Corn Silk Extract Prevents Carrageenan-Induced Inflammatory Edema

Kim Yonghwan,Han Na Choi,Kim Taehee,Kim Su Jin,Kim Yuna,Kim Jin Soo,Lee Sang-Hoon,Goo Young-Tae,Kim Dong Woon,Do Lee Sang 건강기능식품미래포럼 2022 건강기능식품미래포럼 학술지 Vol.2 No.1

Corn silk extract (CSE) has been used as a traditional medicine for edema, cystitis, gout, kidney stones, nephritis, and prostatitis. Although CSE has been shown to be effective against oxidative stress and diabetes, the effects of CSE on peripheral edema are unclear. Therefore, in this study, the effects of CSE on carrageenan-induced peripheral edema in the hind paw of mice were examined. CSE administered orally for a week suppressed the formation of edema and inhibited the swelling of epidermis and the infiltration of inflammatory cells into the dermis. To explore the mechanism of the anti-inflammatory action, CSE was tested on the adhesion between monocytes and endothelial cells using THP-1 cells (a monocyte cell line) and human umbilical vein endothelial cells (HUVECs). CSE inhibited the adhesion only when THP-1 cells were treated with CSE but not HUVECs. This finding suggests that CSE possibly influences the expressions of the membrane proteins of the monocyte involved in the adhesion with endothelial cells. Thus, CSE was treated for 24 hours and the expressions of CD11a, CD11b, CD18, CD49d and CD162 using its respective antibody and flowcytometry. Of these proteins, CD162, also known as P-selectin glycoprotein ligand-1 (PSGL-1), was shown to be reduced in its expression. PSGL-1 is known to be required for the binding of inflammatory cells to intercellular adhesion molecules of endothelial cells. In conclusion, CSE may suppress inflammatory edema by inhibiting the binding of inflammatory cells to the vascular endothelium.

Time-domain analysis of nonlinear motion responses and structural loads on ships and offshore structures

Yonghwan Kim,Kyong-Hwan Kim,Jae-Han Kim,Taeyoung Kim,Min-Guk Seo,Yooil Kim 대한조선학회 2011 International Journal of Naval Architecture and Oc Vol.3 No.1

The present paper introduced a computer program, called WISH, which is based on a time-domain Rankine panel method. The WISH has been developed for practical use to predict the linear and nonlinear ship motion and structural loads in waves. The WISH adopts three different levels of seakeeping analysis: linear, weakly-nonlinear and weak-scatterer approaches. Later, WISH-FLEX has been developed to consider hydroelasticity effects on hull-girder structure. This program can solve the springing and whipping problems by coupling between the hydrodynamic and structural problems. More recently this development has been continued to more diverse problems, including the motion responses of multiple adjacent bodies, the effects of seakeeping in ship maneuvering, and the floating-body motion in finite-depth domain with varying bathymetry. This paper introduces a brief theoretical and numerical background of the WISH package, and some validation results. Also several applications to real ships and offshore structures are shown.

Synthesis of functionalized porous montmorillonite via solid-state NaOH treatment for efficient removal of cesium and strontium ions

Kim, Yonghwan,Kim, Yun Kon,Kim, Jung Hwan,Yim, Man-Sung,Harbottle, David,Lee, Jae W. Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.450 No.-

<P><B>Abstract</B></P> <P>Solid-state NaOH treatment of montmorillonite clay was used to enhance the removal of Cs<SUP>+</SUP> and Sr<SUP>2+</SUP>. Through this facile and low-cost modification, montmorillonite with a large BET surface area (117.1 m<SUP>2</SUP> g<SUP>−1</SUP>) and many surface functional groups (SiONa), demonstrated enhanced sorption kinetics (89% removal for 40 mg L<SUP>−1</SUP> Cs<SUP>+</SUP> and 23 mg L<SUP>−1</SUP> Sr<SUP>2+</SUP> in 1 h) with a sorption capacity of 290.7 mg g<SUP>−1</SUP> for Cs<SUP>+</SUP> and 184.8 mg g<SUP>−1</SUP> for Sr<SUP>2+</SUP>, greatly exceeding the low sorption capacity (137.0 mg g<SUP>−1</SUP> for Cs<SUP>+</SUP> and 15.6 mg g<SUP>−1</SUP> for Sr<SUP>2+</SUP>) of pristine montmorillonite. SEM-EDS and XPS analyses revealed that Cs<SUP>+</SUP> and Sr<SUP>2+</SUP> were ion-exchanged with Na<SUP>+</SUP> on the surface functional groups formed following NaOH treatment. The performance of NaOH-treated montmorillonite was stable following gamma-ray irradiation (at 6 Gy h<SUP>−1</SUP> for 30 min) and across a broad range of pHs (3 to 11), exhibiting a high distribution coefficient (K<SUB>d</SUB>) of 1.5 × 10<SUP>3</SUP> mL g<SUP>−1</SUP> for Cs<SUP>+</SUP> (1.58 mg L<SUP>−1</SUP>) and 3.7 × 10<SUP>3</SUP> mL g<SUP>−1</SUP> for Sr<SUP>2+</SUP> (1.64 mg L<SUP>−1</SUP>) under groundwater conditions where various cations including Na<SUP>+</SUP>, K<SUP>+</SUP>, and Ca<SUP>2+</SUP> (V/m = 1 L/g) were present. The proposed method demonstrated great improvement of the sorption capacity of an abundant and inexpensive montmorillonite.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Microporous sorbent (NaMTs) was produced by reaction of montmorillonite and solid NaOH. </LI> <LI> NaMTs showed high sorption capacities for Cs<SUP>+</SUP> (290.7 mg g<SUP>−1</SUP>) and Sr<SUP>2+</SUP> (184.8 mg g<SUP>−1</SUP>). </LI> <LI> NaMTs were stable following gamma-ray (6 Gy h<SUP>−1</SUP> for 30 min) irradiation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Small hypoxia-primed mesenchymal stem cells attenuate graft-versus-host disease

