Prevalence of Haplorchis taichui among humans and fish in Luang Prabang Province, Lao PDR

Sohn, W.M.,Yong, T.S.,Eom, K.S.,Min, D.Y.,Lee, D.,Jung, B.K.,Banouvong, V.,Insisiengmay, B.,Phommasack, B.,Rim, H.J.,Chai, J.Y. Verlag für Recht und Gesellschaft ; Elsevier 2014 Acta tropica Vol.136 No.-

This study confirmed the prevalence of the intestinal fluke Haplorchis taichui (Trematoda: Heterophyidae) among people and fish in Luang Prabang Province, Lao PDR. Fecal specimens were collected from 559 riparian people (229 males and 330 females), residing in 4 Districts (Luang Prabang, Xieng Ngeun, Pak Ou, and Nam Bak) and were examined by the Kato-Katz fecal smear technique. The overall helminth egg positive rate was 64.9%. The positive rate for small trematode eggs (STE), which may include H. taichui and other heterophyids, Opisthorchis viverrini, and lecithodendriids, was 15.2%. For recovery of adult helminths, 10 STE-positive people were treated with 40mg/kg praziquantel and 15mg/kg pyrantel pamoate, and then purged. Mixed infections with 3 Haplorchis species (H. taichui, H. pumilio, and H. yokogawai), a species of cestode (Taenia saginata), and several species of nematodes including Enterobius vermicularis and hookworms were found. The worm load for trematodes was exclusively high for H. taichui with an average of 7691 specimens per infected person, followed by H. yokogawai (8.3 specimens) and H. pumilio (4.1 specimens). Out of 207 freshwater fish (17 species) purchased in a market in Luang Prabang District, 138 (67%) harboured H. taichui metacercariae (metacercarial burden per fish; 520). Lower prevalence of fish and lower metacercarial density were observed for H. yokogawai (52% and 50 per fish, respectively) and H. pumilio (18% and 3 per fish, respectively). STE found in the surveyed population of Luang Prabang Province were verified to be those of intestinal fukes, particularly H. taichui.

M-13 bacteriophage based structural color sensor for detecting antibiotics

Moon, J.S.,Park, M.,Kim, W.G.,Kim, C.,Hwang, J.,Seol, D.,Kim, C.S.,Sohn, J.R.,Chung, H.,Oh, J.W. Elsevier Sequoia 2017 Sensors and actuators. B Chemical Vol.240 No.-

Color sensor systems that exploit the advantages of M-13 bacteriophage have been shown to be potentially useful for detection of hazardous materials. The properties of M-13 bacteriophage can be systemically modified to impart target-specific selectivity and sensitivity using the phage display technique. Here, we describe a structural color-based sensor that utilizes genetically engineered M-13 bacteriophage to discriminate different types of antibiotics. An M-13 bacteriophage based structural color matrix was fabricated using a simple pulling technique by self-assembly of M-13 bacteriophage. When exposed to organic solvent, M-13 bacteriophage bundles promptly swell and promote distinct structural color change. Color sensors composed of M-13 bacteriophage genetically engineered to possess WHW peptide motifs clearly discriminated three different types of antibiotics, which was based on the color analysis of sensor using principal component analysis. Our sensing approach based on M-13 bacteriophage could be a promising sensor technique such as an environmental monitoring system.

Induction of Cell Death in Human Macrophages by a Highly Virulent Korean Isolate of <i>Mycobacterium tuberculosis</i> and the Virulent Strain H37Rv

Sohn, H.,Lee, K.-S.,Kim, S.-Y.,Shin, D.-M.,Shin, S.-J.,Jo, E.-K.,Park, J.-K.,Kim, H.-J. Blackwell Publishing Ltd 2009 Scandinavian journal of immunology Vol.69 No.1

<P>Abstract</P><P>Recent studies have suggested that virulent strains of <I>Mycobacterium tuberculosis</I> induce apoptosis in macrophages less often than do attenuated strains. K-strain, which belongs to the Beijing family, is the most frequently isolated clinical strain of <I>M. tuberculosis</I> in Korea. In this study, we investigated the differential induction of cell death in human monocytic THP-1 cells by K-strain and H37Rv, a virulent but laboratory-adapted strain of <I>M. tuberculosis</I>. Although no significant difference in growth rate was observed between the cells exposed to K-strain and those exposed to H37Rv, the levels of protective cytokines such as tumour necrosis factor (TNF)-&agr;, interleukin (IL)-6 and IL-12p40 were lower in K-strain-infected cells than in H37Rv-infected cells. Cell viability assays showed that both K-strain and H37Rv, but not heat- or streptomycin-killed bacteria, induced THP-1 cell death in a TNF-independent manner. In contrast, double staining with fluorochrome-labelled inhibitors of caspase and propidium iodide and lactate dehydrogenase release assays revealed that K-strain induced significantly higher levels of necrotic cell death, rather than apoptosis, in THP-1 cells than did H37Rv. Anti-apoptotic <I>Bcl-2</I>, <I>Mcl-1</I>, <I>Bfl-1</I> and <I>Bcl-xL</I> in the cells were significantly upregulated following infection with K-strain compared with H37Rv, whereas <I>Bax</I> was slightly upregulated in response to infection with both H37Rv and K-strain. These results suggest that the highly virulent K-strain keeps cellular apoptosis as a host defense mechanism to a minimum and induces necrosis in macrophages.</P>

