Au decorated core-shell structured Au@Pt for the glucose oxidation reaction

Shim, Kyubin,Lee, Won-Chul,Park, Min-Sik,Shahabuddin, Mohammed,Yamauchi, Yusuke,Hossain, Md Shahriar A.,Shim, Yoon-Bo,Kim, Jung Ho Elsevier 2019 Sensors and actuators. B Chemical Vol.278 No.-

<P><B>Abstract</B></P> <P>Core-shell structured Au@Pt nanoparticles (NPs) with Au cores and dendritic Pt shells have been synthesized using the sonochemical method. Then, the Au is electrochemically incorporated into nano-channels between the Pt shells on the Au@Pt NPs (Au@Pt/Au NPs) to form a non-enzymatic glucose sensor. The electrochemically active surface area (ECSA) of the obtained Au@Pt/Au NPs is enlarged compared with that of Au@Pt NPs, which leads to enhanced glucose sensing performance. The particle sizes of Au@Pt/Au NPs are in the range from 35 nm to 60 nm. The ECSA of Au@Pt/Au NPs is calculated to be 6.19 m<SUP>2</SUP> g<SUB>(Pt)</SUB> <SUP>−1</SUP> and 0.8 m<SUP>2</SUP> g<SUB>(Au)</SUB> <SUP>−1</SUP> by cyclic voltammetry. The Au incorporation into the Pt shell region can boost the glucose oxidation process even at neutral pH. The sensor performance under the optimized experimental conditions has been confirmed in phosphate buffered saline (PBS<SUB>sal</SUB>) solution, showing two wide dynamic ranges for glucose (0.5–10.0 μM and 0.01–10.0 mM) with the correlation coefficient of 0.99. The detection limit of glucose in PBS saline solution has been determined to be 445.7 (±10.3) nM.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bimetallic Au@Pt NPs as core-shell structures demonstrate the enhanced catalytic performance for glucose oxidation. </LI> <LI> Nafion layer and dendritic Pt shells prevent passivation of the Au core. </LI> <LI> Additional Au plating further enhances catalytic performance. </LI> <LI> Rationally designed Au-decorated Au@Pt NPs show enhanced sensitivity, stability, and selectivity towards glucose detection. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A 3D Printed Poly(ε-caprolactone)-Collagen Hybrid Mesh (TissueDerm) for Breast Reconstruction after Mastectomy in a Pig Model

Shim Kyu-Sik,Jo Han-Saem,Kim Shin Hyun,Kim Dohyun,Park Yong-Kyu,Ryu Da Hye,Lee Won Jai,Roh Tai-Suk,백우열 한국조직공학과 재생의학회 2026 조직공학과 재생의학 Vol.23 No.1

