Chemiluminescence competitive aptamer assay for the detection of aflatoxin B1 in corn samples

Shim, W.B.,Mun, H.,Joung, H.A.,Ofori, J.A.,Chung, D.H.,Kim, M.G. Butterworths ; Taylor Francis ; Elsevier Science 2014 FOOD CONTROL Vol.36 No.1

In this study, we developed a chemiluminescence competitive aptamer assay for aflatoxin B1 (AFB1) using a hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme (HRP-DNAzyme) linked with an aptamer specific to AFB1. Single, double, and triple HRP-DNAzymes coupled to the AFB1 aptamer were tested, and the AFB1 aptamer linked with double HRP-DNAzymes that produced sufficient chemiluminescence (CL) values when binding to AFB1-ovalbumin (OVA) used as a coating antigen, was selected. Under conditions optimized by testing key parameters, the aptamer assay exhibited a wide dynamic range from 0.1 to 10 ng/mL and showed a limit of detection of 0.11 ng/mL. Cross-reaction to aflatoxin G1, aflatoxin M1, and zearalenone was observed but no cross-reaction to other mycotoxins or the herbicide (atrazine) was observed. Aqueous methanol (20%) gave a good extraction efficiency and the matrix influence from corn extracts was successfully reduced through 4-fold dilution with water. Recovery from spiked corn samples averaged from 60.4 to 105.5%. Thus, the aptamer linked with HRP-DNAzymes can be useful as a reagent in the development of a biosensor for the rapid and simple detection of AFB1. Results from this study provide the basis for research into the development of various aptasensors for AFB1 analysis in foods.

Comprehensive analysis of plant rapid alkalization factor (RALF) genes

Sharma, A.,Hussain, A.,Mun, B.G.,Imran, Q.M.,Falak, N.,Lee, S.U.,Kim, J.Y.,Hong, J.K.,Loake, G.J.,Ali, A.,Yun, B.W. Elsevier Science B.V., Amsterdam. 2016 Plant Physiology and Biochemistry Vol. No.

<P>Receptor mediated signal carriers play a critical role in the regulation of plant defense and development. Rapid alkalization factor (RALF) proteins potentially comprise important signaling components which may have a key role in plant biology. The RALF gene family contains large number of genes in several plant species, however, only a few RALF genes have been characterized to date. In this study, an extensive database search identified 39, 43, 34 and 18 RALF genes in Arabidopsis, rice, maize and soybean, respectively. These RALF genes were found to be highly conserved across the 4 plant species. A comprehensive analysis including the chromosomal location, gene structure, subcellular location, conserved motifs, protein structure, protein-ligand interaction and promoter analysis was performed. RALF genes from four plant species were divided into 7 groups based on phylogenetic analysis. In silico expression analysis of these genes, using microarray and EST data, revealed that these genes exhibit a variety of expression patterns. Furthermore, RALF genes showed distinct expression patterns of transcript accumulation in vivo following nitrosative and oxidative stresses in Arabidopsis. Predicted interaction between RALF and heme ligand also showed that RALF proteins may contribute towards transporting or scavenging oxygen moieties. This suggests a possible role for RALF genes during changes in cellular redox status. Collectively, our data provides a valuable resource to prime future research in the role of RALF genes in plant growth and development. (C) 2016 Elsevier Masson SAS. All rights reserved.</P>

Dense dislocation arrays embedded in grain boundaries for high-performance bulk thermoelectrics

Kim, Sang Il,Lee, Kyu Hyoung,Mun, Hyeon A,Kim, Hyun Sik,Hwang, Sung Woo,Roh, Jong Wook,Yang, Dae Jin,Shin, Weon Ho,Li, Xiang Shu,Lee, Young Hee,Snyder, G. Jeffrey,Kim, Sung Wng American Association for the Advancement of Scienc 2015 Science Vol.348 No.6230

<P><B>Squeezing out efficient thermoelectrics</B></P><P>Thermoelectric materials hold the promise of converting waste heat into electricity. The challenge is to develop high-efficiency materials that are not too expensive. Kim <I>et al.</I> suggest a pathway for developing inexpensive thermoelectrics. They show a dramatic improvement of efficiency in bismuth telluride samples by quickly squeezing out excess liquid during compaction. This method introduces grain boundary dislocations in a way that avoids degrading electrical conductivity, which makes a better thermoelectric material. With the potential for scale-up and application to cheaper materials, this discovery presents an attractive path forward for thermoelectrics.</P><P><I>Science</I>, this issue p. 109</P><P>The widespread use of thermoelectric technology is constrained by a relatively low conversion efficiency of the bulk alloys, which is evaluated in terms of a dimensionless figure of merit (<I>zT</I>). The <I>zT</I> of bulk alloys can be improved by reducing lattice thermal conductivity through grain boundary and point-defect scattering, which target low- and high-frequency phonons. Dense dislocation arrays formed at low-energy grain boundaries by liquid-phase compaction in Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB> (bismuth antimony telluride) effectively scatter midfrequency phonons, leading to a substantially lower lattice thermal conductivity. Full-spectrum phonon scattering with minimal charge-carrier scattering dramatically improved the <I>zT</I> to 1.86 ± 0.15 at 320 kelvin (K). Further, a thermoelectric cooler confirmed the performance with a maximum temperature difference of 81 K, which is much higher than current commercial Peltier cooling devices.</P>

