33 results on '"Park, Gunwoo"'
Search Results
2. Downregulation of otulin induces inflammasome activation in neutrophilic asthma
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Quoc, Quang Luu, Kim, YeJi, Park, Gunwoo, Cao, Thi Bich Tra, Choi, Youngwoo, Park, Yong Hwan, and Park, Hae-Sim
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- 2024
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3. Author Correction: Human milk oligosaccharide 2'-fucosyllactose promotes melanin degradation via the autophagic AMPK–ULK1 signaling axis
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Heo, Hyojin, Cha, Byungsun, Jang, Dongmin, Park, Chaewon, Park, Gunwoo, Kwak, Byeong-Mun, Bin, Bum-Ho, Park, Ji-Hwan, and Lee, Mi-Gi
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- 2022
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4. Human milk oligosaccharide 2'-fucosyllactose promotes melanin degradation via the autophagic AMPK–ULK1 signaling axis
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Heo, Hyojin, Cha, Byungsun, Jang, Dongmin, Park, Chaewon, Park, Gunwoo, Kwak, Byeong-Mun, Bin, Bum-Ho, Park, Ji-Hwan, and Lee, Mi-Gi
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- 2022
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5. Anti‐inflammatory effect of Trichospira verticillata via suppression of the NLRP3 inflammasome in neutrophilic asthma.
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Yang, Hyeyun, Park, Gunwoo, Lee, Sojung, Lee, Sumin, Kim, YeJi, Zamora, Nelson A., Yi, Dong‐Keun, Kim, Soo‐Yong, Choi, Chun Whan, Choi, Sangho, and Park, Yong Hwan
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NLRP3 protein ,INFLAMMASOMES ,NF-kappa B ,POTASSIUM ,ASTHMA ,REACTIVE oxygen species - Abstract
Trichospira verticillata is an annual herb that belongs to the family Asteraceae. Trichospira verticillata extract (TVE) elicits anti‐plasmodial activity; however, there has been no detailed report about its anti‐inflammatory effects and molecular mechanisms. In addition, herbal plants exhibit anti‐inflammatory effects by suppressing the NLRP3 inflammasome. Therefore, the primary goal of this study was to examine the effects of TVE on NLRP3 inflammasome activation by measuring interleukin‐1β (IL‐1β) secretion. We treated lipopolysaccharides (LPS)‐primed J774A.1 and THP‐1 cells with TVE, which attenuated NLRP3 inflammasome activation. Notably, TVE did not affect nuclear factor‐kappa B (NF‐κB) signalling or intracellular reactive oxygen species (ROS) production and potassium efflux, suggesting that it inactivates the NLRP3 inflammasome via other mechanisms. Moreover, TVE suppressed the formation of apoptosis‐associated speck‐like protein (ASC) speck and oligomerization. Immunoprecipitation data revealed that TVE reduced the binding of NLRP3 to NIMA‐related kinase 7 (NEK7), resulting in reduced ASC oligomerization and speck formation. Moreover, TVE alleviated neutrophilic asthma (NA) symptoms in mice. This study demonstrates that TVE modulates the binding of NLPR3 to NEK7, thereby reporting novel insights into the mechanism by which TVE inhibits NLRP3 inflammasome. These findings suggest TVE as a potential therapeutic of NLRP3 inflammasome‐mediated diseases, particularly NA. [ABSTRACT FROM AUTHOR]
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- 2024
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6. The Slc45a4 Gene Regulates Pigmentation in a Manner Distinct from that of the OCA4 Gene Slc45a2
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Brito, Sofia, Heo, Hyojin, Cha, Byungsun, Lee, Sang Hun, Park, Gunwoo, Kwak, Byeong-Mun, Seong, Je Kyung, Lee, Ho, Park, Ji-Hwan, Weon, Byung Mook, and Bin, Bum-Ho
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- 2024
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7. Vegetation destruction during an extreme flood: Multilevel modelling of an entire river in southern Korea.
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Lee, Keonhak, Lee, Cheolho, Baek, Donghae, Park, Gunwoo, Shim, Taeyong, Kim, Won, Cho, Kang‐Hyun, and Kim, Daehyun
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RIPARIAN plants ,MULTILEVEL models ,EXTREME weather ,RAINFALL ,FLUVIAL geomorphology ,FLOODS ,SHEARING force - Abstract
Human‐induced climate change causes extreme weather events, and flooding induced by heavy rainfall in the riparian system is no exception. The southern Korean Peninsula witnessed record‐breaking rainfall during the summer of 2020, resulting in an extreme flood event that caused extensive damage to the riparian ecosystem along the Seomjin River. This study was aimed at identifying the composite factors of riparian vegetation destruction along the entire river. Based on a spatially explicit multilevel approach, it was found that large‐scale geomorphic characteristics (i.e., alternation of plain and valley topographies) appeared to be essential determinants of hydraulic characteristics of the channel (e.g., shear stress and specific energy), which were the leading causes of vegetation destruction. Moreover, at small spatial scales, several trees situated upstream of a vegetation patch protected other plants on the patch from the direct hydraulic impact of the flood, thereby serving as 'shield' trees. These findings indicate that scale‐dependent fluvial biogeomorphic processes take place during extreme flood events; hence, identifying the optimal scales of these processes and associated factors could help in further understanding riparian hydrology from a biogeomorphic point of view. This study suggests that hydrologists consider both geomorphological and ecological factors when studying hydrological processes. [ABSTRACT FROM AUTHOR]
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- 2023
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8. An anti-EGFR × cotinine bispecific antibody complexed with cotinine-conjugated duocarmycin inhibits growth of EGFR-positive cancer cells with KRAS mutations
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Jin, Junyeong, Park, Gunwoo, Park, Jong Bae, Kim, Soohyun, Kim, Hyori, and Chung, Junho
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- 2018
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9. Does Botulinum Toxin Injection into Masseter Muscles Affect Subcutaneous Thickness?