Background: Implant supporting materials are currently used in breast reconstruction. However, when used in humans, they are associated with several problems. To address these issues, a new mesh called TissueDerm was created by combining a collagen sponge with a 3D printed polycaprolactone (PCL) mesh. It has shown promising results in pig experiments and could potentially replace the most commonly used acellular dermal matrix (ADM) for breast reconstruction. Methods: Four 12-month-old minipigs were used in this experiment. Silicone implants were wrapped with ADM or TissueDerm, and the breast tissue was excised and implanted along with the wrapped implants. Three months later, the minipigs were sacrificed and the skin and mammary gland tissue surrounding the implants were harvested for further analysis. Histological analyses and immunostaining were performed. Results: Although there was no significant difference in capsule thickness between the ADM and TissueDerm groups, collagen was more involved in TissueDerm, leading to better tissue regeneration. TissueDerm also induced lower levels of inflammatory markers TNF-α and IL-6 compared to ADM. However, capsules induced with ADM had significantly higher collagen fiber alignment and alpha-smooth muscle actin (α-SMA) positive immunoreactivity, suggesting that TissueDerm may be less likely to cause spherical contractures in the porcine model compared to ADM. Conclusions: The study found that TissueDerm has advantages over ADM in terms of easier tissue invasion and reduced spheroidization in a porcine model. The results showed that TissueDerm is a promising new mesh for implant-based breast reconstruction (IBBR) and could potentially replace ADM. Background: Implant supporting materials are currently used in breast reconstruction. However, when used in humans, they are associated with several problems. To address these issues, a new mesh called TissueDerm was created by combining a collagen sponge with a 3D printed polycaprolactone (PCL) mesh. It has shown promising results in pig experiments and could potentially replace the most commonly used acellular dermal matrix (ADM) for breast reconstruction. Methods: Four 12-month-old minipigs were used in this experiment. Silicone implants were wrapped with ADM or TissueDerm, and the breast tissue was excised and implanted along with the wrapped implants. Three months later, the minipigs were sacrificed and the skin and mammary gland tissue surrounding the implants were harvested for further analysis. Histological analyses and immunostaining were performed. Results: Although there was no significant difference in capsule thickness between the ADM and TissueDerm groups, collagen was more involved in TissueDerm, leading to better tissue regeneration. TissueDerm also induced lower levels of inflammatory markers TNF-α and IL-6 compared to ADM. However, capsules induced with ADM had significantly higher collagen fiber alignment and alpha-smooth muscle actin (α-SMA) positive immunoreactivity, suggesting that TissueDerm may be less likely to cause spherical contractures in the porcine model compared to ADM. Conclusions: The study found that TissueDerm has advantages over ADM in terms of easier tissue invasion and reduced spheroidization in a porcine model. The results showed that TissueDerm is a promising new mesh for implant-based breast reconstruction (IBBR) and could potentially replace ADM.

Poster Session 2 : Oral Presentation ; Neurobiology : Cloning of Xenopus Laevis TRPV2 by gene prediction

( Won Sik Shim ),( Jung Youn Lee ),( Young Duk Yang ),( Seung Pyo Park ),( Jee Yeon Heo ),( Yun Jong Lee ),( Sang Hee Lee ),( Yong Woo Jang ),( Mi Hyun Lee ),( Mi Sook Kim ),( Byung Moon Kim ),( Uh Ta 생화학분자생물학회 2005 62회 KSBMB Annual Meeting in 2005 Vol.- No.-

Testosterone-independent down-regulation of Oct2 in the kidney medulla from a uranyl nitrate-induced rat model of acute renal failure: Effects on distribution of a model organic cation, tetraethylammonium

Shim, Won-Sik,Park, Joo-Hyun,Ahn, Sun-Joo,Han, Liwei,Jin, Qing-Ri,Li, Hong,Choi, Min-Koo,Kim, Dae-Duk,Chung, Suk-Jae,Shim, Chang-Koo Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of Pharmaceutical Sciences Vol.98 No.2

<P>Although acute renal failure (ARF) has been an area of extensive research in recent decades, our understanding of ARF is far from complete. Organic cations (OCs) are primarily excreted via vectorial transport by various renal organic cation transporters (OCTs). It is reasonable to assume that ARF may alter the expression profiles of these transporters. In a rat ARF model, induction of ARF by uranyl nitrate (UN) treatment significantly decreased the levels of Oct2 (slc22a2) mRNA and protein in the kidney medulla. mRNA expression of the other OCTs was not appreciably altered. The plasma level of testosterone, a well-known regulator of Oct2, was not changed, suggesting that the Oct2 down-regulation is testosterone-independent. The effect of reduced Oct2 expression on the distribution of a model OC, tetraethylammonium (TEA), in various rat tissues including kidney cortex and kidney medulla was investigated during steady state plasma TEA concentrations. The steady state tissue-to-plasma (T/P) TEA ratio was decreased in the kidney medulla (approximately 15-fold) during ARF. These results indicate that, in a rat model of ARF, reduced Oct2 expression in the kidney medulla results in decreased distribution of TEA to the kidney medulla, thereby reducing renal clearance of TEA in UN-ARF rats. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:739–747, 2009</P>