Effect of Ionizing Radiation on Mechanical and Electric Properties of Polymer Composites Based on Polyvinyl ether of Ethyleneglycol

Mun G. A.,Nurkeeva Z. S.,Kovtunets V. A.,Kupchishin A. I.,Akhmetkalieva G. T.,Khutoryanskiy V. V.,Al-Sayed A. A.,Soh Dea-Wha The Korean Institute of Electrical and Electronic 2003 Transactions on Electrical and Electronic Material Vol.4 No.3

Radiation technology is an effective way for regulating polymeric materials to physicochemical and mechanical properties. New polymeric hydrogels based on vinyl ethers have been synthesized by the $\gamma$-initiated polymerization method. In this paper, we have studied the effect of radiation on mechanical and electrochemical properties of new rubber-like polymeric composite materials based on polyvinylether of ethyleneglycol (PVEEG).

Nano-particle enhanced impedimetric biosensor for detedtion of foodborne pathogens

Kim, G,Om, A S,Mun, J H Institute of Physics 2007 Journal of physics. Conference series Vol.61 No.1

<P>Recent outbreaks of foodborne illness have been increased the need for rapid and sensitive methods for detection of these pathogens. Conventional methods for pathogens detection and identification involve prolonged multiple enrichment steps. Even though some immunological rapid assays are available, these assays still need enrichment steps result in delayed detection. Biosensors have shown great potential for rapid detection of foodborne pathogens. They are capable of direct monitoring the antigen-antibody reactions in real time. Among the biosensors, impedimetric biosensors have been widely adapted as an analysis tool for the study of various biological binding reactions because of their high sensitivity and reagentless operation. In this study a nanoparticle-enhanced impedimetric biosensor for <I>Salmonella</I> enteritidis detection was developed which detected impedance changes caused by the attachment of the cells to the anti-<I>Salmonella</I> antibodies immobilized on interdigitated gold electrodes. Successive immobilization of neutravidin followed by anti-<I>Salmonella</I> antibodies was performed to the sensing area to create a biological detection surface. To enhance the impedance responses generated by antigen-antibody reactions, anti-<I>Salmonella</I> antibody conjugated nanoparticles were introduced on the sensing area. Using a portable impedance analyzer, the impedance across the interdigital electrodes was measured after the series of antigen-antibody bindings. Bacteria cells present in solution attached to capture antibodies and became tethered to the sensor surface. Attached bacteria cells changed the dielectric constant of the media between the electrodes thereby causing a change in measured impedance. Optimum input frequency was determined by analyzing frequency characteristics of the biosensor over ranges of applied frequencies from 10 Hz to 400 Hz. At 100 Hz of input frequency, the biosensor was most sensitive to the changes of the bacteria concentration and this frequency was used for the detection experiments. The biosensor was able to detect 10<SUP>6</SUP> CFU/mL in phosphate buffered saline (PBS) with a detection time of 3 minutes. Additional use of nanoparticles significantly enhanced the detection performance. By using the nanoparticles the biosensor could detect 10<SUP>4</SUP> CFU/mL of <I>Salmonella</I> enteritidis in PBS and 10<SUP>5</SUP> CFU/mL of cells in milk.</P>

Biomechanical Evaluation of Dynamic Balance Control Ability During Golf Swing

Choi, A.,Kang, T. G.,Mun, J. H. WALTER H CHANG 2016 Journal of medical and biological engineering Vol.36 No.3

<P>Balance ability seems to be significantly correlated with golfing skill. However, it is unclear whether dynamic balance control has a direct influence on golf swing performance. In this study, the effects of a golfer's skill level on the observed dynamic balance control ability during the golf swing were evaluated. Fifty participants were divided into three groups (professional, advanced, and novice) based on their official handicap scores. Six infrared cameras and two force platforms were used to determine dynamic alterations of the center of mass (COM) and center of pressure (COP). The peak-to-peak displacement and velocity of the COM and COP in the professional golfers were generally lower than those of the other golfers. However, the professional golfers displayed significantly greater COM displacement than that of the advanced amateur golfers in the lead/trail direction (p < 0.01). This does not directly imply deterioration of the dynamic balance ability since the COM-COP separation decreased as the skill level of the golfers increased. The professional golfers had superior dynamic balance ability, achieved by controlling the COP excursion to compensate for the increased variation of COM, leading to a more stable swing mechanism than that of the amateur golfers. This study provides quantitative information for the evaluation of dynamic balance control during the golf swing.</P>

Effect on Ionizing Radiation of Polymer Composites

( Kovtunets V. A ),( Kupchishin A. I ),( Mun G. A ),( Nurkeeva Z. S ),( Akhmetkalieva G. T ),( Khutoryanskiy V. V ),( Dea Wha Soh ) 한국동굴학회 2006 동굴 Vol.76 No.-