Kim, YongHwan,Jin, Hye Jin,Heo, Jinbeom,Ju, Hyein,Lee, Hye-Yeon,Kim, Sujin,Lee, Seungun,Lim, Jisun,Jeong, Sang Young,Kwon, JiHye,Kim, Miyeon,Choi, Soo Jin,Oh, Wonil,Yang, Yoon Sun,Hwang, Hyun Ho,Yu, H Nature Publishing Group UK 2018 Leukemia Vol.32 No.12

<P>Mesenchymal stem cells (MSCs) are of particular interest for the treatment of immune-related diseases due to their immunosuppressive capacity. Here, we show that Small MSCs primed with Hypoxia and Calcium ions (SHC-MSCs) exhibit enhanced stemness and immunomodulatory functions for treating allogeneic conflicts. Compared with naïve cultured human umbilical cord blood-derived MSCs, SHC-MSCs were resistant to passage-dependent senescence mediated via the monocyte chemoattractant protein-1 and p53/p21 cascade and secreted large amounts of pro-angiogenic and immunomodulatory factors, resulting in suppression of T-cell proliferation. SHC-MSCs showed DNA demethylation in pluripotency, germline, and imprinted genes similarly to very small embryonic-like stem cells, suggesting a potential mutual relationship. Genome-wide DNA methylome and transcriptome analyses indicated that genes related to immune modulation, cell adhesion, and the cell cycle were up-regulated in SHC-MSCs. Particularly, polo-like kinase-1 (<I>PLK1</I>), zinc-finger protein-143, dehydrogenase/reductase-3, and friend-of-GATA2 play a key role in the beneficial effects of SHC-MSCs. Administration of SHC-MSCs or <I>PLK1</I>-overexpressing MSCs significantly ameliorated symptoms of graft-versus-host disease (GVHD) in a humanized mouse model, resulting in significantly improved survival, less weight loss, and reduced histopathologic injuries in GVHD target organs compared with naïve MSC-infused mice. Collectively, our findings suggest that SHC-MSCs can improve the clinical treatment of allogeneic conflicts, including GVHD.</P>

Nanostructured potassium copper hexacyanoferrate-cellulose hydrogel for selective and rapid cesium adsorption

Kim, Yonghwan,Kim, Yun Kon,Kim, Sungjun,Harbottle, David,Lee, Jae W. Elsevier 2017 Chemical engineering journal Vol.313 No.-

<P><B>Abstract</B></P> <P>Potassium copper hexacyanoferrate (KCuHCF) was synthesized and immobilized in a cellulose-based hydrogel made of carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC) for the adsorption of cesium ions in aqueous solutions. The immobilization with the cellulose-based hydrogel facilitated the dispersion of nano-sized KCuHCF particles, showing the unprecedented adsorption capacity of the composite. In Cs<SUP>+</SUP> removal experiments, KCuHCF-cellulose hydrogel composites (HCF-gels) exhibited exceptional Cs<SUP>+</SUP> adsorption capacities (2.06–2.32mmolg<SUP>−1</SUP>) which was attributed to the presence of ion-exchangeable sites (COO<SUP>−</SUP>Na<SUP>+</SUP>) in the cellulose hydrogel. The HCF-gels also exhibited a rapid Cs<SUP>+</SUP> removal (90.1% removal for 0.15mmolL<SUP>−1</SUP> of Cs<SUP>+</SUP> in 1h) with the uptake reaction kinetics expressed by a pseudo-second order kinetics model. Notably, the HCF-gels could adsorb Cs<SUP>+</SUP> selectively (>90%) in seawater containing 0.11mmolL<SUP>−1</SUP> Cs<SUP>+</SUP>. Such specificity with fast kinetics is due to the high ion accessibility from the inherent nature of hydrogels and the highly dispersed KCuHCF nanoparticles in the composites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Potassium copper hexacyanoferrate immobilized in a cellulose hydrogel (HCF-gels) as a Cs<SUP>+</SUP> adsorbent. </LI> <LI> HCF-gels exhibited a superior Cs adsorption capacity (2.06–2.32mmolg<SUP>−1</SUP>). </LI> <LI> Enhanced adsorption kinetics (90% removal in 1h) and high selectivity (<I>K</I> <SUB> <I>d</I> </SUB> ≈10<SUP>5</SUP>) for Cs<SUP>+</SUP> even in seawater conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Potassium copper hexacyanoferrate (KCuHCF) was immobilized in a cellulose-based hydrogel for the effective adsorption of cesium ions (HCF-gels). Cesium adsorption occurs both in KCuHCF particle and carboxylate of carboxymethyl cellulose (CMCNa) in the HCF-gels.</P> <P>[DISPLAY OMISSION]</P>