A Case of Occult Splenic Abscess Following Percutaneous Transluminal Coronary Angioplasty(PTCA) : An Unrecognized Complication of PTCA

Shim, Won Heum,Jang, Yang Soo,Lee, Jong Tae,Lee, Kyong Sik Yonsei University, College of Medicine 1988 Yonsei medical journal Vol.29 No.1

Determination of Ag(Ⅰ) Ion at a Modified Carbon Paste Electrode Containing N,N'-Diphenyl Oxamide

Won, Mi-Sook,Yeom, Jeong-Sik,Yoon, Jang-Hee,Jeong, Euh-Duck,Shim, Yoon-Bo Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.7

New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N'-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × $10^{-7}$ - 5.0 × $10^{-9}$ M at the deposition time of 10 min, with the detection limit was 7.0 × $10^{-10}$ M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × $10^{-10}$ M for silver and the relative standard deviation was ± 3.2% at a 5.0 × $10^{-8}$ M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.

Poster Session 2 : Cloning of Xenopus Laevis TRPV2 by gene prediction

( Shim Won Sik ),( Lee Jung Youn ),( Yang Young Duk ),( Seung Pyo Park ),( Heo Jee Yeon ),( Yun Jong Lee ),( Sang Hee Lee ),( Yong Woo Jang ),( Mi Hyun Lee ),( Mi Sook Kim ),( Byung Moon Kim ),( Uh Ta 생화학분자생물학회 2005 생화학분자생물학회 춘계학술발표논문집 Vol.2005 No.-

Comparison of linac-based fractionated stereotactic radiotherapy and tomotherapy treatment plans for intra-cranial tumors

Shim, Jang Bo,Lee, Suk,Cho, Sam Ju,Lee, Sang Hoon,Kim, Juree,Cho, Kwang Hwan,Min, Chul Kee,Huh, Hyun Do,Lee, Rena,Yang, Dae Sik,Park, Young Je,Yoon, Won Seob,Kim, Chul Yong,Kwon, Soo Il science press 2010 Chinese physics. C Vol.34 No.11

<P>This study compares and analyzes stereotactic radiotherapy using tomotherapy and linac-based fractionated stereotactic radiotherapy in the treatment of intra-cranial tumors, according to some cases. In this study, linac-based fractionated stereotactic radiotherapy and tomotherapy treatment were administered to five patients diagnosed with intra-cranial cancer in which the dose of 18–20 Gy was applied on 3–5 separate occasions. The tumor dosing was decided by evaluating the inhomogeneous index (II) and conformity index (CI). Also, the radiation-sensitive tissue was evaluated using low dose factors <I>V</I><SUB>1</SUB>, <I>V</I><SUB>2</SUB>, <I>V</I><SUB>3</SUB>, <I>V</I><SUB>4</SUB>, <I>V</I><SUB>5</SUB>, and <I>V</I><SUB>10</SUB>, as well as the non-irradiation ratio volume (NIV). The values of the II for each prescription dose in the linac-based non-coplanar radiotherapy plan and tomotherapy treatment plan were (0.125±0.113) and (0.090±0.180), respectively, and the values of the CI were (0.899±0.149) and (0.917±0.114), respectively. The low dose areas, <I>V</I><SUB>1</SUB>, <I>V</I><SUB>2</SUB>, <I>V</I><SUB>3</SUB>, <I>V</I><SUB>4</SUB>, <I>V</I><SUB>5</SUB>, and <I>V</I><SUB>10</SUB>, in radiation-sensitive tissues in the linac-based non-coplanar radiotherapy plan fell into the ranges 0.3%−95.6%, 0.1%−87.6%, 0.1%−78.8%, 38.8%-69.9%, 26.6%-65.2%, and 4.2%−39.7%, respectively, and the tomotherapy treatment plan had ranges of 13.6%−100%, 3.5%−100%, 0.4%−94.9%, 0.2%−82.2%, 0.1%−78.5%, and 0.3%−46.3%, respectively. Regarding the NIV for each organ, it is possible to obtain similar values except for the irradiation area of the brain stem. The percentages of NIV 10%, NIV20%, and NIV30%for the brain stem in each patient were 15%−99.8%, 33.4%−100%, and 39.8%−100%, respectively, in the fractionated stereotactic treatment plan and 44.2%-96.5%, 77.7%-99.8%, and 87.8%−100%, respectively, in the tomotherapy treatment plan. In order to achieve higher-quality treatment of intra-cranial tumors, treatment plans should be tailored according to the isodose target volume, inhomogeneous index, conformity index, position of the tumor upon fractionated stereotactic radiosurgery, and radiation dosage for radiation-sensitive tissues.</P>

