Determinants of health promoting behavior of college students in Korea

간호학과/박사[한글] 본 연구는 대학생의 건강증진 행위를 설명하고 예측하는 요인을 규명하고 이들 요인들의 영향력 파악을 통해 대학생의 건강증진을 위한 간호전략수립에 기여하고자 시도되었다. 이를 위하여 Fonder의 건강증진 모형과 문헌고찰을 기초로 한 이론적 기틀과 가설적 모형을 구성하였는데 대학생의 건강증진 행위를 설명하는 예측변수는 사회적지지, 지각된 장애성, 지각된 유익성, 상황적 장애가 외생변수로, 자아존중감, 지각된 건강상태, 자기효능이 내생변수였으며, 이 이론변수들에 대한 측정변수는 16개였다. 본 연구의 자료수집기간은 1998년 4월 13일부터 8월 28일까지이며, 한국의 대학생 수를 고려하여 모집단 비율을 적용하고, 남녀 학생 수와 학년의 비율이 같도록 대상자를 선정하였으며, 최종적으로 분석에 이용된 대상자는503명 이었다. 대상자의 인구 ·사회학적 특성 및 연구 변수에 대한 서술적 통계와 상관관계 분석은 Windows SAS program(v6.12)을 이용하였으며, Windows LISREL program(v8.12a)을 이용하여 공분산 구조 분석을 하였다. 본 연구의 결과는 다음과 같다 1. 모형의 부합도 분석 결과 1) 가설적 모형의 전반적 부합지수는 경험적 자료에 잘 맞지 않음을 보여주었다 [x**2 =322.80, df=81, p=0.00, GFI=.91, AGFI=.86, RMR=.053, NFI=96, NNFI=.95, CN=177.53] 그러나 가설적 모형의 예측변수들이 건강증진 행위를 설명하는 정도는 57%로 비교적 높게 나타났다. 2) 간명하면서도 부합도가 높은 모형을 제시하기 위하여 내생변수인 지각된 건강상태와 2개의 경로를 삭제하고, 수정지수(modification index)가 높은 고정모수를 자유 수로 바꾸어 모수를 추가하였다. 3) 제시된 수정모형의 전반적 부합지수 모두가 경험적 자료에 잘 부합됨을 보여주었다[x**2 =66.83, df=55, p=.13, GFI=.98, AGFI=.96, RMR=0.015, NFI=.99, NNFI=1.0, CN=619.17]. 수정모형의 예측변수들이 건강증진 행위를 설명하는 정도는 59%로 비교적 높게 나타났다. 2. 가설검증 결과 1) 자아존중감은 사회적 지지가 높을수록( γ^^11 =.13, t=5.09), 지각된 유익성이 높을수록(γ^^13 =.11, t=4.65), 지각된 건강상태가 좋을수록(β^^12 =.05,t=2.90), 자기효능(β^^13 =.18, t=6.48)이 높을수록 높은 것으로 나타났으며, 지각된 장애성과 상황적 장애의 효과는 유의하지 않았으며 사회적 지지가 가장 크게 영향하였다. 2) 자신의 건강상태에 대한 지각은 사회적 지지가 높을수록 자신의 건강상태를 긍정적으로 지각하고 있었으며( γ^^21 =.10, t=2.04), 나머지 외생변수와 내생변수의 직접효과는 유의하지 않았다 3) 자기효능은 사회적 지지가 높을수록(γ^^31 =.31, t=11.67), 지각된 장애성이 적을수록( γ^^32 =-.08, t=-3.25), 지각된 유익성이 많을수록( γ^^33 =.08,t=3.31), 자아존중감이 논을수록(β^^31 =.18, 1=6.48), 자기효능을 높게 인지하는 것으로 나타났으며 통계적으로 유의하였다. 상황적 장애가 자기효능에 미치는 직접효과는 유의하지 않았으며 사회적 지지가 가장 크게 영향하였다. 4) 건강증진 행위의 수행정도는 사회적 지지가 높을수록(γ^^41 =.08,t=4.81), 지각된 유익성이 많을수록(γ^^43 =.06, t=3.23), 상황적 장애요인이 많을수록(γ^^74 =-.04, t=-2.47), 지각된 건강상태가 좋을수록(β^^42 =.05, t=3.59), 자기효능이 높을수록(β43=.26, t=8.27) 높은 것으로 나타났으며 지각된 장애성이 건강증진 행위에 미치는 직접효과는 유의하지 않아 기각되었다. 자아존중감이 건강증진 행위에 대한 직접효과는 유의하지 않았으나 간접효과를 포함한 총효과(.08, t=2.31)가 유의하여 지지되었다. 이상의 모형검증 결과 본 연구에서 구축한 한국 대학생의 건강증진 행위예측 구조모형은 실제자료와 잘 부합하여 한국 대학생의 건강증진 행위를 예측하기에 적합한 모형이라고 사려된다. 모형의 검증 결과를 통하여, 대학생의 건강증진 행위 수행에 가장 크게 영향을 미치는 요인은 자기효능이었으며, 사회적 지지, 지각된 유익성, 자아존중감이 중요한 요인임을 확인 할 수 있었다. 지각된 장애성, 상황적 장애요인도 직접 또는 간접적으로 영향하는 것으로 나타났으며 이 들 예측변수의 건강증진 행위에 대한 설명력은 57%로 나타났다. 따라서 건강증진 행위의 실천정도를 높이기 위하여 가족이나 친구 등이포함된 지지모임이나 자조집단의 구성, 역할모델이나 사회적 강화 등의 사회적지지, 행위 수행에 필요한 기술과 지원 및 다양하고 쉽게 접할 수 있는 건강증진 프로그램의 개발과 적용, 건강교육과 같은 중재방안들이 효과적이라고 사려된다. [영문] The purpose of this study was designed to develope and test the structural model that explains health promoting behaviors among college student in Korea. The hypothetical model was constructed on the basis of the pilot study, Fonder's health promoting model(1996) and the findings from past