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Park, Gunwoo, Choi, Young-Chan, Bae, Jung-Hee, and Kim, Seong-Taek
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- 2018
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10. Modeling Ultrafiltration of Interacting Brownian Particles
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Park, Gunwoo and Naegele, Gerhard
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Membrane crossflow ultrafiltration (UF) is widely used for the enrichment and purification of colloids and proteins. In this continuous process, a feed dispersion is steadily pumped through a channel consisting of solvent-permeable membrane walls. The applied transmembrane pressure (TMP) causes the solvent to flow out of the membrane channel. The TMP-induced permeate flux of a colloidal dispersion is commonly smaller than that of pure solvent. This unwarranted permeate flux reduction is due to the following effects. First, the permeate flux transports colloidal particles towards the inner membrane surface where they form a particle-enriched diffuse layer. This so-called concentration polarization (CP) layer increases the osmotic particle pressure which counteracts the applied TMP. Second, membrane-fouling mechanisms are operative, including the formation of adsorbed particle layers partially blocking the membrane pores, and the formation of a cake multi-layer of immobilized particles. Fouling mechanisms decrease the hydraulic permeability of the membrane and possibly cause irreversible damage to the membrane. We have developed a semi-analytic modified boundary layer approximation (mBLA) method to calculate concentration and flow profiles in the UF of colloidal dispersions from knowledge of the concentration-dependent bulk suspension properties [1, 2]. The mBLA is an accurate and fast method, producing results in full agreement with numerically expensive finite-element calculations [1]. Moreover, the semi-analytic mBLA expressions provide the important insight into the influence of dispersion properties such as the collective diffusion coefficient and shear viscosity, which helps to improve the UF efficiency [1, 2]. We present mBLA results for the UF of dispersions of solvent-permeable rigid, and of charge-stabilized colloidal particles in a broad range of particle sizes. A simple cake layer model is used to unravel the relations between critical and limiting permeate fluxes and applied TMP [3]. References[1] G. W. Park and G. Nägele, Journal of Chemical Physics, 2020, 153, 204110.[2] G. W. Park and G. Nägele, Membranes, 2021, 11, 960.[3] G. W. Park, M. Brito, and G. Nägele, manuscript in preparation.
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- 2022
11. Critical Flux in Particle Ultrafiltration of Variable Sizes: Using Interacting Brownian Dispersions
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Park, Gunwoo and Naegele, Gerhard
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Cross-flow ultrafiltration (UF) is a pressure-driven separation process used, e.g., for water purification, blood treatment by (artificial) kidneys, and protein enrichment. In this process, a feed dispersion is steadily pumped through a channel consisting of solvent-permeable membrane walls. The applied transmembrane pressure (TMP) causes solvent to flow out of channel so that a particle-enriched diffuse layer is formed near the membrane walls. This so- called concentration-polarization (CP) reduces the permeate flux and hence the filtration efficiency, due to osmotic pressure built-up counter-acting the TMP. The particle concentration inside the CP layer increases with the applied TMP. When it reaches a freezing concentration where the particles are immobilized, an unwarranted cake layer is formed at the membrane walls. The permeate flux value signaling the onset of cake formation is called the critical flux. Predictions of the critical flux are commonly made using standard film theory which, however, applies only to colloidal particles and proteins of a diameter smaller than 10 nm. When the diameter roughly exceeds 100 nm, the predicted critical flux is an order-of- magnitude smaller than the experimental one. This is referred to as the critical flux paradox.We present theoretical results for the UF concentration and flow profiles, and the critical flux for dispersions of various size of particles. The results are obtained using a recently published modified boundary layer approximation (mBLA) method of cross-flow UF. The semi-analytic mBLA method provides an accurate description of UF concentration and flow profiles, on accounting for the concentration dependence of dispersion transport properties and osmotic pressure. The considered model dispersions encompass impermeable and permeable hard spheres and charge-stabilized particles. For hard-sphere dispersions, the mBLA method is extended to the microfiltration regime where shear-induced migration becomes important.