STUDY OF M82 USING SPECTRA FROM THE INFRARED SPACE OBSERVATORY

SOHN JUNGJOO,ANN H. B.,PAK SOOJONG,LEE H. M. The Korean Astronomical Society 2001 Journal of The Korean Astronomical Society Vol.34 No.1

We have studied the central parts of M82, which is a well-known infrared luminous, starburst galaxy, by analyzing archival data from the Infrared Space Observatory (ISO). M82 was observed at 11 positions covering $\pm$45" from the center along the major axis. We analyzed 4 emission lines, [ArIII] 8.99 ${\mu}m$, $H_2$ 17.034 ${\mu}m$, [FeII] 25,98 ${\mu}m$, and [SiII] 34,815 ${\mu}m$ from $SWSO_2$ data. The integrated flux distributions of these lines are quite different. The $H_2$ line shows symmetric twin peaks at $\~$18" from the center, which is a general characteristic of molecular lines in starburst or barred galaxies. This line appears to be associated with the rotating molecular ring at around $\~$200 pc just outside the inner spiral arm. The relative depletion of the $H_2$ line at the center may be due to the active star formation activity which dissociates the $H_2$ molecules. The other lines have peaks at the center and the distributions are nearly symmetric. The line profiles are deconvolved assuming that both intrinsic and instrumental profiles are Gaussian. The velocity dispersion outside the core is found to be $\~50 km s^{-1}$. The central velocity dispersion is much higher than $50 km s^{-1}$, and different lines give different values. The large central velocity dispersion ($\sigma$) is mostly due to the rotation, but there is also evidence for a high $\sigma$ for [ArIII] line. We also generated position-velocity maps for these four lines. We found very diverse features from these maps.

The Results of Installation and Preliminary Test of 22.9 kV, 50 MVA, 100 m Class HTS Power Cable System at KEPCO

Sohn, S.H.,Lim, J.H.,Yim, S.W.,Hyun, O.B.,Kim, H.R.,Yatsuka, K.,Isojima, S.,Masuda, T.,Watanabe, M.,Ryoo, H.S.,Yang, H.S.,Kim, D.L.,Hwang, S.D. Institute of Electrical and Electronics Engineers 2007 IEEE transactions on applied superconductivity Vol.17 No.2

<P>As high temperature superconducting (HTS) power cables have some merits over conventional cables, several demonstration projects on the HTS cable system are presently under way around the world. Korea Electric Power Corporation (KEPCO) also initiated an HTS cable project in 2002 with the Korean government's support. A three phase 100 m HTS cable system with a capacity of 50 MVA has been installed at Gochang test yard, located in Chonnbuk province, Korea. The HTS cable system is composed of a 100 m-long cable, two terminations and a cooling system. The rated current is 1,250 A<SUB>rms</SUB> and the rated voltage is 22.9 kV considering compatibility with the conventional power distribution system in Korea. Main purposes of this project are to verify the performance of an HTS cable system and to evaluate the potential of the HTS cable system from the viewpoint of power utilities. The real grid application of the HTS cable system requires the demonstration of system reliability, accumulated operation experiences, and it has to meet the practical needs of the utilities. In such a meaning, this project provides various challenges for KEPCO, and the feedback will be delivered to cable manufacturers. This user initiative test will facilitate the introduction of HTS cable systems into a real grid network. The installation process of the HTS cable system and some results of the preliminary test were presented in this paper.</P>

Improvement in the Electrochemical Properties of ZrMn2 Hydrides by Substitution of Elements

Song, M . Y .,Kwon, I . H .,Ahn, D . S .,Sohn, M . S . 대한금속재료학회(대한금속학회) 2001 METALS AND MATERIALS International Vol.7 No.3

