Study on Poly(3,4-ethylenedioxythiophene) Thin Film Vapour Phase-Polymerized with Iron(III)Tosylate on AcOH-Catalyzed 3-Aminopropyltriethoxysilane Self-Assembled Monolayer

Sangil Choi, Wondae Kim, Sungsoo Kim 조선대학교 기초과학연구원 2012 조선자연과학논문집 Vol.5 No.4

In this study, PEDOT thin films polymerized with Iron(III)tosylate (Fe(PTS)3) and grown on acetic acid-catalyzed 3- aminopropyltriethoxysilane self-assembled monolayer (APS-SAM) surfaces by VPP method have been investigated. PEDOT thin films were synthesized on APS self-assembled SiO2 wafer surface at two different concentrations (20 wt% and 40 wt%) and growth time (3 and 30 minutes), and then they were compared. PEDOT vapour phase-polymerized with 40 wt% Fe(PTS)3 oxidant completely formed a thin film on acetic acid-catalyzed APS-SAM surface while with 20 wt% Fe(PTS)3 did not at all. It means that the oxidant can be uniformly coated on acetic acid-catalyzed APS-SAM surface at the 40 wt% concentration, which gives rise to the uniform growth of PEDOT thin film on it.

Development of Highly Conductive Poly(3,4-ethylenedioxythiophene) Thin Film using High Quality 3-Aminopropyltriethoxysilane Self-Assembled Monolayer

Sangil Choi, Wondae Kim, Sungsoo Kim 조선대학교 기초과학연구원 2011 조선자연과학논문집 Vol.4 No.4

Quality of PEDOT electrode thin film vapor phase-polymerized on 3- aminopropyltriethoxysilane (APS) self-assembled monolayer (SAM) is very crucial for making an ohmic contact between electrode and semiconductor layer of an organic transistor. In order to improve the quality of PEDOT film, the quality of APS- SAM laying underneath the film must be in the best condition. In this study, in order to improve the quality of APS-SAM, the monolayer was self-assembled on SiO2 surface by a dip-coating method under strictly controlled relative humidity (< 18%RH). The quality of APS-SAM and PEDOT thin film were investigated with a contact angle analyzer, AFM, FE-SEM, and four-point probe. The investigation showed that a PEDOT film grown on the humidity-controlled SAM is very smooth and compact (sheet resistivity = 20.2 Ohm/sq) while a film grown under the uncontrolled condition is nearly amorphous and contains quite many pores (sheet resistivity = 200 Ohm/sq). Therefore, this study clearly proves that a highly improved quality of APSSAM can offer a highly conductive PEDOT electrode thin film on it.

Development of High-Quality Poly(3,4-ethylenedioxythiophene) Electrode Pattern Array Using SC1 Cleaning Process

Sangil Choi, Wondae Kim, Sungsoo Kim 조선대학교 기초과학연구원 2011 조선자연과학논문집 Vol.4 No.4

Application of self-assembled monolayers (SAMs) to the fabrication of organic thin film transistor has been recently reported very often since it can help to provide ohmic contact between films as well as to form simple and effective electrode pattern. Accordingly, quality of these ultra-thin films is becoming more imperative. In this study, in order to manufacture a high quality SAM pattern, a hydrophobic alkylsilane monolayer and a hydrophilic aminosilane monolayer were selectively coated on SiO2 surface through the consecutive procedures of a micro-contact printing (μCP) and dipcoating methods under extremely dry condition. On a SAM pattern cleaned with SC1 solution immediately after μCP, poly(3,4-ethylenedioxythiophene) (PEDOT) source and drain electrode array were very selectively and nicely vapour phase polymerized. On the other side, on a SC1-untreated SAM pattern, PEDOT array was very poorly polymerized. It strongly suggests that the SC1 cleaning process effectively removes unwanted contaminants on SAM pattern, thereby resulting in very selective growth of PEDOT electrode pattern.

