서울시 대기오염과 천식증상 비교 연구 : 2012 - 2013년 지역사회건강조사 자료를 중심으로

보건대학원/석사서울시는 인구밀집도가 매우 높으며, 이에 따른 교통밀집도도 높아 자동차에 의한 대기오염이 심각한 수준이다. 특히, 서울시 자동차 등록대수는 매년 높은 폭으로 증가하고 있어, 교통량과 대기질, 그리고 거주자의 호흡기건강에 관한 연구가 필요하다. 하지만 최근의 연구들은 단기간, 국소적인 지역을 대상으로 수행되고 있어, 서울시 전체의 포괄적인 연구자료가 필요한 실정이다. 본 연구에서는 국가 대기측정망자료(2012-2013년)를 통하여 행정구역별 미세먼지, 이산화질소, 이산화황의 대기오염농도를 시간별 자료로 구축하였으며, 교통정책의 효과를 계량 및 평가하기 위해 한국교통연구원에서 구축하는 기종점 도로교통량 자료(2012-2013년)를 통하여 서울시 행정구역을 교통량 고노출지역과 저노출지역을 구분하였으며, 질병관리본부의 지역사회건강조사(2012- 2013년) 원시자료를 통하여 고노출지역과 저노출지역에 따른 천식증상의 관계분석에 이용하였다. 수집한 자료를 바탕으로 교통량에 따른 대기오염물질 농도간의 상관관계를 분석하였으며, 교통 환경·요인이 거주자의 천식증상에 미치는 영향을 로지스틱 회귀분석을 통하여 다음과 같은 주요 결과를 도출하였다. 첫째, 저노출지역에 비해 고노출지역은 계절별, 시간별로 이산화질소(NO2), 이산화황(SO2) 농도가 통계적으로 유의하게(p<0.01) 높은 것으로 나타났다. 둘째, 행정구역별 도로교통량과 대기오염물질 농도의 상관관계를 관찰한 결과, 출근 시간인 오전첨두시간(07:00-09:00)에는 통계적으로 유의한 상관관계를 관찰 할 수 없었으며, 퇴근 시간인 오후첨두시간(18:00-20:00)에는 이산화질소의 경우 승용차 교통량과 통계적으로 유의한(p<0.05) 양의 상관관계를 관찰 할 수 있었다. 또한, 일평균 대기측정망 환경농도와 일평균 도로교통량과의 상관관계 분석 결과, 이산화질소는 승용차 교통량과 총 교통량과 통계적으로 유의한(P<0.01) 양의 상관관계를 관찰 할 수 있었으며, 화물차 교통량과도 통계적으로 유의한(p<0.05)양의 상관관계로 나타났다. 이산화황은 화물차 교통량과 통계적으로 유의한(p<0.01) 양의 상관관계로 나타났다. 셋째, 로지스틱 회귀분석을 통해 고노출지역과 저노출지역의 운동성 천식 진단에 대한 보정교차비를 분석한 결과, 보정 전 로지스틱 모형과, 성별과 연령을 보정한 모형(Model 1)과, 성별과 연령과 건강행태 특성과 인구사회학적 특성을 보정한 모형(Model 2)에서 모두 보정교차비가 1을 초과하였지만, 통계적으로 유의하지 않았다. 한편, 최근 1년 중 천식 증상에 대한 보정교차비를 분석한 결과, 저노출지역에 비해 고노출지역에서 최근 1년 중 천식 증상의 보정교차비가 1.316(95% CI: 1.042 - 1.662)로 나타났으며, 통계적으로 유의하였다(p<0.05). 의사천식진단의 경우, 저노출지역에 비해 고노출지역에서 의사 천식 진단의 보정교차비(Model 2)가 1.624 (95% CI: 1.269 - 2.077)로 나타났으며, 통계적으로 유의하였다(p<0.001). 또한 총 도로교통량의 경우 일평균 10,000대가 증가할 경우, 통계적으로 유의하게(p<0.05) 의사 천식 진단의 보정교차비가 3.7% 증가하는 것으로 나타났으며, 이산화질소가 1ppb 증가할 경우 통계적으로 유의하게(p<0.05) 의사 천식 진단의 보정교차비가 3.8% 증가하는 것으로 나타났다. 이상의 연구결과를 종합하여 볼 때, 교통량 저노출지역에 비해 고노출지역은 해당지역 거주자의 최근 1년간 천식증상과 의사 천식 진단율을 증가시키는 것으로 나타났으며, 교통관련 대기오염물질인 이산화질소 농도의 증가는 의사 천식 진단율을 증가 시키는 것을 확인할 수 있었다. 또한 교통관련 대기오염물질인 이산화질소의 일평균 농도와 양의 상관관계가 있는 총 교통량 역시 의사 천식 진단율을 증가시키는 것을 확인할 수 있었다. 향후 지속적인 연구를 통하여 보완하여 통계적으로 검정력 있는 자료를 구축한다면, 서울시의 교통·환경정책을 수립하는 객관성 있는 근거자료로써 활용될 수 있을 것으로 기대해본다.ope