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- 2022
12. The effect of shear-induced migration on crossflow filtration of colloids
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Park, Gunwoo and Naegele, Gerhard
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Membrane crossflow filtration is widely used for the enrichment and purification of colloidal and protein dispersions. In this pressure-driven process, a feed dispersion is steadily pumped through a channel consisting of solvent-permeable membrane walls. The applied transmembrane pressure (TMP) causes advection of the dispersion toward the membrane, and formation of a particle-enriched diffuse layer near its surface. This so-called concentration polarization (CP) layer increases the osmotic particle pressure counteracting the TMP. When the particle concentration reaches a solidification limit, an immobilized particulate layer, termed cake layer, is formed next to the membrane surface. The cake layer adds to the hydraulic membrane resistance and lowers thus the filtration efficiency. A key problem is to understand quantitatively how cake formation is related to filtration operating conditions, and to dispersion and membrane properties. In this study, we theoretically analyze how permeate flux and cake layer formation are influenced by the size, charge and feed concentration of dispersed particles [1]. We consider dispersions of neutral and charge-stabilized colloidal particles. Under conditions where shear-induced migration matters, empirical expressions for shear-rate dependent transport properties are used. Our results for concentration and flow profiles under filtration are obtained using a recently developed modified boundary layer approximation (mBLA) method [2, 3]. The mBLA is a numerically efficient and accurate method for predicting filtration properties. A thorough dicussion of the so-called critical permeate flux related to the onset of cake layer formation is presented. Moreover, an analytic expression for the critical flux is derived and compared with standard predictions by film theory and mass transfer coefficient calculations. References[1] G. W. Park, J. K. G. Dhont, and G. Nägele, manuscript in preparation.[2] G. W. Park and G. Nägele, Journal of Chemical Physics, 2020, 153, 204110[3] G. W. Park and G. Nägele, Membranes, 2021, 11, 960
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- 2022
13. DEAD-box RNA helicase DDX23 modulates glioma malignancy via elevating miR-21 biogenesis
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Yin, Jinlong, Park, Gunwoo, Lee, Jeong Eun, Choi, Eun Young, Park, Ju Young, Kim, Tae-Hoon, Park, Nayun, Jin, Xiong, Jung, Ji-Eun, Shin, Daye, Hong, Jun Hee, Kim, Hyunggee, Yoo, Heon, Lee, Seung-Hoon, Kim, Youn-Jae, Park, Jong Bae, and Kim, Jong Heon
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- 2015
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14. Modeling concentration polarization and fouling layers in cross-flow ultrafiltration
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Park, Gunwoo and Naegele, Gerhard
- Abstract
We present a boundary layer approximation (BLA) method for calculating the concentration-polarization (CP) layer and dispersion flow in crossflow ultrafiltration with a cylindrical membrane [1]. Results are discussed for various feed dispersions of colloidal particles, namely hard spheres, charge-stabilized particles [2], solvent-permeable non-ionic microgels [3, 4], and deswelling ionic microgels [5]. State-of-the-art methods are used for the gradient diffusion coefficient and viscosity entering the calculation of filtration profiles [3, 5]. We show that the BLA profiles are in quantitative agreement with predictions by a finite-element method [1]. The BLA results are compared with predictions by a similarity solution [4]. The BLA method is extended to conditions where a filter cake is formed at the membrane, with permeate flux results presented for a hard-sphere system [6].
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- 2021
15. The effect of dispersion transport properties on the concentration-polarization layer in crossflow ultrafiltration
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Park, Gunwoo, Brito, Mariano, and Naegele, Gerhard
- Abstract
Crossflow filtration is a pressure-driven separation and enrichment process for colloidal dispersions where the feed dispersion is continuously pumped through a membrane pipe. The transmembrane pressure (TMP) causes solvent to flow out of the membrane, while the colloidal particles are retained inside the pipe. Consequently, a particles-enriched diffuse layer is formed near the membrane wall which reduces the filtration efficiency. This so-called concentration-polarization (CP) layer is due to the balance of flow advection of particles towards and gradient diffusion away from the membrane. In the ultrafiltration regime where Brownian motion dominates flow convection, the collective diffusion coefficient and the dispersion viscosity are the key transport properties determining the CP layer in conjunction with the TMP and transmembrane osmotic pressure. In this study, we present a finite-element (FEM) method for calculating the CP layer and suspension flow profiles in a crossflow ultrafiltration setup [1]. We show that the FEM-calculated CP layer profiles are in quantitative agreement with results obtained from a simplifying boundary layer analysis [1]. Results for the filtration and flow profiles are discussed for different globular dispersion particles including colloidal hard spheres (as a reference system), solvent-permeable particles such as non-ionic microgels [2], impermeable charge-stabilized particles [3], and ionic microgels with concentration-dependent size [4]. We pay particular attention to the effect of the different transport properties and osmotic pressure dependencies on the ultrafiltration profiles.References[1] G. W. Park and G. Nägele, “Analytic and numerical approaches to concentration-polarization layers in cross-flow ultrafiltration with a cylindrical membrane pipe” (in preparation)[2] R. Roa et al., “Ultrafiltration modeling of non-ionic microgels,” Soft Matter 11, 4106-4122 (2015) [3] R. Roa et al., “Ultrafiltration of charge-stabilized dispersions at low salinity,” Soft Matter 12,4638-4653 (2016)[4] M. Brito et al., “Deswelling effects on structural and transport properties of ionic microgelsuspensions” (in preparation)
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- 2019
16. Modelling of Cross-flow Ultrafiltration of Non-ionic Microgel Suspensions for a Cylindrical Membrane Pipe
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Park, Gunwoo, Brito, Mariano, Zholkovskiy, and Naegele, Gerhard
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Cross-flow inside-out filtration is a pressure-driven separation and enrichment process of microgel and colloidal suspensions where the feed suspension is continuously pumped tangentially through a membrane pipe. The transmembrane pressure (TMP) causes permeate (solvent) to flow out through the membrane, while the microgel particles are retained inside the pipe. Consequently, a particle-enriched diffuse layer is formed near the membrane wall which reduces the filtration efficiency. This so-called concentration-polarization (CP) layer is due to the balance of flow advection of particles towards and gradient diffusion away from the membrane. The resulting CP layer osmotic pressure operates against the TMP and counteracts the permeate flow.To model the CP layer with its physical effects in the ultrafiltration regime where Brownian motion dominates flow convection, it is crucial to determine the gradient diffusion coefficient, suspension viscosity, and osmotic pressure of concentrated microgel suspensions. In this study, we calculate these properties for non-ionic microgels treated as solvent-permeable and softly interacting colloidal particles. The suspension flow is described by the effective Stokes equation, and the permeate flux by Darcy’s law. Pore-blocking of the membrane is assumed to occur uniformly throughout its surface, with the sole result of increasing the overall hydraulic membrane resistance. We solve the coupled advection-diffusion equations quantifying of our ultrafiltration model by using a finite element method (FEM). The FEM results are compared with the standard similarity solution in boundary layer approximation [1]. As a reference, we also compare with simplifying analytic solutions for pure solvent flow, and for suspension flow where the microgel transport properties are taken as concentration independent [2]. Furthermore, we generalize the FEM analysis to a segmented membrane with impermeable rings to observe the weakening of the CP layer [3].References[1] R. Roa, E. Zholkovskiy, and G. Nägele, “Ultrafiltration modeling of non-ionic microgels,” Soft Matter 11, 4106–4122 (2015).[2] G. W. Park and G. Nägele, work in progress.[3] G. W. Park, M. Brito, E. Zholkovskiy, and G. Nägele, work in progress.
