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.

Geological and Geotechnical Characteristics of Marine Clay in Busan New Port

Chung, S.G,E. Ninjgarav,M. Suneel,K.Ganapathi Rao,Kim, G.J. 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

Since early 1990s reclamation projects for Busan and its vicinity in Nakdong River plain have been performed for industrial and residential complexes. As well it has started to build a new port (Busan Newport) with increase in overloads of Busan port since late 1990s. In the area the sedimentary deposit is composed of soft clay of about 30m thick, thin sand layer of 3-4m thick, hard clayey soil, and then basal conglomerates and sandy sediments, total thickness of which is about 70m at maximum under seawater. For the huge project many contract companies have simultaneously performed geotechnical investigations to get design parameters. Based on the harmful experiences gained by the previous projects, it was also required to pay careful attention to sampling and laboratory and field tests for theproject. Nevertheless the results of laboratory tests were so scattered and then resulted in difficulty to evaluate the design parameters. Existing data has been reviewed to evaluate the validity or cause of their variation. In addition geological study, sampling and soil tests have been carefully carried out at a few locations. Using the results the clay would be effectively characterized for depositional environment and its relation to soil properties.

New emergence pattern with variant porcine epidemic diarrhea viruses, South Korea, 2012-2015

Chung, H.C.,Lee, J.H.,Nguyen, V.G.,Huynh, T.M.L.,Lee, G.E.,Moon, H.J.,Park, S.J.,Kim, H.K.,Park, B.K. ELSEVIER 2016 VIRUS RESEARCH Vol.226 No.-

Since outbreaks of porcine epidemic diarrhea virus (PEDV) in the United States in 2013, explosive outbreaks of PED in South Korea have infected all age groups of pigs in 2014-2015year. This study analyzed a large collection of the Spike protein coding gene to infer the spatial-temporal diffusion history of PEDV. The studying results suggested that PEDVs in Korea belonged to different genogroups. While classical G1 was continuingly circulating between provinces of Korea, the pandemic G2a were recently introduced from China and USA. By the application of Bayesian phylogeographical analysis, this study demonstrated the spatial-temporal transmission of PEDVs within Korea. Of the recent emerged G2a viruses, J3142 strains showed potential recombination breakpoint (376-2,143nt) of S1 gene between KNU1303_Korea strain_G2a (KJ451046) and 45RWVCF0712_Thailand strain_G2b (KF724935). The pandemic G2a virus was partial neutralized by the antibodies invoked by the G1- based PED vaccine virus.

Structural and Functional Analysis of a β₂-Adrenergic Receptor Complex with GRK5

Komolov, Konstantin E.,Du, Yang,Duc, Nguyen Minh,Betz, Robin M.,Rodrigues, Joã,o P.G.L.M.,Leib, Ryan D.,Patra, Dhabaleswar,Skiniotis, Georgios,Adams, Christopher M.,Dror, Ron O.,Chung, Ka Young Cell Press 2017 Cell Vol. No.

<P><B>Summary</B></P> <P>The phosphorylation of agonist-occupied G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) functions to turn off G-protein signaling and turn on arrestin-mediated signaling. While a structural understanding of GPCR/G-protein and GPCR/arrestin complexes has emerged in recent years, the molecular architecture of a GPCR/GRK complex remains poorly defined. We used a comprehensive integrated approach of cross-linking, hydrogen-deuterium exchange mass spectrometry (MS), electron microscopy, mutagenesis, molecular dynamics simulations, and computational docking to analyze GRK5 interaction with the β<SUB>2</SUB>-adrenergic receptor (β<SUB>2</SUB>AR). These studies revealed a dynamic mechanism of complex formation that involves large conformational changes in the GRK5 RH/catalytic domain interface upon receptor binding. These changes facilitate contacts between intracellular loops 2 and 3 and the C terminus of the β<SUB>2</SUB>AR with the GRK5 RH bundle subdomain, membrane-binding surface, and kinase catalytic cleft, respectively. These studies significantly contribute to our understanding of the mechanism by which GRKs regulate the function of activated GPCRs.</P> <P><B>PaperClip</B></P> <P>Display Omitted</P> <P><B>Highlights</B></P> <P> <UL> <LI> GRK5-β<SUB>2</SUB>AR binding is enhanced by receptor and kinase ligands and acidic lipids </LI> <LI> GRK5 binding to the β<SUB>2</SUB>AR involves a multi-site interaction </LI> <LI> Receptor binding triggers substantial conformational changes in GRK5 </LI> <LI> RH/catalytic domain separation in GRK5 is essential for receptor phosphorylation </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Identification and characterization of a thermostable endolytic β-agarase Aga2 from a newly isolated marine agarolytic bacteria <i>Cellulophaga omnivescoria</i> W5C

