A field application feasibility assessment of naphthoquinone derivatives for the mitigation of freshwater diatom Stephanodiscus blooms

Joo, J. H.,Kang, Y. H.,Park, B. S.,Park, C. S.,Cho, H.,Han, M. S. Springer Science + Business Media 2016 Journal of applied phycology Vol.28 No.3

<P>Although many algicidal substances have been developed, their field application remains a serious challenge due to their high toxicity in the ecosystem and also due to economic reasons. Therefore, we evaluated the claim that naphthoquinone (NQ) derivatives can be used for the efficient mitigation of natural Stephanodiscus hantzschii blooms in freshwater. We tested a total of 23 algicidal NQ compounds to select the best based on the algicidal activity of S. hantzschii species. Among them, NQ 4-6 showed the highest algicidal activities (96 % at a parts per thousand yen0.2 mu M). We conducted an acute toxicity assessment of the new algicide and found that NQ 4-6 had advanced solubility and lower toxicity, as represented by the survival rates of Selenastrum capricornutum, Daphnia magna, and Danio rerio, which are interconnected components of the freshwater ecosystem. None of these organisms seemed to be affected by the highest NQ concentration (2 mu M), indicating a lack of significant toxic effects. These results indicate that the NQ 4-6 compound is promising for use as a selective control agent for S. hantzschii that does not cause negative side effects in the freshwater ecosystem. To evaluate the possibility of field application of NQ 4-6, we first performed microcosm tests. In the microcosm tests (60 L), S. hantzschii was completely eliminated 10 days after inoculation with the NQ 4-6 compound (0.2 mu M). In the microcosm experiments, the dynamics of the biotic (except the phytoplankton) and abiotic factors showed similar trends in the control and treatment groups. Therefore, the NQ 4-6 compound has potential as an alternative algicidal substance to effectively mitigate natural S. hantzschii blooms.</P>

Antimicrobial Susceptibility of Coagulase-Negative Staphylococci Isolated from Bovine Mastitis Between 2003 and 2008 in Korea

( J. M. Kim ),( S. K. Lim ),( J. S. Moon ),( Nam H. M. ),( H. M. Kang ),( G. C. Jang ),( S. H. Wee ),( Y. S. Joo ),( S. C. Jung ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.10

A total of 1,444 coagulase-negative staphylococci (CNS) isolates from bovine mastitic milk samples collected during 2003-2008 in Korea were identified to the species level. Of 14 species identified, S. simulans, S. haemolyticus, and S. sciuri accounted for over 60% of the isolates. All the CNS isolates were tested for susceptibility to eight antimicrobials commonly used in dairy cattle. With a few exceptions, similar resistance patterns were observed among the CNS species: penicillin and ampicillin showed the lowest activity, whereas amikacin, cephalothin, and gentamicin were highly effective. About 39% (557/1,444) of the CNS isolates were pan-susceptible, whereas 12% (175/1,444) showed resistance to four or more antimicrobials tested.

Small phytoplankton contribution to the total primary production in the highly productive Ulleung Basin in the East/Japan Sea

Joo, H.,Son, S.,Park, J.W.,Kang, J.J.,Jeong, J.Y.,Kwon, J.I.,Kang, C.K.,Lee, S.H. Pergamon Press 2017 Deep-sea research. Part II, Topical studies in oce Vol.143 No.-

The Ulleung Basin in the southwestern East/Japan Sea (hereafter East Sea) is known as a biologically productive ''hot spot'' but climate-associated changes in the physicochemical oceanographic conditions and some biological changes have been reported. In this study, our main objective was to determine the contribution of small phytoplankton to the total primary production, which is valuable information for detecting marine ecosystem changes in the Ulleung Basin. The small phytoplankton productivity contributions determined by Moderate-Resolution Imaging Spectroradiometer (MODIS)-derived monthly productivities using a phytoplankton community-based productivity algorithm was significantly consistent with the field-measured productivity contributions of small phytoplankton in this study. The daily primary productivity of small phytoplankton ranged from 42.7 to 418.7mgCm<SUP>-2</SUP>d<SUP>-1</SUP> with an average of 172.9mgCm<SUP>-2</SUP>d<SUP>-1</SUP> (S.D. = +/-61.4mgC m<SUP>-2</SUP> d<SUP>-1</SUP>, n = 120), and the annual contribution of small phytoplankton ranged from 19.6% to 28.4% with an average of 23.6% (S.D. = +/-8.1%) in the Ulleung Basin from 2003 to 2012. Overall, large phytoplankton were a major contributor to the total primary production in the Ulleung Basin (76.4 +/- 8.2%) from 2003 to 2012, which indicates that the Ulleung Basin is a highly productive region. A significantly negative relationship (p < 0.05) was found between the small phytoplankton primary productivity contribution and the annual primary production in this study. This finding revealed that the recent decreasing annual primary production in the Ulleung Basin could be a consequence of the increasing contribution of small phytoplankton. The response of phytoplankton to ongoing climate change depending on different-size phytoplankton compositions should be a subject for further investigation in the Ulleung Basin as a biologically highly productive region in the East Sea.

