Highly regioselective hydroxylation of polydatin, a resveratrol glucoside, for one-step synthesis of astringin, a piceatannol glucoside, by P450 BM3

Le, T.K.,Jang, H.H.,Nguyen, H.T.H.,Doan, T.T.M.,Lee, G.Y.,Park, K.D.,Ahn, T.,Joung, Y.H.,Kang, H.S.,Yun, C.H. IPC Science and Technology Press ; Elsevier Scienc 2017 Enzyme and microbial technology Vol.97 No.-

<P>Enzymatic conversion of natural glycosides to their corresponding hydroxylated products using cytochromes P450 has significant advantages over synthetic chemistry and even enzyme-catalyzed glycosylation of chemicals. At present, the basic strategy for making glycosides of stilbenoid compounds is to use the glycosylation activity of enzymes, such as glycosyltransferases. Here, an efficient synthesis of a valuable (E)-astringin, a piceatannol glucoside, was developed using CYP102A1 via the highly regioselective C-3' hydroxylation of polydatin, a resveratrol glucoside. (E)-astringin is a high added value compound found in plants and wine. Benzylic hydroxylation of polydatin provides an attractive route to (E)-astringin, a catechol product. Thus far, chemical and enzymatic methods of producing (E)-astringin have not been developed. In the present study, a set of CYP102A1 mutants from Bacillus megaterium was found to catalyze regioselective hydroxylation of polydatin at the C-3' position to generate an (E)-astringin, a piceatannol glucoside. (C) 2016 Elsevier Inc. All rights reserved.</P>

Role of Leu188 in the Fatty Acid Hydroxylase Activity of CYP102A1 from Bacillus megaterium

Jang, H.H.,Shin, S.M.,Ma, S.H.,Lee, G.Y.,Joung, Y.H.,Yun, C.H. Elsevier 2016 Journal of molecular catalysis Enzymatic Vol.133 No.-

<P>P450 BM3 (CYP102A1) from Bacillus megaterium catalyzes the subterminal hydroxylation of fatty acids with 12-22 carbons at the omega-1, omega-2 and omega-3 positions. Several amino acids located at the substrate channel and active sites are known to be important for the catalytic activity of CYP102A1. The L188 residue at the C-terminus of alpha-helix F undergoes a large shift upon substrate binding and has frequently been found in different combinations of multiple mutations showing enhanced and altered activities. In this study, we examined the role of the L188 residue by comparing the catalytic activities of wild-type CYP102A1 and 19 mutants of L188. The mutants were made with site-directed mutagenesis and functionally expressed in Escherichia coll. The enzymatic properties of the mutants for a set of fatty acids (C-10-C-16) were compared to the properties of the wild-type. L188Q and L188 P mutants showed especially strong increases in hydroxylase activity toward C-10-C-13 fatty acids, although they did not have activity changes for C-14-C-16 fatty acids. Although most mutants showed very similar overall hydroxylation rates for myristic acid, 14 mutants showed apparent changes in the regioselectivity of hydroxylation with a preference for the omega-3 position over the omega-1 position. A possible role for the L188 residue has been discussed in the context of the structure and function of CYP102A1. (C) 2016 Elsevier B.V. All rights reserved.</P>

축분뇨 액비 저장조의 운영실태 및 악취 물질 발생량 조사

김태일,송준익,정선,정종원,정의수,유용희,양창범,김민규,Kim T. I.,Song J. I.,Joung S.,Jeong J. W.,Chung E. S.,Barroga A. J.,Yoo Y. H.,Yang C. B.,Kim M. K. 한국축산환경학회 2005 축산시설환경학회지 Vol.11 No.3