Decreased Secretory Transport of a Quarternary Ammonium, TBuMA, across LLC-PK1 Cells by the Anionic Kidney Extract

Shim, Won-Sik,Choi, Min-Koo,Kim, In-Wha,Kwon, Tae-Sik,Song, Im-Sook,Han, Liwei,Kim, Dae-Duk,Chung, Suk-Jae,Shim, Chang-Koo 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.5

The effect of organic anionic (OA) fractions of various rat organ tissues on the apparent partition coefficients (APC) of quarternary ammoniums (QAs) between n-octanol and phosphate buffer (pH 7.4) and QAs transport across the LLC-PK1 cell monolayer was examined. The OA fraction was prepared by filtering the aqueous extract of each tissue through an ion-exchange cartridge (Bond Elut C18). In the presence of OA fractions of liver and kidney extracts, substantial increase in APC was observed for tributylmethylammonium (TBuMA, Mw 200) and berberine (Mw 335), but not for triethylmethylammonium (TEMA, Mw 116) and tetraethylammonium (TEA, Mw 130). Because only QAs with higher Mw than a threshold (i.e., > 200) are known to form lipophilic ion-pair complexes with certain organic anions (e.g., bile salts such as taurodeoxycholate), above results are consistent with the hypothesis that only larger Mw QAs form lipophilic ion-pair complexes with endogenous organic anionic components of the liver and kidney extracts. Considering the comparable effect between the liver and kidney extracts on the APC of TBuMA regardless of far less (1/5) content of bile salts in the kidney extract, OAs other than bile salts in the kidney appear to contribute to the formation of lipophilic ion-pair complexes. Most interestingly, the secretory (i.e., basolateral to apical direction) transport of TBuMA and berberine across the LLC-PK1 cell monolayer was decreased by the cis-presence of the kidney extract, while remained unchanged for the transport of TEMA and TEA. The kidney extract had no effect on the absorptive (i.e., apical to basolateral direction) transport and cellular (LLC-PK1) accumulation of all of these QAs. Regardless of underlying mechanisms,it is notable that OA components of liver and kidney extracts influence the APC and secretory transport of QAs with Mw >200.

Molecular mechanisms of pruritus in dry skin conditions

( Won-sik Shim ) 한국피부장벽학회 2020 한국피부장벽학회지 Vol.22 No.2

We all take it for granted that dry skin causes itch, but it is surprisingly unclear how dry skin evokes the unpleasant sensation. The underlying mechanism of itch was once thought to be mainly mediated by histamine, an endogenous itch-inducing agent (pruritogen) released from the mast cell. Once histamine is released from the mast cell, it binds to the histamine receptor, leading to the activation ion channel in the sensory neurons to relay the itch signal. Indeed, antihistamine agents are based on this mechanism, which interferes with the binding of histamine to its receptors. However, antihistamines are not fully effective in many diseases characterized by dry skin, implying the symptom may rely on histamine-independent mechanisms. Fortunately, animal models for dry skin, which is achieved by applying a mixture of acetone and ether followed by water (AEW), significantly helped researchers to reveal underlying mechanisms related to the symptom. It was found that sensory neurons, keratinocytes, and spinal cords in AEW mice undergo significant changes at molecular levels. The present talk will summarize findings related to pruritus in dry skin conditions.