Quantifying herbicide dose-response and resistance in <i>Echinochloa</i> spp. by measuring root length in growth pouches

Zhang, C. J.,Lim, S. H.,Kim, J. W.,Song, J. S.,Yook, M. J.,Nah, G.,Valverde, B. E.,Kim, D. S. Canadian Science Publishing 2015 Canadian journal of plant science. Revue canadienn Vol.95 No.6

<P> Zhang, C. J., Lim, S. H., Kim, J. W., Song, J. S., Yook, M. J., Nah, G., Valverde, N. E. and Kim, D. S. 2015. Quantifying herbicide dose-response and resistance in Echinochloa spp. by measuring root length in growth pouches. Can. J. Plant Sci. 95: 1181-1192. The aim of the presented study was to develop a bioassay for rapid diagnosis of herbicide dose-response and resistance in Echinochloa. Pre-germinated seeds of Echinochloa spp. were incubated in growth pouches (18 cm×16.5 cm) containing herbicide solutions in a range of concentrations. Shoot and root lengths were measured after 6 d of incubation. Dose-responses estimated by measuring root lengths in the growth pouches were well-described by the log-logistic dose-response model and similar to those estimated by a whole-plant assay. Accurate dose-response curves were successfully generated for several herbicides with different modes of action, suggesting that the growth pouch method can be used for herbicide bioassays. The suitability of the growth pouch method for rapid diagnosis of acetyl coenzyme-A carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor resistance in Echinochloa spp. was also tested. For cyhalofop-butyl, resistant and susceptible biotypes were discriminated at 180-300 mg a.i. L<SUP>−1</SUP> and 80-120 mg a.i. L<SUP>−1</SUP> for barnyardgrass (E. crus-galli) and late watergrass (E. oryzicola), respectively. For penoxsulam, the discriminatory dosage was 350-500 mg a.i. L<SUP>−1</SUP> for barnyardgrass and 650-1000 mg a.i. L<SUP>−1</SUP> for late watergrass. The method was further used to identify late watergrass biotypes resistant and susceptible to two other ALS inhibitors, azimsulfuron and bispyribac-sodium. Our results show that the growth pouch method can be reliably used in herbicide dose-response studies and to diagnose herbicide resistance in Echinochloa spp., with significant time and cost savings compared with conventional whole-plant assays. </P>

Electrocatalytic activity of chemically deposited Cu_xS thin film for counter electrode in quantum dots-sensitized solar cells

Lim, I.,Lee, D.Y.,Patil, S.A.,Shrestha, N.K.,Kang, S.H.,Nah, Y.C.,Lee, W.,Han, S.H. Elsevier Science Publishers 2014 Materials chemistry and physics Vol.148 No.3

The compact (c-Cu<SUB>x</SUB>S) and the porous (p-Cu<SUB>x</SUB>S) with particle decorated films of coppers-ulfidearesynthesized using a chemical bath deposition technique, and the films are characterized using electrochemical techniques. In addition, the chemically deposited Cu<SUB>x</SUB>S films are investigated as a counter electrode in quantum dots-sensitized solar cells (QSSCs). The available redox active reaction sites of the p-Cu<SUB>x</SUB>S film are found to be 57.9% higher than those available in the c-Cu<SUB>x</SUB>S film. From the electrochemical impedance spectroscopy, the effective diffusion coefficients of the polysulfide electrolyte in the c-Cu<SUB>x</SUB>S and p-Cu<SUB>x</SUB>S films are estimated to be 3.67 x 10<SUP>-5</SUP> and 6.35 x 10<SUP>-5</SUP> cm<SUP>2</SUP> s<SUP>-1</SUP>, respectively. These results can be ascribed to the improvement in the available redox active reaction sites and the electrocatalytic activity of the Cu<SUB>x</SUB>S counter electrode. As compared to the c-Cu<SUB>x</SUB>S film, the p-Cu<SUB>x</SUB>S film as a counter electrode exhibits an enhanced photovoltaic performance of the QSSCs with the power conversion efficiency of 3.17%, short-circuit current of 11.89 mA c<SUP>-</SUP>m<SUP>2</SUP>, open-circuit voltage of 0.50 V, and fill factor of 53.29. The improved performance of the QSSCs is ascribed to the improvements on the available redox active reaction sites, electrocatalytic activity and the diffusion coefficients, which are directly related to the surface morphology of the sulfide films.