Ramos, Kristine Rose M.,Valdehuesa, Kris Niñ,o G.,Nisola, Grace M.,Lee, Won-Keun,Chung, Wook-Jin Elsevier 2018 New biotechnology Vol.40 No.2

<P><B>Abstract</B></P> <P>Research on the enzymatic breakdown of seaweed-derived agar has recently gained attention due to the progress in green technologies for marine biomass utilization. The enzymes known as agarases catalyze the cleavage of glycosidic bonds within the polysaccharide. In this study, a new β-agarase, Aga2, was identified from <I>Cellulophaga omnivescoria</I> W5C. Aga2 is one of four putative agarases from the W5C genome, and it belongs to the glycoside hydrolase 16 family. It was shown to be exclusive to the <I>Cellulophaga</I> genus. Agarase activity assays showed that Aga2 is an endolytic-type β-agarase that produces tetrameric and hexameric neoagaro-oligosaccharides, with optimum activity at 45°C and pH 8.0. Zinc ions slightly enhanced its activity while manganese ions had inhibitory effects even at very low concentrations. Aga2 has a K<SUB>m</SUB> of 2.59mgmL<SUP>−1</SUP> and V<SUB>max</SUB> of 275.48Umg<SUP>−1</SUP>. The K<SUB>cat</SUB> is 1.73×10<SUP>2</SUP> s<SUP>−1</SUP>, while the K<SUB>cat</SUB>/K<SUB>m</SUB> is 8.04×10<SUP>6</SUP> s<SUP>−1</SUP> M<SUP>−1</SUP>. Aga2 also showed good thermostability at 45°C and above, and retained >90% of its activity after repeated freeze-thaw cycles. Bioinformatic analysis of its amino acid sequence revealed that intrinsic properties of the protein (e.g. presence of certain dipeptides and the relative volume occupied by aliphatic amino acids) and tertiary structural elements (e.g. presence of salt bridges, hydrophobic interactions and H-bonding) contributed to its thermostability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endolytic β-agarase Aga2 was identified from <I>Cellulophaga omnivescoria</I> W5C. </LI> <LI> Aga2 optimum activity was at 45°C, pH 8.0, with NA4 and NA6 as major products. </LI> <LI> Aga2 was thermostable at high temperatures as well as after many freeze-thaw cycles. </LI> <LI> Intrinsic properties and tertiary structural elements confer the thermostability. </LI> </UL> </P>

Compost of Swine Manure Slurry Using the Thermophilic Aerobic Oxidation (TAO) Syst

Lee, W.I.,Tsujii, H.,Lee, M.G.,Cha, G.C.,Chung, J.C. The Korean Society of Animal Environmental Science 2004 축산시설환경학회지 Vol.10 No.1

