promoting female dispersal. Our study also highlights cryptic species diversity in a temperate bat that should have a priority for conservation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
47. Astrocytes phagocytose adult hippocampal synapses for circuit homeostasis.
- Author
-
Lee, Joon-Hyuk, Kim, Ji-young, Noh, Seulgi, Lee, Hyoeun, Lee, Se Young, Mun, Ji Young, Park, Hyungju, and Chung, Won-Suk
- Abstract
In the adult hippocampus, synapses are constantly formed and eliminated1,2. However, the exact function of synapse elimination in the adult brain, and how it is regulated, are largely unknown. Here we show that astrocytic phagocytosis3 is important for maintaining proper hippocampal synaptic connectivity and plasticity. By using fluorescent phagocytosis reporters, we find that excitatory and inhibitory synapses are eliminated by glial phagocytosis in the CA1 region of the adult mouse hippocampus. Unexpectedly, we found that astrocytes have a major role in the neuronal activity-dependent elimination of excitatory synapses. Furthermore, mice in which astrocytes lack the phagocytic receptor MEGF10 show a reduction in the elimination of excitatory synapses; as a result, excessive but functionally impaired synapses accumulate. Finally, Megf10-knockout mice show defective long-term synaptic plasticity and impaired formation of hippocampal memories. Together, our data provide strong evidence that astrocytes eliminate unnecessary excitatory synaptic connections in the adult hippocampus through MEGF10, and that this astrocytic function is crucial for maintaining circuit connectivity and thereby supporting cognitive function.In adult mice, astrocytes carry out phagocytosis of excitatory hippocampal synapses through MEGF10 to maintain synaptic and circuit homeostasis. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
48. Degradation of different pesticides in water by microplasma: the roles of individual radicals and degradation pathways.
- Author
-
Khan, Muhammad Saiful Islam, Lee, Na Ri, Ahn, Jaehwan, Kim, Ji Young, Kim, Jong Hoon, Kwon, Ki Hyun, and Kim, Yun-Ji
- Subjects
DDT (Insecticide) ,HYDROGEN peroxide ,ORGANOPHOSPHORUS pesticides ,PESTICIDES ,ORGANOCHLORINE pesticides ,HIGH performance liquid chromatography ,NITROGEN oxides ,HYDROXYL group - Abstract
Pesticides are emergent toxins often identified in aquatic environments. In the present study, microplasma was employed to reduce the pesticide content in water. The degradation efficacy, rate, and pathways of standard organophosphorus pesticides (namely, chlorpyrifos, chlorpyrifos oxone, and diazinone) and an organochlorine pesticide (namely, DDT solution) were evaluated using microplasma. High-performance liquid chromatography (HPLC) analysis was performed to elucidate the degradation efficiency of pesticides as a function of plasma-produced substances that originally contributed to the main reduction procedure. Microplasma produces several types of radicals or reactive substances, for instance dissolved ozone (O
3 ), nitrogen oxides, hydroxyl radicals (OH radicals), and hydrogen peroxide (H2 O2 ). The removal potential differs due to the existence or absence of varieties of plasma-produced substances. The functions of major plasma-produced species on pesticide removal were determined by a passive technique. Nitrogen oxides showed a key role in organophosphorus pesticide removal, whereas dissolved ozone and OH radicals played major roles in DDT degradation. HPLC data showed that plasma-induced pesticide removal showed first-order reaction kinetics. The pesticide removal pathways through microplasma were validated by investigating the achieved data from LC-MS and GC-MS. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
49. First-principles study of the ternary effects on the plasticity of γ-TiAl crystals.
- Author
-
Lee, Taegu, Kim, Seong-Woong, Kim, Ji Young, Ko, Won-Seok, and Ryu, Seunghwa
- Subjects
CRYSTALS ,POINT defects ,SHEARING force ,SUPERLATTICES ,YIELD strength (Engineering) - Abstract
We studied the effects of important ternary elements, such as Cr, Nb, and V, on the plasticity of γ -TiAl crystals by calculating the point defect formation energy and the change in the generalized stacking fault energy (GSFE) surface from first-principles calculations. For all three elements, the point defect formation energies of the substitutional defects are lower in the Ti site than in the Al site, which implies that substitution on the Ti site is energetically more stable. We computed the GSFE surfaces with and without a substitutional solute and obtained the ideal critical resolved shear stress (ICRSS) of each partial slip. The change in the GSFE surface indicates that the substitution of Ti with Cr, Nb, or V results in an increase in the yield strength because the ICRSS of the superlattice intrinsic stacking fault (SISF) partial slip increases. Interestingly, we find that Cr substitution on an Al site could occur owing to the small difference between the substitutional defect formation energies of the Ti and Al sites. In that case, the reduction of ICRSSs of the SISF partial slip and twinning would lead to improved twinnability. We discuss the implications of the computational predictions by comparing them with experimental results in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
50. Effects of Nonreciprocal Peer Tutoring With Preschool Students.
- Author
-
Morgan, Georgette A., Kim, Ji Young, and Fienup, Daniel M.
- Published
- 2020
- Full Text
- View/download PDF
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