Effect of dextromethorphan on human K_v1.3 channel activity: Involvement of C-type inactivation

Lee, J.H.,Choi, S.H.,Shin, T.J.,Lee, B.H.,Hwang, S.H.,Kim, H.C.,Nah, S.Y. North-Holland ; Elsevier Science Ltd 2011 european journal of pharmacology Vol.651 No.1

Dextromethorphan exhibits neuroprotective effects against inflammation-mediated neurodegeneration. However, relatively little is known regarding the molecular mechanism for this inflammation-mediated neuroprotection. Human K<SUB>v</SUB>1.3 channels, one of the voltage-gated potassium channels, are widely expressed in the immune and nervous systems. Activation of human K<SUB>v</SUB>1.3 channels causes neuroglia-mediated neurodegeneration. Agents that inhibit human K<SUB>v</SUB>1.3 channel activity have been developed as novel drugs for immunosuppression. In the present study, we investigated the effects of dextromethorphan on human K<SUB>v</SUB>1.3 or K<SUB>v</SUB>1.2 channel activity heterologously expressed in Xenopus laevis oocytes. The channel currents were measured with the two-electrode voltage clamp technique. Activation of both channels induced outward peak and steady-state currents. Dextromethorphan treatment induced a slight inhibition of peak currents in human K<SUB>v</SUB>1.2 and K<SUB>v</SUB>1.3 channels, whereas dextromethorphan profoundly inhibited the steady-state currents of human K<SUB>v</SUB>1.3 channels compared to K<SUB>v</SUB>1.2 channel currents. Dextromethorphan's action on steady-state currents of human K<SUB>v</SUB>1.3 channels was in a concentration-dependent manner. The half-maximal inhibitory concentration (IC<SUB>50</SUB>) on steady-state currents of human K<SUB>v</SUB>1.3 channels was 12.8+/-1.6μM. Dextromethorphan also accelerated the C-type inactivation rate, increased the current decay rate, and inhibited currents in a use-dependent manner. These results indicate that dextromethorphan accelerates C-type inactivation of human K<SUB>v</SUB>1.3 channels and acts as an open-channel blocker. These results further suggest the possibility that dextromethorphan-mediated acceleration of C-type inactivation of human K<SUB>v</SUB>1.3 channels might be one of the cellular bases of dextromethorphan-mediated protection against inflammation-mediated neurodegeneration.

연료전지용 터보압축기 회전축의 동특성 해석에 관한 연구

김홍건,나석찬,김성철,강영우,양균의,이희관,최문창 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.1

A 3-D EM (Finite Element Method) analysis of the turbe-blower shaft attached to a fuel cell was performed using Lanczos algorithm. The modal analysis was analyzed in order to investigate natural frequency and maximum displacement for 10 times. It was found that the first mode of natural frequency is 109.1Hz with the maximum displacement of 0.16mm while the tenth mode of natural frequency is 2464Hz with the maximum displacement of 0.25mm. Consequently, the results of modal analysis of the turbo-blower for a fuel cell system show good dynamic responses.

MK-801, but not naloxone, attenuates high-dose dextromethorphan-induced convulsive behavior: Possible involvement of the GluN2B receptor

Tran, H.Q.,Chung, Y.H.,Shin, E.J.,Tran, T.V.,Jeong, J.H.,Jang, C.G.,Nah, S.Y.,Yamada, K.,Nabeshima, T.,Kim, H.C. Academic Press 2017 Toxicology and applied pharmacology Vol.334 No.-

Dextromethorphan (DM) is a dextrorotatory isomer of levorphanol, a typical morphine-like opioid. When administered at supra-antitussive doses, DM produces psychotoxic and neurotoxic effects in humans. Although DM abuse has been well-documented, few studies have examined the effects of high-dose DM. The present study aimed to explore the effects of a single high dose of DM on mortality and seizure occurrence. After intraperitoneal administration with a high dose of DM (80mg/kg), Sprague-Dawley rats showed increased seizure occurrence and intensity. Hippocampal expression levels of N-methyl-d-aspartate (NMDA) receptor subunits (GluN1<GluN2A<GluN2B), c-Fos and pro-apoptotic factors (Bax and cleaved caspase-3) were upregulated by DM treatment; while levels of anti-apoptotic factors (Bcl-2 and Bcl-xL) were downregulated. Consistently, DM also induced ultrastructural degeneration in the hippocampus. A non-competitive NMDA receptor antagonist, MK-801, attenuated these effects of high-dose DM, whereas an opioid antagonist, naloxone, did not affect DM-induced neurotoxicity. Moreover, pretreatment with a highly specific GluN2B subunit inhibitor, traxoprodil, was selectively effective in preventing DM-induced c-Fos expression and apoptotic changes. These results suggest that high-dose DM produces convulsive behaviors by activating GluN2B/NMDA signaling that leads to pro-apoptotic changes.

경동맥 조영술시 파열된 거대 동맥류 : 증례 보고

나중환,김상진,박중겸,도종웅 대한신경외과학회 1980 Journal of Korean neurosurgical society Vol.9 No.1

The authers report a case of giant anterior communicating artery aneurysm which was ruptured into lateral ventricle during carotid angiography.

터보압축기의 과도동적해석에 관한 연구

김홍건,양성모,노홍길,나석찬,강영우 한국공작기계학회 2003 한국공작기계학회 춘계학술대회논문집 Vol.2003 No.-

An analysis of the turbe-blower shaft attached to fuel cell using 3-D FEA (Finite Element Analysis) is proposed by Lanczos algorithm. The modal analysis was performed in order to investigate natural frequencies for 10 times. It is found that the first mode of natural frequency is 111.243 and the maximum displacement is 0.16mm. Consequently, It is found that the dynamic design of turbo-blower shows a good responses transiently.

