• 융합정보논문지
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• 제10권6호
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• pp.164-176
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• 2020

인체 적응 면역 반응을 일으키는데 중요한 항원 특이적 T 세포를 활용한 면역 세포 치료에서 T 세포를 체외에서 배양하고 클론 확장시키는 과정은 매우 섬세하고 복잡하여 조절하기가 쉽지 않아 T 세포의 활성화와 클론 확장을 유도하면서도 조절 및 취급이 용이한 인공 항원제시세포 개발의 필요성이 대두되고 있다. 인공 항원제시세포는 인체의 항원제시세포의 세포 표면 분자와 작용을 모방하게 되는데, 기본적인 신호 분자인 MHC-항원 복합체, 공동 자극 분자, 그리고 용해성 면역 조절 분자를 필수적으로 발현하여야 한다. 또한 T 세포가 항원과 접촉할 때, 이들 분자들이 잘 조직화되어 작용하는 것이 효과적인 T 세포 활성화에 중요하다. 본 논문에서는 여러 인공 항원제시세포 제작 방법과 세포 표면 분자들의 결합 방법과 물리적인 특성이 T 세포와의 상호작용에 중요함을 고찰하였으며, 효과적인 T 세포 활성화를 유도하며 면역세포치료에 적용 가능한 인공항원제세세포의 제작 방법을 살펴보았다.

• Biomolecules & Therapeutics
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• 제12권1호
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• pp.1-8
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• 2004

In chronic airway inflammatory diseases such as asthma and chronic bronchitis, it has been suggested that matrix metalloproteinases secreted from infiltrating neutrophil contribute the pathogenesis of the disease and have been a focus of intense investigation. We report here that hamster tracheal surface epithelial goblet cells (HTSE cells) produce matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2). Matrix metalloproteinase activities were investigated using [$^3H$]collagen-digestion assay and gelatin zymography. The subtype of matrix metalloproteinases expressed from HTSE cells was MMP-2 (gelatinase A), which was determined by Western blot with various subtype selective anti-matrix metalloproteinase antibodies. The MMP-2 and TIMP-2 cDNAs from HTSE cells were partially cloned by RT-PCR and they reveal more than 90% of sequence homology with those from human, rat and mouse. The collagenolytic activity was increased with the secretory differentiation of the HTSE cell and it was found that zymogen activation was responsible for the increased MMP-2 activity in HTSE cells. The results from the present study suggest that the metaplastic secretory differentiation of airway goblet cells may affect chronic airway inflammatory process by augmenting the zymogen activation of MMP-2.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.333-333
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• 2011

We studied the H/D exchange kinetics of pure and acid dopped water-ice film by using the techniques of reactive ions scattering (RIS) and low energy sputtering (LES) with low kinetic energy cesium ion beam (<35 eV). From RIS, neutral water isotopomers were detected in the form of cesium-molecule ion clusters, $CsX^+$ (X= $H_2O$, HDO, $D_2O$). Ionic species, like $H_3O^+$, $DH_2O^+$, $D_2HO^+$, $D_3O^+$, adsorbed on the surface were ejected via LES process. Those techniques allowed us to trace the isotopomeric populations of water-ice film. To show the catalytic effect of excess proton in the H/D exchange reaction, our study was conducted with two types of water-ice films. In film 1, about 0.5 BL of $H_2O$ was adsorbed on HCl (0.1 ML) dopped $D_2O$ (8 BL) film. In film 2, similar amount of $H_2O$ used in film 1 was adsorbed on pure $D_2O$ film. Kinetic data were obtained from each film type for 90-110 K (film 1) and 110-130 K (film 2) and fitted with numerically integrated lines. Through the Arrhenius plot of kinetic coefficient deduced from fitting of the H/D exchange reaction, the activation energy of film 1 and 2 were estimated to be $10{\pm}3kJmol^{-1}$ and $17{\pm}4kJmol^{-1}$. This activation barrier difference could be understood from detailed pictures of H/D exchange. In film 2, both the formation of ion pair, $H_3O^+$ and OH. and proton transfer were needed for the H/D exchange. However, in film 1, only proton transfer was necessary but ion pair formation was not, so this might reduce the activation energy.