studies. The conceptual framework was built around eight constructs. Exogenous variables included in the model were social support, perceived barriers, perceived benefits, situational barriers. Endogenous variable were self-efficacy, perceived health status, self-esteem, health promoting behaviors. Data were collected by serf(-reported questionnaires from 503 college student in Seoul, from April to August, 1998. The reliabilities of instruments were adequate(Cronbach's alpha= .54-.91) SAS PC+ 6.12 program was utilized for descriptive statistics and correlation analysis. LISREL 8.12 program was used to find the best fit model which assumes causal relationships among variables The results are as follows; 1. The overall fit of the hypothetical model to the data was good except chi-sfluare value and AGFI(x^^2 =322.8, df=81, p=.00, GFI=.91, AGFI=.86, NFI=.96, NNFI=.95, RMR=.053, CN=177.53). 2. Path and variable of the model were modified by considering both its theoretical implication and statistical significance of parameter estimates, Endogenous variable, perceived health status, and two path was removed in the hypothetical model. 3. Compared to the hypothetical model, the revised model has become parsimonious and had a better fit to the data(72=66.8, df=55, p=.13, GFI=.98, AGFI=.96, NFI=.99, NNFI=1.0, RMR=.015, CN=619.17). 4. The results of hypothetical testing were as follows; 1) Social support, perceived benefits, situational barriers, self-efficacy, perceived health status, and self-esteem have significant effects on health promoting behaviors. Of these variables, self-efficacy was most significant factor. And social support was most significant effect on self-efficacy. 2) Social support, perceived benefits, perceived health status, self-efficacy have significant effects on self-esteem. Of these variables, social support and self-efficacy were significant factor. These predictive variables of self-esteem explained 39% of variance. 3) Social support, perceived benefits, perceived benefits, and self-esteem have significant effects on self-efficacy. Of these variables, social support was most significant factor. These predictive variables of self-efficacy explained 46% of valiance. 4) Social support has only significant effects on perceived health status, These predictive variables of perceived health status explained3% of variance. 5) The results of this study showed that self-efficacy had the most significant direct effects on health promoting behaviors. Social support and self-esteem have significant effects on this self-efficacy. All predictive vanables of health promoting behaviors, especially socials upport, perceived benefits, situational barriers, self-efficacy, perceived health status, self-esteem explained 57% of total variance in model.restrictio

