To improve the etch rate of Si3N4 thin film, H2SiF6 is added to increase etching rate by more than two times. SiO3H2 is gradually added to obtain a selectivity of 170: 1 at 600 ppm. Moreover, when SiO3H2 is added, the etching rate of the SiO2 thin film increases in proportion to the radius of the wafer. In Si3N4 thin film, there is no difference in the etching rate according to the position. However, in the SiO2 thin film, the etching rate increases in proportion to the radius. At the center of the wafer, the re-growth phenomenon is confirmed at a specific concentration or above. The difference in etch rates of SiO2 thin films and the reason for regrowth at these positions are interpreted as the result of the flow rate of the chemical solution replaced with fresh solution.

일반적으로 세포·조직 및 장기이식 성공 예측은 수여자와 공여자간의 백혈구항원 일치도이고, 불일치 시 심각한 거부 반응을 유발함으로 세포치료제로 사용할 때 우선적으로 백혈구 항원일치도가 고려된다. 그러나 중간엽줄기세포(Mesenchymal Stem Cells, MSCs)는 다른 체세포와 비교하여 상대적으로 낮은 MHC I 항원발현과, 극히 낮은 MHC II 항원을 가지고 있으므로 동종세포치료제로서 주목을 받고 있다. 따라서 본 연구에서는 개 모델에서 MSCs 의 동종세포치료제로서 효능을 예측하기 위해 선행연구로 백혈구 항원(Dog Leukocyte Antigen, DLA)형 및 가계도내 일치도와 유전적다형성(Polymorphism) 을 분석하였다. DLA 분석을 위해 한가계도의 비글(Covance Beagles) 4 두(모견 1 두, 자견 3 두)로 부터 전혈을 채취하고, 밀도구배를 이용하여 백혈구만을 분리 후 DNA들을 각각 추출하였다. DLA 분석은 ClassII 유전자(DLA-DQA, DLA-DQB, DLA-DRB)에서 엑손 2 영역(약 300bp)을 증폭하고 Direct Sequencing 을 통해 밝혀진 염기서열을 NCBI Blast 와 IPD(Immuno Polymorphism Database)를 기반으로 하여 Universal nomenclature 에 따라 유전자형을 판독 하였다. 그 결과 DLA-DQA(022:01/022:01)와 DLA-DQB(107:01/102:01)는 4마리 모두 유전자형이 동일하였으나, DLA-DQB 는 각각 046:01/022:02, 03701/022:02, 00201/022:02, 03701/022:02 로 차이를 보였다. 이 결과를 통해 모견과 자견이 공통적으로 가지는 일배체형(Haplotype)은 DLA–DQA*022:01, DLA-DQB*022:02, DLA-DRB*102:01 이었음을 확인할 수 있었다. 그리고 일부 유전자의 염기서열에서 99% 유사도를 보이는 후보군들이 4 개씩 검색되었는데 이는 단일염기다형성(SNP)에 기인한 유전적다형성(Polymorphism)이 매우 높다는 선행보고들과 유사한 결과를 보였다. 본 실험결과는 향후 DLA 의 일치군과 비 일치군의 개중간엽줄기세포와 말초혈액단핵구세포(PBMC)들의 공배양을 통해 동종세포치료제 연구에 사용될 예정이다. * 본 성과물은 농촌진흥청 반려동물 연구사업(세부과제명 : 반려견에서 DLA 일치하는 줄기세포의 체외 치료능 평가, 세부과제 번호 : PJ013957022018)의 지원에 의해 이루어짐.

Somatic cell nuclear transfer (SCNT) is a useful biotechnological tool for animal cloning. Until now, SCNT has been inefficient, especially in dog. It is believed that an embryo developmental block in SCNT embryos is cause of low production efficiency. However, no studies have been performed on canines for embryo developmental block. In this study, we attempted to evaluate the beneficial role of EDTA in canine parthenogenic (PA) embryos development to overcome embryo developmental block. The PA embryos were divided into 0.01 mM EDTA treated and non-treated groups. Embryo developmental efficiency was measured by activating chemically parthenote. After EDTA induction, PA embryos were evaluated for embryonic development, Reactive Oxygen Species (ROS) activity, mitochondrial integrity, ATP production and genomic activation. The EDTA treated PA embryos showed significantly higher survival rate and improved cavity formation compared to non-treated. Furthermore, cytoplasmic ROS level was mitigated and mitochondrial membrane potential was found significantly higher in EDTA treated group followed by higher ATP production. Moreover, major embryonic genomic activation specific markers/factors were also elevated in EDTA treated group. Conclusively, we elucidated that EDTA showed substantially positive effect to overcome embryo developmental block in canine.