현장규모 (8.6${\times}$2.5${\times}$2.4 m) 및 파이롯트규모 (1.39${\times}$0.89${\times}$0.89 m)의 고온호기산화장치를 이용하여 공기투입량 및 처리온도에 따른 양돈분뇨의 감량화 효율을 검토하였다. 현장규모에서 공기투입장치, 거품제거장치의 설치조건이 양돈슬러리 증발량과 처리온도에 모두 영향을 미치고 있음을 알 수 있었다. 현장규모 연구는 3가지의 처리방법 (처리A:공기공급량 120㎥/h, 수중펌프 2대, 소포장치2대: 처리 B: 공기공급량 180㎥/h, 수중펌프 3대, 소포장치 3대; 처리C: 공기공급량 180㎥/h, 수중펌프 3대, 소포장치 4대)으로 실행되었다. 1일 5㎥ 양돈슬러리를 동일하게 투입하면서 얻어진 연구결과, 수위변화, 온도변화 및 증발량은 각각 처리A: 50∼100cm, 31∼$64^{\circ}C$, 55L/$\m^2$ㆍday, 처리B: 40∼90cm, 29∼$52^{\circ}C$, 75L/$\m^2$ㆍday, 처리C: 40∼70cm, 45∼$54^{\circ}C$, 120L/$\m^2$ㆍday이었다. 한편 파이롯트 규모 연구는 반 연속식으로 양돈분뇨를 투입하면서 매일 투입량을 처리1: 50L/2h, 처리2: 50L/3h, 처리3: 40L/3h, 처리4: 60L/4h으로 하여 최대 슬러리 감량조건을 도출하기 위해 수행하였다. A field-scale(8.6${\times}$2.5${\times}$2.4 m) and pilot-scale(1.39${\times}$0.89${\times}$0.89 m) thermophilic aerobic oxidation (TAO) units were installed to investigate the volume reduction efficiency of slurry, by varying the aeration and treatment temperature of swine manure, and the collected liquid was evaluated as a liquid fertilizer. In the field-scale unit, the aeration level and numbers of foam breakers made different effects on the slurry volume and temperature in the TAO system. The experiments were peformed for three cases, using different levels of aeration and numbers of foam breakers: Treat-A (aeration rate; 120 ㎥ air/hr using 2 air pumps and 2 foam breakers), Treat-B (aeration rate; 180 ㎥ air/hr using 3 air pumps and 3 foam breakers) and Treat-C (aeration rate; 180 ㎥ air/hr using 3 air pumps and 4 foam breakers). With the same input volume (5 ㎥/day) of swine manure slurry, the resulting liquid levels, temperatures and evaporation rates were 50∼100 cm, 31∼$64^{\circ}C$ and 55 $\ell/m^2$/day for Treat-A; 40∼90 cm, 29∼$52^{\circ}C$ and 75 $\ell/m^2$/day for Treat-B; and 40∼70 cm, 45∼$54^{\circ}C$ and 120.0 $\ell/m^2$/day for Treat-C. In the pilot-scale unit, semi-continuous flow of swine manure slurry was introduced. 50 $\ell$ every 2hr(T-1), 50 $\ell$ every 3hr(T-2), 40 $\ell$ every 2hr (T-3) and 60 $\ell$ every 4hr (T-4) within 24 hours, in order to find the maximum slurry volume reduction conditions.

Honeycomb-layer structured Na3Ni2BiO6 as a high voltage and long life cathode material for sodium-ion batteries

Bhange, D.,Ali, G.,Kim, D. H.,Anang, D.,Shin, T.,Kim, M. G.,Kang, Y. M.,Chung, K.,Nam, K. W. Royal Society of Chemistry 2017 Journal of Materials Chemistry A Vol.5 No.3

<P>The need to find sodium ion battery (SIB) cathodes with high voltage, capacity and improved cycle life has stimulated research on sodium containing layered transition metal oxides. With this perspective, the electrochemical properties of highly ordered, honeycomb layered Na3Ni2BiO6 with a monoclinic superstructure are explored as a cathode material in SIBs. It has been demonstrated that Na3Ni2BiO6 delivers a discharge capacity of 106 mA h g(-1), having high voltage plateaus at 3.50 and 3.25 V, with marginal capacity fading after 50 cycles. Operando X-ray diffraction studies during charging/discharging reveal two reversible two-phase transition mechanisms (initial O3 phase -> P3 intermediate phase -> O1 final phase) during sodium extraction. Ex situ X-ray absorption spectroscopy reveals the charge compensation mechanism for the reversible Ni3+/Ni2+ as an active redox couple while Bi5+ being inactive during cycling. Extended X-ray absorption fine structure analysis shows highly reversible local structural changes around both Ni and Bi atoms occurring during electrochemical cycling. In addition, unique local structure changes especially around Ni atoms due to the honeycomb ordering and size mismatch between Ni2+ and Bi5+ ions are revealed by EXAFS analysis during charging and discharging, which is quite different from the local structure changes in regular layer structured NaMO2 (M = transition metals) cathode materials. The present results suggest that honeycomb layered metal oxides with the general formula, Na3M((II)) M-2(V) O-6, can be considered as candidates for high voltage and long life cathode materials for SIBs.</P>

Characterization of aerosol composition, concentrations, and sources at Baengnyeong Island, Korea using an aerosol mass spectrometer

Lee, T.,Choi, J.,Lee, G.,Ahn, J.,Park, J.S.,Atwood, S.A.,Schurman, M.,Choi, Y.,Chung, Y.,Collett, J.L. Pergamon Press ; Elsevier [distribution] 2015 Atmospheric environment Vol.120 No.-