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- 2019
17. Uniqueness of gait kinematics in a cohort study.
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Park, Gunwoo, Lee, Kyoung Min, and Koo, Seungbum
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KINEMATICS , *WALKING , *COMPUTER vision , *MACHINE learning , *MOTION capture (Human mechanics) - Abstract
Gait, the style of human walking, has been studied as a behavioral characteristic of an individual. Several studies have utilized gait to identify individuals with the aid of machine learning and computer vision techniques. However, there is a lack of studies on the nature of gait, such as the identification power or the uniqueness. This study aims to quantify the uniqueness of gait in a cohort. Three-dimensional full-body joint kinematics were obtained during normal walking trials from 488 subjects using a motion capture system. The joint angles of the gait cycle were converted into gait vectors. Four gait vectors were obtained from each subject, and all the gait vectors were pooled together. Two gait vectors were randomly selected from the pool and tested if they could be accurately classified if they were from the same person or not. The gait from the cohort was classified with an accuracy of 99.71% using the support vector machine with a radial basis function kernel as a classifier. Gait of a person is as unique as his/her facial motion and finger impedance, but not as unique as fingerprints. [ABSTRACT FROM AUTHOR]
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- 2021
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18. Exploring Shear Thickening of Telechelic Associating Polymers through Stochastic Simulations
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Park, Gunwoo and Ianniruberto, G.
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Hydrophobically modified exthoxylated urethane (HEUR) is one of the most popular examples of telechelic associating polymer. In a certain range of HEUR concentration in aqueous solution, (i) linear viscoelasticity follows a single-Maxwellian behavior with a characteristic time controlled by the network relaxation due to association/dissociation kinetics. In simple shear flows, HEUR systems often (ii) exhibit strain hardening in the transient startup when the shear rate exceeds the reciprocal relaxation time, and (iii) at steady state deviate from the Cox-Merz rule, deviations including (iv) a shear-thickening phenomenon. Recently, Park and Ianniruberto [1] suggested a new stochastic simulation to describe the complex rheological behavior listed in (i-iv). The results indicate that finite extensibility effects are mostly responsible for the strain hardening, while deviations from the Cox-Merz rule are due to the persistence of bridge chains. However, the detailed mechanism behind the shear thickening is still unclear. In this study, we show additional observables by using the same simulation method for a better understanding of the shear-thickening phenomenon. Furthermore, we extend the range of the parameter space explored in [1] by examining larger (and more reasonable) values of the ratio between the loop dissociation time and the Brownian diffusion time of flower-like micelles. [1] G. W. Park and G. Ianniruberto, J. Rheol. 61, 1293 (2017)
- Published
- 2018
19. Modulation of Nogo receptor 1 expression orchestrates myelin-associated infiltration of glioblastoma.
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Hong, Jun-Hee, Kang, Sangjo, Sa, Jason K, Park, Gunwoo, Oh, Young Taek, Kim, Tae Hoon, Yin, Jinlong, Kim, Sung Soo, D'Angelo, Fulvio, Koo, Harim, You, Yeonhee, Park, Saewhan, Kwon, Hyung Joon, Kim, Chan Il, Ryu, Haseo, Lin, Weiwei, Park, Eun Jung, Kim, Youn-Jae, Park, Myung-Jin, and Kim, Hyunggee
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GLIOBLASTOMA multiforme ,METHYLGUANINE ,MYELIN oligodendrocyte glycoprotein ,TREATMENT effectiveness ,GENES ,GENE ontology ,STEM cells ,CANCER cell differentiation ,PROTEIN metabolism ,ANIMAL experimentation ,GLIOMAS ,PROTEOLYTIC enzymes ,BRAIN tumors ,NERVE tissue ,CELL lines ,MICE - Abstract
As the clinical failure of glioblastoma treatment is attributed by multiple components, including myelin-associated infiltration, assessment of the molecular mechanisms underlying such process and identification of the infiltrating cells have been the primary objectives in glioblastoma research. Here, we adopted radiogenomic analysis to screen for functionally relevant genes that orchestrate the process of glioma cell infiltration through myelin and promote glioblastoma aggressiveness. The receptor of the Nogo ligand (NgR1) was selected as the top candidate through Differentially Expressed Genes (DEG) and Gene Ontology (GO) enrichment analysis. Gain and loss of function studies on NgR1 elucidated its underlying molecular importance in suppressing myelin-associated infiltration in vitro and in vivo. The migratory ability of glioblastoma cells on myelin is reversibly modulated by NgR1 during differentiation and dedifferentiation process through deubiquitinating activity of USP1, which inhibits the degradation of ID1 to downregulate NgR1 expression. Furthermore, pimozide, a well-known antipsychotic drug, upregulates NgR1 by post-translational targeting of USP1, which sensitizes glioma stem cells to myelin inhibition and suppresses myelin-associated infiltration in vivo. In primary human glioblastoma, downregulation of NgR1 expression is associated with highly infiltrative characteristics and poor survival. Together, our findings reveal that loss of NgR1 drives myelin-associated infiltration of glioblastoma and suggest that novel therapeutic strategies aimed at reactivating expression of NgR1 will improve the clinical outcome of glioblastoma patients. [ABSTRACT FROM AUTHOR]
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- 2021
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20. Does Botulinum Toxin Injection into Masseter Muscles Affect Subcutaneous Thickness?