Compromised ventilation caused by tracheoesophageal fistula and gastrointestinal endoscope undergoing removal of disk battery on esophagus in pediatric patient -A case report-

Kyung-Woo Kim,Ji Yeon Kim,Jung Won Kim,Jang Su Park,최원주,Kyung-Tae Kim,Sangil Lee 대한마취통증의학회 2011 Korean Journal of Anesthesiology Vol.61 No.3

Ingestion of disk batteries may have serious complications such as esophageal burn, perforation, and tracheoesophageal fistula, particularly when the battery is caught in the esophagus. Proper placement of the tracheal tube is critical when tracheoesophageal fistula was occurred from esophageal impaction the battery. Endoscopy of upper gastrointestinal tract in infants and children is an important and effective tool for the diagnosis and treatment of foreign body ingestion. But upper gastrointestinal endoscopy in infant and children has very high risk of tracheal compression and airway compromise. We present a case of ventilatory compromise during insertion of the upper gastrointestinal endoscopy in 16-month-old child with tracheoesophageal fistula secondary to disk battery ingestion

First-Pass Recanalization with EmboTrap II in Acute Ischemic Stroke (FREE-AIS): A Multicenter Prospective Study

Baek Jang-Hyun,Kim Byung Moon,Suh Sang Hyun,Jeon Hong-Jun,Ihm Eun Hyun,Park Hyungjong,Kim Chang-Hyun,Cha Sang-Hoon,Choi Chi-Hoon,Yi Kyung Sik,Kim Jun-Hwee,Suh Sangil,Kim Byungjun,Chang Yoonkyung,Kim S 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.2

Objective: We aimed to evaluate the efficacy of EmboTrap II in terms of first-pass recanalization and to determine whether it could yield favorable outcomes. Materials and Methods: In this multicenter, prospective study, we consecutively enrolled patients who underwent mechanical thrombectomy using EmboTrap II as a front-line device. The primary outcome was the first pass effect (FPE) rate defined by modified Thrombolysis In Cerebral Infarction (mTICI) grade 2c or 3 by the first pass of EmboTrap II. In addition, modified FPE (mFPE; mTICI grade 2b–3 by the first pass of EmboTrap II), successful recanalization (final mTICI grade 2b–3), and clinical outcomes were assessed. We also analyzed the effect of FPE on a modified Rankin Scale (mRS) score of 0–2 at 3 months. Results: Two hundred-ten patients (mean age ± standard deviation, 73.3 ± 11.4 years; male, 55.7%) were included. Ninetynine patients (47.1%) had FPE, and mFPE was achieved in 150 (71.4%) patients. Successful recanalization was achieved in 191 (91.0%) patients. Among them, 164 (85.9%) patients underwent successful recanalization by exclusively using EmboTrap II. The time from groin puncture to FPE was 25.0 minutes (interquartile range, 17.0–35.0 minutes). Procedure-related complications were observed in seven (3.3%) patients. Symptomatic intracranial hemorrhage developed in 14 (6.7%) patients. One hundred twenty-three (58.9% of 209 completely followed) patients had an mRS score of 0–2. Sixteen (7.7% of 209) patients died during the follow-up period. Patients who had successful recanalization with FPE were four times more likely to have an mRS score of 0–2 than those who had successful recanalization without FPE (adjusted odds ratio, 4.13; 95% confidence interval, 1.59–10.8; p = 0.004). Conclusion: Mechanical thrombectomy using the front-line EmboTrap II is effective and safe. In particular, FPE rates were high. Achieving FPE was important for an mRS score of 0–2, even in patients with successful recanalization.

Valence states and spin structure of spinel FeV2O4with different orbital degrees of freedom

Kang, J.-S.,Hwang, Jihoon,Kim, D. H.,Lee, Eunsook,Kim, W. C.,Kim, C. S.,Kwon, Sangil,Lee, Soonchil,Kim, J.-Y.,Ueno, T.,Sawada, M.,Kim, Bongjae,Kim, Beom Hyun,Min, B. I. American Physical Society 2012 Physical review. B, Condensed matter and materials Vol.85 No.16

Development of accurate dimethyl sulphide primary standard gas mixtures at low nanomole per mole levels in high-pressure aluminium cylinders for ambient measurements

