• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.669-669
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• 2013

Hierarchical N doped TiO2 nanostructured catalyst with micro, meso and macro porosity have been synthesized by a facile self-formation route using ammonia and titanium isopropoxide precursor. The samples were calcined in different calcination temperature ranging from $300^{\circ}C$ to $800^{\circ}C$ at slow heating rate ($5^{\circ}C$/min) and designated as NHPT-300 to NHPT-800. $TiO_2$ nanostructured catalyst have been characterized by physico-chemical and spectroscopy methods to explore the structural, electronic and optical properties. UV-Vis diffuse reflectance spectra confirmed the red shift and band gap narrowing due to the doping of N species in TiO2 nanoporous catalyst. Hierarchical macro porosity with fibrous channel patterning was observed (confirmed from FESEM) and well preserved even after calcination at $800^{\circ}C$, indicating the thermal stability. BET results showed that micro and mesoporosity was lost after $500^{\circ}C$ calcination. The photocatalytic activity has been evaluated for methanol oxidation to formaldehyde in visible light. The enhanced photocatalytic activity is attributed to combined synergetic effect of N doping for visible light absorption, micro and mesoporosity for increase of effective surface area and light harvestation, and hierarchical macroporous fibrous structure for multiple reflection and effective charge transfer.

• 한국미생물·생명공학회지
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• 제36권4호
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• pp.314-319
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• 2008

Penicillin G amidase(PGA, benzylpenicillinamidohydrolase, EC 3.5.1.11)는 penicillin G를 phenylacetic acid(PAA)와 6-aminopenicillanic acid(6-APA)로 분해하는 효소이다. Escherichia coli(E. coli) ATCC 11105의 PGA는 24 kDa의 small subunit과 65 kDa의 large subunit으로 구성되어 있고, precursor polypeptide에서 signal peptide와 spacer peptide가 절단되어 활성을 가진 heterodimer가 형성된다. 본 연구에서는 E. coli ATCC 11105에서 PCR(polymerase chain reaction)을 통해 증폭한 pga gene을 expression vector에 넣어 pET-pga plasmid를 제작하였고, 이것을 E. coli BL21 (DE3) 균주에 형질 전환하여 PGA를 발현하고 그 활성을 분석하였다. E. coli BL21(DE3)/pET-pga 균주의 고밀도 배양액을 SDS-PAGE로 분석 했을 때, PGA의 precursor, large subunit, 그리고 small subunit으로 보이는 protein band가 나타났으며, PGA가 soluble form의 precursor로 발현되어 processing을 거쳐서 large subunit과 small subunit으로 절단되기도 하고, 일부는 insoluble form의 precursor로 발현되기도 하는 것으로 생각된다. 유가배양시 온도변화 전략을 사용하여 고농도 배양에서 발현을 유도하였다. 온도변화 전략은 $37^{\circ}C$에서 $28^{\circ}C$를 거쳐 $22^{\circ}C$로 3단계로 변화시켰다. 이러한 전략으로 PGA활성은 19.6 U/mL이며 균체량은 600 nm에서 흡광도가 62까지 도달하였다.

• 한국환경복원기술학회지
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• 제19권6호
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• pp.19-30
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• 2016

The projection of climate-related range shift is critical information for conservation planning of Korean fir (Abies koreana E. H. Wilson). We first modeled the distribution of Korean fir under current climate condition using five single-model species distribution models (SDMs) and the pre-evaluation weighted ensemble method and then predicted the distributions under future climate conditions projected with HadGEM2-AO under four $CO_2$ emission scenarios, the Representative Concentration Pathways (RCP) 2.6, 4.5, 6.0 and 8.5. We also investigated the predictive uncertainty stemming from five individual algorithms and four $CO_2$ emission scenarios for better interpretation of SDM projections. Five individual algorithms were Generalized linear model (GLM), Generalized additive model (GAM), Multivariate adaptive regression splines (MARS), Generalized boosted model (GBM) and Random forest (RF). The results showed high variations of model performances among individual SDMs and the wide range of diverging predictions of future distributions of Korean fir in response to RCPs. The ensemble model presented the highest predictive accuracy (TSS = 0.97, AUC = 0.99) and predicted that the climate habitat suitability of Korean fir would increase under climate changes. Accordingly, the fir distribution could expand under future climate conditions. Increasing precipitation may account for increases in the distribution of Korean fir. Increasing precipitation compensates the negative effects of increasing temperature. However, the future distribution of Korean fir is also affected by other ecological processes, such as interactions with co-existing species, adaptation and dispersal limitation, and other environmental factors, such as extreme weather events and land-use changes. Therefore, we need further ecological research and to develop mechanistic and process-based distribution models for improving the predictive accuracy.