본 연구는 국내에 설치되어 있는 액비저장조의 운영실태를 조사하고, 액비저장조에서 발생되는 악취물질을 구명하고자 수행하였다. 1. 국내에 200톤 규모의 액비저장조를 설치한 60 농가를 대상으로 한 본 조사에서 약 $93\%$가 액비저장조를 제대로 가동을 하고 있었으며 이중 $57\%$가 액비제조시 폭기 처리하고 있었다. 2. 조사 농가 중 년간 액비의 활용 횟수는 2회가 $50\%$로 나타났고 액비의 부숙 효과를 높이고 악취를 저감시키기 위한 목적으로 $64\%$가 미생물제제를 첨가하고 있었다. 반면에 액비 이용시 인력 장비의 비용 및 악취물질 발생 저감을 위한 첨가제 비용이 $43\%$로 조사되어 액비이용 시 문제점으로 지적되었다. 3. 액비 제조 형태별 악취물질 발현양상으로 호기 제조시 액비저장조내에서는 iso-valeric acid가 0.012에서 0.07ppm, Propionic acid가 $0.17\~2.85ppm$의 범위로 검지되었으며 혐기 제조시에는 n-Butyric acid가 1.5에서 2.3ppm, n-valeric acid가 $1.3\~1.8ppm$, acetaldehyde가 0.8에서 2.1ppm로 검지되어 호기 제조방법과 혐기 제조방법 모두 휘발성 지방산의 농도는 악취방지법의 규제농도 이상이었다. 부지경계선에서의 악취물질을 보면 호기시에는 미검출로 나타났고 혐기 제조시에는 Acetaldehyde가 $0.4\~0.9ppm$ 수준으로 검지되어 악취방지법의 규제농도를 초과였다. This study was carried out to determine the acceptability of liquid manure bin among livestock farmers and agricultural farmers, and quantify its malodorous compounds. The results were as follows; 1. The size of the manure bins owned by $93\%$ of 60 farmers surveyed was 200 M/T and were all in normal operation. Around $57\%$ of the normally operated bins were processed under aerobic condition. 2. Filly percent of the respondents utilized their liquid manure bin twice a year while $64\%$ used commercial microbial products to enhance maturity of their liquid manure and abatement of malodorous emissions. On the other hand, $43\%$ mentioned problems on the labor requirement, mechanical maintenance and lending cost of liquid manure processing and utilization, and the price of the commercial microbial products. 3. Malodorants emitted from livestock liquid manure bins and their boundary bin depended upon the livestock liquid manure processing condition. Within bin under the aerobic processing condition, Iso-valeric and propionic acid were ranged 0.012 to 0.07ppm and 0.17 to 2.85ppm, respectively. Within bin under the anoxic processing condition, n-butyric, n-valeric acid, and acetaldehyde were ranged 1.5 to 2.3ppm, 1.3 to 1.8ppm, and 0.8 to 2.1ppm, respectively. Malodorants emitted from the boundary of livestock liquid manure bins under the anoxic processing condition were detected the range of 0.4 to 0.9 ppm, more than the concentration of law regulation, as an acetaldehyde, but under the aerobic processing condition, they did not any detection.

Piezoelectric nanogenerators synthesized using KNbO3 nanowires with various crystal structures

Joung, M. R.,Xu, H.,Seo, I. T.,Kim, D. H.,Hur, J.,Nahm, S.,Kang, C. Y.,Yoon, S. J.,Park, H. M. Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.43

Structural dependence of the piezoelectric properties of KNbO₃ nanowires synthesized by the hydrothermal method

Joung, M.R.,Seo, I.T.,Kim, J.S.,Xu, H.,Han, G.,Kang, M.G.,Kang, C.Y.,Yoon, S.J.,Nahm, S. Elsevier Science 2013 ACTA MATERIALIA Vol.61 No.10

Because of the presence of OH<SUP>-</SUP> and H<SUB>2</SUB>O in the KN unit cell, tetragonal KNbO<SUB>3</SUB> (KN) nanowires were formed when the synthesis was carried out at 120<SUP>o</SUP>C for 48h. However, when the fabrication was conducted at high temperatures (≥150<SUP>o</SUP>C) or at 120<SUP>o</SUP>C for a long period of time (≥72h), orthorhombic KN nanowires were formed. Moreover, the KN nanowires synthesized at 120<SUP>o</SUP>C for 60h showed a morphotropic phase boundary (MPB) structure in which both tetragonal and orthorhombic structures coexisted. Tetragonal, orthorhombic and MPB KN nanowires were also grown on the Nb<SUP>5+</SUP>-doped SrTiO<SUB>3</SUB> substrate, and their d<SUB>33</SUB> values were measured for the first time. A tetragonal KN nanowire exhibited a d<SUB>33</SUB> value of 23.5pmV<SUP>-1</SUP>, which is larger than that of the orthorhombic KN nanowire (11.6pmV<SUP>-1</SUP>), probably because of the softening effect of the metal vacancies. The MPB KN nanowires exhibited a larger d<SUB>33</SUB> value of 40.0pmV<SUP>-1</SUP>. The d<SUB>33</SUB> values of KN nanowires increased to 104.5, 137.1 and 146.0pmV<SUP>-1</SUP> for the orthorhombic, tetragonal and MPB KN nanowires, respectively, after the KN nanowires were poled along the [100] direction by application of a DC voltage of 10V.