• 원예과학기술지
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• 제32권5호
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• pp.710-720
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• 2014

Movements of the upper and lower limb muscles during five common gardening tasks were analyzed by using electromyography (EMG). Twenty adults aged in their twenties (mean age, $24.8{\pm}2.4$ years) were recruited. On two separate occasions, subjects visited a garden plot to perform digging, raking, troweling, weeding, and hoeing; all tasks were performed three times with 20 s intervals for each trial. To measure muscle activation during the five gardening tasks, surface EMG was used. Bipolar surface EMG electrodes were attached to eight upper limb muscles (bilateral anterior deltoid, biceps brachialis, brachioradialis, and flexor carpi ulnaris) or eight lower limb muscles (bilateral vastus lateralis, vastus medialis, biceps femoris, and gastrocnemius) on both sides of the body, for a total of 16 muscles. During the five tasks, photographs were taken of movement phases using a digital video camera. The right flexor carpi ulnaris and brachioradialis showed higher activation than the other upper and lower limb muscles measured during the tasks. All 16 upper and lower limb muscles were actively used only during digging. According to movement analysis of each activity, digging was classified into four movement phases, whereas raking, troweling, weeding, and hoeing each were divided into three movement phases. In each activity, there were high-impact phases in terms of muscle activation; the flexor carpi ulnaris and brachioradialis were identified as major muscles in each impact phase. This analysis may be used to generate biomechanical profiles of gardening tasks for practitioners when designing efficient gardening interventions for physical health or rehabilitation.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.769-774
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• 2011

NaOH 활성화법을 이용하여 다공성 탄소나노섬유(carbon nanofibers; 이하 CNF)를 온도 범위 700~$900^{\circ}C$에서 합성하였고, 상기 제조된 다공성 CNF를 담지체로 하여 직접메탄올 연료전지의 연료극용 촉매를 제조하고 평가하였다. NaOH 활성화에 의한 CNF 표면 특성의 변화를 비표면적 및 기공 크기 분포 자료를 통하여 조사하였고, 형상 및 구조의 변화를 전자현미경을 통하여 관찰하였다. 활성화 CNF에 담지된 촉매의 활성을 메탄올 산화 특성 및 단위전지를 통하여 평가하였다. 본 활성화 방법에 의한 기공의 형성과 이에 담지된 촉매의 활성과의 관계에 대한 고찰을 하였다.

• 한국진공학회지
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• 제17권6호
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• pp.544-548
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• 2008

반도체 공정에서 가장 많은 시간과 비용을 차지하는 공정 중 하나는 Photoresist strip 공정이다. 따라서 보다 빠르게 PR의 strip 공정을 단축하기 위한 연구가 계속 진행중에 있다. 하지만 기존 사용중인 strip용액을 대체하기 위한 물질을 찾는 것은 많은 비용을 수반한다. 본 연구에서는 PR의 strip 시간을 최대한 단축시키고 PR strip 잔여물의 빠른 제거를 위하여 기존 공정에서 사용 중인 strip 약액을 플라즈마에 의하여 활성화하는 방법(Plasma Liquid-Vapor Activation: PLVA)으로 PR strip 시간을 최대한 줄이는 방법에 대한 연구를 진행하였으며, 활성화된 strip용액이 더욱 빠른 strip율 성능을 나타내는 것을 확인하였다. 또한 PR strip에서 이온에 의한 영향을 받은 HDI-PR (high dose implanted photoresist)은 기존 strip용액으로 제거가 불가능하였다. 하지만 본 연구에서 제시한 PLVA 방법으로 활성화된 용액에서는 그 가능성을 확인하였고, 이러한 PLVA방법에 대한 물리적 연구를 위하여 HDI-PR 표면 내력의 변화를 측정하였다. 그 결과 PLVA 처리 전 후 HDI-PR의 표면 내력에 큰 변화를 확인하였다.

