고품질 4H-SiC 단결정 성장을 위한 다공성 흑연 판의 역할

이희준,이희태,신희원,박미선,장연숙,이원재,여임규,은태희,김장열,전명철,이시현,김정곤,Lee, Hee-Jun,Lee, Hee-Tae,Shin, Hee-Won,Park, Mi-Seon,Jang, Yeon-Suk,Lee, Won-Jae,Yeo, Im-Gyu,Eun, Tai-Hee,Kim, Jang-Yul,Chun, Myoung-Chul,Lee, Si-Hyun 한국결정성장학회 2015 한국결정성장학회지 Vol.25 No.2

본 연구에서는 PVT법으로 4H-SiC 단결정 성장 시 다공성 흑연판을 사용하여 Si/C 비율이나 온도구배, 물질전달의 향상시킴으로써 고품질의 SiC 단결정 기판 제작을 목적으로 연구를 진행하였다. 연구에 사용된 SiC 소스 물질은 흑연 도가니에 넣어 흑연 단열재로 쌓인 구조로 실험을 하였다. 성장온도는 $2100{\sim}2300^{\circ}C$, 그리고 성장압력은 10~30 Torr의 압력으로 아르곤과 질소 분위기에서 성장시켰다. 종자정은 2인치의 $4^{\circ}$ off-axis 4H-SiC의 C면 (000-1)을 사용하였고 다공성 흑연판은 SiC 소스 물질 위에 삽입하였다. 4H-SiC 결정다형 안정화를 위한 C-rich 조건이나 균일한 온도구배를 만들어주기 위해 다공성 흑연판을 삽입하여 실험을 진행하였다. 일반적인 도가니의 경우, 성장된 wafer에서 6H-, 15R-SiC와 같은 다양한 결정다형이 관찰된 반면에 다공성 흑연판을 삽입한 도가니에서는 4H-SiC만 관찰되었다. 또한 다공성 흑연판을 삽입한 도가니에서 성장된 결정에서 MP나 EP의 낮은 결함밀도를 보였으며 결정성 또한 향상된 것을 학인하였다. The present research is focused on the effect of porous graphite what is influenced on the 4H-SiC crystal growth by PVT method. We expect that it produces more C-rich and a change of temperature gradient for polytype stability of 4H-SiC crystal as adding the porous graphite in the growth cell. The SiC seeds and high purity SiC source materials were placed on opposite side in a sealed graphite crucible which was surrounded by graphite insulator. The growth temperature was around $2100{\sim}2300^{\circ}C$ and the growth pressure was 10~30 Torr of an argon pressure with 5~15 % nitrogen. 2 inch $4^{\circ}$ off-axis 4H-SiC with C-face (000-1) was used as a seed material. The porous graphite plate was inserted on SiC powder source to produce a more C-rich for polytype stability of 4H-SiC crystal and uniform radial temperature gradient. While in case of the conventional crucible, various polytypes such as 6H-, 15R-SiC were observed on SiC wafers, only 4H-SiC polytype was observed on SiC wafers prepared in porous graphite inserted crucible. The defect level such as MP and EP density of SiC crystal grown in the conventional crucible was observed to be higher than that of porous graphite inserted crucible. The better crystal quality of SiC grown using porous graphite plate was also confirmed by rocking curve measurement and Raman spectra analysis.