Immunochemical and Biological Analysis of Allergenicity with Excretory-Secretory Products of <i>Anisakis simplex</i> Third Stage Larva

Kim, J.S.,Kim, K.H.,Cho, S.,Park, H.Y.,Cho, S.W.,Kim, Y.T.,Joo, K.H.,Lee, J.S. S. Karger AG 2005 International archives of allergy and immunology Vol.136 No.4

<P><I>Background:</I><I>Anisakis simplex</I> third stage larvae (L3) are parasites that frequently give rise to allergic responses. The larvae molt into fourth stage larvae (L4), and at each stage they produce L3-excretory-secretory products (L3-ESP) and L4-ESP, respectively, which are different in their main protein constituents. Although the allergenicity of L4-ESP has been investigated by several research groups, research on the allergenicity of L3-ESP has not been carried out by any researcher. In this investigation, the allergenicity and antigenicity of L3-ESP were investigated in comparison with L4-ESP, using rat sera. <I>Methods:</I> Rat sera were produced by L3 oral infection two times with a 9-week interval. Larvae ESP prepared by culture were concentrated and fractioned using lyophilizer and a centrifugal filter device, respectively. Immunochemical analysis was performed using both indirect ELISA and immunoblot. Biological allergenicity was analyzed by RBL-2H3 exocytosis. <I>Results:</I> With the indirect ELISA, the optical density (OD) value of the nonfractioned (NF)-L3ESP was only one third of that of the NF-L4ESP in both specific IgM and IgG. On measuring specific IgE, the OD of NF-L3ESP was less than one tenth of that of NF-L4ESP. In addition, neither antigen nor allergen was shown in NF-L3ESP, but it was shown in NF-L4ESP with immunoblot. However, the biological allergenicity of NF-L3ESP was comparable to that of NF-L4ESP. To demonstrate the presence of any allergen, L3-ESP was fractioned and found to carry twelve visualized allergen bands from 10 to 186 kDa by immunoblot. <I>Conclusions:</I> These results indicate that L3-ESP may include the important allergens necessary to induce the allergy by L3 oral infection, as compared to L4-ESP.</P><P>Copyright © 2005 S. Karger AG, Basel</P>

패킷 s / w 성능분석 Tool의 설계 및 구현

박병섭(B.S.Park),이재범(J.B.Lee),김성천(S.C.Kim),주성순(S S Joo),전경표(K.P.Jeon) 한국정보과학회 1992 한국정보과학회 학술발표논문집 Vol.19 No.2

본 논문은 패킷 교환망이 연결설정 프로토콜에 적용할 수 있는 패킷 s/w의 성능분석 도구의 설계 및 구현에 관한 연구로서, 본 논문에서는 프로토콜의 대수적명세로 부터 자동적으로 프로토콜의 성능을 분석하는 방법론과 프로토콜의 대수적 명세를 사상하는 규칙과 각 event의 지수적인 발생 비율을 가지고 timing behavior의 probability attribute의 probability값을 계산하는 방법을 제시 하였다. 본 논문에서 개발한 성능분석 도구의 유용성은 기능 및 성능명세와 프로토콜의 분석을 통합한 s/w의 개발과 구현에 있다. 이러한 통합환경은 프로토콜 설계자가 그 분야에서 전문적인 지식 없이도 프로토콜 성능을 분석할 수 있게 한다.