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Gunwoo Park, Young-Chan Choi, Jung-Hee Bae, Seong-Taek Kim, Park, Gunwoo, Choi, Young-Chan, Bae, Jung-Hee, and Kim, Seong-Taek
- Abstract
Background: Botulinum toxin (BoNT) is widely used to treat masseter muscle hypertrophy. Changes in the muscle thickness have been found in many studies, but there has been no report on changes in the thickness from the skin surface to the masseter muscle.Objectives: We aimed to use ultrasonography to measure not only changes in the muscle thickness but also changes in subcutaneous thickness.Methods: This study enrolled 20 volunteer patients: 10 were assigned to an experimental group (injected with each side 25 U of botulinum toxin into both masseter muscles) and 10 to a control group (injected with normal saline). The thicknesses were measured before the injection and at 4, 8, and 12 weeks after the injection both at rest and during maximum muscle contraction.Results: The subcutaneous thickness did not differ significantly over time either at rest (P = 0.063) or during maximal contraction (P = 0.392), or between the experimental and control groups at rest (P = 0.392) or during maximum contraction (P = 0.259). The muscle thickness in the experimental group differed significantly over time.Conclusions: Botulinum toxin injection only changes the muscle thickness and does not affect the subcutaneous thickness from the skin surface to the masseter muscle. [ABSTRACT FROM AUTHOR]- Published
- 2018
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21. Correction: Pigment Epithelium-Derived Factor (PEDF) Expression Induced by EGFRvIII Promotes Self-renewal and Tumor Progression of Glioma Stem Cells.
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Yin, Jinlong, Park, Gunwoo, Kim, Tae Hoon, Hong, Jun Hee, Kim, Youn-Jae, Jin, Xiong, Kang, Sangjo, Jung, Ji-Eun, Kim, Jeong-Yub, Yun, Hyeongsun, Lee, Jeong Eun, Kim, Minkyung, Chung, Junho, Kim, Hyunggee, Nakano, Ichiro, Gwak, Ho-Shin, Yoo, Heon, Yoo, Byong Chul, Kim, Jong Heon, and Hur, Eun-Mi
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PIGMENT epithelium-derived factor , *CELL tumors , *CANCER invasiveness - Abstract
Corrections to the article "Pigment Epithelium-Derived Factor (PEDF) Expression Induced by EGFRvIII Promotes Self-renewal and Tumor Progression of Glioma Stem Cells" are presented.
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- 2016
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22. A 16.8 Gbps/Channel Single-Ended Transceiver in 65 nm CMOS for SiP-Based DRAM Interface on Si-Carrier Channel.
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Lee, Hyunbae, Song, Taeksang, Byeon, Sangyeon, Lee, Kwanghun, Jung, Inhwa, Kang, Seongjin, Kwon, Ohkyu, Cheon, Koeun, Seol, Donghwan, Kang, Jongho, Park, Gunwoo, and Kim, Yun-Saing
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COMPLEMENTARY metal oxide semiconductors ,SILICON compounds ,ION channels ,BIT error rate ,ELECTRIC power consumption - Abstract
A 16.8 Gbps/channel single-ended transceiver for SiP-based DRAM interface on silicon carrier channel is proposed in this paper. A transmitter, receiver, and channel are all included in a single package as SiP. A current mode 4:1 MUX with 1-tap feed-forward equalizer (FFE) is used as a serializer, and this 4:1 MUX uses 25% duty clock to prevent short circuit current when consecutive 2-phase clocks overlap. Additionally, an open drain output driver with asynchronous type 1-tap FFE is used in the transmitter. Because of its small physical size, a common mode variation of Si-carrier channel from process variation is more serious than that of conventional PCB. This common mode variation degrades bit error rates (BER) at single-ended signaling. To obtain effective single-ended signaling on Si-carrier channel, a source follower-based continuous time linear equalizers and self-VREF generator with training algorithm on the receiver are proposed. An implemented Si-carrier channel uses meshed layer as a reference to reduce insertion loss. A BER less than 1e-12 is achieved in 65 nm CMOS and the power efficiency of the transceiver is 5.9 pJ/bit with 120 \Omega terminations at each transceiver side. [ABSTRACT FROM PUBLISHER]
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- 2015
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23. A 16.8Gbps/channel single-ended transceiver in 65nm CMOS for SiP based DRAM interface on Si-carrier channel.