Early repolarization pattern predicts cardiac death and fatal arrhythmia in patients with vasospastic angina

Oh, C.M.,Oh, J.,Shin, D.H.,Hwang, H.J.,Kim, B.K.,Pak, H.N.,Lee, M.H.,Joung, B. Elsevier/North-Holland Biomedical Press 2013 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.167 No.4

Background: Early repolarization (ER), which is characterized by an elevation of J-point, is sometimes associated with fatal arrhythmia and sudden cardiac death in patients without structural heart disease. This study investigated the prevalence and prognostic significance of ER in patients with vasospastic angina (VA). Methods: We assessed the ER pattern in 281 VA patients (mean age, 50.5+/-7.9years), and the prognostic modulation of ER-associated risk by ST-segment variations. Results: Any type of ER≥0.1mV in inferior and/or lateral leads was persistently observed after chest pain in 60 (21.4%) VA patients. During the follow up period of 7.6+/-4.7years, patients with ER had higher incidence of cardiac events including cardiac death, aborted sudden cardiac death or fatal arrhythmia than those with no ER (20.0% vs. 5.4%, p=0.001). Patients with ER≥0.1mV and horizontal/descending ST variant (n=18) had an increased age- and sex-adjusted hazard ratio of cardiac events (relative risk 8.12; 95% confidence interval 3.45-19.12). When modeled for ER in inferior leads and horizontal/descending ST-segment variant, the hazard ratio of cardiac events increased to 8.89 (95% confidence interval 3.78-20.91). However, in subjects with ascending ST variant, the relative risk for arrhythmic death was not significantly increased. Conclusion: ER was observed in a fifth of VA patients, and was associated with an increased risk of cardiac events in VA. However, it is also possible that, in patients with ER, VA might cause an adverse event or facilitate the diagnosis of ER.

자동차용 경량화 소재 동향

문민석(M. S. Moon),유명한(M. H. Yoo),송준혁(J. H. Song),박나라(N. R. Park),정근성(G. S. Joung),오제하(J. H. Oh),정동철(D. C. Joung) 한국기계가공학회 2017 한국기계가공학회 춘추계학술대회 논문집 Vol.2017 No.10

Left ventricular diastolic dysfunction is associated with atrial remodeling and risk or presence of stroke in patients with paroxysmal atrial fibrillation

Kim, T.H.,Shim, C.Y.,Park, J.H.,Nam, C.M.,Uhm, J.S.,Joung, B.,Lee, M.H.,Pak, H.N. Japanese College of Cardiology 2016 Journal of cardiology Vol.68 No.2

<P>Background: Although the degree of electroanatomical remodeling of the left atrium (LA) is influenced by left ventricular (LV) diastolic function, clinical implications of estimated LV filling pressure (E/Em) are limited in patients with atrial fibrillation (AF). We hypothesized that increased E/Em is related to an advanced LA remodeling, a high CHA(2)DS(2)-VASc score, and the presence of stroke or transient ischemic attack (TIA) in patients with paroxysmal AF. Methods: We included 1098 patients with paroxysmal AF (male 74.5%, 57.6 +/- 11.3 years old) who underwent AF catheter ablation. We compared E/Em to clinical parameters, echocardiography, and three-dimensional -computed tomography findings. Results: The E/Em > 15 group (n = 98) was older (p < 0.001) and had more females (p < 0.001), greater LA volume index (p < 0.001), higher CHA(2)DS(2)-VASc score (p < 0.001), and stroke/TIA prevalence (p = 0.001) than groups with an E/Em of 8-15 (n = 676) or <8 (n = 324). An E/Em was independently associated with the presence of stroke/TIA (OR 1.638, 95% CI 1.050-2.554, p = 0.030) after adjusting for age, sex, body surface area, LA volume index, and LA appendage volume index. Conclusions: In patients with paroxysmal AF, the elevated LV filling pressure estimated by E/Em is independently associated with the presence of stroke or TIA. (C) 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</P>