Seamustard (Undaria pinnatifida) Improves Growth, Immunity, Fatty Acid Profile and Reduces Cholesterol in Hanwoo Steers

Hwang, J.A.,Islam, M.M.,Ahmed, S.T.,Mun, H.S.,Kim, G.M.,Kim, Y.J.,Yang, C.J. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.8

The study was designed to evaluate the effect of 2% seamustard (Undaria pinnatifida) by-product (SW) on growth performance, immunity, carcass characteristics, cholesterol content and fatty acid profile in Hanwoo steers. A total of 20 Hanwoo steers (ave. 22 months old; 619 kg body weight) were randomly assigned to control (basal diet) and 2% SW supplemented diet. Dietary SW supplementation significantly (p<0.05) improved average daily gain and gain:feed ratio as well as serum immunoglobulin G concentration. Chemical composition and quality grade of meat and carcass yield grades evaluated at the end of the trial were found to be unaffected by SW supplementation. Dietary SW significantly reduced meat cholesterol concentration (p<0.05). Dietary SW supplementation significantly reduced the myristic acid (C14:0) and palmitoleic acid (C16:ln-7) concentration, while SW increased the concentration of stearic acid (C18:0) and linolenic acid (C18:3n-3) compared to control (p<0.05). Dietary SW supplementation had no effect on saturated fatty acids (SFA), unsaturated fatty acids, poly unsaturated fatty acid (PUFA) or mono unsaturated fatty acid content in muscles. A reduced ratio of PUFA/SFA and n-6/n-3 were found in SW supplemented group (p<0.05). In conclusion, 2% SW supplementation was found to improve growth, immunity and fatty acid profile with significantly reduced cholesterol of beef.

Clinical and angiographic long-term follow-up of completely coiled intracranial aneurysms using endovascular technique

Choi, Dae Seob,Kim, Mun Chul,Lee, Seon Kyu,Willinsky, Robert A.,Terbrugge, Karel G. Journal of Neurosurgery Publishing Group 2010 Journal of Neurosurgery Vol.112 No.3

<B>Object</B><P>The anatomical evolution and clinical outcome of completely coiled intracranial aneurysms after endovascular embolization have rarely been studied separately. From their prospective database, the authors reviewed follow-up angiography and clinical outcome of 87 patients whose aneurysms were designated as 100% obliterated on immediate postembolization angiography.</P><B>Methods</B><P>Ninety-one aneurysms (56 ruptured and 35 unruptured) in 87 patients were included in this study. Clinical outcome was evaluated using the Glasgow Outcome Scale. Follow-up angiographic findings were assessed and categorized as 1 of the following: no recanalization, recanalization with a neck remnant, or recanalization with a body remnant. For statistical analysis, the recanalization rate was correlated with: clinical presentation; the largest aneurysm diameter, aneurysm neck size, and dome-to-neck ratio; aneurysm location; and use of special techniques such as usage of a surface modified coil, balloon remodeling technique, or stent.</P><B>Results</B><P>At the latest clinical evaluation (mean 34.3 months), 81 (93.1%) of the 87 patients (91 aneurysms) had good clinical outcomes (Glasgow Outcome Scale Score 5). The procedure-related morbidity rate (permanent neurological deficit) was 2.3% (2 of 87), and there were no procedure-related deaths. On the latest follow-up angiography (mean 26.4 months), the recanalization rate was 26.4% (24 of 91 aneurysms): 16 (17.6%) with neck remnants and 8 (8.8%) with body remnants. The neck size of the recanalized aneurysms was statistically significantly larger than that of the nonrecanalized aneurysms (p = 0.006), and aneurysms with wide necks (≥4 mm) had a higher recanalization rate than those with a narrow neck (< 4 mm) (p = 0.002). There was no bleeding after endovascular treatment during the follow-up period.</P><B>Conclusions</B><P>Completely coiled aneurysms after endovascular embolization demonstrated good clinical outcome, and there was no bleeding episode after endovascular treatment; however, there was a relatively high recanalization rate.</P>

Adsorptive Li⁺ mining from liquid resources by H₂TiO₃: Equilibrium, kinetics, thermodynamics, and mechanisms

Lawagon, C.P.,Nisola, G.M.,Mun, J.,Tron, A.,Torrejos, R.E.C.,Seo, J.G.,Kim, H.,Chung, W.J. Korean Society of Industrial and Engineering Chemi 2016 Journal of industrial and engineering chemistry Vol.35 No.-

<P>Metatitanic acid (H2TiO3) is an emerging lithium ion sieve (LIS) that can potentially replace the well-known manganese-based LIS. Systematic adsorption studies on the effects of solution pH, solid/liquid ratio, temperature, and feed concentration were conducted. H+ accumulation critically limited the Li+ capacity (q(e)), but was circumvented under optimal conditions. Li+ adsorption was Langmuir-type and followed pseudo-second-order rate model; thermodynamic parameters reveal its feasibility, spontaneity, and endothermicity. H2TiO3 was highly stable and reusable; its highest q(e) (94.5 mg g(-1)) is superior over other known LIS. Li+ was effectively recovered from seawater, demonstrating its high industrial potential for aqueous Li+ mining. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>