The hydrogen-storage properties and the electrochemical properties are investigated for the alloys ZrMn₂Nix, ZrMnNi_(1+x), Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(1-x)Fe_x and Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15). The C14 Laves phase forms in all the alloys ZrMn₂Ni_x (x=0.0, 0.3, 0.6, 0.9 and 1.2). Among the alloys ZrMn₂Ni_x, ZrMn₂Ni_(0.6) has the largest discharge capacity (29 mAh/g) and a relatively good cycling performance, and shows a relatively easy activation. The C14 Laves phase also forms in all the alloys ZrMnNi_(1+x) (x=0.0, 0.1, 0.2, 0.3 and 0.4). Among the alloys ZrMnNi_(1+x), ZrMnNi_(1.0) has the largest discharge capacity (42 mAh/g) and a relatively good cycling performance, and shows the easiest activation. Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(1+x)Fe_x (x=0.00, 0.15, 0.30, 0.45 and 0.60) has the C14 Laves phase hexagonal structure. Their hydrogen storage capacities do not show significant differences. The discharge capacity just after activation decreases with an increase in the amount of the substituted Fe but the cycling performance is improved. The discharge capacity after activation of the alloy with x=0.00 is about 240 mAh/g at the current density 60 mA/g. Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) is the best composition with a relatively large discharge capacity and a good cycling performance. The increase in the discharge capacity of Zro.sTio.sMno.qVo.bNio,asFeo.,s with the increase in the current density (from 60 mA/g to 125 mA/g) is considered to result from the self-discharge property of the electrode. Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) (M=Fe, Co, Cu, Mo and Al) alloys also have the C14 Laves phase hexagonal structure. The alloys with M=Co and Fe have relatively larger hydrogen storage capacities. The discharge capacities just after activation are relatively large in the case of the alloys with M=Co and Fe. The Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) alloy is best with a relatively large discharge capacity (257 mAh/g at the current density 250 mA/g for the 12^(th) cycle) and a good cycling performance. During activation form Ni-rich and Fe-rich regions on the surface of the Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) alloy. They may act as the active sites for the electrochemical reaction. With the increase in the number of charge-discharge cycles for the Zr_(0.5)Ti_(0.5)Mn_(0.4)V_(0.6)Ni_(0.85)M_(0.15) alloy, the quantities of the Zr and Fe dissolved in the electrolyte solution increase.

Effect of Tm3+ on the Strong Magnetic Anisotropy in the High-Tc Superconductor TmBa2Cu3Oy

J. H. Lee,김영철,D. Ahmad,김동진,정대영,I. S. Park,최민석,M. H. Sohn,장민수,Rock-Kil Ko,S. S. Ahn 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.4

The rare-earth superconductor TmBa2Cu3Ox(TmBCO) shows strong anisotropies in both para- magnetism and superconductivity. We discussed the eect of Tm3+ on the strong anisotropies of TmBCO. The magnetization (M) of TmBCO above the critical temperature (Tc) is very well described by the Brillouin function BJ (g¹BB=kBT) with J = 6, meaning that the paramagnetic signal of TmBCO is mainly generated from Tm3+ ions. The anisotropy of the magnetization values for T > Tc appears to be much stronger than that of YBCO. This can be explained by spin-orbit coupling of the two unpaired electrons of the Tm3+ ions in noncubic symmetry orbitals. From the superconducting signal below Tc, an anisotropy of the critical current density (Jcjj < Jc?) has been observed, where Jcjj and Jc? are the critical current densities measured under a .eld applied parallel to the c-axis (Hjj) and a .eld applied parallel to the ab-plane (H?), respectively. The super- conducting anisotropy can be explained by the local .eld intensity on the Cu-O planes depending on the spin alignment direction of the two unpaired electrons of the Tm3+ ion determined by H. In addition, Jc?(H) for H > 20 kOe increased a little as H increased, showing non-collective °ux pinning behavior. This means that the Tm3+ ions under H? serve as pinning centers in high .elds.ame=JP0

Multicenter phase II study of docetaxel plus oxaliplatin combination chemotherapy in patients with advanced gastric cancer: Daegu Gyeongbuk Oncology Group

Kim, J G,Sohn, S K,Chae, Y S,Song, H S,Kwon, K-Y,Do, Y R,Kim, M K,Lee, K H,Hyun, M S,Ryoo, H M,Bae, S H,Park, K U,Lee, W S,Baek, J H,Chung, H Y,Yu, W Nature Publishing Group 2008 The British journal of cancer Vol.98 No.3

