• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.243-244
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• 2013

Over the past 15 years, several groups have incorporated radio-frequency quadrupole (RFQ) based instruments before the accelerator in accelerator mass spectrometry (AMS) systems for ion-gas interactions at low kinetic energy (＜40 eV). Most AMS systems arebased on a tandem accelerator, which requires negative ions at injection. Typically, AMS sensitivity abundance ratios for radioactive-to-stable isotope are limited to Xr/Xs ＞10^-15, and the range of isotopes that can be analyzed is limited because of theneed to produce rather large negative ion beams and the presence of atomic isobaric interferences after stripping. The potential of using low-kinetic energy ion-gas interactions for isobar suppression before the accelerator has been demonstrated for several negative ion isobar systems with a prototype RFQ system incorporated into the AMS system at IsoTrace Laboratory, Canada (Ontario, Toronto). Requisite for any such RFQ system applied to very rare isotope analysis is large transmission of the analyte ion. This requires proper phase-space matching between the RFQ acceptance and the ion beam phase space (e.g. 35 keV, ${\varphi}3mm$, +-35 mrad), and the ability to control the average ion energy during interactions with the gas. A segmented RFQ instrument is currently being designed at Korea Institute for Science and Technology (한국과학기술연구원, KIST). It will consist of: a) an initial static voltage electrode deceleration region, to lower the ion energy from 35 keV down to ＜40 eV at injection into the first RFQ segment; b) the segmented quadrupole ion-gas interaction region; c) a static voltage electrode re-acceleration region for ion injection into a tandem accelerator. Design considerations and modeling will be discussed. This system should greatly lower the detection limits of the 6 MV AMS system currently being commissioned at KIST. As an example, current detection sensitivity of 41Ca/Ca is limited to the order of 10^-15 while the 41Ca/Ca abundance in modern samples is typically 41Ca/Ca~10^-14 - 10^-15. The major atomic isobaric interference in AMS is 41K. Proof-of-principal work at IsoTrace Lab. has demonstrated that a properly designed system can achieve a relative suppression of KF3-/41CaF3- ＞4 orders of magnitude while maintaining very high transmission of the 41CaF3- ion. This would lower the 41Ca detection limits of the KIST AMS system to at least 41Ca/Ca~10^-19. As Ca is found in bones and shells, this would potentially allow direct dating of valuable anthropological archives and archives relevant to our understanding of the most pronounced climate change events over the past million years that cannot be directly dated with the presently accessible isotopes.

• 한국대기환경학회지
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• 제34권4호
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• pp.554-566
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• 2018

The rice husk contains nutrients which can be easily utilized by microorganisms, and also has a water retaining ability, which played a crucial part in enabling it to become a biofilter media. In this study, we evaluated the applicability of rice husk pellet bio-scrubber as a microbiological carrier. The pelletization experiment of rice husk as a biological media was performed using PVA and EVA binder. Also, the feasibility tests of rice husk as a biological media for odor removal were carried out in order to know whether rice-husk contains useful components as a media for microbiological growth or not. Lastly, a combined test for odor gas absorption and biological oxidation was conducted using a lab scale bio-filter set-up packed with rice-husk pellets as wet-scrubber. The major components of the rice husk were carbon, hydrogen, nitrogen, and oxygen, while carbon acted as the main ingredient which comprised up to 23.00%. The C : N : P ratio was calculated as 45 : 1 : 2. Oxygen uptake rate, yield and decay rate of the rice husk eluent was calculated to be $0.0049mgO_2/L/sec$, 0.24 mgSS/mgCOD and 0.004 respectively. The most stable form of rice husk pellets was produced when the weight of the rice husk, EVAc, PVAc, and distilled water was 10 : 2 : 0.2 : 10. The prepared rice husk pellets had an apparent density of 368 g/L and a porosity of 59.00% upon filling. Dry rice husks showed high adsorption capacity for ammonia gas but low adsorption capacity for hydrogen sulfide. The bio-filter odor removal column filled with rice husk pellets showed more than 99.50% removal efficiency for NH3 and H2S gas. Through the analysis of circulation water, the prime removal mechanism is assumed to be the dissolution by water, microbial nitrification, and sulfation. Finally, it was confirmed that the microorganisms could survive well on the rice husk pellets, which provided them a stable supply of nutrients for their activity in this long-term experiment. This adequate supply of nutrients from the rice husk enabled high removal efficiency by the microorganisms.

