• 생명과학회지
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• 제32권9호
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• pp.734-741
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• 2022

전세계적으로 약 4천만 명의 사람들이 인체면역결핍증바이러스(HIV) 감염이 되어 있으며, HIV에 감염된 세포의 수가 치명적인 수준에 다르면 후천성면역결핍증후군을 일으키게 된다. HIV에 감염이 되면 완치 치료가 어려우며 현재 알려진 치료방법으로는 감염, 복제 및 바이러스 방출 억제를 위해 항레트로 바이러스 치료법이 병용되고 있다. 하지만 HIV 바이러스는 지속적인 돌연변이 유발 및 약물에 대한 내성을 갖게 하므로 장기간 약물복용 시 심각한 부작용을 초래한다. 이에 새로운 치료방법과 효능약물에 대한 연구가 필요한 실정이다. 식물유래 천연물은 수많은 생리활성물질들이 보고되어 있으며, 이는 항HIV 효능 지닌 잠재성을 가진 후보 물질이 될 수 있다. 1990년 세계보건기구에서는 플라보노이드, 쿠마린, 탄닌 및 테르펜의 항 HIV 효능을 보고하였으며, 이러한 물질은 SARS-CoV-2와 같은 바이러스 감염을 또한 억제하는 것으로 밝혀졌다. 따라서, 본 연구에서는 항 HIV 효능을 나타내는 식물 추출물 및 파이토케미컬에 대한 최신 연구동향(2021-현재)을 검토하였으며, 이를 통해 항HIV 효능을 지닌 새로운 천연물 발굴의 기초자료로 활용될 것으로 사료된다.

• 멤브레인
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• 제32권5호
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• pp.283-291
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• 2022

재생에너지의 보급과 기후변화를 대응하기 위한 해결책으로 수소에너지에 대한 관심이 늘어나고 있다. 수소는 미이용 전력을 대용량 장주기로 저장하기에 가장 적합한 수단이며 이러한 수소를 생산하는 기술 중 수전해는 물에 전기에너지를 인가하여 수소를 생산하는 친환경적 수소생산 기술로 알려져 있다. 수전해의 구성 요소 중 분리막은 음극과 양극을 물리적으로 분리할 뿐만 아니라 생성되는 수소와 산소의 섞임 현상을 방지하며 이온의 전달을 가능하게 하는 복합적인 역할을 수행한다. 특히 기존의 수전해 기술들의 단점을 보완할 수 있는 차세대 음이온 교환막 수전해에서의 핵심은 우수한 음이온 교환막을 확보하는 것이다. 높은 이온 전도성과 알칼리 환경에서 우수한 내구성을 동시에 가지려는 많은 연구들이 진행되고 있으며 다양한 소재에 대한 탐색이 이루어지고 있다. 본 총설에서는 상용 블록 공중합체인 Polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS)를 기반으로 하는 음이온 교환막에 대한 연구에 대해 살펴보며 최신 연구 동향과 앞으로 나아가야할 점에 대해 논하고자 한다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.124-124
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• 2003