Effects of Gintonin-Enriched Fraction in an Atopic Dermatitis Animal Model: Involvement of Autotaxin Regulation

Lee, B.-H.,Kim, H.-K.,Jang, M.,Kim, H.-J.,Choi, S.-H.,Hwang, S.-H.,Kim, H.-C.,Rhim, H.,Cho, I.-H.,Nah, S.-Y. PHARMACEUTICAL SOCIETY OF JAPAN 2017 Biological & pharmaceutical bulletin Vol.40 No.7

<P>Ginseng extract has been used for prevention of atopic dermatitis (AD) in experimental animal models. However, little is known about its active ingredients and the molecular mechanisms underlying its anti-AD effects. Recently, we isolated a unique lysophosphatidic acid (LPA) receptor ligand, gintonin, from ginseng. Gintonin, the glycolipoprotein fraction of ginseng, contains LPAs, mainly LPA C-18:2 with other minor lysophospholipid components. A line of evidence showed that serum autotaxin (ATX) activity and level are significantly elevated in human AD patients compared to those in normal controls, which indicates that ATX may be involved in human AD. In a previous study, we demonstrated that gintonin exerted anti-inflammatory effects via inhibition of microglial activation and proinflammatory cytokine production by immune cells and that it strongly inhibited ATX activity. In this study, we investigated whether oral administration of the gintonin-enriched fraction (GEF) could ameliorate the symptoms of 2,4-dinitrofluorobenzene (DNFB)-induced AD in NC/Nga mice. We found that oral administration of GEF to DNFB-induced AD mice for 2 weeks reduced ear swelling and AD skin index. In addition, oral administration of GEF reduced the serum levels of immunoglobulin E, histamine, interleukin-4, and interferon-gamma. Histological examination showed that oral administration of GEF attenuated skin inflammation and significantly reduced eosinophil and mast cell infiltration into the skin. Moreover, oral administration of GEF not only decreased serum ATX level but also reduced serum ATX activity. The present study shows that the anti-AD effects of ginseng might be attributed to GEF-induced anti-inflammatory activity and ATX regulation.</P>

트랙터 견인형 TMR 배합기의 개발(Ⅲ) : 경제성 분석 Cost analysis

박경규,김혁주,서상훈,장철,이종순,나규동,홍동혁,하유신 한국농업기계학회 2000 바이오시스템공학 Vol.25 No.4

Molecular Mechanisms of Large-Conductance Ca ^<b>2+</b> -Activated Potassium Channel Activation by Ginseng Gintonin

Choi, S. H.,Lee, B. H.,Hwang, S. H.,Kim, H. J.,Lee, S. M.,Kim, H. C.,Rhim, H. W.,Nah, S. Y. Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>Gintonin is a unique lysophosphatidic acid (LPA) receptor ligand found in <I>Panax ginseng</I>. Gintonin induces transient [Ca<SUP>2+</SUP>]<SUB>i</SUB> through G protein-coupled LPA receptors. Large-conductance Ca<SUP>2+</SUP>-activated K<SUP>+</SUP> (BK<SUB>Ca</SUB>) channels are expressed in blood vessels and neurons and play important roles in blood vessel relaxation and attenuation of neuronal excitability. BK<SUB>Ca</SUB> channels are activated by transient [Ca<SUP>2+</SUP>]<SUB>i</SUB> and are regulated by various Ca<SUP>2+</SUP>-dependent kinases. We investigated the molecular mechanisms of BK<SUB>Ca</SUB> channel activation by gintonin. BK<SUB>Ca</SUB> channels are heterologously expressed in <I>Xenopus oocytes</I>. Gintonin treatment induced BK<SUB>Ca</SUB> channel activation in oocytes expressing the BK<SUB>Ca</SUB> channel <I><I>α</I></I> subunit in a concentration-dependent manner (EC<SUB>50</SUB> = 0.71 ± 0.08 <I>µ</I>g/mL). Gintonin-mediated BK<SUB>Ca</SUB> channel activation was blocked by a PKC inhibitor, calphostin, and by the calmodulin inhibitor, calmidazolium. Site-directed mutations in BK<SUB>Ca</SUB> channels targeting CaM kinase II or PKC phosphorylation sites but not PKA phosphorylation sites attenuated gintonin action. Mutations in the Ca<SUP>2+</SUP> bowl and the regulator of K<SUP>+</SUP> conductance (RCK) site also blocked gintonin action. These results indicate that gintonin-mediated BK<SUB>Ca</SUB> channel activations are achieved through LPA1 receptor-phospholipase C-IP<SUB>3</SUB>-Ca<SUP>2+</SUP>-PKC-calmodulin-CaM kinase II pathways and calcium binding to the Ca<SUP>2+</SUP> bowl and RCK domain. Gintonin could be a novel contributor against blood vessel constriction and over-excitation of neurons.</P>