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Lee, Hyunbae, Song, Taeksang, Byeon, Sangyeon, Lee, Kwanghun, Jung, Inhwa, Kang, Seongjin, Kwon, Ohkyu, Cheon, Koeun, Seol, Donghwan, Kang, Jongho, Park, Gunwoo, and Kim, Yunsaing
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- 2014
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24. Pigment Epithelium-Derived Factor (PEDF) Expression Induced by EGFRvIII Promotes Self-renewal and Tumor Progression of Glioma Stem Cells.
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Yin, Jinlong, Park, Gunwoo, Kim, Tae Hoon, Hong, Jun Hee, Kim, Youn-Jae, Jin, Xiong, Kang, Sangjo, Jung, Ji-Eun, Kim, Jeong-Yub, Yun, Hyeongsun, Lee, Jeong Eun, Kim, Minkyung, Chung, Junho, Kim, Hyunggee, Nakano, Ichiro, Gwak, Ho-Shin, Yoo, Heon, Yoo, Byong Chul, Kim, Jong Heon, and Hur, Eun-Mi
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CANCER invasiveness , *PIGMENT epithelium-derived factor , *CANCER cell growth , *CORPUS callosum , *STEM cells , *CELLULAR signal transduction - Abstract
Epidermal growth factor receptor variant III (EGFRvIII) has been associated with glioma stemness, but the direct molecular mechanism linking the two is largely unknown. Here, we show that EGFRvIII induces the expression and secretion of pigment epithelium-derived factor (PEDF) via activation of signal transducer and activator of transcription 3 (STAT3), thereby promoting self-renewal and tumor progression of glioma stem cells (GSCs). Mechanistically, PEDF sustained GSC self-renewal by Notch1 cleavage, and the generated intracellular domain of Notch1 (NICD) induced the expression of Sox2 through interaction with its promoter region. Furthermore, a subpopulation with high levels of PEDF was capable of infiltration along corpus callosum. Inhibition of PEDF diminished GSC self-renewal and increased survival of orthotopic tumor-bearing mice. Together, these data indicate the novel role of PEDF as a key regulator of GSC and suggest clinical implications. [ABSTRACT FROM AUTHOR]
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- 2015
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25. Soft pre-charge H/V switch for 3D Solid State Drive with NAND flash memories.
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Kim, Youngil, Choi, Sungwook, Lee, Jaeho, Cho, Hyunchul, Won, Samkyu, Choi, Sungdae, Kim, Duckju, Kim, Taeyun, Park, Gunwoo, and Lee, Sangsun
- Published
- 2013
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26. Partial Interference Alignment in Heterogeneous Networks.
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Seo, Jongpil, Yang, Chamsol, Park, Gunwoo, and Chung, Jaehak
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- 2013
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27. To Enhance Web Search Based on Topic Sensitive_Social Relationship Ranking Algorithm in Social Networks.
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Park, GunWoo, Lee, SooJin, and Lee, SangHoon
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- 2009
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28. Dynamic Routing Algorithm for Asymmetric Link in Mobile Ad Hoc Networks.
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Choi, Jongoh, Cha, Si-Ho, Park, GunWoo, Jo, Minho, and Song, JooSeok
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This paper proposes an improved algorithm that can replace the existing algorithms that use the unidirectional link. The proposed algorithm allows a first sink node of the unidirectional link to detect the unidirectional link and its reverse route and provide information regarding the reverse route to other sink nodes, thereby minimizing unnecessary flows and effectively using the unidirectional link. This paper also proposes a redirection process that actively supports a unidirectional link generated during data transmission to deal with a topology change due to the movement of node. Further, this paper proves the superiority of the proposed algorithm to the existing algorithms in terms of a delay in data transmission and throughput through a simulation in which the performance of the proposed algorithm is compared with those of the existing algorithms. [ABSTRACT FROM AUTHOR]
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- 2008
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29. Optimizing implant osseointegration, soft tissue responses, and bacterial inhibition: A comprehensive narrative review on the multifaceted approach of the UV photofunctionalization of titanium.
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Park G, Matsuura T, Komatsu K, and Ogawa T
- Abstract
Titanium implants have revolutionized restorative and reconstructive therapy, yet achieving optimal osseointegration and ensuring long-term implant success remain persistent challenges. In this review, we explore a cutting-edge approach to enhancing implant properties: ultraviolet (UV) photofunctionalization. By harnessing UV energy, photofunctionalization rejuvenates aging implants, leveraging and often surpassing the intrinsic potential of titanium materials. The primary aim of this narrative review is to offer an updated perspective on the advancements made in the field, providing a comprehensive overview of recent findings and exploring the relationship between UV-induced physicochemical alterations and cellular responses. There is now compelling evidence of significant transformations in titanium surface chemistry induced by photofunctionalization, transitioning from hydrocarbon-rich to carbon pellicle-free surfaces, generating superhydrophilic surfaces, and modulating the electrostatic properties. These changes are closely associated with improved cellular attachment, spreading, proliferation, differentiation, and, ultimately, osseointegration. Additionally, we discuss clinical studies demonstrating the efficacy of UV photofunctionalization in accelerating and enhancing the osseointegration of dental implants. Furthermore, we delve into recent advancements, including the development of one-minute vacuum UV (VUV) photofunctionalization, which addresses the limitations of conventional UV methods as well as the newly discovered functions of photofunctionalization in modulating soft tissue and bacterial interfaces. By elucidating the intricate relationship between surface science and biology, this body of research lays the groundwork for innovative strategies aimed at enhancing the clinical performance of titanium implants, marking a new era in implantology.