다양한 화학적 소독제를 이용한 뮤린노로바이러스의 불활성화 평가

Thesis(masters) --서울대학교 보건대학원 :환경보건학과(환경보건학전공),2010.2.Maste

사회운동에서의 공간의 탈영역화 전략 - 마포 민중의 집과 서울시 청년일자리허브를 사례로 -

학위논문 (석사)-- 서울대학교 대학원 : 사회교육과, 2015. 2. 박배균.전통적인 사회운동에서 주된 공간 전략은 특정 장소에 대한 무단 점거로 대표되는 영역화 전략이다. 영역화 전략은 높은 가시성과 이목 끌기를 통해 운동의 지지 기반을 마련할 수 있으며, 적어도 일정 기간 동안은 저항 세력에게 의존의 공간을 제공해준다는 장점이 있다. 그러나 영역화는 기본적으로 배타적/배제적이며 탈개인화와 단수의 정체성을 요구한다는 점에서 운동의 확산에 제약이 될 수 있다. 또한 보수적인 militant particularism으로 귀결될 위험도 있다. 본 연구에서는 기존의 영역화 전략이 지닌 이러한 한계를 보완할 공간 전략으로 탈영역화 전략을 제시하고 이를 개념화하고자 하였다. 정치지리학에서 강조하는 탈영역화의 핵심 기제는 1)경계 허물기, 2)외부에의 비차별적인 개방, 3)다양성의 수용이다. 이를 바탕으로 연구자는 과거 유럽에 번성했던 급진 공간들의 공간 전략에 착안, 대표적인 탈영역화 전략으로 거점 공간의 공유를 제시하였다. 사례로 든 마포 민중의 집과 서울시 청년일자리허브는 공간의 문턱을 낮추기 위해 다양한 경계 허물기 전략을 구사하고 거점의 공유를 지향한다는 공통점이 있다. 연구자는 이러한 새로운 공간 전략을 거점 공간의 경계 허물기와 공유적 전유를 통한 탈영역화 전략으로 규정하고, 그 효과와 한계를 살펴보았다. 결론적으로 탈영역화 전략의 효과는 다음과 같다. 첫째, 타자를 인식하고 조우할 수 있는 기회를 제공한다. 둘째, 네트워크를 확장하고 연대를 촉진한다. 셋째, (특히 민중의 집의 경우) 다양한 생활 정치로 의제를 확장하고 운동을 진화시킨다. 그러나 탈영역화 전략의 현실적인 한계 또한 존재한다. 비차별적인 개방과 공유를 지향하지만, 민중의 집과 청년허브 모두 아직까지는 이용자가 제한되어 있기 때문이다. 그렇기에 탈영역화 전략이 결과적으로 영역화나 확장된 재영역화로 이어질 가능성도 엿보인다. 이러한 한계에도 불구하고 거점 공간을 공유하는 방식의 탈영역화 전략은 자본주의 사회에서 공간이 생산되고 소비되는 지배 구조에 저항하며 공간의 공공성을 강화하는 수단이 될 수 있다. 또한 공간을 통해 운동의 능동적 주체가 창출될 수 있음을 보여준다는 면에서 비판적 공간 연구와 사회운동 전반에 큰 시사점을 제공한다.제1장 서론 ························································· 1 제1절 연구배경 및 연구목적 ···································· 1 1. 공간 열풍과 공간 결핍 ············································ 1 2. 공간이 운동한다. ··················································· 3 제2절 연구대상 및 연구방법 ··································· 6 1. 연구대상 ····························································· 6 1.1. 마포 민중의 집 ················································ 6 1.2. 서울시 청년일자리허브 ····································· 10 2. 연구방법 ···························································· 15 제3절 논문의 구성 ·············································· 18 제2장 이론 논의 ················································ 20 제1절 지리학에서의 사회운동 연구에 대한 비판적 검토 ··· 20 제2절 사회운동에서의 공간 전략 연구에 대한 비판적 검토 · 25 제3절 사회운동에서의 공간의 탈영역화 전략 ·············· 31 1. 영역화 전략과 사회운동 ·········································· 31 2. 탈영역화 전략과 사회운동 ······································· 35 2.1. Radical Space ················································ 37 2.2. 공간의 전유 ·················································· 40 2.3. 공공성과 공공공간 ·········································· 43 2.3.1. 공공성 ················································· 43 2.3.2. 공공공간의 이상 ····································· 44 3. 영역화와 탈영역화의 변증법····································· 46 제3장 마포 민중의 집의 공간 전략 ······················ 48 제1절 물리적 공간 구조 ······································· 48 제2절 경계 허물기와 공간의 공유적 전유 ·················· 51 1. 경계 허물기 ························································ 51 2. 공간의 공유적 전유 ··············································· 61 제3절 효과 ······················································· 66 1. 타자와의 조우 ······················································ 66 2. 네트워크의 확장과 연대 ·········································· 69 3. 다양한 생활 정치로의 진화 ······································ 71 제4절 한계 및 전망 ············································· 73 제4장 서울시 청년일자리허브의 공간 전략 ··········· 75 제1절 물리적 공간 구조 ······································· 75 제2절 경계 허물기와 공간의 공유적 전유 ·················· 80 1. 경계 허물기 ························································ 80 1.1. 다양한 유도 전략 ············································ 80 1.2. 청년참 ························································· 83 2. 공간의 공유적 전유 ··············································· 87 제3절 효과 ······················································ 93 1. 타자와의 조우 ······················································ 93 2. 네트워크의 확장과 연대 ·········································· 96 제4절 한계 및 전망 ············································· 98 제5장 요약 및 결론 ·········································· 100 참고문헌 ························································· 103 Abstract ························································ 113Maste