• 해양환경안전학회지
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• 제18권3호
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• pp.193-198
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• 2012

겨울철 해표면 수온 및 한국 주변역 생태계의 장기 변화 특성 및 상관관계를 분석하였다. 기후 및 해양환경의 변화와 동반된 어획강도의 변화는 1970 년대 이후 어획량 증가의 주요 원인으로 나타났다. 한국 주변역의 겨울철 SST는 1980년대 후반 기후체제변환 시점을 중심으로 상대적으로 저수온에서 고수온으로 변화되었다. 평균영양단계(MTL)는 1970년대 중반 이후 지속적으로 감소하기 시작하였으며, 하위영양단계 어류의 어획량 증가가 중요 변수로 작용하였다. 통합생태계 기반 자원평가 방법중 한가지인 FIB 지수는 1970년 초부터 1970년 후반까지 증가하였으며, 이후 일정 수준을 유지하였다. 특히, 중간영양단계에 위치하는 멸치와 정어리의 개체수 변화는 1970년대 초 이후 MTL 변화의 주요 인자로 작용하였다.

• 한국항행학회논문지
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• 제15권6호
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• pp.1152-1162
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• 2011

본 논문에서는 등장성 수축(isotonic contraction)시 연령에 따른 변화의 추이 등을 알아보기 위해 일상생활에서 주로 사용하는 대퇴사두근의 근 활성도(muscle activity)와 근 피로도(muscle fatigue) 해석에 관한 연구를 하였다. 실험은 남자 20대와 50대 각 10명씩을 대상으로 무릎 확장운동으로 각 피 실험자가 할 수 있는 최대 부하(1RM)를 측정한 다음 그 부하의 20-90%부하를 차례로 증가 시키면서 대퇴사두근(Quadriceps Femoris :QF)은 내측광근(vastus medialis : VM), 대퇴직근(rectus femoris : RF), 외측광근(vastus lateralis : VL) 등을 각각 근전도 신호를 추출하고, 수축, 이완모드에서 각속도를 측정하였다. 20대와 50대의 속도를 비교분석한 결과 대퇴사두근의 20대 근육에서는 (p < 0.89)로 50대에서는 (p < 0.70)로 유의차가 없는 것으로 나타났다. 생체 동역학 연구와 체육 분야의 선수 훈련방법, 산업분야에서 상해방지와 근육부상방지, 재활의약분야의 부상치료 등에 응용할 수 있을 것으로 사료된다.

• Journal of Microbiology
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• 제39권3호
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• pp.162-167
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• 2001

Methylovorus sp. strain SS1 DSM 11726 was found to grow continuously when it was transferred from 30$\^{C}$ to 40$\^{C}$ and 43$\^{C}$. A shift in growth temperature from 30$\^{C}$ to 45$\^{C}$, 47$\^{C}$ and 50$\^{C}$ reduced the viability of the cell population by more than 10$^2$, 10$^3$and 10$\^$5/ folds, respectively, after 1h cultivation. Cells transferred to 47$\^{C}$ and 50$\^{C}$ after preincubation for 15 min at 43$\^{C}$, however, exhibited 10-fold increase in viability. It was found that incubation for 15 min at 40$\^{C}$ of Methylovorus sp. strain SSl grown at 30$\^{C}$ was sufficient to accelerate the synthesis of a specific subset of proteins. The major heat shock proteins had apparent molecular masses of 90, 70, 66, 60, and 58 kDA. The 60 and 58 kDa proteins were found to cross-react with the antiserum raised against GroEL protein. The heat shock response persisted for over 1h. The shock proteins were stable for 90 min in the cell. Exposure of the cells to methanol induced proteins identical to the heat shock proteins. Addition of ethanol induced a unique protein with a molecular mass of about 40 kDa in addition to the heat-induced proteins. The proteins induced in paraquat-treated cells were different from the heat shock proteins, except the 70 and 60 kDa proteins.

• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.477-487
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• 1995

The purpose of this study was to assess the thermographic differences of craniomandibular area between normal individual and patients with craniomandibular disorders and to compare the differences between clinical and thermographical assessment. The author had used 50 subjects as materials for this study, which was divided into 2 groups (first group included 15 healthy subjects and second group included 35 patients) with craiomandibular disorders; 17 subjects had normal disc-condyle relationship, 13 subjects had disc displacement with reduction and 5 subjects had disc displacement without reduction. Agema 870 thermovision(D.I.T.I.) was used to take thermographs with $0.1^{\circ}C$ difference of gradual temperature shift. The results were as follows : 1. Of 34 patients with craniofacial pain, 15(44%) subjects showed hyperthermia on the pain site in the thermography, 8(23.5%)exhibited hyperthermia on the site opposed to the pain site, and 11(32.4%) did not show any significant thermal change. One patient without craniofacial pain showed hyperthermia on the site opposed to the site of disc displacement without reductin. 2. Of 35 patients with craniofacial pain or disc displacement, 24(68.6%) subjects showed a significant thermal difference between symptomatic and asymptomatic sides of the face, but 11(31.4%) did not show any difference. 3. Of 17 patients with pain but with normal disc-condyle relationship, 8(47.1 subjects showed hyperthermia on the pain site, 4(23.5%) showed on the site opposed to the pain site, and 5(29.4%) did not show any significant thermal change. 4. Or 13 patients with pain and disc displacement with reduction, 6(46.2%) subjects showed hyperthermia on the pain site, 3(23.1%) showed on the site opposed to the pain site, and 4(30.8%) did not show any significant thermal change. 5. 15 healthy subjects did not show any thermal differences between the both sides of the face.

• 대한화학회지
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• 제18권3호
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• pp.180-188
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• 1974

Layer silicate 에 지지된 陽이온상에서의 일어난 acetaldehyde, acrolein, 그리고 crotonaldehyde의 吸着機構에 對하여 IR과 X-ray로서 硏究하였다. $1720∼1580㎝^{-1}$의 범위에서 일어난 4個의 특성적인 吸捉 band를 分析한 結果 $130㎝^{-1}$程度로 shift한 carbonyl band 는 >C=O${\cdots}$M형 complex 形成에 基因하는 것이었고, acetaldehyde는 $1722㎝^{-1}$에서, 다른 알데히드는 $1690㎝^{-1}$에서 sharp하게 나타난 carbonyl band는 >C=O와 surface -O-H와의 interaction에서 일어난 것이었다. 그리고 1710∼1660㎝-1에서 나타난 broad한 band는 >C=O와 陽이온 -O-H와의 사이에 일어난 水素結合에 依한 것이었다. 그리고 $1640∼1660㎝^{-1}$사이에 나타난 弱한 band는 carbonyl group 의 强한 吸着에 依하여 誤起된 >C=C< 二重結合에 依한 것이었다. 이 사실들은 X-ray 廻折에 依하여 다시 確認하였다.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3199-3204
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• 2014

Two novel phosphorescent heteroleptic cationic Ir(III) complexes, Ir(bt)2(dmpe) (Ir1) and Ir (bt)2(dppe) (Ir2), where bt is 2-phenylbenzothiazole, dmpe is 1,2-bis(dimethylphosphino)ethane, and dppe is 1,2-bis(diphenyl-phosphino) ethane, were designed and synthesized. Their photophysical and electrochemical properties and the X-ray structure of the Ir1 complex were investigated. The prepared Ir(III) complexes exhibited blue-green emissions at 503-538 nm with vibronic fine structures in dichloromethane solution and PMMA film, implying that the lowest excited states are dominated by ligand-based $^3{\pi}-{\pi}^*$ transitions. The ${\pi}$-acceptor ability of the diphosphine ancillary ligand leads to blue-shift emission. The room temperature photoluminescent quantum yields (PLQYs) of Ir1 and Ir2 were 52% and 45%, respectively, in dichloromethane solution. These high PLQYs resulted from steric hindrances by the bulky cationic iridium complexes. The crystal structure of Ir1 was determined by X-ray crystallography, which revealed that central iridium adopted a distorted octahedral structure coordinated with two bt ligands (N^C) and one dmpe ligand (P^P) showing cis C-C and trans N-N dispositions. The bent nature of the dmpe ligand resulted in a relatively wide bite angle of $83.83^{\circ}$ of P-Ir-P.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3433-3436
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• 2011

Some of metal nanoparticles have the potential for use as colorimetric assays for estimating solution properties, such as pH and temperature due to localized surface plasmon (LSP) phenomena. This report describes the use of silver nanoparticles (AgNP) conjugated with cytochrome c (Cyt c) for the colorimetric determination of solution pHs. When the pH of a solution decreases, the Cyt c immobilized on the AgNP undergoes a conformational change, leading to a decrease in the interparticle distance between Cyt c-AgNP probes and consequent red-shift in LSP. As a result, the color of the Cyt c-AgNP probe solution changes from yellow to red and finally to a grayish blue in the pH range from 11 to 3. This gradual color change can be used to determine the pH of a solution over a wide pH range, compared to other colorimetric methods that use gold nanoparticles.