구상나무(Abies Koreana Wilson)는 우리나라 특산종으로, 멸종위기에 처해있다. 따라서, 본 연구는 기후변화 생물지표수종으로 지정되어 점차 쇠퇴해가는 구상나무의 효율적인 증식을 위해 종자를 활용한 증식기술개발을 목적으로 수행되었다. 4개의 집단으로부터 구상나무 종자를 채집하고 집단간 종자 및 발 아특성에 대하여 기외와 기내로 나누어 조사하였다. 기외에서는 벽소령 004818과 004825종자가 21일부 터 최초 발아를 시작하였으며 기내의 경우 노고단 004696종자와 벽소령 004818종자가 8일부터 최초 발 아하였다. 기외에서 가장 높은 종자의 발아율은 벽소령 004825종자가 48.5%로, 가장 낮은 종자의 발아 율은 덕유산 004703종자가 0.5%로 조사되었으며, 기내에서는 돼지평전 004694종자가 36%로, 덕유산 004703종자가 0.7%로 조사되었다. 그 결과, 같은 종자임에도 기외와 기내에서의 종자 발아율에 차이를 나타내는 것을 확인하였고, 종자의 중량과 형태는 발아율과 무관한 것으로 나타났다.

The game industry, which has been rapidly developing these days in Korean society, is a socially debated issue for the fact that some games are allegedly likely to stir up a speculative drive in people. Among others, the speculativeness of games has been paid more attention by game developers because of the prevalent belief in Korean society that basically games are gambling, which has been more consolidated by reported illegal activities committed by some users of illegal games. More disturbingly, if regulations are put on the act of gaming, not on some speculative games, the nature of games could be distorted and an unexpected adverse effect would arise as a result. This study examines the appropriateness and the effect of the current game regulation from a perspective of game developers and investigates how the regulation and its operation affect the change of the nature of games. The findings of this study are expected to bring about the deeper exploration of the effect of game regulation and broaden the view on the Korean game industry.

Tissue engineering (TE) has been developed to create functional organs and tissue by combining 3D matrix and cells in vitro. Vascularization and angiogenesis are utmost important for supply of nutrients and oxygen in tissue engineered organs. The present study was performed to isolate and characterize primary endothelial cells (EC) from aorta of alpha 1, 3-enzyme galactosyltransferase knock out (GalT KO) pig, to minimize immune rejection and analyze body immune system for future xenotransplantation studies. Isolation of primary EC from aorta were performed by incubation with dispase for 8-10 min at 37°C. Primary EC were cultured in EC growth medium on different extra cellular matrix (ECM), either collagen or gelation. Primary EC exhibits morphological characteristics and showed positive expressions of EC specific marker proteins i.e. PECAM1, KDR and VWF despite of their ECM surface; however, on collagen based surface they showed increase in mRNA level analyzed by qPCR. Primary EC cultured on collagen were sorted by flow cytometer using KDR marker and cultured as KDR positive cells and KDR negative cells, respectively. KDR positive cells showed dramatically increased in PECAM1 and VWF level as compared to KDR negative cells. Based on the above results, primary EC derived from GalT KO are successfully isolated and survived continuously in culture without becoming overgrown by fibroblast. Therefore, they can be utilize for xeno organ transfer, tissue engineering, and immune rejection study in future.

For enhanced cavitation erosion resistance of vessel propellers, an electroless Ni-P plating method was introduced to form a coating layer with high hardness on the surface of Cu alloy (CAC703C) used as vessel propeller material. An electroless Ni-P plating reaction generated by Fe atoms in the Cu alloy occurred, forming a uniform amorphous layer with P content of ~10 wt%. The amorphous layer transformed to (Ni3P+Ni) two phase structure after heat treatment. Cavitation erosion tests following the ASTM G-32 standard were carried out to relate the microstructural changes by heat treatment and the cavitation erosion resistance in distilled water and 3.5 wt% NaCl solutions. It was possible to obtain excellent cavitation erosion resistance through careful microstructural control of the coating layer, demonstrating that this electroless Ni-P plating process is a viable coating process for the enhancement of the cavitation erosion resistance of vessel propellers.