Intrinsic rotation reversal, non-local transport, and turbulence transition in KSTAR L-mode plasmas

Shi, Y.J.,Kwon, J.M.,Diamond, P.H.,Ko, W.H.,Choi, M.J.,Ko, S.H.,Hahn, S.H.,Na, D.H.,Leem, J.E.,Lee, J.A.,Yang, S.M.,Lee, K.D.,Joung, M.,Jeong, J.H.,Yoo, J.W.,Lee, W.C.,Lee, J.H.,Bae, Y.S.,Lee, S.G.,Yo International Atomic Energy Agency 2017 Nuclear fusion Vol.57 No.6

<P>Experiments of electron cyclotron resonance heating (ECH) power scan in KSTAR tokamak clearly demonstrate that both the cutoff density for non-local heat transport (NLT) and the threshold density for intrinsic rotation reversal can be determined by the collisionality. We demonstrate that NLT can be affected by ECH, and the intrinsic rotation direction follows the changes of NLT. The cutoff density of NLT and threshold density for rotation reversal can be significantly increased by ECH. The poloidal flow of turbulence in core plasma is in the electron and the ion diamagnetic direction in ECH plasmas and high density OH plasma, respectively. The auto-power spectra of density fluctuation are almost the same in the outer region for both ECH and OH plasmas. On the other hand, the divergence in density fluctuation spectra at high frequency range between OH and ECH plasma is clearly observed in core region. The features of linear confinement and saturated confinement also appeared in ECH plasma, which is similar to the linear ohmic confinement (LOC) mode and saturate ohmic confinement (SOC) mode. All these observations in macroscopic parameters and micro fluctuations suggest a possible link between the macro phenomena and the structural changes in turbulence mode.</P>

Structural and electrical properties of Bi₂O₃-Nb₂O₅ thin films grown at low temperatures by pulsed laser deposition

Sun, J.W.,Kang, L.S.,Kim, J.S.,Joung, M.R.,Nahm, S.,Seong, T.G.,Kang, C.Y.,Kim, J.H. Elsevier Science 2011 Acta materialia Vol.59 No.14

The dielectric constant (ε<SUB>r</SUB>) of the films grown at 100<SUP>o</SUP>C increased as the beam energy density increased and a saturated value of 80 was obtained for the film grown under 6.0Jcm<SUP>-2</SUP>. The larger ε<SUB>r</SUB> value was attributed to the increased amount of nano-sized Bi<SUB>3</SUB>NbO<SUB>7</SUB> crystals. The ε<SUB>r</SUB> values also increased with the beam energy density for films grown at 300<SUP>o</SUP>C and a very high ε<SUB>r</SUB> value of 135.6 with a low loss of 3.0% at 100kHz was obtained for the film grown at 300<SUP>o</SUP>C under a beam density of 3.0Jcm<SUP>-2</SUP>. The crystalline BiNbO<SUB>4</SUB> phase developed, but the amount of Bi<SUB>3</SUB>NbO<SUB>7</SUB> crystals decreased as the beam energy density increased, indicating that the increased ε<SUB>r</SUB> values of the films grown at 300<SUP>o</SUP>C could be due to the formation of the crystalline BiNbO<SUB>4</SUB> phase. The electrical properties of the films grown at 300<SUP>o</SUP>C under a beam density of 3.0Jcm<SUP>-2</SUP> were considerably influenced by the oxygen partial pressure (OPP) during annealing. The film annealed at 300<SUP>o</SUP>C under a 50.0torr OPP exhibited a low leakage current density of 5.4x10<SUP>-9</SUP>Acm<SUP>-2</SUP> at 0.3MVcm<SUP>-1</SUP> with a relatively high breakdown field of 0.4MVcm<SUP>-1</SUP>1.