The effects of human genetic and environmental factors on the gut and airway microbiome

학위논문 (박사)-- 서울대학교 보건대학원 : 보건학과 보건미생물학전공, 2015. 8. 고광표.The human microbiome consists of an enormous variety of microorganisms including bacteria, archaea, fungi, and viruses that reside in all body surfaces that are exposed to the external environment such as the skin, oral cavity, airway, vagina, and gut. Although the human microbiome has long been known to play important roles in human health and disease, only the recent advances in high-throughput sequencing methods and analytic techniques have enable detailed investigation of the human microbiome composition, function, and host-microbe interactions. Through these studies, it has become apparent that in the healthy state, the human microbiota is involved in a broad range of activities for the maintenance of human health, including nutrient metabolism, epithelial cell proliferation, development and maintenance of the immune system, and protection against pathogens. Meanwhile, disruption of the normal microbiota (dysbiosis) has been linked to the various diseases such as obesity, cancer, a variety of inflammatory diseases of the airways, skin, mouth, and intestinal tract. To direct future therapy for microbiome-related diseases, it is necessary to first characterize the normal microbiota in the healthy population and identify factors that are associated with compositional changes in human microbiome. For these purposes, in this thesis, a large-scale investigation of the gut microbiota and the airway microbiota was conducted in Korean twins and their families. First, we identified that the gut microbiota of healthy Koreans were clustered into two enterotypes using metagenomic sequencing data which was generated from 36 fecal samples of healthy Korean monozygotic (MZ) twins. The two enterotypes were enriched by either Bacteroides or Prevotella. We observed that the enterotype of an individual was stable over time, and that most co-twins shared their enterotypes. We also found that the subjects enterotypes were significantly associated with the serum uric acid level and the long-term intakes of nutrients such as dietary fiber, vitamins, and minerals. These results suggest that both host genetics and dietary habits could be important contributors to the enterotype of an individual. Second, we characterized the gut microbiota of 655 MZ (N=306) and dizygotic (DZ) (N=74) twins, and family members of twin pairs (N=275), of which approximately 18% (121 individuals) had metabolic syndrome (MetS). We found that Methanobrevibacter, Lactobacillus, and Sutterella were significantly enriched in MetS individuals, while Akkermansia, Odoribacter, and Bifidobacterium were significantly enriched in healthy individuals. Among the gut microbes associated with MetS status, Actinobacteria, to which the Bifidobacterium belong, had the highest heritability (45.7%). Even after adjustment for MetS status, reduced abundances of Actinobacteria and Bifidobacterium were significantly linked to the minor allele at the apolipoprotein A-V gene (APOA5) SNP rs651821, which is associated with triglyceride level and MetS. Therefore, our results demonstrate that altered gut microbiota mediated by a specific host genotype can contribute to the development of MetS. Third, we assessed the influences of host genetics and lifestyles such as smoking, alcohol consumption, and physical activity on the airway microbiota composition. A total of 257 sputum samples from 74 MZ twin pairs (n=148), 14 DZ twin pairs (n=28), and their parents and siblings (n=81) were analyzed for airway microbiota composition using next-generation sequencing of partial 16S rRNA gene sequences. We found that several taxa, including Providencia and Bacteroides, were significantly influenced by host genetic factors. Smoking had the strongest effect on the overall microbial community structure among the various host lifestyle factors. The pack-year value was positively associated with abundance of the Veillonella genus, which is known to be related to airway inflammation, but negatively associated with that of Haemophilus. Co-occurrence network analysis showed that the taxa were clustered according to the direction of correlations or trends for smoking, and that the taxa influenced by host genetics were closely correlated with each other. These results demonstrate that the composition of the airway microbiota is shaped by complex interactions among host genetics and lifestyle factors, such as smoking. In conclusion, this study shows that the composition of the healthy human microbiome is influenced not only by extrinsic environmental factors including diet and lifestyle but also by host genetics, and that the changes in the abundances of the specific microbial taxa caused by these factors are associated with metabolic syndrome and possibly airway inflammation. These data suggest that personalized approaches will be required in the prevention and treatment of microbiome-related diseases.ABSTRACT................................................................................................................... i CONTENTS ................................................................................................................ iv LIST OF TABLES....................................................................................................... vi LIST OF FIGURES ..................................................................................................viii LIST OF ABBREVIATIONS..................................................................................... xi CHAPTER I. BACKGROUNDS Human microbiome ....................................................................................... ２ Gut microbiome ............................................................................................. ５ Airway microbiome ....................................................................................... ７ Techniques for studying the human microbiome........................................... ８ Objectives and Hypotheses........................................................................ １１ CHAPTER II. STABILITY OF GUT ENTEROTYPES IN KOREAN MONOZYGOTIC TWINS AND THEIR ASSOCIATION WITH BIOMARKERS AND DIET Introduction................................................................................................ １３ Materials and Methods............................................................................... １５ Results........................................................................................................ １９ Discussion.................................................................................................. ４０ v CHAPTER III. THE EFFECT OF HERITABILITY AND HOST GENETICS ON THE GUT MICROBIOTA AND METABOLIC SYNDROME Introduction................................................................................................ ４６ Materials and Methods............................................................................... ４９ Results........................................................................................................ ５４ Discussion.................................................................................................. ７３ CHAPTER IV. HUMAN GENETICS AND SMOKING SHAPE THE AIRWAY MICROBIOTA Introduction................................................................................................ ７９ Materials and Methods............................................................................... ８１ Results........................................................................................................ ８５ Discussion.............................................................................................. １０３ CHAPTER V. CONCLUSIONS Summary and Conclusions .................................................................... １０９ BIBLIOGRAPHY.............................................................................................. １１１ APPENDICES.................................................................................................... １２５ ABSTRACT IN KOREAN................................................................................ １３６Docto