• 한국응용곤충학회지
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• 제54권3호
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• pp.233-245
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• 2015

백두대간은 한반도의 다양한 생물 서식지이며 동물의 이동통로로 새로운 서식지로의 이주와 재서식을 하는데 중요한 역할을 할 것으로 기대되고 있다. 본 연구는 2013-2014년에 4월부터 9월까지 백두대간 구룡령(명계리)과 고직령(서벽리)의 나비군집을 모니터링 하고, 두 지역의 나비를 과거기록과 비교하여 분포지의 변화가 있는지를 알아보았다. 그 결과 명계리 65종 1098개체, 서벽리 63종 1161개체가 조사되었다. 두 지역의 비교에서 명계리에서만 출현한 종은 15종, 서벽리에서만 출현한 종은 13종으로 나타났다. 종 순위별 개체수에서는 명계리는 큰줄흰나비 127 (11.6%), 줄흰나비 100 (9.1%), 산제비나비 90 (8.2%), 서벽리는 뿔나비 146 (12.6%), 줄흰나비 134 (11.5%), 네발나비 69 (5.9%)종으로 나타났다. 그리고 3개체 이하를 보인 종은 명계리 24종, 서벽리 23종으로 나타나 높은 비율을 차지하였다. 두 지역의 유사도는 비교적 높게 나타나고 있을 뿐만 아니라 한국적색목록의 나비가 다수 분포하고 있으며, 출현종을 과거 분포자료와 비교한 결과 뚜렷한 변화는 없었다. 이에 백두대간의 나비는 아직까지 잘 보전되고 있는 것으로 보여 거시적으로 백두대간의 서식지 경관이 연속성을 유지하도록 하는 것이 필요하다.

• 한국대기환경학회지
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• 제24권1호
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• pp.91-99
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• 2008

A multilayer tower-type photoreactor, in which $TiO_2$-coated glass-tubes were installed, was used to measure the vapor-phase BTEX removal efficiencies by ozone oxidation ($O_3$/UV), photocatalytic oxidation ($TiO_2$/UV) and the combination of ozone and photocatalytic oxidation ($O_3/TiO_2$/UV) process, respectively. The experiments were conducted under various relative humidities, temperatures, ozone concentrations, gas flow rates and BTEX concentrations. As a result, the BTEX removal efficiency and the oxidation rate by $O_3/TiO_2$/UV system were highest, compared to $O_3$/UV and $TiO_2$/UV system. The $O_3/TiO_2$/UV system accelerated the low oxidation rate of low-concentration organic compounds and removed organic compounds to a large extent in a fixed volume of reactor in a short time. Therefore, $O_3/TiO_2$/UV system as a superimposed oxidation technology was developed to efficiently and economically treat refractory VOCs. Also, this study demonstrated feasibility of a technology to scale up a photoreactor from lab-scale to pilot-scale, which uses (i) a separated light-source chamber and a light distribution system, (ii) catalyst fixing to glass-tube media, and (iii) unit connection in series and/or parallel. The experimental results from $O_3/TiO_2$/UV system showed that (i) the highest BTEX removal efficiencies were obtained under relative humidity ranging from 50 to 55% and temperature ranging from 40 to $50^{\circ}C$, and (ii) the removal efficiencies linearly increased with ozone dosage and decreased with gas flow rate. When applying Langmuir-Hinshelwood model to $TiO_2$/UV and $O_3/TiO_2$/UV system, reaction rate constant for $O_3/TiO_2$/UV system was larger than that for $TiO_2$/UV system, however, it was found that adsorption constant for $O_3/TiO_2$/UV system was smaller than that for $TiO_2$/UV system due to competitive adsorption between organics and ozone.

• 한국작물학회지
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• 제57권1호
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• pp.89-97
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• 2012

1. 30년 장기 연용구의 연작 대비 윤작에 의한 옥수수 및 콩의 수량증대는 옥수수보다 콩이 더 컸으며, 연작시 무경운에 따라 수량이 감소되었던 옥수수는 윤작에 의해 수량이 많이 회복되었다. 콩은 연 윤작구 모두 무경운에서도 수량이 감소하지 않았다. 2. 윤작구의 작물재배기간의 이산화탄소 누적발생량은 재배작물 및 처리간 차이가 없었으며, 메탄은 콩의 재배시 plow 경운구에서 생육초기에 증가하였다. 3. 아산화질소의 발생은 옥수수 생육초기 질소시비 후에 질소비료의 무기화 과정에서 발생량이 증가하였는데, 경운방법에 따라 차이가 뚜렷하여 chisel 경운에서 가장 높았고, 무경운에서 가장 낮았다. 4. 콩-옥수수 윤작체계에서 plow 및 chisel 경운에 비해 무경운(no-tillage)의 채택에 따라 작물의 수량 감소없이 콩 재배 시 메탄 $0.7kg\;C\;ha^{-1}$ 및 옥수수 재배 시 아산화질소 $2{\sim}4kg\;N\;ha^{-1}$ 발생량을 감소시킬 수 있었다.

