광음향효과를 이용한 MnSO₄ㆍ4H₂O,MnC₂ㆍ4H₂O,CuSO₄ㆍ5H₂O,Al₂O₃ : Cr의 전자상자성 공명 검출 Cr Crystals

윤수인,김학수,최규만,정중현 부산대학교 물성연구소 1985 물성연구소연구논문집 Vol.4 No.-

광음향효과를 이용하여 MnSO₄ㆍ4H₂O, MnCl₂ㆍ4H₂O, CuSO₄ㆍ5H₂O 및 Al₂O₃ : Cr 결정의 상자성 공명을 검출했다. X-밴드 마이크로파의 도파관 내에 광음향 cell을 장치하고 관내에 넣은 short의 위치를 조절하여 도파관 자체가 공명공동이 되도록 함으로써 장치의 감도를 개선했다. g값과 공명신호의 자기장반가폭으로 MnSO₄ㆍ4H₂O의 Mn²^(+)로 부터 1.99±0.03과 260 gauss를, CuSO₄ 5H₂O의 Cu²^(+)로부터 2.31±0.02와 200 gauss를, MnCl₂ 4H₂O로부터 2.06±0.04와 690 gauss를 그리고 Al₂O₃:Cr의 Cr³^(+)로부터 1.97±0.03과 480 gauss를 얻었다. The electron paramagnetic resonances were observed at room temperature in concentrated system, MnSO₄ㆍ4H₂O, MnCl₂ㆍ4H₂O and CuSO₄ㆍ5H₂O and in the dilute system, Al₂O₃: Cr, using photoacoustic technique. A commercial x-band microwave system was modified by introducing the photoacoustic (PA) cell into the microwave cavity to improve the sensitivity of the PA system. The observed g-values and half-widths were 1.99±0.03 and 260 gauss for Mn²^(+) in MnSO₄ㆍ4H₂O crystal, 2.31±0.02 and 200 gauss for Cu²^(+) in CuSO₄ 5H₂O crystal, 2.06±0.04 and 690 gauss for MnCl2 4H₂O crystal, and 1.97±0.03 and 480 gauss for CrCr³^(+) in Al₂O₃:Cr crystal, respectively.

Contribution of small phytoplankton to total primary production in the Chukchi Sea

Lee, S.H.,Sun Yun, M.,Kyung Kim, B.,Joo, H.,Kang, S.H.,Keun Kang, C.,Whitledge, T.E. Pergamon Press ; Elsevier Science Ltd 2013 Continental shelf research Vol.68 No.-

Given a projection of thriving small phytoplankton in the Arctic Ocean under climate-induced environmental changes, it is important to estimate the contribution of small phytoplankton (0.7-5μm) to the total primary production in the Chukchi Sea, which is an important conduit of organic matter from the North Pacific to the Arctic Ocean. Based on a <SUP>13</SUP>C-<SUP>15</SUP>N dual isotope tracer technique, small phytoplankton productivity measurements were taken during two consecutive cruises in the Chukchi Sea in 2004. The total phytoplankton carbon uptake rates ranged from 0 to 25.38mgCm<SUP>-3</SUP>h<SUP>-1</SUP>, whereas the uptake rates of small phytoplankton ranged from 0 to 2.87mgCm<SUP>-3</SUP>h<SUP>-1</SUP>. In comparison with the carbon uptake rates, total phytoplankton nitrate uptake rates ranged from 0 to 4.40mgNm<SUP>-3</SUP>h<SUP>-1</SUP> while small phytoplankton nitrate uptake rates ranged from 0 to 0.39mgNm<SUP>-3</SUP>h<SUP>-1</SUP>. Ammonium uptake rates ranged from 0 to 8.34mgNm<SUP>-3</SUP>h<SUP>-1</SUP> and from 0.01 to 2.18mgNm<SUP>-3</SUP>h<SUP>-1</SUP>, for total and small phytoplankton, respectively. Small phytoplankton contributed 24.80% (S.D.=+/-23.0%) to the total chlorophyll-a concentration, and 59.41% (S.D.=+/-52.12%) to the total carbon biomass due to its higher particulate organic carbon per chlorophyll-a unit during the two cruises in 2004. In the Chukchi Sea, the average contributions of small phytoplankton to carbon and total nitrogen (nitrate+ammonium) uptake rates were 31.72% (S.D.=+/-23.59%) and 37.31% (S.D.=+/-26.06%), respectively.