<P>The present study was conducted to evaluate the efficacy and safety of a combination regimen of docetaxel plus oxaliplatin in patients with advanced gastric cancer. Patients with previously untreated metastatic or recurrent, measurable gastric cancer received intravenous docetaxel 65 mg m<SUP>−2</SUP> plus oxaliplatin 120 mg m<SUP>−2</SUP> on day 1 based on a 3-week cycle. Forty-two patients were enrolled in the current study, among whom 39 were assessable for efficacy and all assessable for toxicity. One complete response and 18 partial responses were confirmed, giving an overall response rate of 45.2% (95% confidence interval (CI); 31.7–59.7%). At a median follow-up of 7.7 months, the median time to progression and median overall survival was 5.7 (95% CI; 4.3–7.2) months and 9.9 (95% CI; 7.8–12.0) months, respectively. Grade 3/4 neutropenia occurred in 11 patients (26.1%) and febrile neutropenia was observed in four patients (9.5%). The common non-haematologic toxicity was fatigue (grade 1/2, 61.9%) and nausea (grade 1/2, 47.7%). The combination of docetaxel and oxaliplatin was found to be well tolerated and effective in patients with advanced gastric cancer.</P>

Display of membrane proteins on the heterologous caveolae carved by caveolin-1 in the Escherichia coli cytoplasm

Shin, J.,Jung, Y.H.,Cho, D.H.,Park, M.,Lee, K.E.,Yang, Y.,Jeong, C.,Sung, B.H.,Sohn, J.H.,Park, J.B.,Kweon, D.H. IPC Science and Technology Press ; Elsevier Scienc 2015 Enzyme and microbial technology Vol.79 No.-

Caveolae are membrane-budding structures that exist in many vertebrate cells. One of the important functions of caveolae is to form membrane curvature and endocytic vesicles. Recently, it was shown that caveolae-like structures were formed in Escherichia coli through the expression of caveolin-1. This interesting structure seems to be versatile for a variety of biotechnological applications. Targeting of heterologous proteins in the caveolae-like structure should be the first question to be addressed for this purpose. Here we show that membrane proteins co-expressed with caveolin-1 are embedded into the heterologous caveolae (h-caveolae), the cavaolae-like structures formed inside the cell. Two transmembrane SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, Syntaxin 1a and vesicle-associated membrane protein 2 (VAMP2), were displayed on the h-caveolae surface. The size of the h-caveolae harboring the transmembrane proteins was ~100nm in diameter. The proteins were functional and faced outward on the h-caveolae. Multi-spanning transmembrane proteins FtsH and FeoB could be included in the h-caveolae, too. Furthermore, the recombinant E. coli cells were shown to endocytose substrate supplemented in the medium. These results provide a basis for exploiting the h-caveolae formed inside E. coli cells for future biotechnological applications.

Sonocatalytical degradation enhancement for ibuprofen and sulfamethoxazole in the presence of glass beads and single-walled carbon nanotubes

Al-Hamadani, Y.A.J.,Chu, K.H.,Flora, J.R.V.,Kim, D.H.,Jang, M.,Sohn, J.,Joo, W.,Yoon, Y. Elsevier Science 2016 Ultrasonics sonochemistry Vol.32 No.-

Sonocatalytic degradation experiments were carried out to determine the effects of glass beads (GBs) and single-walled carbon nanotubes (SWNTs) on ibuprofen (IBP) and sulfamethoxazole (SMX) removal using low and high ultrasonic frequencies (28 and 1000kHz). In the absence of catalysts, the sonochemical degradation at pH 7, optimum power of 0.18WmL<SUP>-1</SUP>, and a temperature of 15<SUP>o</SUP>C was higher (79% and 72%) at 1000kHz than at 28kHz (45% and 33%) for IBP and SMX, respectively. At the low frequency (28kHz) H<SUB>2</SUB>O<SUB>2</SUB> production increased significantly, from 10μM (no GBs) to 86μM in the presence of GBs (0.1mm, 10gL<SUP>-1</SUP>); however, no enhancement was achieved at 1000kHz. In contrast, the H<SUB>2</SUB>O<SUB>2</SUB> production increased from 10μM (no SWNTs) to 31μM at 28kHz and from 82μM (no SWNTs) to 111μM at 1000kHz in the presence of SWNTs (45mgL<SUP>-1</SUP>). Thus, maximum removals of IBP and SMX were obtained in the presence of a combination of GBs and SWNTs at the low frequency (94% and 88%) for 60min contact time; however, >99% and 97% removals were achieved for 40 and 60min contact times at the high frequency for IBP and SMX, respectively. The results indicate that both IBP and SMX degradation followed pseudo-first-order kinetics. Additionally, the enhanced removal of IBP and SMX in the presence of catalysts was because GBs and SWNTs increased the number of free OH<SUP>?</SUP> radicals due to ultrasonic irradiation and the adsorption capacity increase with SWNT dispersion.