• 한국지반신소재학회논문집
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• 제20권4호
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• pp.33-41
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• 2021

장석은 석영과 더불어 국내에서 산출빈도가 가장 높은 광물이나 유리, 도료 등의 제조에 제한적인 이용을 제외하면 물질적 특성과 용도 개발에 대한 연구는 거의 이루어지지 않아 잠재적 가치가 매우 낮게 평가되고 있다. 본 논문에서는 다공성 구조를 특징으로 하는 장석의 재료특성과 열적, 기계적, 화학적, 경량화 활성기법을 적용하여 반응성 개선 특성을 분석하였다. 풍화된 장석의 표면에서 관찰되는 공동의 구조적 특징을 살펴보면 공동들의 배열이 불규칙하게 분포하고 있으며, 공동끼리는 서로 연결되어 있다. 이러한 풍화된 장석의 표면에서 관찰되는 비정형의 연결된 공동으로 인하여 풍화된 장석은 반응면적이 확대되며 시멘트와의 결합재료로서 반응성이 높은 포졸란 재료 역할을 하는 것으로 판단된다. 다공성 장석의 기능성을 향상시키기 위하여 열적, 기계적, 화학적 활성기법을 적용한 결과 양이온교환능력, 밀도, 일축압축강도 특성이 개선되었다. 이러한 다공성 특성에 의하여 풍화된 장석은 물리·화학적 특성이 우수한 친환경 건설재료로 활용이 가능할 것으로 판단된다.

• 한국환경과학회지
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• 제32권1호
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• pp.57-65
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• 2023

The advanced oxidation treatment using persulfate and zero-valent iron (ZVI) has been evaluated as a very effective technology for remediation of soil and groundwater contamination. However, the high rate of the initial reaction of persulfate with ZVI causes over-consumption of an injected persulfate, and the excessively generated active species show a low transfer rate to the target pollutant. In this study, ZVI was modified using selenium with very low reactivity in the water environment with the aim of controlling the persulfate activation rate by controlling the reactivity of ZVI. Selenium-modified ZVI (Se/ZVI) was confirmed to have a selenium coating on the surface through SEM/EDS analysis, and low reductive reactivity to trichlroethylene (TCE) was observed. As a result of inducing the persulfate activation using the synthesized Se/ZVI, the persulfated consumption rate was greatly reduced, and the decomposition rate of the model contaminant, anisole, was also reduced in proportion. However, the final decomposition efficiency was rather increased, which seems to be the result of preventing persulfate over-consumption. This is because the transfer efficiency of the active species (SO4-∙) of persulfate to the target contaminant has been improved. Selenium on the surface of Se/ZVI was not significantly dissolved even under oxidation conditions by persulfate, and most of it was present in the form of Se/ZVI. It was confirmed that the persulfate activation rate could be controlled by controlling the reactivity of ZVI, which could greatly contribute to the improvement of the persulfate oxidation efficiency.

• 한국대기환경학회지
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• 제31권3호
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• pp.302-314
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• 2015

There is an adsorption method using activated carbon as a typical method for removing elemental mercury. Physical characteristics of activated carbon such as specific surface area and volume of pore (micro and meso) have positive effect for mercury adsorption. Activated carbon is carbon-based material with a high specific surface area. This activated carbon can be manufactured through carbonization and activation process. In this process, physical characteristics of specific surface area and pore distribution are changed by controlling operating parameters like temperature, time and reagent of activation. In this study, we evaluated characteristics of activated carbons manufactured from pinewood and coal with the operating parameters. We evaluated mercury adsorption capacities of the activated carbons having excellent physical characteristics and compared those to the commercial activated carbon.

• 한국수소및신에너지학회논문집
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• 제17권4호
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• pp.418-424
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• 2006

In order to improve the activation properties of the $AB_2$ type hydrogen storage alloys for Ni-MH battery, the alloy surface was modified by employing high energy ball milling. The $Zr_{0.54}Ti_{0.45}V_{0.54}Ni_{0.87}Cr_{0.15}Co_{0.21}Mn_{0.24}$ alloy powder was ball milled for various period by using the high energy ball mill. As the ball milling time increased, activation of the $AB_2$ type composite powder electrodes were enhanced regardless of additives. When the ball milling time was small discharge capacities of the $AB_2$ type composite powder electrodes increased with the milling time. On the other hand for large milling time it decreased with increasing milling time. The maximum discharge capacity was obtained by ball milling for 3-4 min.