Genetic Distinctness of Sorex caecutiens hallamontanus (Soricomorpha: Mammalia) from Jeju Island in Korea

Hung Sun Koh,Kyung Hee Jang,Seong Teak In,Eui Dong Han,Jae Eun Jo,Eui Jeong Ham,Seon Ki Jeong,Jong Hyek Lee,Kwang Seon Kim,Gu Hee Kweon 한국동물분류학회 2012 Animal Systematics, Evolution and Diversity Vol.28 No.3

To examine genetic divergences of two endemic Sorex caecutiens subspecies from Korea (S. c. hallamontanus in Korean Jeju Island and S. c. annexus in the mainland Korean Peninsula), we obtained partial cytochrome oxidase I (COI) sequences (429 bp) and complete cytochrome b sequences (1,140 bp) from the two Korean subspecies, and we compared these sequences to the corresponding sequences of S. caecutiens, obtained from GenBank. We found that Jeju S. c. hallamontanus is one of three clades within S. caecutiens, with an average Jukes-Cantor distance of 1.57% in the COI sequences and the distance of 2.07% and 11 fixed site differences in the cytochrome b sequences, indicating that Jeju S. c. hallamontanus is one endemic subspecies with concordant genetic distinctness, although further analyses with nuclear DNA sequences are necessary to confirm these findings. However, S. c. annexus from the mainland Korean Peninsula was not divergent from S. c. macropygmaeus from northeastern China and adjacent Russia, indicating that S. c. annexus from the mainland Korean Peninsula is another endemic subspecies with only morphological differences, although it is necessary to reexamine the subspecies status of S. c. annexus.

Efficacy of the Over-the-Scope Clip System for Treatment of Gastrointestinal Fistulas, Leaks, and Perforations: A Korean Multi-Center Study

Hang Lak Lee,Joo Young Cho,조준형,Jong-Jae Park,Chan Gyoo Kim,Seong Hwan Kim,Joung-Ho Han 대한소화기내시경학회 2018 Clinical Endoscopy Vol.51 No.1

Background/Aims: Currently, a new over-the-scope clip (OTSC) system has been introduced. This system has been used forgastrointestinal perforations and fistulas in other countries. The aim of our study is to examine the therapeutic success rate ofendoscopic treatment using the OTSC system in Korea. Methods: This was a multicenter prospective study. A total of seven endoscopists at seven centers performed this procedure. Results: A total of 19 patients were included, with gastrointestinal leakages from anastomosis sites, fistulas, or esophageal perforationsdue to Boerhaave’s syndrome. Among these, there were three gastrojejunostomy sites, three esophagojejunostomy sites, fouresophagogastrostomy sites, one esophagocolonostomy site, one jejuno-jejunal site, two endoscopic full thickness resection site closures,one Boerhaave’s syndrome, two esophago-bronchial fistulas, one gastrocolonic fistula, and one colonopseudocyst fistula. The size of theleakage ranged from 5 to 30 mm. The median procedure time was 16 min. All cases were technically successful. Complete closure ofthe leak was achieved in 14 of 19 patients using OTSC alone. Conclusions: The OTSC system is a safe and effective method for the management of gastrointestinal leakage, especially in cases ofanastomotic leakage after surgery.

Use of Extracorporeal Membrane Oxygenation in a Fulminant Course of Amniotic Fluid Embolism Syndrome Immediately after Cesarean Delivery

Jae Ha Lee,Hang Jea Jang,Jin Han Park,Yong Kyun Kim,Ho Ki Min,Sun Young Kim,Hyun-kuk Kim 대한중환자의학회 2016 Acute and Critical Care Vol.31 No.3

Amniotic fluid embolism is rare but is one of the most catastrophic complications in the peripartum period. This syndrome is caused by a maternal anaphylactic reaction to the introduction of fetal material into the pulmonary circulation. When amniotic fluid embolism is suspected, the immediate application of extracorporeal mechanical circulatory support such as veno-arterial extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass should be considered. Without the application of extracorporeal mechanical circulatory support, medical supportive care might not be sufficient to maintain cardiopulmonary stabilization in severe cases of amniotic fluid embolism. In this report, we present the case of a 36-year-old pregnant woman who developed an amniotic fluid embolism immediately after a cesarean section. Her catastrophic event started with the sudden onset of severe hypoxia, followed by circulatory collapse within 8 minutes. The veno-arterial mode of extracorporeal membrane oxygenation was initiated immediately. She was successfully resuscitated but with impaired cognitive function. Thus, urgent ECMO should be considered when amniotic fluid embolism syndrome is suspected in patients presenting acute cardiopulmonary collapse.