Effects of HA and NA glycosylation pattern changes on the transmission of avian influenza A(H7N9) virus in guinea pigs

Park, S.,Lee, I.,Kim, J.I.,Bae, J.Y.,Yoo, K.,Kim, J.,Nam, M.,Park, M.,Yun, S.H.,Cho, W.I.,Kim, Y.S.,Ko, Y.Y.,Park, M.S. Academic Press 2016 Biochemical and biophysical research communication Vol.479 No.2

Avian influenza H7N9 virus has posed a concern of potential human-to-human transmission by resulting in seasonal virus-like human infection cases. To address the issue of sustained human infection with the H7N9 virus, here we investigated the effects of hemagglutinin (HA) and neuraminidase (NA) N-linked glycosylation (NLG) patterns on influenza virus transmission in a guinea pig model. Based on the NLG signatures identified in the HA and NA genetic sequences of H7N9 viruses, we generated NLG mutant viruses using either HA or NA gene of a H7N9 virus, A/Anhui/0½013, by reverse genetics on the 2009 pandemic H1N1 virus backbone. For the H7 HA NLG mutant viruses, NLG pattern changes appeared to reduce viral transmissibility in guinea pigs. Intriguingly, however, the NLG changes in the N9 NA protein, such as a removal from residue 42 or 66 or an addition at residue 266, increased transmissibility of the mutant viruses by more than 33%, 50%, and 16%, respectively, compared with a parental N9 virus. Given the effects of HA-NA NLG changes with regard to viral transmission, we then generated the HA-NA NLG mutant viruses harboring the H7 HA of double NLG addition and the N9 NA of various NLG patterns. As seen in the HA NLG mutants above, the double NLG-added H7 HA decreased viral transmissibility. However, when the NA NLG changes occurred by a removal of residue 66 and an addition at 266 were additionally accompanied, the HA-NA NLG mutant virus recovered the transmissibility of its parental virus. These demonstrate the effects of specific HA-NA NLG changes on the H7N9 virus transmission by highlighting the importance of a HA-NA functional balance.

Multi-layered hydrogenated p-type microcrystalline silicon windows for a-Si:H thin film solar cells on opaque substrates

Lee, Y.J.,Lee, S.H.,Schropp, R.E.I.,Lee, K.S.,Lim, J.W.,Yun, S.J. Pergamon Press 2016 International journal of hydrogen energy Vol.41 No.15

<P>The effects of multi-layered p-type microcrystalline (mu c-) Si:H windows on the performance of substrate-type amorphous Si:H thin film solar cells on opaque substrates were investigated. The results were well explained in terms of H-2-plasma-induced damage (HPID) at the p/i-interface and the near-interface region of the light-absorbing layer. The mu c-Si:H was deposited using plasma enhanced chemical vapor deposition in a H-2-rich atmosphere. A high microcrystalline volume fraction was obtained with a high H-2 dilution ratio, which can cause considerable HPID. Cell efficiency was enhanced with a multi-layered p-type mu c-Si:H composed of films with low and high crystalline volume fraction, compared to cells with single-layered mu c-Si:H. In the multi-layered p-type mu c-Si:H, the low crystalline film was placed on an i-Si:H layer to reduce HPID. The present work demonstrated that HPID was reduced at the p/i-interface and the near-interface region of the light-absorbing layer, and that the quality of the p-type mu c-Si:H needs to be a significant consideration to achieve high efficiency. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.</P>

Induction of bone formation by <i>Escherichia coli</i>‐expressed recombinant human bone morphogenetic protein‐2 using block‐type macroporous biphasic calcium phosphate in orthotopic and ectopic rat models

Park, J‐,C.,So, S‐,S.,Jung, I‐,H.,Yun, J‐,H.,Choi, S‐,H.,Cho, K‐,S.,Kim, C‐,S. Blackwell Publishing Ltd 2011 Journal of periodontal research Vol.46 No.6

<P><I>Park J‐C, So S‐S, Jung I‐H, Yun J‐H, Choi S‐H, Cho K‐S, Kim C‐S. Induction of bone formation by</I> Escherichia coli<I>‐expressed recombinant human bone morphogenetic protein‐2 using block‐type macroporous biphasic calcium phosphate in orthotopic and ectopic rat models. J Periodont Res 2011; 46: 682–690. © 2011 John Wiley & Sons A/S</I></P><P><B>Background and Objective: </B> The potential of the <I>Escherichia coli</I>‐expressed recombinant human bone morphogenetic protein‐2 (ErhBMP‐2) to support new bone formation/maturation using a block‐type of macroporous biphasic calcium phosphate (bMBCP) carrier was evaluated in an orthotopic and ectopic rat model.</P><P><B>Material and Methods: </B> Critical‐size (Φ 8 mm) calvarial defects and subcutaneous pockets in 32 Sprague–Dawley rats received implants of rhBMP‐2 (2.5 μg) in a bMBCP carrier or bMBCP alone (control). Implant sites were evaluated using histological and histometric analysis following 2‐ and 8‐wk healing intervals (eight animals/group/interval).</P><P><B>Results: </B> ErhBMP‐2/bMBCP supported significantly greater bone formation at 2 and 8 wk (10.8% and 25.4%, respectively) than the control at 2 and 8 wk (5.3% and 14.0%, respectively) in calvarial defects (<I>p</I> < 0.01). Bone formation was only observed for the ErhBMP‐2/bMBCP ectopic sites and was significantly greater at 8 wk (7.5%) than at 2 wk (4.5%) (<I>p</I> < 0.01). Appositional and endochondral bone formation was usually associated with a significant increase in fatty marrow at 8 wk. The bMBCP carrier showed no evidence of bioresorption.</P><P><B>Conclusion: </B> ErhBMP‐2/bMBCP induced significant bone formation in both calvarial and ectopic sites. Further study appears to be required to evaluate the relevance of the bMBCP carrier.</P>