• 한국치위생학회지
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• 제11권4호
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• pp.441-451
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• 2011

Objectives : The purpose of this study was to examine the eating behavior of patients in a bid to facilitate the improvement of their eating behavior, as eating behavior seemed to affect oral health and dietary habits. Methods : The subjects in this study were 235 patients who visited the dental hygiene practice lab at C college in South Jeonla Province. After a survey was conducted, the collected data were analyzed with the statistical package SPSS 12.0. Results : 1. When their self-awareness of dietary habits and oral health was checked in consideration of eating behavior, those who thought they had very good dietary habits and were in good oral health had meals three times a day. Their eating time was very irregular, and they took 15 to 20 minutes to eat. Their overeating frequency was three or four times a week, and their frequency of eating between meals was once or twice a week. 2. On the contrary, the daily eating frequency of the patients who found themselves to have very bad dietary habits and to be in bad oral health was not fixed, and their eating time was neither regular nor irregular. They spent less than 10 minutes having a meal, and their overeating frequency was once or twice a week. Their frequency of having a snack was three or four times a week, and as for food preference, they had a liking for meat. 3. The patients considered themselves to be in better health when they had balanced meals and good eating behavior, namely good dietary habits. And they rated their own dietary habits higher when they were in a good oral state, had no experiences to feel pain in the mouth and didn't receive any dental treatment, namely when they were in good oral health. Conclusions : This study attempted to investigate the influence of eating behavior on oral health awareness. Another limitation of this study is that the geographic scope was just confined to an urban community in South Jeonla Province without checking any possible regional gaps. However, it's quite evident that eating behavior exerts an influence on oral health awareness, and it seems worth doing to examine a larger number of subjects by utilizing objective oral health guidelines.

• Biomolecules & Therapeutics
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• 제3권4호
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• pp.266-272
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• 1995

The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently through the use of specific antibodies. To generate and characterize a moloclonal antibody against $\beta$-adrenergic receptor, a synthetic $\beta$2-adrenergic receptor peptide (Phe-Gly-Asn-Phe-Trp-Cys-Phe-Trp-Thr-Ser-lle-Asp-Val-Leu) which may comprise part of $\beta$-adrenergic receptor ligand binding pocket was coupled to Keyhole Limpet Hemocyanin (KLH) and used as an immunogen. Male BALB/C mice were immunized with this antigen and the immunized spleen was fused with myeloma SP2/0-Ag14 cells to produce monoclonal antibodies. Two clones were obtained but one of monoclonal antibodies, mAb5G09, was used throughout in this study because the other clone, mAb5All showed weak immunoreactivity against KLH as well. The mouse monoclonal antibody mAb5G09 produced in this study showed immunoreactivity to peptide-KLH conjugates and also to human A43l cells and guinea pig lung $\beta$2-adrenergic receptor as revealed by ELISA and western blot. In the course of determination of the effects of mAb5G09 on $\beta$-receptor ligand binding, it was observed that mAb5G09 specifically bound $\beta$-adrenergic radioligand [$^3$H]dihydroalprenolol (DHA) with a dissociation constant (Kd) of 60 nM. The [$^3$H]DHA binding activity of mAb5G09 had characteristics of immunoglobulins and the binding activity was not observed in the control anti-KLH monoclonal antibody. The monoclonal antibody, mAb5G09 produced in this study may provide useful models for the study of the structure of receptor binding sites.

• 핵의학기술
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• 제21권1호
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• pp.23-28
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• 2017

Purpose Recently, there has been increasing demands for clinical departments at Asan Medical center in Seoul. They want to see the results of lab tests about blood samples as soon as possible and to be reported to them on the day. As the main contents of the survey, we explained the goodness of Asan medical center's in vitro and the points to be improved. Based on this, it became an opportunity to create a positive image of In vitro laboratory. In addition, we could identify their specific requirements through the surveys. Materials and Methods In September 2016, a total of 14 questionnaire surveys were conducted for 49 clinical departments and outpatient nurses at Asan Medical center in Seoul. The survey consists of description questions to be able to express the intention of the individual and the questions made on the Likert 4 point scale. The main contents of 14 questions are composed of goodness of In Vitro laboratory and points to be improved. Results 62% answered that the best service in In Vitro laboratory was "good accuracy and reproducibility". On the other hand, as an inconvenience when requesting blood tests, 73% pointed out that "the result report time was long", which was recognized as a part to be improved. There are many contents that "The result of all tests is reported within 2 hours" on the day of the examination. In the question - 'Are there some examination results which do not coincide well with clinical observations?', 55 of 56 people answered "no". Above all, the majority answered that waiting for re-examination results is too long. This problem must be causing discomfort to the patients. Conclusion In order to improve these problems, the first thing is to increase the number of blood tests by using the current personnel, equipments and reagents to the fullest by item in Asan Medical Center's Nuclear medicine in vitro part. Secondly, in case of re-examinations, we use the "AMIS message" to show other clinical departments the reporting time. This methode improves the efficiency of work with nurses and increases satisfaction of custom service. Thirdly, the correlation was evaluated by selecting the test species that can be carried out by the shortening method. Currently, C-peptide and insulin are implemented in the reaction process to shorten 2 hours into 1 hour. Finally, we are considering purchasing new equipments for quick test results.