An aerodynamic model for insect flapping wings in forward flight

Han, Jong-Seob,Chang, Jo Won,Han, Jae-Hung IOP Publishing 2017 Bioinspiration & biomimetics Vol.12 No.3

<P>This paper proposes a semi-empirical quasi-steady aerodynamic model of a flapping wing in forward flight. A total of 147 individual cases, which consisted of advance ratios J of 0 ( hovering), 0.125, 0.25, 0.5, 0.75, 1 and infinity, and angles of attack alpha of -5 to 95 degrees at intervals of 5 degrees, were examined to extract the aerodynamic coefficients. The Polhamus leading-edge suction analogy and power functions were then employed to establish the aerodynamic model. In order to preserve the existing level of simplicity, K-P and K-V, the correction factors of the potential and vortex force models, were rebuilt as functions of J and alpha. The estimations were nearly identical to direct force/moment measurements which were obtained from both artificial and practical wingbeat motions of a hawkmoth. The model effectively compensated for the influences of J, particularly showing outstanding moment estimation capabilities. With this model, we found that using a lower value of a during the downstroke would be an effective strategy for generating adequate lift in forward flight. The rotational force and moment components had noticeable portions generating both thrust and counteract pitching moment during pronation. In the upstroke phase, the added mass component played a major role in generating thrust in forward flight. The proposed model would be useful for a better understanding of flight stability, control, and the dynamic characteristics of flapping wing flyers, and for designing flapping-wing micro air vehicles.</P>

Ornithopter Modeling for Flight Simulation

Jae-Hung Han,Jin-Young Lee,Dae-Kwan Kim 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

This paper presents the flight simulation of flapping-wing air vehicles (ornithopters) based on a refined flapping-wing aerodynamic model; the modified strip theory (MST). Compared with conventional types of micro air vehicles (MAVs), flapping MAVs show more complicated flight behaviors due to their complex wing motions and aerodynamics. In this paper, a flight dynamic model of an ornithopter is presented to analyze its stability and controllability. This paper focuses on the stabilization and path-following control of the ornithopter by adjusting the flapping frequency and tail-wing’s elevation angle. In spite of its nonlinear and complex behavior, controlling the tail-wing pitch angle can be effective for the stabilization in longitudinal motion of the ornithopter.

Survivin silencing and TRAIL expression using oncolytic adenovirus increase anti-tumorigenic activity in gemcitabine-resistant pancreatic cancer cells

Han, Zhezhu,Lee, Seungha,Je, Suyeon,Eom, Chi-Yong,Choi, Hye Jin,Song, Jae J.,Kim, Joo-Hang Springer-Verlag 2016 Apoptosis Vol.21 No.3

<P>In this study, we demonstrated that survivin downregulation with TRAIL expression greatly enhanced the cytotoxic death of pancreatic cancer cells after gemcitabine treatment. Using real-time RT-PCR, we analyzed five survivin shRNAs to identify the best target sequence for suppression of human survivin, with the goal of treating gemcitabine-resistant pancreatic cancer cells. Survivin shRNA 5, corresponding to target 5, showed the greatest reduction in survivin mRNA levels. Furthermore, combined treatment with survivin shRNA-expressing adenovirus with gemcitabine plus TRAIL decreased uncleaved PARP and increased consequent PARP cleavage, which was correlated with the greatest levels of survivin downregulation and cell death. These results indicate that survivin functions as a common mediator of gemcitabine-and TRAIL-induced cell death. Using a nude mouse model implanted with MiaPaCa-2 pancreatic cancer cells, we observed tumor regression induced by an oncolytic adenovirus expressing survivin shRNA and TRAIL plus gemcitabine. Together, our findings provide a strong rationale for treating pancreatic cancer patients with both gemcitabine and oncolytic adenovirus armed with survivin shRNA and TRAIL.</P>

The advance ratio effect on the lift augmentations of an insect-like flapping wing in forward flight

Han, Jong-Seob,Chang, Jo Won,Han, Jae-Hung Cambridge University Press 2016 Journal of fluid mechanics Vol.808 No.-