화장품 동시사용 시나리오에 기반한 종합노출평가법 개발

학위논문(박사)--서울대학교 대학원 :보건대학원 환경보건학과,2020. 2. 이기영.전통적인 화학물질 노출평가는 단일 노출원을 통한 노출에 한정된다. 인체에 노출되는 화학물질의 양을 현실적으로 추정하기 위해서는 단일 화학물질의 다양한 노출원과 노출경로를 고려한 종합노출평가를 실시할 필요가 있다. 화학물질의 노출 및 위해성평가에 사용되는 단계적 접근법은 종합노출평가에도 적용이 가능하지만, 구체적인 적용방법은 아직 논의된 바 없다. 본 연구의 목표는 소비자제품의 동시사용을 고려한 높은 단계의 종합노출평가법을 개발하는 것이다. 대상 제품은 화장품이며, 대상 화학물질은 디에틸헥실프탈레이트(di(2-ethylhexyl) phthalate, DEHP), 디부틸프탈레이트(di-n-butyl phthalate, DnBP), 디에틸 프탈레이트(diethyl phthalate, DEP)의 프탈레이트 3종이다. 인구구성비에 근거한 비례대표추출을 통해 한국인 1,001명의 표본을 구축하고 가정방문설문조사를 통해 화장품 31종 사용에 대한 노출계수를 수집하였다. GC-MS-MS를 통해 214개 화장품 내의 프탈레이트 농도를 분석하였다. 첫번째 연구(chapter 2)는 화장품 사용을 통한 프탈레이트 노출을 수용체 기반 노출평가를 통해 추정하고 제품 기반 노출평가 결과와 비교하고자 하였다. 수용체 기반 노출평가는 개인이 동시에 사용(co-use)하거나 사용하지 않는(non-use) 제품을 고려하여 제품별 실제 노출계수를 통해 노출평가가 이루어진다. 제품 기반 노출평가는 제품 사용자의 노출계수에 인구집단의 사용률을 반영하여 노출평가가 이루어지며, 두가지 방법으로 추정한 노출량을 비교하였다. 수용체 기반 노출평가 방법으로 추정한 프탈레이트의 평균 종합노출량은 DEHP가 0.68 ± 0.87 μg/kg/day, DnBP가 1.08 ± 5.71 μg/kg/day, DEP가 2.47 ± 9.05 μg/kg/day이다. 수용체 기반 노출평가량에 기여율이 높은 화장품 분류는 DEHP는 스킨케어용품와 바디케어용품, DEP는 손톱케어용품, DEP는 방향용품과 헤어케어용품이었다. 인구학적 분류로는 젊은 여성 집단의 프탈레이트 노출량이 가장 높았다. 수용체 기반 노출평가 방법은 인구집단의 평균노출을 제품 기반 노출평가 방법보다 낮게 추정하였으나, DnBP와 DEP의 경우, 90분위수 이상의 고노출군의 노출량은 제품 기반 노출평가 방법보다 높게 추정하였다. 두번째 연구(chapter 3)는 화장품의 동시사용 패턴의 특징을 파악하고 성별과 연령에 따른 인구집단의 화장품 동시사용 시나리오를 작성하고자 하였다. 화장품의 동시사용 패턴은 정확한 종합노출평가를 위해 중요한 요소이다. 한국인의 국민대표 화장품 노출계수 데이터베이스가 화장품 동시사용 패턴 분석에 사용되었다. 1,001명의 화장품 31종의 사용여부를 사용과 비사용의 범주형 변수로 처리하였다. 동시사용 패턴 분석을 위해 세가지 분석법을 사용하였다. 첫째, 제품쌍의 상관성 분석을 위해 Cohen의 kappa 상관계수를 사용하였고, 화장품의 동시사용 패턴에 성별의 차이가 미치는 영향을 확인하였다. 둘째, 계층적 군집 분석을 위해 이원적 연결법을 사용하였고, 화장품의 군집이 많은 수의 제품이 포함된 거대한 하나의 클러스터와 1개 혹은 2개의 제품이 포함된 작은 클러스터로 분류되는 현상을 확인하였다. 셋째, 빈발 패턴 마이닝을 위해 eclat 알고리즘을 사용하였고, 사용하는 화장품의 개수와 동시사용 패턴은 성별과 연령이 모두 영향을 미치는 것을 확인하였다. 화장품의 동시사용 패턴은 새로움 제품이 기존의 제품 사용 패턴에 더해지는 누적성이 나타났다. 세 가지 분석법을 통해 확인한 화장품의 동시사용 패턴의 특징을 모두 반영하여, 동시사용 패턴 내 빈발 순위와 인구집단의 화장품 사용개수 분포를 결합하여 화장품 동시사용 시나리오를 작성하였다. 4가지 인구집단의 25, 50, 75, 95 분위수에 대한 화장품 31종의 동시사용 시나리오 16가지를 결정하였다. 세번째 연구(chapter 4)는 제품 동시사용 시나리오를 기반으로 종합노출평가를 실시하고 수용체 기반 노출평가법과의 비교를 통해 새로운 평가법을 검증하고자 하였다. 제품의 동시사용을 고려한 종합노출평가법은 모든 제품의 노출량을 합산하는 종합노출평가법보다 높은 단계의 평가법이다. 화장품 동시사용 시나리오를 통해 화장품 사용을 통한 DEHP, DnBP, DEP의 종합노출량을 확률론적 방법으로 추정하였다. 성별과 연령에 의한 4가지 인구집단의 25, 50, 75, 95분위수에 해당하는 종합노출량이 도출되었다. 민감도 분석을 통해 동시사용 시나리오 기반 종합노출량에 기여율이 큰 화장품을 규명하였다. 동시사용 기반 종합노출평가량은 인구집단의 75분위수 이하에서는 수용체 기반 종합노출평가량보다 컸고, 95분위수에서는 수용체 기반 종합노출평가량 보다 작았다. 새로운 종합노출평가법이 낮은 단계의 평가법인 제품 기반 노출평가법보다 가장 높은 단계의 평가법인 수용체 기반 노출평가법에 근접하여 중간 단계의 평가법임을 알 수 있었다. 본 연구를 통해 개발한 동시사용 시나리오 기반 종합노출평가법을 통해 개인의 실제 사용 제품의 패턴과 노출계수를 매번 새롭게 조사할 필요없이 적은 종류의 입력값만으로도 종합노출평가를 실시할 수 있다. 