헤어미용사의 자기효능감과 노동의 강도가 삶의 만족도에 미치는 영향 : 소득 만족도의 매개효과와 고객불평행동 경험의 조절효과

이시연 국제뇌교육종합대학원대학교 뇌교육연구소 2021 뇌교육연구 Vol.27 No.-

The purpose of this study is to investigate the factors affecting the life satisfaction of hairdressers. To this end, I surveyed 73 hairdressers working in Dangjin and Seosan from January 11 to March 8, 2021. The significance of the mediating effect was verified by analyzing the sample with SPSS 25.0 using Hayes’ process macro. As a result of the study, there was a complete mediating effect on the effect of self-efficacy on the satisfaction of life in income satisfaction. Self-effcacy affects life satisfaction, but it is effective only when income satisfaction is satisfied. The experience of customer complaint behavior caused a negative moderating effect on the effect of labor intensity on life satisfaction. It was found that the intensity of labor affects the satisfaction of life, and the influence is regulated according to the experience of customer impersonal behavior. 본 연구는 헤어미용사의 삶의 만족도에 영향을 미치는 요인에 대한 연구이 다. 이를 위해 2021년 1월 11일부터 3월 8일까지 당진, 서산에서 근무하는 미 용사 73명을 조사하였다. 연구방법으로 매개효과와 조절효과 유의성을 검증하 기 위해 Hayes의 Process mac r o를 활용하여 SPSS 25.0으로 분석하였다. 연구 결과 첫째, 자기효능감이 삶의 만족도에 미치는 영향에 대하여 소득의 만족도 는 완전 매개효과가 있었다. 자기효능감이 삶의 만족도에 영향을 미치나, 소득 의 만족도가 충족되어야 효과가 나타났다. 둘째, 고객불평행동 경험은 노동의 강도가 삶의 만족도에 미치는 영향에 대하여 부적 조절효과가 있었다. 노동의 강도는 삶의 만족도에 영향을 미치며, 고객불평행동 경험에 따라 그 효과가 조절되는 것으로 나타났다. 헤어미용사의 삶의 만족도를 높이기 위해서는 소 득 만족도를 높일 필요가 있고, 고객불평행동에 적절하게 대처할 수 있는 능 력이 필요하다는 것을 시사한다.

사회공포증과 관련된 양육태도검사의 개발 연구

이시형,오강섭,허묘연 대한소아ㆍ청소년정신의학회 1998 소아청소년정신의학 Vol.9 No.2

청소년 자활지원관에서의 사례관리 적용과정에 관한 연구

이시연,박은미 한국청소년복지학회 2004 청소년복지연구 Vol.6 No.2

The purpose of this study is to review the present state of youth self-sufficiency supporting centers, to understand the importance of case management application as an effective practice methodology to support juveniles, and to apply case management application processes for youth self-sufficiency supporting centers. With this purpose, literatures were reviewed the present state of youth self-sufficiency supporting centers and to show the importance for case management application. Case study was used to show the process of case management application. Case study is known as an effective and qualitative research method. There are 25 youth self-sufficiency supporting centers nationwide. Major roles of theses centers is to support impoverished juveniles by helping them finish school, get hands-on-job training, and to provide cultural opportunities in order to prevent cycle of poverty. It has also been founded that there is a great need to develop some effective intervention methods to achieving these goals. Case management has reviewed and suggested one of the most effective intervention methods. In this research four cases were analyzed, each providing detail process information for case management application. Conclusive results show that an insufficient number of workers, lack of knowledge and skills about case management are the major limitations in implementing case management.

PCR과 SDS-PAGE를 이용한 Bifidobacteria의 동정

박시홍,송희성,이지연,김해영 경희대학교식량자원개발연구소 2005 硏究論文集 Vol.24 No.-

SDS-PAGE를 이용한 단백질 패턴의 분석결과, 같은 종의 Bifidobacterium은 동일한 단백질 패턴을 보이며, 다른 종의 Bifidobacterium은 서로 다른 패턴을 보이고 있는 것을 확인하였다. 따라서 SDS-PAGE를 이용한 whole cell protein 패턴 분석으로 Bifidobacterium을 간편하고 빠르게 동정할 수 있는 가능성을 보였다. DNA homology 98% 이상으로 PCR에 의해 동정에 어려움이 많았던 B. catenulatum, B. Pseudocatenulatum group, B. animalis을 SDS-PAGE로 확인한 결과, B. catenulatum과 B. pseudocatenulatum, B. animalis는 뚜렷한 단백질 패턴의 차이를 보임으로써 구별이 가능했다. PCR 수행 시 primer제작은 기존에 보고된 것과 NCBI blast program을 통하여 제작을 하였으며, 그 결과 B. longum, B. bifidum, B. adolescentis 3종류의 종에서만 특이적으로 band가 나타나는 것을 확인할 수가 있었다. 본 실험에서는 SDS-PAGE와 PCR을 이용한 균주 동정법으로 신속하고 정확하게 Bifidobacterium을 탐색할 수 있었으며, 발효유 제조나 의약품 제조 등 산업적으로 이용 될 수 있을 것이다 (Mitsuoka, 1984). Bifidobacterium is a Gram-positive obligate anaerobic bacterium which is able to change cellular shape by nutritional conditions and dominant species in intestinal microflora of human. In order to identify Bifidobacteria spp. in human intestine, PCR and SDS-PAGE of whole cell proteins were used. Species-specific primer sets based on the 16S rRNA, 16S-23S intergenic spacer and heat shock protein genes of three Bifidobacteria spp. were constructed using NCBI blast program (Bifidobacteria adolescentis, B. longum and B. bifidum). PCR products using each primer sets showed the same sizes of expected target genes. From the SDS-PAGE of whole cell proteins in bifidobacteria, profiles of SDS-PAGE between 13 type strains showed distinct differences. These methods will be useful for monitoring and evaluating Bifidobacteria spp. in human intestine microbial population.