Bottom-gate poly-Si thin-film transistors by nickel silicide seed-induced lateral crystallization with self-aligned lightly doped layer

Lee, S.K.,Seok, K.H.,Chae, H.J.,Lee, Y.H.,Han, J.S.,Jo, H.A.,Joo, S.K. Pergamon Press ; Elsevier Science Ltd 2017 Solid-state electronics Vol.129 No.-

We report a novel method to reduce source and drain (S/D) resistances, and to form a lightly doped layer (LDL) of bottom-gate polycrystalline silicon (poly-Si) thin-film transistors (TFTs). For application in driving TFTs, which operate under high drain voltage condition, poly-Si TFTs are needed in order to attain reliability against hot-carriers as well as high field-effect mobility (μ<SUB>FE</SUB>). With an additional doping on the p<SUP>+</SUP> Si layer, sheet resistance on S/D was reduced by 37.5% and an LDL was introduced between the channel and drain. These results contributed to not only a lower leakage current and gate-induced drain leakage, but also high immunity of kink-effect and hot-carrier stress. Furthermore, the measured electrical characteristics exhibited a steep subthreshold slope of 190mV/dec and high μ<SUB>FE</SUB> of 263cm<SUP>2</SUP>/Vs.

Carbon contribution of sea ice floes in the Arctic Ocean

Lee, S.H.,Kyung Kim, B.,Joo, H.T.,Woo Park, J.,Han Lee, J.,Joo, H.M.,Byoul Lee, D.,Kang, C.K.,Kang, S.H. Pergamon Press 2015 Deep-sea research. Part II, Topical studies in oce Vol.120 No.-

To estimate detailed contributions of particulate organic carbon (POC) as a potential food source in various environments of the Arctic sea ice floes, intensive investigations were executed at two different types of sea ice stations (ST 1 and ST 2) in the northern Chukchi Sea during the summer period in 2011. The average uptake rates of carbon and nitrogen in melt ponds from this study were within the range measured previously. The surface ice of melt ponds at ST 1 had the highest POC concentration with a mean of 148.0mgCm<SUP>-3</SUP> (S.D.=+/-86.0mgCm<SUP>-3</SUP>), followed by sea ice cores at ST 2 (mean+/-S.D.=125.7+/-128.2mgCm<SUP>-3</SUP>). The POC concentrations in melt ponds ranged between 90.0mgCm<SUP>-3</SUP> (S.D.=+/-12.7mgCm<SUP>-3</SUP>) and 103.9mgCm<SUP>-3</SUP> (S.D.=+/-47.7mgCm<SUP>-3</SUP>) at ST 1 and ST 2, respectively. Major POC contributors to melt ponds were diatoms with a mean biovolume contribution of 48.7% (S.D.=+/-39.1%) which was strongly related to in situ salinity. Although the total POC concentration of entire sea ice floes ranged from 2.8% to 5.3% of the POC concentration within the euphotic water column at the study locations, the carbon contribution of sea ice floes could be important to higher trophic levels because of the concentrated POC within sea ice floes.

Paricalcitol prevents cisplatin-induced renal injury by suppressing apoptosis and proliferation

Park, J.W.,Cho, J.W.,Joo, S.Y.,Kim, C.S.,Choi, J.S.,Bae, E.H.,Ma, S.K.,Kim, S.H.,Lee, J.,Kim, S.W. North-Holland ; Elsevier Science Ltd 2012 european journal of pharmacology Vol.683 No.1

The present study was performed to examine whether paricalcitol may prevent the cisplatin-induced kidney injury. Furthermore, potential molecular mechanisms underlying the protective effect of paricalcitol were explored. Male Sprague-Dawley rats were treated with vehicle (n=12), cisplatin (n=12, 6mg/kg/day, i.p.), or cisplatin+paricalcitol (n=12, 0.2μg/kg/day, s.c.) for 4days. In another series of experiment, HK-2 cells were treated with cisplatin (50μM), with or without paricalcitol (0.2ng/ml). Paricalcitol counteracted the cisplatin-induced decline in renal function. Paricalcitol also suppressed the expression of TGF-β1, Smad signaling, and the subsequent epithelial-to-mesenchymal process in cisplatin-treated rats. The expression of P-p53 and p21 was increased in cisplatin-induced nephropathy. These changes were completely prevented or significantly attenuated with paricalcitol co-treatment. The expression of p27<SUP>kip1</SUP> was increased in cisplatin-treated rats, which was, however, further augmented by the paricalcitol co-treatment. In HK-2 cells, cisplatin increased the expression of p-ERK½ and P-p38. Cisplatin also increased the expression of fibronectin and CTGF. Cisplatin increased the expression of pro-apoptotic markers. The expression of CDK2 and Cyclin E as well as that of PCNA was increased. These changes were completely prevented or significantly attenuated by the paricalcitol pretreatment. In contrast, cisplatin increased the expression of p27<SUP>kip1</SUP>, which was further augmented by the paricalcitol-pretreatment. These results suggest that paricalcitol may ameliorate cisplatin-induced renal injury by suppressing the fibrotic, apoptotic and proliferative factors. Its underlying mechanisms may include inhibition of TGF-β1, mitogen-activated protein kinase signaling, p53-induced apoptosis, and augmentation of p27<SUP>kip1</SUP>.