Inhibitory effect of chloroform on fermentative hydrogen and methane production from lipid-extracted microalgae

Yun, Y.M.,Cho, S.K.,Jung, K.W.,Kim, M.S.,Shin, H.S.,Kim, D.H. Pergamon Press 2014 International journal of hydrogen energy Vol.39 No.33

To improve the sustainability of microalgae as a bioenergy feedstock, lipid-extracted microalgae (LEM) are often further treated by anaerobic digestion (AD). However, the residual chloroform used for extracting lipids as a solvent could inhibit this process, an aspect that has not been studied to date. In this study, the inhibitory effect of chloroform on H<SUB>2</SUB> and CH<SUB>4</SUB> production was investigated by performing batch tests. To prepare the feedstock, Chlorella vulgaris was ultrasonicated and the supernatant was discarded after centrifugation. In case of H<SUB>2</SUB> production, it was found that the H<SUB>2</SUB> yield fell to almost half that of the control (15.6 mL H<SUB>2</SUB>/g COD<SUB>added</SUB>) at 100 mg CHCl<SUB>3</SUB>/L. The reason for the decrease of the H<SUB>2</SUB> yield with the increase of chloroform level was due to the change of metabolites from acetate and butyrate to lactate via a non-hydrogenic reaction. In comparison with H<SUB>2</SUB> production, a much more severe inhibitory effect of chloroform on CH<SUB>4</SUB> production was observed. The inhibitor concentration (IC<SUB>30, 60, and 90</SUB>) on H<SUB>2</SUB> production was 138, 319, and 622 mg CHCl<SUB>3</SUB>/L, respectively, while concentrations of 15, 37, and 86 mg CHCl<SUB>3</SUB>/L were obtained on CH<SUB>4</SUB> production. When the chloroform concentration was ≥25 mg/L on CH<SUB>4</SUB> production, more than 2 g COD/L of organic acids remained, resulting in a decrease of CH<SUB>4</SUB> yield. These findings indicate that the residual chloroform in LEM should be seriously considered to prevent possible microbial inhibition when designing a process for additional energy recovery from microalgae via AD.

The regulation of TIM-3 transcription in T cells involves c-Jun binding but not CpG methylation at the TIM-3 promoter

Yun, S.J.,Jun, K.J.,Komori, K.,Lee, M.J.,Kwon, M.H.,Chwae, Y.J.,Kim, K.,Shin, H.J.,Park, S. Pergamon Press 2016 Molecular immunology Vol.75 No.-

<P>Tim-3 is an immunomodulatory protein that is expressed constitutively on monocytes but is induced in activated T cells. The mechanisms involved in the regulation of TIM-3 transcription are poorly understood. In the present study, we investigated whether methylation of the TIM-3 promoter is involved in regulating TIM-3 transcription in T cells, and identified a transcription factor that regulates TIM-3 transcription by associating with the TIM-3 minimal promoter region. Pyrosequencing of the TIM-3 promoter up to 1440 bp revealed 11 hypermethylated CpG sites and 4 hypomethylated CpG sites in human CD4(+) T cells as well as in CD11b(+) cells. Dimethylation of histone H3 lysine 4 (H3K4), a mark of transcriptional activation, was predominantly found in the proximal TIM-3 promoter 954 to 34 by region, whereas trimethylation of H3K9 and H3K27, which are markers of transcriptional suppression, were mostly observed in the distal promoter -1549 to -1048 bp region in human CD4+ T cells and CD11b(+) cells. However, no change in the methylation status of CpG sites and the histone H3 in the TIM-3 promoter was found during induction of TIM-3 transcription in T cells. Finally, AP-1 involvement in TIM-3 transcription was shown in relation with the TIM-3 minimal promoter 146 to +144 by region. The present study defines the minimal TIM-3 promoter region and demonstrates its interaction with c-Jun during TIM-3 transcription in CD4(+) T cells. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Effects of electron beam irradiation on six insect pests in different sections of flower boxes for export