동시사용 시나리오 기반 종합노출평가법은 수용체 기반 노출평가법보다 간단하고, 모든 제품이 아닌 동시사용과 비사용 제품을 고려한 현실적인 추정법이며, 종합 노출 및 위해성에 기반한 화학물질 및 제품 관리에 활용할 수 있다.Traditional chemical exposure assessments were conducted to a single exposure source. For a realistic estimation of chemical exposures to human body, aggregate assessment of a chemical across multiple routes and sources should be considered. The tiered approach for chemical exposure and risk assessment could applied to aggregate exposure assessment. However, the specific application method was not yet developed. The objective of this study were to develop a higher tier aggregate exposure assessment methodology based on co-use scenarios of multiple consumer products and to apply for phthalate aggregate exposure assessment. The target consumer products were cosmetic products, and the target chemicals were three phthalates, that is, di(2-ethylhexyl)phthalate (DEHP), di-n-butyl phthalate (DnBP), and diethyl phthalate (DEP). Exposure factors for 31 cosmetic products were collected by face-to-face interviews with 1,001 subjects who were selected by national representative sampling of Korean population. The concentrations of phthalates in 214 cosmetic products were analyzed by GC-MS-MS. The first study aimed to estimate receptor-based aggregate exposures to phthalates through cosmetics and to compare with product-based aggregate exposures. A receptor-based aggregate exposure assessment was conducted according to individuals exposure factors and simultaneous use patterns including co-use and non-use. A product-based aggregate exposure assessment was conducted by product usage rates of population and users exposure factors. The average aggregate exposure dose (AED) determined by the receptor-based method for DEHP, DnBP, and DEP were 0.68 ± 0.87, 1.08 ± 5.71, and 2.47 ± 9.05 μg/kg/day, respectively. Based on the receptor-based AED, the most contributing cosmetics were skin care and body care products for DEHP, nail care products for DnBP, and fragrance and hair care products for DEP. The young female group showed the highest exposure. Although average population exposure by product-based aggregate exposure underestimated, 95th percentiles of product-based aggregate exposure for DnBP and DEP were significantly overestimated. The second study aimed to characterize co-use patterns of cosmetics and to determine the co-use scenarios for gender-age population groups. The co-use patterns of cosmetics should be critical for accurate aggregate exposure assessment. The Korean national representative exposure factor database was used to analyze the co-use patterns of cosmetics. The use or non-use of 31 cosmetics was treated as a categorical variable. Three analytical methods were applied to determine the co-use patterns. Cohens kappa coefficient was used to analyze the correlation between pairs of cosmetics. This method revealed an influence of gender on the co-use pattern of cosmetics. Hierarchical clustering analysis was performed using the binary linkage distance method. The clusters were divided into one large cluster and small clusters of one or two cosmetics. Frequent pattern mining was performed using the eclat algorithm. The number of used cosmetics and co-use pattern were influenced by gender and age of the population. The co-use patterns exhibited