The successful development of embryos cloned by nuclear transfer (NT)have been dependent on a wide range of known factors including cell cycle of donor and recipient ooplast, oocyte quality, NT procedure and oocyte activation. The present study compared the development of cloned porcine embryos following different activation treatments. Cumulus-oocyte complexes (COCs) were aspirated from 26 mm follicles of slaughterhouse ovaries and cultured for 22 h in NCSU #23 medium supplemented with 10% porcine follicular fluid, 0.57 mM cysteine, 0.5 g/mL LH, 0.5 g/mL FSH and 10 ng/mL EGF. The COCs were further cultured for an additional 22 h in the same medium at $39{\cird}C$ in an atmosphere of 5% $CO_2$ in air, without hormonal supplements. Primary cultures of fibroblasts isolated from a female fetus on day 40 of gestation were established in DMEM + 15% FCS. For nuclear donation, cells at the 5th-6th passage were cultured in DMEM +0.5% FCS for 5 days in order to arrest the cells in G0/Gl. After enucleation, oocytes were reconstructed by transfer of donor cells and fusion with three DC pulses (1.4 KV/cm, 30 sec) in 0.28 M mannitol containing 0.01 mM $CaCl_2$ and 0.01 mM $MgCl_2$. Eggs were then divided into three treatment groups, control (without further treatment, Group 1), eggs cultured in 10 g/ml cycloheximide (CHX) for 5 h (Group 2), and eggs cultured in 1.9 mM 6-dimethylaminopurine (6-DMAP) for 5 h (Group 3). The eggs were then cultured in sets of 30 in 60 I drops of NCSU#23 supplemented with 4mg/ml BSA (essentially fatty acid free) until day 7 at $39{\circ}C$ in a humidified atmosphere of 5% $CO_2$. On day 4 the culture were fed by adding 20 I NCSU #23 supplemented with 10% FBS. Development rates into blastocysts were significantly higher (P<0.05) in Group 3 embryos compared to Group 1 controls ($27.6 \mu 2.7% vs. 20.1 \mu 4.1%$, respectively), but rates did not differ in Group 2 compared to control ($23.8 \mu 5.7%$). Total cell number in Group 3 blastocysts was however significantly higher (P<0.05) than in Groups 1 and 2 ($44.6 \mu 2.4 vs. 19.9 \mu 1.9 and 21.9 \mu 2.1$, respectively). These results suggest that 6-DMAP is more efficient than cycloheximide in the activation of electrically fused NT oocytes during in vitro production of cloned porcine embryos.

• Ocean and Polar Research
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• 제45권3호
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• pp.141-153
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• 2023

Biological pump processes generated by diatom production in the surface water of the Southern Ocean play an important role in exchanging CO₂ gas between the atmosphere and ocean. In this study, the biogenic opal content of the sediments was measured to elucidate the variation in the primary production of diatoms in the surface water of the Southern Ocean since the last glacial period. A piston core (COR-1bPC) was collected from the Conrad Rise, which is located in the Indian sector of the Southern Ocean. The sediments were mainly composed of siliceous ooze, and sediment lightness increased and magnetic susceptibility decreased in an upward direction. The biogenic opal content was low (38.9%) during the last glacial period and high (73.4%) during the Holocene, showing a similar variation to that of Antarctic ice core ΔT and CO₂ concentration. In addition, the variation of biogenic opal content in core COR-1bPC is consistent with previous results reported in the Antarctic Zone, south of the Antarctic Polar Front, in the Southern Ocean. The glacial-interglacial biogenic opal production was influenced by the extent of sea ice coverage and degree of water column stability. During the last glacial period, the diatom production was reduced due to the penetration of light being limited in the euphotic zone by the extended sea ice coverage caused by the lowered seawater temperature. In addition, the formation of a strong thermocline in more extensive areas of sea ice coverage led to stronger water column stability, resulting in reduced diatom production due to the reduction in the supply of nutrient-rich subsurface water caused by a decrease in upwelling intensity. Under such environmental circumstances, diatom productivity decreased in the Antarctic Zone during the last glacial period, but the biogenic opal content increased rapidly under warming conditions with the onset of deglaciation.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.58-61
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• 2023

PEMFC(Proton Exchange Membrane Fuel Cells)는 초기 성능향상을 위해 활성화(Activation) 과정이 필수적이다. 제일 많이 사용되는 활성화 방법은 전압변화(부하변화) 방법으로 과잉으로 진행될 경우 전극 촉매 열화를 동반할 수 있다. 많은 활성화 과정에서 전압변화 범위를 0.4 V에서 OCV 까지 넓은 범위에서 활성화를 진행시키는데 전극 촉매 열화 방지와 활성화 시간을 단축시키기 위해 전압변화 범위를 감소시키는 연구가 필요하다. 그래서 본 연구에서는 활성화 전압범위를 0.4~0.6 V, 0.4~0.8 V, 0.4~OCV로 했을 때 성능과 전극, 고분자막의 특성 변화를 분석해 효과적인 활성화 방법을 연구개발하고자 하였다. 0.4 V에서 제일 높은 OCV 까지 전압 범위를 넓힌 활성화에서 성능 향상도 제일 낮고 56 사이클 활성화 했을 때 활성화 전보다 오히려 성능이 10% 감소했다. 0.4~0.6 V 활성화 사이클에 의해 성능이 최고 20%까지 제일 높게 향상되고 과잉 활성화에 의한 성능 감소도 제일 작아서 최적 임을 보였다.