Polyethersulfone (PES) 고분자 상변환막의 성능을 향상시키기 위해 PES 고분자에 나노 크기의 ZnO 무기입자를 함침시킨 혼합기질막(mixed matrix membrane)을 제조하고 특성을 평가하였다. PES-ZnO 혼합기질막은 ZnO 나노입자를 PES 대비 최대 0.375 wt%의 낮은 비율로 첨가시킨 PES-ZnO-NMP(N-methyl-1-pyrrolidone)로 이루어진 캐스팅 용액을 사용하여 상변환법을 통해 제조하였다. 제조된 혼합기질 막의 물성과 특성은 막의 단면구조 관찰, 접촉각 측정, 인장강도 측정, 순수 투과량 측정 및 BSA 단백질 용액의 한외여과 실험을 통해 평가하였다. 이 결과 혼합기질 막은 PES 고분자 matrix에 함유된 ZnO 나노입자로 인해 막의 친수성이 증가하여 막오염 발생이 억제되어 투과량이 증가하였다. ZnO 나노입자는 혼합기질막의 제조에 있어 막오염의 발생 억제와 투과량 증가에 유용하게 사용될 수 있는 무기물 첨가제임을 알 수 있다.

나노섬유는 기존 합성 섬유와 비교하여 섬유의 직경을 획기적으로 줄여줌으로써 표면적을 비약적으로 향상시킬 수 있어 각종 필터 및 분리막, 전자 기기의 벤 트용 소재, 투습방수용 의류 등 산업 전 분야에 적용이 시도되고 있는 소재이다. 전기방사 기술은 섬유의 직경과 세공 등 물성과 성능을 쉽게 설계, 적용할 수 있어 고품질, 고성능의 멤브레인을 제공하고 있으나, 경제성을 갖춘 양산규모의 전기방사 기술이 어려워 긴 역사에 비해 기술적 성취도는 매우 낮은 상태이며, 부직포 타입으로 인해 응용분야의 한계가 있었다. 최근, 나노섬유를 장섬유 섬 유사로 개발하여 다양한 분야에 적용을 시도하려는 연구가 활발하게 진행되고 있다. 본 고에서는 다양한 나노섬유 양산화 기술 동향과 응용분야, 나노섬유 기반 장섬유 섬유사를 제조하는 최신 기술동향에 대해서 소개하고자 한다.

The purpose of this paper is to check the Game Rating and Administration Committee(GRAC), established in 2013 as revision of law to the Game Industry Promotion Act, restricts the freedom of expression. Game Rating system in Korea is not formed spontaneously in the market, unlike oversea, the Government has designed public systems. The GRAC has classified only “Rating”, but it regulates the expressions of the Game and gaming industry itself by other than raising rating. In cases the GRAC issued decisions of rating rejection are suspected to be in mistake in the interpretation of relevant laws, resulting in expressions of the game is limited. The content modification notifying system has unclear criteria, and it regulates not the contents of the game but the ways of using games. It is contrary to the principle of the content centrality of rating, and Operators have to impose self-censorship when they change game contents.

We selected lactic acid bacteria to reduce cholesterol levels in vitro and in vivo. Among the 140 strains tested, a strain ID9201 was shown to reduce cholesterol in the spent medium over 30% and to increase cholesterol in cell pellet. A strain ID9201 isolated from breast milk-fed Korean infant feces was identified as Enterococcus faecium on the basis of morphological analysis, biochemical analysis (API kit), and 16S rDNA sequence analysis. A freeze-dried powder of the strain was fed to Sprague-Dawley(SD) rats with high cholesterol diet for 6 wk. In the control group fed cholesterol enriched diet without probiotics, the serum cholesterol increased by 1.9 times in comparison with the initial value. Among the test group, ID9201 group showed the lowest cholesterol increase, 1.5 times of initial serum cholesterol, as in the blank group fed normal diet without probiotics. Based on these data, we assumed that ID9201 inhibited intestinal absorption of dietary cholesterol.