Yun, S.H.,Koo, H.N.,Kim, H.K.,Cho, S.,Kim, G.H. 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.20 No.3

We explored effects of electron beam irradiation on disinfestation of six floriculture insect pests (Liriomyza trifolii, Spodoptera litura, Myzus persicae, Tetranychus urticae, Bemisia tabaci, and Frankliniella intonsa) placed at top, middle, or bottom section in boxes of roses and chrysanthemums. After irradiation with an electron beam of 200Gy, eggs of T. urticae, B. tabaci, and F. intonsa were prevented from hatching at every position in the boxes, whereas some eggs of L. trifolii and S. litura hatched at the bottom of the boxes. The pupation and emergence of L. trifolii and S. litura larvae and B. tabaci nymphs were inhibited at every position in the boxes. However, the emergence of T. urticae and M. persicae nymphs was not inhibited, even at the top of the boxes. When pupae were irradiated, the emergence of L. trifolii was inhibited at every section in the boxes, whereas S. litura was not inhibited completely, even at the top section. When adult T. urticae were irradiated, the hatching of the F<SUB>1</SUB> generation was completely inhibited at the middle section in rose boxes but not completely in chrysanthemum boxes. The insect pests that were not inhibited completely at 200Gy were completely inhibited at 300Gy, except for T. urticae. Therefore, the doses of electron beam irradiation required might depend on the types of flowers, the species of insect pests, and the insect pest sections within the boxes.

Analysis of the regenerative H₂S poisoning mechanism in Ce_0.8Sm_0.2O₂-coated Ni/YSZ anodes for intermediate temperature solid oxide fuel cells

Yun, J.W.,Yoon, S.P.,Park, S.,Kim, H.S.,Nam, S.W. Pergamon Press ; Elsevier Science Ltd 2011 International journal of hydrogen energy Vol.36 No.1

Ceria is used as a sulfur sorbent due to its high affinity for sulfide at high temperatures. In addition, the ionic conductivity of ceria can be dramatically increased by doping with rare metals, including lanthanum, samarium, and gadolinium. Therefore, to enhance sulfur tolerance and improve anode performance, we modified an Ni-based anode with a thin layer coating of Sm<SUB>0.2</SUB>Ce<SUB>0.8</SUB>O<SUB>2-δ</SUB> (SDC) on the pore wall surface of an Ni/YSZ anode. The anode-supported cells were tested with varying H<SUB>2</SUB>S concentrations (0-100 ppm) at 600 and 700 <SUP>o</SUP>C. The cell performance was improved in the ceria- (by 20%) and in the SDC- (by 50%) modified anode by extending the additional TPB area in the anode. Under varying H<SUB>2</SUB>S exposure, the polarization resistance was reduced by ceria and the SDC coating on the anode pore wall surface, which led to improved cell performance. A porous SDC layer on the Ni/YSZ anode pore wall acted as a sulfur sorbent as well as an additional TPB area. Otherwise, ceria mainly acted as a sulfur sorbent at high concentrations of H<SUB>2</SUB>S (>60 ppm).

Production of (S)-3-hydroxybutyrate by metabolically engineered Saccharomyces cerevisiae

Yun, E.J.,Kwak, S.,Kim, S.R.,Park, Y.C.,Jin, Y.S.,Kim, K.H. Elsevier Science Publishers 2015 Journal of biotechnology Vol.209 No.-

(S)-3-Hydroxybutyrate (S-3HB) can be used as a precursor for the synthesis of biodegradable polymers such as polyhydroxyalkanoate and stereo-specific fine chemicals such as antibiotics, pheromones, and drugs. For the production of S-3HB in yeast, the biosynthetic pathway of S-3HB from acetyl-CoA, consisting of the three enzymes, acetyl-CoA C-acetyltransferase (ACCT), acetoacetyl-CoA reductase (ACR), and 3-hydroxybutyryl-CoA thioesterase (HBT), was introduced into Saccharomyces cerevisiae. An engineered yeast strain overexpressing ERG10, hbd, and tesB genes not only exhibited enzyme activities of AACT, ACR, and HBT, but also produced S-3HB from ethanol. In order to increase the titer of S-3HB, a fed-batch fermentation based on pulse feeding of ethanol as a carbon source was performed, and a final S-3HB titer of 12.0g/L was achieved. This is the first report on the production of 3HB by engineered yeast, utilizing ethanol as the carbon source, suggesting that the industrially preferred S. cerevisiae can be a promising host for producing S-3HB.