• Experimental and Molecular Medicine
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• 제51권2호
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• pp.1.1-1.14
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• 2019

Hypoxia-inducible factor-$1{\alpha}$ ($HIF-1{\alpha}$) mediates tumor cell adaptation to hypoxic conditions and is a potentially important anticancer therapeutic target. We previously developed a method for synthesizing a benzofuran-based natural product, (R)-(-)-moracin-O, and obtained a novel potent analog, MO-460 that suppresses the accumulation of $HIF-1{\alpha}$ in Hep3B cells. However, the molecular target and underlying mechanism of action of MO-460 remained unclear. In the current study, we identified heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) as a molecular target of MO-460. MO-460 inhibits the initiation of $HIF-1{\alpha}$ translation by binding to the C-terminal glycinerich domain of hnRNPA2B1 and inhibiting its subsequent binding to the 3'-untranslated region of $HIF-1{\alpha}$ mRNA. Moreover, MO-460 suppresses $HIF-1{\alpha}$ protein synthesis under hypoxic conditions and induces the accumulation of stress granules. The data provided here suggest that hnRNPA2B1 serves as a crucial molecular target in hypoxiainduced tumor survival and thus offer an avenue for the development of novel anticancer therapies.

• 한국과학교육학회지
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• 제39권4호
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• pp.511-523
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• 2019

미래의 과학자 양성을 목표로, 진정한 과학 탐구의 경험을 강조하고 있는 고등학생들의 R&E 활동에서 점진적으로 주목하고 있는 것은 진정한 탐구 주체로서의 학생의 활동이다. 본 연구에서는 고등학교에서 수행되고 있는 R&E 활동 중에서 특히 학생이 그 주체가 되어 연구의 과정을 결정하고 실행하는 학생 주도의 R&E를 대상으로 연구 수행의 주요 흐름을 파악하고, 각 단계에서 드러나는 학생의 인식적 행위주체성을 탐색하고자 하였다. 이를 위하여 과학영재학교 1학년 학생들이 수행한 교내 R&E 활동에 대하여 18개월에 걸친 질적 사례 연구를 수행하였으며, 연구 참여자와의 반 구조화된 면담 자료, 연구자의 참여관찰 일지, 학생과의 논의 과정에 대한 녹음자료, 학생 산출물 등과 같은 질적 자료를 수집, 근거이론에 기반한 지속적 비교분석법에 따라 귀납적으로 분석하였다. 연구 결과, 학생 주도의 R&E 활동은 주제 탐색의 단계-연구 설계의 단계-실험활동 수행의 단계-해석 및 고찰의 단계-과학적 의사소통의 단계를 거치는 것으로 드러났으며, 이와 같은 연구의 흐름은 비선형적이며 단계 간 중첩과 회귀가 빈번하게 드러나는 동적인 특징을 지님을 알 수 있었다. 두 번째로, 학생 주도의 R&E 활동에서 학생의 인식적 행위주체성은 R&E 구조와의 지속적인 상호작용을 통해 발현되었다. R&E의 구조에 의한 인식적 행위주체성의 촉발은 연구의 진행에 따라 점차 자발적 발현으로 전환되었으며, 특히 학생의 인식적 신념과 깊은 관련성을 보였다. 또한 인식적 행위주체성의 발현 과정에서 학생들은 스스로를 R&E 활동의 의사결정자로 배치하는 모습을 보였으며, 이는 R&E 활동에 대한 권위의 재분배와도 밀접한 관련성을 드러냈다. 학생 주도의 R&E 활동이 어떠한 흐름을 가지고 이루어지며, 그 가운데 학생들이 어떠한 인식적 행위주체성을 보이는지에 대한 본 연구는 지속적으로 확산되고 있는 고등학생들의 연구 활동 참여에 대한 심층적 이해를 제공함과 동시에, 학생들이 스스로의 탐구 활동에서 진정한 주체로 자리매김 할 수 있도록 지원하고자 하는 많은 교육 연구자들에게 그 방향성 수립을 위한 단초를 제공할 수 있을 것이다.