an additive property in that new cosmetics were added to previous combinations with increases in the number of cosmetics. In addition to the three analytical methods, a co-use scenario was proposed using the rank of frequency of occurrence in co-use patterns and percentile values of the distribution of the number of used cosmetics. The 16 co-use scenarios for the 31 cosmetics were determined to the 25, 50, 75, and 95th percentiles of the distribution of four gender-age population groups. The third study aimed to perform aggregate exposure assessment based on co-use scenarios from the second study and to validate the novel methodology by comparing with the results of receptor-based aggregate exposure assessment. Aggregate exposure assessment considering specific products in co-use scenario was a higher tier approach than product-based aggregate exposure assessment. The aggregate exposures to DEHP, DnBP, and DEP in cosmetics were estimated by co-use scenario based aggregate exposure assessment by probabilistic approaches. The AED values were derived representing 25, 50, 75 and 95th percentiles of four population groups by gender and age. The most contributing cosmetics to co-use scenario based AED were determined by sensitivity analysis. The validation of co-use scenario based aggregate exposure assessment methodology was conducted by comparison with receptor-based AED. The co-use scenario based AEDs were slightly higher than receptor-based AED below 75th percentiles of population, and slightly lower at 95th percentile. The aggregate exposure assessment methodology using co-use scenarios was closer to the receptor-based AED than product-based AED. These studies shows that co-use scenario based estimations could be useful to perform aggregate exposure assessment with less resources, rather than investigating each individuals actual product usage patterns each time. It was relatively simple estimation than the receptor-based estimation, nevertheless realistic estimation that considering co-use and non-use rather than all available products, and could be applied easily for integrated risk management of chemicals.Chapter I. Introduction 1 1.1. Background 2 1.2. Objectives 15 Chapter II. Receptor-based aggregate exposure assessment of phthalates using individuals simultaneous use of multiple cosmetic products 18 2.1. Introduction 19 2.2. Methods 22 2.3. Results 29 2.4. Discussion 47 2.5. Conclusions 56 Chapter III. Characteristics of cosmetics co-use pattern and determination of co-use scenarios for aggregate exposure assessment 57 3.1. Introduction 58 3.2. Methods 61 3.3. Results 65 3.4. Discussion 84 3.5. Conclusions 90 Chapter IV. Application and validation of aggregate exposure assessment for phthalates based on cosmetic co-use scenarios 91 4.1. Introduction 92 4.2. Methods 95 4.3. Results 99 4.4. Discussion 108 4.5. Conclusions 113 Chapter V. Summary and Conclusions 114 References 119 Supplements 134 국문초록 148Docto