혼합매질 막의 제조에 널리 사용되고 있는 TiO2 나노입자의 대안으로서 ZnO 나노입자가 혼합된 Polyethersulfone(PES) 막을 제조하고 특성을 평가하였다. ZnO는 TiO2에 상응하는 기능적 특성을 갖고 있으면서도 가격이 낮다는 장점이 있어 혼합매질 막의 제조에 활용이 가능할 것으로 예상된다. 본 연구에서는 N-methyl pyrrolidone(NMP)를 용매로 사용하여 각기 다른 농도의 PES 용액에 낮은 비율로 ZnO 나노입자를 혼합시켜 침지침강에 의한 상변환법을 사용하여 혼합매질 막을 제조한 후 표면 및 단면 관찰, 접촉각 측정, 여과/막오염 특성, 그리고 인장 강도를 측정하여 특성을 평가하였다. 그 결과 낮은 비율의 ZnO 나노입자로 순수 투과도와 막오염 정도를 충분히 개선할 수 있었다.

본 연구는 한국과 정치적, 사회·경제적, 문화적으로 깊은 연관을 지닌 베트남에 관해 학생들이 다양한 활동을 함으로써 미래지향적인 글로벌 시민의식을 함양하는 과정에 초점을 두고 연구를 진행하였다. 기 한국의 미래 사회를 짊어지고 갈 우리 청소년들이 한·베 간의 긍정적인 상호 관계를 이해하고 실천할 수 있는 인재가 될 수 있도록 지도하였다. 본 연구는, 먼저 베트남 및 한·베 관계 이해 활동, 다음으로 다양성과 상호 존중 이해 활동, 미래지향적 세계관 확립 활동, 나눔과 배려 실천 활동, 베트남어 교수·학습 활동으로 진행되었다. 학생들은 자기주도적인 조사·발표 활동들을 통해 한·베 관계 이해의 필요성을 스스로 인식하였고, 또한 미래지향적인 글로벌 시민의식을 함양할 수 있었다.

Since the conventional methods of physical therapy may decrease the motivation of a patient for rehabilitation due to repetitive, monotonous movement, a new physical therapy system inducing a motivation from the patient is needed. The present study is intended to develop a physical therapy serious game for enhancement of dynamic balance control. The balance control therapy game was developed by the following steps: (1) survey of existing balance control therapy systems, (2) analysis of balance control literature, (3) ideation and architecture planning of the balance control therapy game, and (4) implementation of the balance control therapy game. The proposed physical therapy serious game can provide better usability, satisfaction, clinical effectiveness for balance control than the conventional methods.

Kegel exercise is commonly prescribed to improve the urination and evacuation capabilities of a patient. Assistive devices developed for Kegel exercise are found limited in terms of clinical effectiveness and motivation. The present study is intended to develop a serious game to support active and sustainable Kegel exercise for patients. A four-step process (benchmarking, analysis of patent and technology, ideation of hardware and software, and implementation) is applied in the present study to development of a Kegel serious game. The proposed serious game for active Kegel exercise needs to be validated in urology clinics.

Although motivation and fun are important for effective speech therapy, the conventional speech therapy is often conducted by using a textbook which can be boring to the speech-handicapped. The present study is to develop a speech therapy serious game for rehabilitation of the handicapped with articulation and fluency in speech. A speech therapy game was developed in the present study through the following four-step approach: (1) benchmarking analysis of 8 speech therapy systems, (2) analysis of 22 parents, (3) development of the framework of the speech therapy game and ideas for speech therapy game contents, and (4) implementation of the speech therapy serious game system using C# and the game engine Unity. The speech therapy serous game developed in the study can be of help for rehabilitation of articulation and fluency for the speech-handicapped.

The purpose of this study was to investigate the performance of new hollow reinforced concrete (RC) bridge pier sections with triangular reinforcement details. The proposed triangular reinforcement details are economically feasible and rational and facilitate shorter construction periods. A model of pier sections with triangular reinforcement details was tested under quasi-static monotonic loading. As a result, proposed triangular reinforcement details was equal to existing reinforcement details in terms of required performance. In the companion paper, the parametric study for the performance assessment of new hollow RC bridge pier sections with triangular reinforcement details is performed.