대인불안과 사회문화적 요인의 상관관계

오강섭,허묘연,이시형 대한신경정신의학회 1999 신경정신의학 Vol.38 No.1

연구목적 : 한국 일반인들에 대한 사회공포 증상의 정도와 양상, 기능의 손상정도 등을 알아보고, 대인불안과 성격특성, 부모의 양육태도, 대인관계에서의 특징들간의 상관정도를 알아보기 위한 것이다. 방 법 : 서울지역에 거주하는 일반 중학생, 고등학생, 대학생 및 성인 1087명을 대상으로 전반적인 사회적 상황에서의 불안과 회피 정도, 증상과 상황, 대처방법, 가해의식, 일상생활에의 영향을 조사하였고, 내-외향성 검사, 부모양육태도 검사와 대인관계태도 검사를 이용하여 대인 불안과 관련된 성격과 사회적인 요인을 평가하였다. 결 과 : 대인불안 증상은 정시곤란, 실수공포, 표정공포, 횡시공포, 타인시선공포가 전 연령에 걸쳐 높게 나타났다. 청소년기는 전반적으로 대인상황에 대한 불안 수준이 올라가 있고, 중학생과 고등학생의 경우 남자가 여자에 비해 유의미하게 높은 정도의 대인불안을 갖고 있는 것으로 나타났다. 가해의식은 성인으로 갈수록 줄어드는 경향이 있었다. 대인불안의 상황은 모든 연령에서 연단이나 면접상황에서 가장 많은 어려움이 호소하였으며, 대처방식의 경우, 연령이 증가할수록 ‘그럴 수 있다’ 건강한 대처방식의 비율이 높아지는 것으로 나타났다. 내향성에 대한 자신의 평가와 타인의 평가를 비교해보면, 모든 연령집단에서 타인이 평가하는 것보다는 자신이 스스로를 더 내성적인 것으로 생각하였다. 양육태도의 경우에는 아버지나 어머니 모두, 거부나 높은 기대, 불안, 통제적인 태도는 대인불안이 높은 것과 관련되어 있는 반면에 감정적인 지지를 나타내는 태도는 낮은 대인불안과 관련되어 있었다. 대인관계태도에서 자기 바하나, 은근성, 타인의 의견을 지나치게 염려하는 태도, 체면 등은 대인불안과 유의미한 관련성을 나타냈으며, 사교성이나 응석은 대인불안과 부적인 관계를 갖는 것으로 나타났다. 결 론 : 대인불안의 정도, 내향성, 대인불안 및 회피 정도와 일상생활에서의 지장 정도간에 서로 깊은 상관관계를 나타내어, 대인불안의 정도와 내향성이 높을수록 일상생활에의 지장이 많은 것으로 판단되었다. 부모의 양육태도에서는 거부, 높은 기대, 불안, 통제적 태도 등이, 대인관계태도에서는 자기비하, 은근성, 타인의견 염려, 체면 등이 대인불안과 관련되는 것으로 나타났다. Objectives : We examined the degree of social anxiety and physical symptoms, situations, maneuvers in phobic situations, the degree of offending others, disability in normal Korean sample. And We also studied the correlations of social anxiety and socio-cultural factors (personality characteristics, child rearing attitudes and interpersonal attitudes). Methods : The subjects were total of 1087 including junior high school students, high school students, college students and adult population living in Seoul. We administered the following scales : SAD(Social Avoidance and Distress Scale), Social Anxiety Symptom and Situation, Maneuvers in Phobic situations, Offending others, SDS(Sheehan's Disability Scale), EPQ(Eysenck Personality Questionnaire), Child Rearing Scale and Interpersonal Attitude Scale. Results : Among social phobic symptoms, fear of eye to eye contact, fear of mistake, fear of facial expression, fear of side glancing and fear of other's gazing were prevalent in decreasing order. The level of general social anxiety were high in junior high school and high school students, and male subjects reported more social anxiety. the degree of offending others decreased with age. The most difficult social anxiety situations were public speaking and interviewing. The frequently used maneuver in phobic situations was reasoning. All subjects perceived themselves more introverted than others did. On the Child rearing attitude, rejection, high expectation, anxious, control subscales of both parent were correlated with high level of social anxiety, and the emotional care was correlated with low level of social anxiety. On the interpersonal attitudes, self-devaluation, indirectedness, overconcern of other's opinion, face saving subscales were positively correlated with social anxiety, and the socialization and eungseok were negatively correlated with social anxiety. Conclusion : The social anxiety and the introversion were associated with the disability of daily activity. Some subscales of child rearing attitudes and interpersonal attitudes were also associated with the social anxiety.