• 한국프랜차이즈경영연구
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• 제8권4호
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• pp.43-54
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• 2017

Purpose - Recently, the meaning and importance of entrepreneurship has been emphasized in order to achieve innovation-led economic growth through entrepreneurship. Various forms of entrepreneurship education have been established centering on universities, and the scale of the entrepreneurship support programs of the government and the private sector has been increasing. Entrepreneurial education can enhance entrepreneurship and promote entrepreneurial intention. The purpose of this study is to examine the effect of experience of entrepreneuship education and social awareness of entrepreneurship on entrepreneurial intention through entrepreneurship, focusing on women who were relatively alienated from entrepreneurial activities. This study will provide suggestions for women's entrepreneurship in the future. Research design, data, and methodology - Recently, the meaning and importance of entrepreneurship has been emphasized in order to achieve innovation-led economic growth through entrepreneurship. Various forms of entrepreneurship education have been established centering on universities, and the scale of the entrepreneurship support programs of the government and the private sector has been increasing. Entrepreneurial education can enhance entrepreneurship and promote entrepreneurial intention. The purpose of this study is to examine the effect of experience of entrepreneuship education and social awareness of entrepreneurship on entrepreneurial intention through entrepreneurship, focusing on women who were relatively alienated from entrepreneurial activities. This study will provide suggestions for women's entrepreneurship in the future. Result - Recently, the meaning and importance of entrepreneurship has been emphasized in order to achieve innovation-led economic growth through entrepreneurship. Various forms of entrepreneurship education have been established centering on universities, and the scale of the entrepreneurship support programs of the government and the private sector has been increasing. Entrepreneurial education can enhance entrepreneurship and promote entrepreneurial intention. The purpose of this study is to examine the effect of experience of entrepreneuship education and social awareness of entrepreneurship on entrepreneurial intention through entrepreneurship, focusing on women who were relatively alienated from entrepreneurial activities. This study will provide suggestions for women's entrepreneurship in the future. Conclusions - Although women's economic activity is increasing, women's activities in the field of business start-up are still passive. The purpose of this study is to examine the effect of entrepreneurship on entrepreneuship education and the social perception of entrepreneurship. As a result, we found that social awareness, entrepreneurship education, and entrepreneurship all had a significant influence on the intention of entrepreneurship. Positive social atmosphere for entrepreneurship induces interest in entrepreneurship education and forms a virtuous cycle structure that fosters entrepreneurship through entrepreneuship education. In addition, the introduction of diverse programs that encourage entrepreneurship should enhance the attractiveness of promising talent to enter the entrepreneurial market.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권spc호
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• pp.40-54
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• 2023

산업혁명 이후 화석연료의 광범위한 사용, 삼림 벌채, 토지사용의 변화 등과 같은 인위적 활동은 대기 중 온실가스(GHGs, greenhouse gases) 농도를 지속적으로 증가시켜 지구의 기후위기를 유발하였다. 우리나라의 경우 최근 30년 사이 평균 온도가 1.4℃ 상승하였으며, 국제사회의 일원으로 책임을 다하기 위해 2016년 11월 3일 파리협정을 비준하였다. 이에 파리협정의 목표인 산업화 이전 대비 지구 평균온도 상승을 2℃ 아래, 가능한 1.5℃ 아래로 억제하기 위해 2050년까지 CO₂ 순배출량을 0으로 만들어야 하며, 이를 위해 다양한 정책 마련과 함께 경제 및 사회 전반에 걸쳐 많은 노력이 경주되고 있는 실정이다. 탄소중립을 달성하기 위해서는 첫 번째로 GHGs 배출을 줄이고, 두번째로 대기에서 CO₂ 포집을 촉진하기 위해 현재 가동되는 다양한 산업분야의 생산 시스템을 개혁하는 것이 가장 중요한 과제로 고려되고 있다. 그동안 지하수토양 관련 연구분야에서는 지속가능성(sustainability), 복원성(resilience), 녹색성장(green growth) 등과 같은 사회적 요구에 부응하여, 녹색정화(green remediation), 자연 저감(natural attenuation), 탄소포집저장(carbon capture and sequestration), 지열발전등의 기술이 초기단계로 개발이 되고 연구가 되어 왔다. 이러한 기존 연구들은 탄소중립2050의 달성을 위해 고도화되어야하며, 추가적으로 자연 및 인위기원 탄소배출 연구, 토양의 역할을 고려한 저탄소 토지이용 기술, 광물탄산화 등의 연구 및 기술개발이 필요하다고 판단된다. 본 논문에서는 탄소중립2050의 간단한 내용과 함께, 이를 달성하기 위한 지하수토양 분야의 혁신기술 및 선도연구를 소개하였다.