Kim, Mi Eon,Kang, Ji Hwan,Kim, Yong Doo,Lee, Dong Soo,Lee, Sangil BUREAU INTERNATIONAL DES POIDS ET MESURES 2018 METROLOGIA -BERLIN- Vol.55 No.2

<P>Dimethyl sulphide (DMS) plays an important role in atmospheric chemistry and climate change. Ambient DMS is monitored in a global network and reported at sub-nanomole per mole (nmol/mol) levels. Developing traceable, accurate DMS standards at ambient levels is essential for tracking the long-term trends and understanding the role of DMS in the atmosphere. Gravimetrically prepared gas standards in cylinders are widely used for calibrating instruments. Therefore, a stable primary standard gas mixture (PSM) is required for traceable ambient DMS measurement at remote sites. In this study, to evaluate adsorption loss on the internal surface of the gas cylinder, 6 nmol mol<SUP>−1</SUP> DMS gas mixtures were prepared in three types of aluminium cylinders: a cylinder without a special coating on its internal surface (AL), an Aculife IV  +  III-treated cylinder (AC), and an Experis-treated cylinder (EX). There was little adsorption loss on the EX cylinder, whereas there was substantial adsorption loss on the other two cylinders. The EX cylinder was used to prepare 0.5, 2, 5, and 7 nmol mol<SUP>−1</SUP> DMS PSMs with relative expanded uncertainties of less than 0.4%. The DMS PSMs were analytically verified and consistent within a relative expanded uncertainty of less than 1.2%. The long-term stability of the 7 nmol mol<SUP>−1</SUP> DMS PSM was assessed by tracking the ratio of the DMS to the internal standard, benzene. The results showed that the DMS was stable for about seven months and it was projected to be stable for more than 60 months within a relative expanded uncertainty of 3%.</P>

Hopf bifurcation analysis and optimal control of Treatment in a delayed oncolytic virus dynamics

Kim, Kwang Su,Kim, Sangil,Jung, Il Hyo Elsevier 2018 Mathematics and computers in simulation Vol.149 No.-

<P><B>Abstract</B></P> <P>During cancer viral therapy, there is a time delay from the initial virus infection of the tumor cells up to the time those infected cells reach the stage of being able to infect other cells. Because the duration of this “time delay” varies with each virus, it is important to understand how the delay affects the cancer viral therapy. Herein, we have introduced a mathematical model to explain this time delay. The existence of equilibrium (i.e., whether the treatment was unsuccessful or partially successful) was determined in this model by using a basic reproduction ratio of viral infection ( <SUB> R 0 </SUB> ) to immune response ( <SUB> R 1 </SUB> ). By using the bifurcation parameter as a delay τ , we proved a sufficient condition for the local asymptotic stability of two equilibrium points and the existence of Hopf bifurcation. In addition, we observed that the time delay caused the partial success equilibrium to be unstable and worked together with Hopf bifurcation to create a stable periodic oscillation. Therefore, we investigated the effects of viral cytotoxicity or infection rate, which are characteristics of viruses, on the Hopf bifurcation point. In order to support the analytical findings and to further analyze the effects of delay during cancer viral therapy, we reconstructed the model to include two controls: cancer viral therapy and immunotherapy. In addition, using numerical simulation, we suggested an optimal control problem to examine the effects of delay on oncolytic immunotherapy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This study performed a stability and bifurcation analysis of the suggested model, which includes a time delay. </LI> <LI> Existence of Hopf bifurcation was proved to explain it as a time delay change. </LI> <LI> We identified the conditions that allow a Hopf bifurcation point to exist. </LI> <LI> Optimal oncolytic immunotherapy treatment method was investigated according to the time delay. </LI> </UL> </P>

West meets East: How do rainforest beetles become circum-Pacific? Evolutionary origin of <i>Callipogon relictus</i> and allied species (Cerambycidae: Prioninae) in the New and Old Worlds

Kim, Sangil,de Medeiros, Bruno A.S.,Byun, Bong-Kyu,Lee, Seunghwan,Kang, Jung-Hoon,Lee, Bongwoo,Farrell, Brian D. Elsevier 2018 Molecular phylogenetics and evolution Vol.125 No.-