Stress-relieved Si anode on a porous Cu current collector for high-performance lithium-ion batteries

Moon, Sang-Hyun,Kim, Si-Jin,Kim, Min-Cheol,So, Jin-Young,Lee, Ji-Eun,Shin, Yeon-Kyung,Bae, Won-Gyu,Park, Kyung-Won Elsevier 2019 Materials chemistry and physics Vol.223 No.-

<P><B>Abstract</B></P> <P>To overcome the mechanical stress generated during the cycling process in lithium-ion batteries, Si anode is fabricated on a porous Cu current collector with holes using sputtering deposition method. The porous Cu/Si shows superior high-rate and cycling performance in lithium-ion batteries compared to the Si anode on the flat Cu. The excellent high-rate performance and stable cyclability of the porous Cu/Si can be predominantly attributed to the efficient relief of the stress generated by the volumetric expansion of the Si anode on the porous Cu current collector.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Si anode for LIBs was fabricated on a porous Cu current collector having holes. </LI> <LI> The porous Cu/Si showed the superior high-rate and cycling performance. </LI> <LI> The excellent performance of the porous Cu/Si can be due to the relief of the stress. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Non-invasive stem cell tracking in hindlimb ischemia animal model using bio-orthogonal copper-free click chemistry

Lee, Si Yeon,Lee, Sangmin,Lee, Jangwook,Yhee, Ji Young,Yoon, Hwa In,Park, Soon-Jung,Koo, Heebeom,Moon, Sung-Hwan,Lee, Hyukjin,Cho, Yong Woo,Kang, Sun Woong,Lee, Sang-Yup,Kim, Kwangmeyung Elsevier 2016 Biochemical and biophysical research communication Vol.479 No.4

<P><B>Abstract</B></P> <P>Labeling of stem cells aims to distinguish transplanted cells from host cells, understand <I>in vivo</I> fate of transplanted cells, particularly important in stem cell therapy. Adipose-derived mesenchymal stem cells (ASCs) are considered as an emerging therapeutic option for tissue regeneration, but much remains to be understood regarding the <I>in vivo</I> evidence. In this study, a simple and efficient cell labeling method for labeling and tracking of stem cells was developed based on bio-orthogonal copper-free click chemistry, and it was applied in a mouse hindlimb ischemia model. The human ASCs were treated with tetra-acetylated <I>N</I>-azidoacetyl-<SMALL>D</SMALL>-mannosamine (Ac<SUB>4</SUB>ManNAz) to generate glycoprotein with unnatural azide groups on the cell surface, and the generated azide groups were fluorescently labeled by specific binding of dibenzylcyclooctyne-conjugated Cy5 (DBCO-Cy5). The safe and long-term labeling of the hASCs by this method was first investigated <I>in vitro</I>. Then the DBCO-Cy5-hASCs were transplanted into the hindlimb ischemia mice model, and we could monitor and track <I>in vivo</I> fate of the cells using optical imaging system. We could clearly observe the migration potent of the hASCs toward the ischemic lesion. This approach to design and tailor new method for labeling of stem cells may be useful to provide better understanding on the therapeutic effects of transplanted stem cells into the target diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new method was proposed for labeling and tracking of stem cells. </LI> <LI> This method enables safe and long-term monitoring of stem cells <I>in vivo</I>. </LI> <LI> We observed the migration of the stem cells toward the ischemic lesion. </LI> </UL> </P>

Prenatal diagnosis of interchromosomal insertion of Y chromosome heterochromatin in a family

Lee, Bom-Yi,Park, Ju-Yeon,Lee, Yeon-Woo,Oh, Ah-Rum,Lee, Shin-Young,Park, So-Yeon,Ryu, Hyun-Mee,Lee, Si-Won Korean Society of Medical Genetics and Genomics 2017 대한의학유전학회지 Vol.14 No.2