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- 2024
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30. Modulation of Nogo receptor 1 expression orchestrates myelin-associated infiltration of glioblastoma.
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Hong JH, Kang S, Sa JK, Park G, Oh YT, Kim TH, Yin J, Kim SS, D'Angelo F, Koo H, You Y, Park S, Kwon HJ, Kim CI, Ryu H, Lin W, Park EJ, Kim YJ, Park MJ, Kim H, Kim MS, Chung S, Park CK, Park SH, Kang YH, Kim JH, Saya H, Nakano I, Gwak HS, Yoo H, Lee J, Hur EM, Shi B, Nam DH, Iavarone A, Lee SH, and Park JB
- Subjects
- Animals, Cell Line, Tumor, Female, Gene Expression Regulation, Neoplastic, Humans, Inhibitor of Differentiation Protein 1 metabolism, Inhibitor of Differentiation Proteins metabolism, Mice, Inbred BALB C, Myelin Sheath pathology, Ubiquitin-Specific Proteases metabolism, Mice, Brain Neoplasms metabolism, Brain Neoplasms pathology, Glioblastoma metabolism, Glioblastoma pathology, Myelin Sheath metabolism, Nogo Receptor 1 metabolism
- Abstract
As the clinical failure of glioblastoma treatment is attributed by multiple components, including myelin-associated infiltration, assessment of the molecular mechanisms underlying such process and identification of the infiltrating cells have been the primary objectives in glioblastoma research. Here, we adopted radiogenomic analysis to screen for functionally relevant genes that orchestrate the process of glioma cell infiltration through myelin and promote glioblastoma aggressiveness. The receptor of the Nogo ligand (NgR1) was selected as the top candidate through Differentially Expressed Genes (DEG) and Gene Ontology (GO) enrichment analysis. Gain and loss of function studies on NgR1 elucidated its underlying molecular importance in suppressing myelin-associated infiltration in vitro and in vivo. The migratory ability of glioblastoma cells on myelin is reversibly modulated by NgR1 during differentiation and dedifferentiation process through deubiquitinating activity of USP1, which inhibits the degradation of ID1 to downregulate NgR1 expression. Furthermore, pimozide, a well-known antipsychotic drug, upregulates NgR1 by post-translational targeting of USP1, which sensitizes glioma stem cells to myelin inhibition and suppresses myelin-associated infiltration in vivo. In primary human glioblastoma, downregulation of NgR1 expression is associated with highly infiltrative characteristics and poor survival. Together, our findings reveal that loss of NgR1 drives myelin-associated infiltration of glioblastoma and suggest that novel therapeutic strategies aimed at reactivating expression of NgR1 will improve the clinical outcome of glioblastoma patients., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
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31. Preclinical development of a humanized neutralizing antibody targeting HGF.
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Kim H, Hong SH, Kim JY, Kim IC, Park YW, Lee SJ, Song SW, Kim JJ, Park G, Kim TM, Kim YH, Park JB, Chung J, and Kim IH
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- Animals, Antibodies, Monoclonal, Humanized adverse effects, Antibodies, Monoclonal, Humanized immunology, Antibodies, Neutralizing adverse effects, Antibodies, Neutralizing immunology, Antineoplastic Agents, Immunological adverse effects, Antineoplastic Agents, Immunological therapeutic use, Dogs, Female, Hep G2 Cells, Hepatocyte Growth Factor immunology, Humans, Macaca fascicularis, Madin Darby Canine Kidney Cells, Mice, Mice, Inbred BALB C, Mice, Nude, Proto-Oncogene Proteins c-met antagonists & inhibitors, Proto-Oncogene Proteins c-met immunology, Antibodies, Monoclonal, Humanized therapeutic use, Antibodies, Neutralizing therapeutic use, Antineoplastic Agents, Immunological pharmacology, Brain Neoplasms drug therapy, Glioblastoma drug therapy, Hepatocyte Growth Factor antagonists & inhibitors
- Abstract
Hepatocyte growth factor (HGF) and its receptor, cMET, play critical roles in cell proliferation, angiogenesis and invasion in a wide variety of cancers. We therefore examined the anti-tumor activity of the humanized monoclonal anti-HGF antibody, YYB-101, in nude mice bearing human glioblastoma xenografts as a single agent or in combination with temozolomide. HGF neutralization, The extracellular signal-related kinases 1 and 2 (ERK1/2) phosphorylation, and HGF-induced scattering were assessed in HGF-expressing cell lines treated with YYB-101. To support clinical development, we also evaluated the preclinical pharmacokinetics and toxicokinetics in cynomolgus monkeys, and human and cynomolgus monkey tissue was stained with YYB-101 to test tissue cross-reactivity. We found that YYB-101 inhibited cMET activation in vitro and suppressed tumor growth in the orthotopic mouse model of human glioblastoma. Combination treatment with YYB-101 and temozolomide decreased tumor growth and increased overall survival compared with the effects of either agent alone. Five cancer-related genes (TMEM119, FST, RSPO3, ROS1 and NBL1) were overexpressed in YYB-101-treated mice that showed tumor regrowth. In the tissue cross-reactivity assay, critical cross-reactivity was not observed. The terminal elimination half-life was 21.7 days. Taken together, the in vitro and in vivo data demonstrated the anti-tumor efficacy of YYB-101, which appeared to be mediated by blocking the HGF/cMET interaction. The preclinical pharmacokinetics, toxicokinetics and tissue cross-reactivity data support the clinical development of YYB-101 for advanced cancer.