METEAL STRUCTURE FOR FORMING SKYRMION AND METHOD FOR FORMING SKYRMION IN METAL STRUCTURE}

본 발명은 메탈 구조물 및 그 제조 방법에 관한 것으로, 헤비메탈층(Heavy Metal layer); 상기 헤비메탈층 상에 형성되는 강자성층(Ferromagnetic layer); 및 상기 강자성층 상에 형성되는 반강자성층(Anti-Ferromagnetic layer)을 포함하고, 상기 반강자성층은 상기 강자성층과 접합되어 있는 제1 영역과 상기 강자성층과 접합되어 있지 않은 제2 영역을 포함하는 것을 특징으로 한다

Investigation of Ingredients and Hazardous Substances in Disinfectants Used against COVID-19 and Some Livestock Diseases

Objectives: The Coronavirus Disease 2019 (COVID-19) pandemic has caused the death of 740,000 people around the world as of August 12, 2020. Foot-and-Mouth Disease, Avian Influenza, and African Swine Fever are serious livestock diseases. Government agencies in Korea have provided ingredient information and usage instructions for disinfectants used to counter those infectious diseases. The purpose of this study was to provide information on the chemical ingredients in disinfectant products used against COVID-19 and certain livestock diseases. Methods: We collected information from the Korean government. The Central Disaster Management Headquarters and Central Disease Control Headquarters provided information on disinfectant products used against COVID-19. The Animal and Plant Quarantine Agency of Korea provided information on efficacy�certified disinfectant products for use against selected livestock diseases. Health hazard and environmental hazard information on the ingredients in the disinfectants was collected from the Korea Occupational Safety & Health Agency’s Material Safety Data Sheets, and toxicity value information was collected from United States Environmental Protection Agency’s CompTox Chemicals Dashboard. Results: There were 76 COVID-19 disinfectant products in use, and the most common ingredients were benzalkonium chloride (51%), alkylbenzyl dimethyl ammonium (30%), and ethanol (3%). There were 216 livestock disease disinfectant products comprised of 89 acidic, 88 oxidic, 30 aldehydic, three alkaline, and six other products. Among the 49 active ingredients used in the disinfectants that were investigated, health and environmental hazard information was provided for many of them, but only 20 chemicals had official toxicological information. Conclusion: Since the disinfectants included numerous chemicals, an understanding of their chemical characteristics could be critical to prevent unintended human or environmental exposure.N

MEMORY DEVICE BY USING BLOCH-POINT STRUCTURE AND MANUFACTURING METHOD THEREOF

본 발명에 따른 블로흐 포인트 구조체를 이용한 메모리 디바이스는, 블로흐 포인트 구조체를 이용한 메모리 디바이스에 있어서, 소정 패턴 구조의 제 1 강자성층(ferromagnetic layer)과, 상기 제 1 강자성층 상에 형성된 비자성층(non-magnetic layer)과, 상기 제 1 강자성층과 상기 비자성층을 매립하는 형태로 수평하게 형성되어 상기 비자성층의 상부를 노출시키는 제 1 반강자성층(antiferromagnetic layer)과, 상기 비자성층과 상기 제 1 반강자성층 상에 형성된 제 2 강자성층과, 상기 제 2 강자성층 상에 형성된 제 2 반강자성층을 포함하고, 상기 메모리 디바이스는, 상기 제 1 강자성층과 상기 비자성층의 상부가 제 1 영역으로 구획되고, 상기 제 1 영역을 제외한 나머지 상부가 제 2 영역으로 구획될 수 있다