Interchromosomal insertion of Y chromosome heterochromatin in an autosome was identified in a fetus and a family. A fetal karyotype was analyzed as 46,XX,dup(7)(?q22q21.1) in a referred amniocentesis at 16 weeks of gestation for advanced maternal age. In the familial karyotype analyses for identification of der(7), the mother, the first daughter and the maternal grandmother showed the same der(7) as the fetus's. CBG-banding was positive at 7q22 region of der(7) that indicated inserted material was originated from heterochromatin. The origin of heterochromatic insertion region in der(7) of the fetus and the mother was found in Yq12 region by fluorescent in situ hybridization with a DYZ1 probe. In the specific analysis of Y chromosomal heterochromatic region of ins(7;Y) of the mother, 15 sequence tagged sites from Yp11.3 region including SRY to Yq11.223 region was not detected. Final karyotypes of the mother, the first daughter and the maternal grandmother were reported as 46,XX,der(7)ins(7;Y)(q21.3;q12q12). All female carriers of ins(7;Y) in the family showed normal phenotype and the mother and the maternal grandmother were fertile. A healthy girl was born at term. We report a rare case of familial interchromosomal insertion of Y chromosome heterochromatin detected only in female family members with normal phenotype that was diagnosed prenatally.

과열증기처리가 압출 쌀스낵의 이화학적 특성에 미치는 영향

이시연 ( Si Yeon Lee ),고범수 ( Bum Soo Ko ),박준규 ( Jun Kyu Park ),최은희 ( Eun Hee Choi ),이미연 ( Mi Yeon Lee ),유영미 ( Young Mi Yoo ),조은경 ( Eun Kyong Jo ),이재권 ( Jae Kwon Lee ) 한국산업식품공학회 2015 산업 식품공학 Vol.19 No.3

과열증기처리한 백미로 제조한 압출스낵의 물리화학적 특성과 미세구조를 조사하여 과열증기처리 및 과열증기온도(200, 250, 350oC)가 압출스낵의 품질특성에 미치는 영향을 검토하였다. 압출스낵의 이화학적 특성 측정결과, 팽화도는 과열증기처리에 따라 증가하였으나 과열증기온도의 영향은 미미하였다. 압출스낵의 경도는 과열증기처리에 따라, 과열증기온도가 높을수록 감소하였다. 손상전분함량은 과열증기처리에 따라 78.1%에서 80-81%로 다소 증가하였으나 과열증기온도에 따른 손상전분함량의 유의 차는 없었으며, 이로써 과열증기처리가 전분호화에 미치는 영향은 크지 않은 것을 확인하였다. 과열증기처리에 따라 수분흡수지수(WAI)는 유사한 측정치를 나타낸 반면 수분용해지수(WSI)는 비교적 크게 증가하여 과열증기처리가 압출공정에서 전분분자의 저분자화를 증가시키는 것으로 판단되었다. 압출스낵의 수분흡수율은 과열증기처리에 따라 증가하였으며 과열증기온도가 높을수록 수분흡수율은 증가하였다. 압출스낵의 미세구조 관측결과, 압출스낵 내부의 기공크기와 기공 막 두께는 과열증기처리에 따라 감소하며, 이와 같은 내부구조 변화로 인하여 과열증기처리 압출스낵의 팽화도, 경도 및 수분흡수율 측정결과는 대조구와 상이하였다. 한편 과열증기처리에 따른 압출스낵의 미세구조 변화는 과열증기처리가 쌀의 배유조직 내에 미세한 균열(stress crack)을 발생하고, 미세 균열 내의 공기가 압출과정에 유입되어 보다 많은 핵심이 생성되며, 이로 인하여 다 공성이 높아지는 것으로 추정된다. This study was carried out to examine the effect of superheated steam (SHS) treatment combined with extrusion process on the physicochemical properties of extruded rice snack. Milled rice grains were heated for 2 min using the SHS at 200℃, 250℃, and 350℃, then processed into extruded rice snacks using a single screw extruder. Bulk density, hardness, water solubility index (WSI), and water uptake capacity of extruded rice snack were significantly influenced by the SHS treatment and temperature of SHS. Increasing SHS temperature resulted in extruded rice snack with a higher expansion, WSI, and water uptake capacity than those of the control snack. Meanwhile, hardness decreased greatly with increasing SHS temperature. The microstructure of extruded rice snack revealed that the sizes and thickness of air cells and air cell walls decreased after SHS treatment with increasing SHS temperature, resulting in better expansion and softer texture. Presumably, the influence of SHS treatment on structural changes was attributed to the increased number of micro-bubbles nucleated in the starch melt during the extrusion process.