To improve understanding of the sources and chemical properties of particulate pollutants on the western side of the Korean Peninsula, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) measured non-refractory fine (PM<SUB>1</SUB>) particles from May to November, 2011 at Baengnyeong Island, South Korea. Organic matter and sulfate were generally the most abundant species and exhibited maximum concentrations of 36 μg/m<SUP>3</SUP> and 39 μg/m<SUP>3</SUP>, respectively. Nitrate concentrations peaked at 32 μg/m<SUP>3</SUP> but were typically much lower than sulfate and organic matter concentrations. May, September, October, and November featured the highest monthly average concentrations, with lower concentrations typically observed from June through August. Potential source contribution function (PSCF) analysis and individual case studies revealed that transport from eastern China, an area with high SO<SUB>2</SUB> emissions, was associated with high particulate sulfate concentrations at the measurement site. Observed sulfate aerosol sometimes was fully neutralized by ammonium but often was acidic; the average ammonium to sulfate molar ratio was 1.49. Measured species size distributions revealed a range of sulfate particle size distributions with modes between 100 and 600 nm. Organic aerosol source regions were widespread, including contributions from eastern China and South Korea. Positive matrix factorization (PMF) analysis indicated three ''factors,'' or types of organic aerosol, comprising one primary, hydrocarbon-like organic aerosol (HOA) and two oxidized organic aerosol (OOA) components, including a more oxidized (MO-OOA) and a less oxidized (LO-OOA) oxidized organic aerosol. On average, HOA and OOA contributed 21% and 79% of the organic mass (OM), respectively, with the MO-OOA fraction nearly three times as abundant as the LO-OOA fraction. Biomass burning contributions to observed OM were low during the late spring/early summer agricultural burning season in eastern China, since airflow into eastern China during the Asian Monsoon generally prevents transport of emissions eastward to the Korean Peninsula. Concentrations of the m/z 60 AMS biomass burning marker were more abundant in autumn, when transport patterns appeared to bring some smoke from fires in northern Asia to the island.

A SUPER-JUPITER MICROLENS PLANET CHARACTERIZED BY HIGH-CADENCE KMTNET MICROLENSING SURVEY OBSERVATIONS OF OGLE-2015-BLG-0954

신인구,Y.-H. Ryu,A. Udalski,M. Albrow,S.-M. Cha,J.-Y. Choi,S.-J. Chung,C. Han,K.-H. Hwang,Y. K. Jung,D.-J. Kim,S.-L. Kim,C.-U. Lee,Y. Lee,B.-G. Park,H. Park,R. W. Pogge,J. C. Yee,P. Pietrukowicz,P. Mroz 한국천문학회 2016 Journal of The Korean Astronomical Society Vol.49 No.3

We report the characterization of a massive $(m_p=3.9\pm 1.4 M_{\rm jup})$ microlensing planet (OGLE-2015-BLG-0954Lb) orbiting an M dwarf host ($M=0.33\,\pm 0.12 M_\odot$) at a distance toward the Galactic bulge of $0.6^{+0.4}_{-0.2}\,$kpc, which is extremely nearby by microlensing standards. The planet-host projected separation is $a_\perp \sim 1.2\,\au$. The characterization was made possible by the wide-field ($4\,\rm deg^2$) high cadence ($\Gamma = 6\,\rm hr^{-1}$) monitoring of the Korea Microlensing Telescope Network (KMTNet), which had two of its three telescopes in commissioning operations at the time of the planetary anomaly. The source crossing time $t_*=16\,$min is among the shortest ever published. The high-cadence, wide-field observations that are the hallmark of KMTNet are the only way to routinely capture such short crossings. High-cadence resolution of short caustic crossings will preferentially lead to mass and distance measurements for the lens. This is because the short crossing time typically implies a nearby lens, which enables the measurement of additional effects (bright lens and/or microlens parallax). When combined with the measured crossing time, these effects can yield planet/host masses and distance.

OGLE-2016-BLG-1469L: Microlensing Binary Composed of Brown Dwarfs

Han, C.,Udalski, A.,Sumi, T.,Gould, A.,Albrow, M. D.,Chung, S.-J.,Jung, Y. K.,Ryu, Y.-H.,Shin, I.-G.,Yee, J. C.,Zhu, W.,Cha, S.-M.,Kim, S.-L.,Kim, D.-J.,Lee, C.-U.,Lee, Y.,Park, B.-G.,Soszyń,ski, American Astronomical Society 2017 The Astrophysical journal Vol.843 No.1

<P>We report the discovery of a binary composed of two brown dwarfs, based on the analysis of the microlensing event OGLE-2016-BLG-1469. Thanks to the detection of both finite-source and microlens-parallax effects, we are able to measure both the masses M-1 similar to 0.05M(circle dot) and. M-2 similar to 0.01M(circle dot), and the. distance D-L similar to 4.5 kpc, as well as the projected separation a(perpendicular to) similar to 0.33 au. This is the third brown-dwarf binary detected using the microlensing method, demonstrating the usefulness of microlensing in detecting field brown-dwarf binaries with separations of less than 1 au.</P>