• Journal of Veterinary Science
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• 제25권1호
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• pp.15.1-15.15
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• 2024

Background: The anti-programmed death 1 (PD-1) antibody has led to durable clinical responses in a wide variety of human tumors. We have previously developed the caninized anti-canine PD-1 antibody (ca-4F12-E6) and evaluated its therapeutic properties in dogs with advance-staged oral malignant melanoma (OMM), however, their therapeutic effects on other types of canine tumors remain unclear. Objective: The present clinical study was carried out to evaluate the safety profile and clinical efficacy of ca-4F12-E6 in dogs with advanced solid tumors except for OMM. Methods: Thirty-eight dogs with non-OMM solid tumors were enrolled prospectively and treated with ca-4F12-E6 at 3 mg/kg every 2 weeks of each 10-week treatment cycle. Adverse events (AEs) and treatment efficacy were graded based on the criteria established by the Veterinary Cooperative Oncology Group. Results: One dog was withdrawn, and thirty-seven dogs were evaluated for the safety and efficacy of ca-4F12-E6. Treatment-related AEs of any grade occurred in 13 out of 37 cases (35.1%). Two dogs with sterile nodular panniculitis and one with myasthenia gravis and hypothyroidism were suspected of immune-related AEs. In 30 out of 37 dogs that had target tumor lesions, the overall response and clinical benefit rates were 6.9% and 27.6%, respectively. The median progression-free survival and overall survival time were 70 days and 215 days, respectively. Conclusions: The present study demonstrated that ca-4F12-E6 was well-tolerated in non-OMM dogs, with a small number of cases showing objective responses. This provides evidence supporting large-scale clinical trials of anti-PD-1 antibody therapy in dogs.

• 한국지역지리학회지
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• 제2권1호
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• pp.133-150
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• 1996

농촌의 최하위 계층 중심지에 발달한 정기시의 이동상인과 소비자의 공간적 특성을 파악하기 위하여 오래 전부터 개시(開市)된 옥천군 청산 정기시를 대상으로 출시자를 조사하여 분석한 결과 다음과 같은 점이 밝혀졌다. 이동상인은 장년 내지 노년층으로 구성되어 있으며, 일용잡화와 농산물을 취급하고, 정기시 출시(出市)의 주된 유형은 청산$\rightarrow$원남$\rightarrow$보온의 유형과 청산$\rightarrow$영동$\rightarrow$용산의 유형이다. 상인의 거주지는 정기시가 입지한 지역이 가장 많고 이어서 인접해 있는 하위 중심지인 청성면, 상위계층 중심지인 보은 영동읍과 대전시, 그리고 보은군 원남면으로, 이들은 정기시를 매일 자기 집에서 5일에 3일 이상 출시하거나 특정한 하나의 정기시만을 5일에 하루 출시하는 형태를 취하고 있다. 정기시를 이용하는 소비자는 $30{\sim}50$대가 대부분이고, 한달에 $2{\sim}6$회 정기시에서 재화를 구입하며, 이용하는 교통수단은 주로 버스이다. 그리고 생활필수품을 구입하기 위하여 출시하는데, 구입하는 상품은 주로 식료품이고 전문계도 고차 중심지보다 이 지역의 상위 중심지인 청산에서 구입하는데 이는 타 지역과 교통이 불편하고 거리도 밀어 상품을 구입할 매 비용이 추가되며, 상품을 구입한 후에도 아프터서비스를 받는데에도 불리하기 때문이다. 그러나 청산 정기시에서 구입하지 못하는 선매재나 전문재는 거리가 가까운 보은읍보다는 상위 중심지인 영동읍이나 대전시에서 구입하고 있다. 최하위 중심지의 정기시는 농촌인구의 감소, 주민의 소득증대와 생활수준의 향상, 중심지의 상설 상업시설의 등장, 유통기구의 변화, 교통기관의 발달 등 정기시의 외적 환경들이 변화됨에 따라 이동상인의 출시형태가 변화되었으나 상대적으로 교통이 불편한 지역의 소비자는 편의(便宜) 선매재(選買財)뿐만 아니라 전문재(專門財)도 최저차 중심지에서 많이 구입하고 있다는 점이 밝혀졌다.