<P>Time-varying force/moment measurements and digital particle image velocimetry (DPIV) were conducted to reveal the influence of an advance ratio $J$ on an insect-like flapping wing. A scaled-up robotic model and a servo-driven towing tank were employed to investigate nine individual $J$ cases – $J=0$ (hovering), 0.0625, 0.1250, 0.1875, 0.25, 0.50, 0.75, 1.0 and $\infty$ (gliding motion) – at a high Reynolds number ($Re\sim 10^{4}$). At $J\leqslant 0.25$, the aerodynamic forces slightly increased from those in hover ($J=0$). The centres of pressure in these cases were concentrated in the outboard section, and the leading-edge vortices (LEVs) grew more conically than those in hover. Spanwise cross-sectional DPIV indicated that the wings generated more balanced downwashes, which effectively supported the slight lift increments in this range. At $J>0.25$, a drastic force drop appeared as $J$ increased. The DPIV results in the $J=0.5$ case clearly showed a strong trailing-edge vortex on the outboard trailing edges encroaching into the upper surface, which had been occupied by the LEV for lower $J$. The LEV vorticity was noticeably weakened, and coherent substructures with substantial turbulence accompanied this vorticity. In the $J=1.0$ case, such encroachment was extended to 50 % of the section, and the LEV outboard became significantly irregular. The near-wake structures also showed that the $J=1.0$ case had the narrowest downwash area, with unstable root and tip vortices, which reflected considerable attenuation in the lift enhancements. It was of note that all of these vortical behaviours were clearly distinguishable from aspect ratio ($AR$) effects. The $J$ even played a similar role to that of the $AR$ in the Navier–Stokes equation. These findings clearly indicated that the $J$ could be an independent quantity governing the overall vortical system and lift enhancing mechanism on a flapping wing of a flapping-wing micro air vehicle.</P>

Manufacturing and foaming of high melt viscosity of polypropylene by using electron beam radiation technology

Han, Do-Hung,Jang, Jae-Hyuk,Kim, Hye-Young,Kim, Byung-Nam,Shin, Boo-Young Wiley Subscription Services, Inc., A Wiley Company 2006 Polymer engineering and science Vol.46 No.4

<P>The high melt viscosity of polypropylene was studied by grafting bifunctional monomers, 1,6-hexanediol diacrylate (HDDA) and tripropylene glycol diacrylate (TPGDA), onto homopolypropylene (HPP) and random ter-polypropylene (RTPP) under electron-beam irradiation. Creation of the high-melt-viscosity polypropylene was possible at low radiation dosage and low monomer content, under a prohibition of both radiation degradation and homopolymerization. TPGDA monomer was more effective in increasing the melt viscosity of HPP compared with RTPP, whereas HDDA monomer was more effective for enhancing the melt viscosity of RTPP. Such different effects of monomers on melt viscosity may arise from different monomer structures, namely, TPGDA has additional three methyl groups, but HDDA has no methyl groups. Electron-beam radiation technology, on an increase of the melt viscosity, was much more effective in HPP than RTPP, when compared with virgin polymers. Modified RTPP and HPP with high melt viscosity were capable of foaming with numerous fine cells, of which the modified HPP with 1.5 mmol TPGDA and 0.5 kGy could create more spherical foam cells and its bending strength was 1.5 times more than that of the foamed RTPP. POLYM. ENG. SCI., 46:431–437, 2006. © 2006 Society of Plastics Engineers.</P>

Characteristics and distributions of soil microorganism of citrus orchard as affected by different fertilizer application rates in volcanic ash soils

Jae-Ho Joa,Han-Choel Lim,Kyung-Hwan Moon,Gap-Seung Han,Hang-Yon, Won 한국토양비료학회 2005 한국토양비료학회 학술발표회 초록집 Vol.2005 No.9

Bacterial Black Stem Rot on Angelica acutiloba Caused by Xanthomonas campestris

Han, Kwang-Seop,Shim, Myoung-Youg,Oh, In-Seok,Han, Kyu-Hung,Park, Jae-Eul The Korean Society of Plant Pathology 2002 Plant Pathology Journal Vol.18 No.1

Soaked black rot symptom was observed on the stem of Angelica acutiloba from July to August 2000 at Kumsan, Chungnam in Korea. This disease usually occurred under humid and high temperature conditions. The lesions on the stem appeared as soft rot with brown elliptical spots, which developed into large black spots at a later stage. When the bacterial isolates from the diseased plants were inoculated onto healthy plants by artificial needle prick method, symptoms similar to that observed in the fields developed. According to the cultural characteristics and pathogenicity of the isolates on the host plant the causal bacterium was identified as Xanthomonas campestris. This study proposed that the disease be named "bacterial black stem rot of A. acutiloba"loba".