Comparison of Sloshing Pressures in 2D and 3D Tanks

Kim, Yonghwan,Kim, Sang-Yeob,Kim, Jieung,Lee, Jae-Hoon Korean Society of Ocean Engineers 2013 International journal of ocean system engineering Vol.3 No.4

This paper introduces the experimental results of sloshing model tests carried out at Seoul National University. Two 1/50-scale tanks, i.e., 2D and 3D models with the same shape, were manufactured for the comparative study. Particular interest was taken in the differences in impact pressures between the 2D and 3D models. Regular motion tests were conducted for different filling depths. For each filling depth, 500 cycles of regular excitation were imposed at each frequency. To observe the characteristics and severity of sloshing from the acquired pressure data, statistical analyses were performed, not only for the peak pressure, but also for the area-concept indices, which represented the amount of impulse.

An Estimation Model of Nasopharyngeal Specimen Collection Path for Non-face-to-face Automatic Sampling Robot

Yonghwan Moon,Jihoon Kim,Suhun Jung,Sang Kyung Kim,Jeongryul Kim,Keri Kim 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

Due to the worldwide spread of COVID-19, each government invests many human resources and money in screening tests. The spread of the virus has led to the development of robots that track the location of specimen collection or drive directly through master-slave devices by installing special equipment on patients noses to reduce the physical burden on medical staff and prevent infection during screening tests. Sampling robots proposed in previous studies have a rather complicated specimen collection process or make it impossible to collect specimens when the patient cannot wear special equipment. Therefore, we propose a deep learning-based model that predicts the nasopharyngeal specimen sampling path without additional equipment. The test bench for the collection of learning datasets was configured, and the nasopharyngeal specimen sampling path was expressed using an augmented reality marker to learn the estimated value. In addition, we add weight factors to the proposed model to compare the root mean square error of the direction vector.

The Therapeutic Effects of Human Mesenchymal Stem Cells Primed with Sphingosine-1 Phosphate on Pulmonary Artery Hypertension

Kang, Hyunsook,Kim, Kang-Hyun,Lim, Jisun,Kim, You-Sun,Heo, Jinbeom,Choi, Jongjin,Jeong, Jaeho,Kim, YongHwan,Kim, Seong Who,Oh, Yeon-Mok,Choo, Myung-Soo,Son, Jaekyoung,Kim, Su Jung,Yoo, Hyun Ju,Oh, Won Mary Ann Liebert 2015 STEM CELLS AND DEVELOPMENT Vol.24 No.14

An Energy Efficient <tex> $V_{\rm PP}$</tex> Generator With Fast Ramp-Up Time for Mobile DRAM

Kyu-Young Kim,Yonghwan Kim,Doo-Chan Lee,Yu-Ri Kang,Hoonki Kim,Soo-Won Kim,Jongsun Park IEEE 2011 IEEE journal of solid-state circuits Vol.46 No.6

<P>An energy efficient <I>V</I><SUB>PP</SUB> generator with fast ramp-up time for mobile DRAM is presented in this paper. Instead of using a fixed pumping clock frequency as in the conventional <I>V</I><SUB>PP</SUB> generator, the proposed <I>V</I><SUB>PP</SUB> generator adopts a voltage-controlled oscillator (VCO) and uses variable pumping frequencies to improve the ramp-up time as well as energy efficiency. Numerical results show that the VCO based <I>V</I><SUB>PP</SUB> generators achieve energy savings of up to 34% with 40% improvement on ramp-up time when compared to the conventional ring oscillator (RO) based design. Our proposed <I>V</I><SUB>PP</SUB> generator, which uses a three-stage voltage doubler as a charge pump, was implemented and fabricated in CMOS 0.13 μm process. The <I>V</I><SUB>PP</SUB> generator chip's core occupies 0.6 mm<SUP>2</SUP> area and consumes 1162 nJ (average power of 47.8 mW during 24 μs ramp-up time) while generating 3.0 V output voltage with 1.0 nF load capacitor, 2.0 mA current load and 1.2 V supply voltage.</P>

실리콘 나노와이어/탄소 코어-쉘 나노구조체의 염료감응 태양전지 적용 연구

김준희(Junhee Kim),이용환(Yonghwan Lee),김한중(Han-Jung Kim),김윤갑(Yoonkap Kim),김수민(Soomin Kim),전용석(Yongseok Jun) 한국태양에너지학회 2021 한국태양에너지학회 학술대회논문집 Vol.2021 No.11