<P><B>Abstract</B></P> <P>The longhorn beetle genus <I>Callipogon</I> Audinet-Serville represents a small group of large wood-boring beetles whose distribution pattern exhibits a unique trans-Pacific disjunction between the East Asian temperate rainforest and the tropical rainforest of the Neotropics. To understand the biogeographic history underlying this circum-Pacific disjunct distribution, we reconstructed a molecular phylogeny of the subfamily Prioninae with extensive sampling of <I>Callipogon</I> using multilocus sequence data of 99 prionine and four parandrine samples (ingroups), together with two distant outgroup species. Our sampling of <I>Callipogon</I> includes 18 of the 24 currently accepted species, with complete representation of all species in our focal subgenera. Our phylogenetic analyses confirmed the purported affinity between the Palearctic <I>Callipogon relictus</I> and its Neotropical congeners. Furthermore, based on molecular dating under the fossilized birth–death (FBD) model with comprehensive fossil records and probabilistic ancestral range reconstructions, we estimated the crown group <I>Callipogon</I> to have originated in the Paleocene circa 60 million years ago (Ma) across the Neotropics and Eastern Palearctics. The divergence between the Palearctic <I>C. relictus</I> and its Neotropical congeners is explained as the result of a vicariance event following the demise of boreotropical forest across Beringia at the Eocene-Oligocene boundary. As <I>C. relictus</I> represents the unique relictual species that evidentiates the lineage’s expansive ancient distribution, we evaluated its conservation importance through species distribution modelling. Though we estimated a range expansion for <I>C. relictus</I> by 2050, we emphasize a careful implementation of conservation programs towards the protection of primary forest across its current habitats, as the species remains highly vulnerable to habitat disturbance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The first molecular phylogeny of world prionine longhorn beetles is presented. </LI> <LI> Wide ancient distribution of stem lineage <I>Callipogon relictus</I> is revealed. </LI> <LI> Systematic affinity between <I>C. relictus</I> and Neotropical congeners is confirmed. </LI> <LI> Climate-mediated Beringian vicariance explains the current disjunct distribution. </LI> <LI> Conservation importance of <I>C. relictus</I> is evaluated through distribution modelling. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effects of intensity and seasonal timing of disturbances on a rocky intertidal benthic community on the southern coast of Korea

Kim, Sangil,Kang, Yun Hee,Choi, Chang Jae,Won, Nam‐,Il,Seo, In‐,Soo,Lee, Hyuk Je,Jung, Sukgeun,Park, Sang Rul Springer Japan 2014 Ecological research Vol.29 No.3

<P><B>Abstract</B></P><P>The effects of intensity and timing of disturbances on recovery of marine benthic organisms were investigated on a rocky intertidal shore in Gwangyang Bay, Korea. We hypothesized that the recovery pattern of the benthic community structure would be affected by disturbance intensity and season. Twenty‐eight permanent plots were set up, with disturbance intensity (cleared plots and sterile plots) and seasonal disturbance (fall 1999 and spring 2000) incorporated into the experimental design. To monitor natural seasonal variation in benthic community abundances, we established seven permanent unmanipulated plots. Turf‐forming algae were observed in the unmanipulated plots throughout the experimental period, whereas green algae and invertebrate presence varied with season. In the disturbance‐intensity experiment, turf‐forming and green algae were dominant in cleared plots. The highest coverage of sessile organisms was observed in sterile plots, which exhibited the highest species richness because of their relatively low macroalgal coverage. Seasonal effects of disturbance were an important factor in the recovery pattern of benthic organisms under high disturbance intensity. Coverage of green algae was higher in sterile spring plots than in sterile fall plots; this result was attributed to low spatial competition, as the disturbances occurred just before green algal blooms. On the other hand, the abundances of barnacles and bivalves were highest on sterile fall plots, as these organisms were suppressed by green algal blooms in other periods. These results indicate that the effects of disturbance intensity on benthic community recovery patterns can be influenced by season of disturbance.</P>