• Journal of Ecology and Environment
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• 제42권4호
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• pp.210-218
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• 2018

Background: Soil respiration (Rs) is a major factor of the absorption and accumulation of carbon through photosynthesis in the ecosystem carbon cycle. This directly affects the amount of net ecosystem productivity, which affects the stability and sustainability of the ecosystem. Understanding the characteristics of Rs is indispensable to scientifically understand the carbon cycle of ecosystems. It is very important to study Rs characteristics through analysis of environmental factors closely related to Rs. Rs is affected by various environmental factors, such as temperature, precipitation, soil moisture, litter supply, organic matter content, dominant plant species, and soil disturbance. This study was conducted to analyze the effects of micro-topographical differences on Rs in forest vegetation by measuring the Rs on the ridge and southern slope sites of the broadly established Quercus mongolica forest in the central Korean area. Method: Rs, Ts, and soil moisture data were collected at the southern slope and ridge of the Q. mongolica forest in the Mt. Jeombong area in order to investigate the effects of topographical differences on Rs. Rs was collected by the closed chamber method, and data collection was performed from May 2011 to October 2013, except Winter seasons from November to April or May. For collecting the raw data of Rs in the field, acrylic collars were placed at the ridge and southern slope of the forest. The accumulated surface litter and the soil organic matter content (SOMC) were measured to a 5 cm depth. Based on these data, the Rs characteristics of the slope and ridge were analyzed. Results: Rs showed a distinct seasonal variation pattern in both the ridge and southern slope sites. In addition, Rs showed a distinct seasonal variation with high and low Ts changes. The average Rs measurements for the two sites, except for the Winter periods that were not measured, were $550.1\;mg\;CO_2m^{-2}h^{-1}$ at the ridge site and $289.4\;mg\;CO_2m^{-2}h^{-1}$ at the southern slope, a difference of 52.6%. There was no significant difference in the Rs difference between slopes except for the first half of 2013, and both sites showed a tendency to increase exponentially as Ts increased. In addition, although the correlation is low, the difference in Rs between sites tended to increase as Ts increased. SMC showed a large fluctuation at the southern slope site relative to the ridge site, as while it was very low in 2013, it was high in 2011 and 2012. The accumulated litter of the soil surface and the SOMC at the depth range of 0~5 cm were $874g\;m^{-2}$ and 23.3% at the ridge site, and $396g\;m^{-2}$ and 19.9% at the southern slope site. Conclusions: In this study, Rs was measured for the ridge and southern slope sites, which have two different results where the surface litter layer is disturbed by strong winds. The southern slope site shows that the litter layer formed in autumn due to strong winds almost disappeared, and while in the ridge site, it became thick due to the transfer of litter from the southern slope site. The mean Rs was about two times higher in the ridge site compared to that in the southern slope site. The Rs difference seems to be due to the difference in the amount of litter accumulated on the soil surface. As a result, the litter layer supplied to the soil surface is disturbed due to the micro-topographical difference, as the slope and the change of the community structure due to the plant season cause heterogeneity of the litter layer development, which in turn affects SMC and Rs. Therefore, it is necessary to introduce and understand these micro-topographical features and mechanisms when quantifying and analyzing the Rs of an ecosystem.