Seasonal carbon uptake rates of phytoplankton in the northern East/Japan Sea

Lee, S.H.,Joo, H.,Lee, J.H.,Lee, J.H.,Kang, J.J.,Lee, H.W.,Lee, D.,Kang, C.K. Pergamon Press 2017 Deep-sea research. Part II, Topical studies in oce Vol.143 No.-

Korea-Russia joint expeditions have been conducted mainly in the less studied Russian sector of the East/Japan Sea to understand the physical and ecological structures. In this study, the carbon uptake rates of phytoplankton measured in 2012 (middle-late October) and 2015 (middle April-early May) were analyzed to understand seasonal and spatial distributions of phytoplankton production, using a <SUP>13</SUP>C-<SUP>15</SUP>N dual isotope tracer technique. The water columns in the euphotic layers were well mixed during our cruise periods in both years. The water column-integrated chl-a concentrations (mean +/- S.D. = 2.28 +/- 1.47mgm<SUP>-3</SUP>) in 2015 was significantly higher (t-test, p < 0.01) than in 2012 (mean +/- S.D. = 0.49 +/- 0.29mgm<SUP>-3</SUP>) because of different sampling seasons. Small phytoplankton (< 2 μm) were relatively dominant in 2012, whereas different sizes of phytoplankton were evenly distributed in 2015 although a spatial distribution of large phytoplankton (> 20 μm) was observed near the Russian coast. The daily carbon uptake rates in this study were 180.5 and 441.6mgC m<SUP>-2</SUP> d<SUP>-1</SUP> in 2012 and 2015, respectively which are significantly (t-test, p < 0.01) lower than the averaged values previously reported in the East/Japan Sea (863 +/- 679.6mgC m<SUP>-2</SUP> d<SUP>-1</SUP>). The potential reasons for the lower rate in this study are discussed. The small phytoplankton contribution (47.4%) averaged from the two different cruises in this study is consistent with the result (47%) reported in temperate regions. Moreover, a significantly (t-test, p < 0.01) lower contribution of small phytoplankton in total primary production than total phytoplankton biomass in this study is consistent with the results from other regions. Lower total primary production might be expected due to increasing contribution of small phytoplankton under warmer conditions.

A study on electromagnetic and mechanical characteristics of the field coil in HTS motor

Kim, S.B.,Kadota, T.,Joo, J.H.,Sano, H.,Murase, S.,Lee, S.H.,Hong, J.P.,Kim, H.M.,Kwon, Y.K.,Jo, Y.S. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.20

High temperature superconducting (HTS) motors electromagnetically consist of a rotator wound with HTS wires and an armature with conventional copper wires like Litz wire. The HTS rotor windings, as field coils, consist of a straight part and an end-ring part. Because a major rotation torque is induced by an interaction between magnetic fields and current-carrying conductors in the straight part, most of mechanical stresses in the motor occur at the straight part. An end-ring is placed in the edge of the straight part and used to connect to each adjacent straight-part coils. The magnetic fields by coil currents concentrate on the end-ring part, therefore, it is expected that the critical current of the entire coil, straight and end-ring, can be determined by the magnitude of the field in the end-ring. This paper deals with the overall J<SUB>c</SUB> degradation in the end-ring part by self-field generated from the coil. In addition to electromagnetic analyses, we have performed a numerical analysis in order to evaluate mechanical stresses in the straight part of field coil by armature reaction on steady-state operation. The analytical results will be presented in this paper.