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- 2017
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32. The Effectiveness of Ferritin as a Contrast Agent for Cell Tracking MRI in Mouse Cancer Models.
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Lee CW, Choi SI, Lee SJ, Oh YT, Park G, Park NY, Yoon KA, Kim S, Kim D, Kim YH, and Suh JS
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- Animals, Brain Neoplasms pathology, Cell Line, Tumor, Colonic Neoplasms pathology, Disease Models, Animal, Female, Genes, Reporter, Glioma pathology, Humans, Injections, Intravenous, Macrophages, Male, Mice, Neoplasm Transplantation, Skin Neoplasms pathology, Time Factors, Brain Neoplasms diagnostic imaging, Cell Tracking methods, Colonic Neoplasms diagnostic imaging, Contrast Media administration & dosage, Ferritins administration & dosage, Glioma diagnostic imaging, Magnetic Resonance Imaging methods, Skin Neoplasms diagnostic imaging
- Abstract
Purpose: We aimed to investigate the effectiveness of ferritin as a contrast agent and a potential reporter gene for tracking tumor cells or macrophages in mouse cancer models., Materials and Methods: Adenoviral human ferritin heavy chain (Ad-hFTH) was administrated to orthotopic glioma models and subcutaneous colon cancer mouse models using U87MG and HCT116 cells, respectively. Brain MR images were acquired before and daily for up to 6 days after the intracranial injection of Ad-hFTH. In the HCT116 tumor model, MR examinations were performed before and at 6, 24, and 48 h after intratumoral injection of Ad-hFTH, as well as before and every two days after intravenous injection of ferritin-labeled macrophages. The contrast effect of ferritin in vitro was measured by MR imaging of cell pellets. MRI examinations using a 7T MR scanner comprised a T1-weighted (T1w) spin-echo sequence, T2-weighted (T2w) relaxation enhancement sequence, and T2*-weighted (T2*w) fast low angle shot sequence., Results: Cell pellet imaging of Ad-hFTH in vitro showed a strong negatively enhanced contrast in T2w and T2*w images, presenting with darker signal intensity in high concentrations of Fe. T2w images of glioma and subcutaneous HCT116 tumor models showed a dark signal intensity around or within the Ad-hFTH tumor, which was distinct with time and apparent in T2*w images. After injection of ferritin-labeled macrophages, negative contrast enhancement was identified within the tumor., Conclusion: Ferritin could be a good candidate as an endogenous MR contrast agent and a potential reporter gene that is capable of maintaining cell labeling stability and cellular safety., Competing Interests: The authors have no financial conflicts of interest.
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- 2017
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33. CPEB1 modulates differentiation of glioma stem cells via downregulation of HES1 and SIRT1 expression.
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Yin J, Park G, Lee JE, Park JY, Kim TH, Kim YJ, Lee SH, Yoo H, Kim JH, and Park JB
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors genetics, Brain Neoplasms genetics, Brain Neoplasms metabolism, Brain Neoplasms pathology, Cell Differentiation physiology, Down-Regulation, Female, Glioma genetics, Glioma metabolism, HEK293 Cells, Heterografts, Homeodomain Proteins genetics, Humans, Mice, Mice, Inbred BALB C, Sirtuin 1 genetics, Transcription Factor HES-1, Transcription Factors genetics, Transcription Factors metabolism, Transcription, Genetic, Transfection, mRNA Cleavage and Polyadenylation Factors genetics, mRNA Cleavage and Polyadenylation Factors metabolism, Basic Helix-Loop-Helix Transcription Factors biosynthesis, Glioma pathology, Homeodomain Proteins biosynthesis, Neoplastic Stem Cells pathology, Sirtuin 1 biosynthesis, Transcription Factors biosynthesis, mRNA Cleavage and Polyadenylation Factors biosynthesis
- Abstract
Glioma stemness has been recognized as the most important reason for glioma relapse and drug resistance. Differentiation of glioma stem cells (GSCs) has been implicated as a novel approach to target recurrent glioma. However, the detailed molecular mechanism involved in the differentiation of GSCs has not yet been elucidated. This study identified CPEB1 as the key modulator that induces the differentiation of GSCs at the post-transcriptional level. Gain and loss of function experiments showed that CPEB1 expression reduced sphere formation ability and the expression of stemness markers such as Nestin and Notch. To elucidate the detailed molecular mechanism underlying the action of CPEB1, we investigated the interacting ribonome of the CPEB1 complex using a Ribonomics approach. CPEB1 specifically suppressed the translation of HES1 and SIRT1 by interacting with a cytoplasmic polyadenylation element. The expression profile of CPEB1 negatively correlated with overall survival in glioma patients. Overexpression of CPEB1 decreased the number of GSCs in an orthotopically implanted glioma animal model. These results suggest that CPEB1-mediated translational control is essential for the differentiation of GSCs and provides novel therapeutic concepts for differentiation therapy.
- Published
- 2014
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