대면적 그래핀의 전자기파 흡수 및 가스 배리어 특성과 스마트 어플리케이션에의 응용 연구

학위논문 (박사)-- 서울대학교 대학원 : 자연과학대학 화학부, 2019. 2. 홍병희.Graphene is an atomically thin carbon material with a two-dimensional hexagonal lattice that shows outstanding electrical and mechanical properties as well as excellent biocompatibility. Thanks to its outstanding electrical property, graphene can be utilized as very high performance electromagnetic (EM) wave shielding materials with extreme thin and transparent, light-weight. It is reported that ideal graphene can block as much as 97.8% of EMI. Also, It is reported that the monolayer graphene synthesized by CVD has an average SE value of 2.27dB, corresponding to 40% shielding, presenting 7 times (in terms of dB) greater SE than gold film. In addition, small gas molecules cannot pass through graphene, because its densely packed hexagonal lattice structure of carbon atoms. In these reasons, I believe that graphene is the most suitable materials to realize such smart electronics (wearable contact lens device, heater for automobile, so on) We report a CVD graphene-based highly conducting contact lens platform that reduces the exposure to EM waves and dehydration. Additionally, we demonstrate simple contact lens platform micro LED operating devices fabricated by CVD graphene-based conductive layers. Thus, we believe that the graphene-coated contact lens would provide a healthcare and bionic platform for wearable technologies in the future. We also demonstrate EM wave shielding mechanism of graphene. Graphene generate a heat energy as a result of EM wave shielding. Therefore, this allows graphene heater to be used widely in fields of automobile defogging/deicing systems, smart heating windows and EM-wave detecting sensors.탄소 원자가 2차원 방향으로 육각 격자 구조를 이루고 있는 그래핀은 뛰어난 기계적, 전기적 특성 뿐 아니라 생체친화적인 재료로 알려져 있다. 뛰어난 전기적 특성 때문에 그래핀은 가볍고 투명하면서도 매우 우수한 전자기 차폐 재질로 활용 될 수 있다. 구조적인 결함이 없는 이상적인 그래핀은 97.8%의 전자기 차폐 특성을 구현 할 수 있다고 보고 되고 있다. 실험적으로는 그래핀을 대면적으로 합성 할 수 있는 CVD법으로 제작 한 그래핀에서 모노레이어 기준으로 40%의 전자기 차폐 효과를 얻을 수 있고, 이는 단위 두께로 환산 시 금 박막과 비교하여 7배에 해당하는 수치이다. 또한 그래핀은 탄소 원자가 육각형의 안정적인 구조로 밀집 해 있어 가스 투과를 차단하는 특성도 가지고 있다. 이렇듯 그래핀은 가볍고, 투명하며 생체친화적인 재질에다 전기적, 기계적 특성이 우수하여, 최근 각광 받고 있는 스마트 일렉트로닉스를 구현하는데 있어 가장 적합한 재료로 판단 된다. 이 논문에서는 CVD 그래핀의 우수한 전자기파 차폐 및 가스 투과 차단 특성을 이용하여, 그래핀이 코팅 된 컨택트 렌즈에서 전자파 차폐 및 안구 건조를 방지하는 효과기 있음을 간접적인 방법으로 증명 하였다. 또한 컨택트 렌즈 위에 그래핀을 정밀 패턴하고 간단한 Micro LED Device를 제작 함으로서 그래핀을 스마트 컨택트 렌즈를 구현하는데 있어 다양한 용도의 물질로 활용 할 수 있음을 보였다. 또한 CVD 그래핀의 EM 차폐 메커니즘이 그래핀의 높은 전자이동도 및 반자성 특성 때문이라는 것을 증명 하였다. 그래핀의 전자파 차폐 과정에서 열 에너지가 효율적으로 발생되는 것을 이용하여 차량용 방습 히터 등의 어플리케이션으로 활용 가능성을 보였다.Abstract 1 Contents 3 List of Figures 5 1. General Introduction 1.1 Graphene 13 1.2 Graphene Synthesis 23 1.3 Scope of the Thesis 34 1.4 References 35 2. Smart Contact Lenses with Graphene Coating for Electro Magnetic Interference Shielding and Dehydration Protection 2.1 INTRODUCTION 40 2.2 RESULTS AND DISCUSSION 42 2.3 CONCLUSIONS 53 2.4 EXPERIMENTAL SECTION 54 2.5 REFERENCES 61 3. Efficient heat generation in large-area graphene films by electromagnetic wave absorption 3.1 INTRODUCTION 66 3.2 RESULTS AND DISCUSSION 68 3.3 CONCLUSION 78 3.4 EXPERIMENTAL SECTION 79 3.5 REFERENCES 87 Appendix (List of Publications) 92 Abstract (Korean) 93 Acknowledgement (Korean) 95Docto

Reasons for Surgery Cancellation in a General Hospital: A 10-year Study

Background: This study researched related causes that make scheduled surgeries canceled not to be conducted and based on the research it is to derive issues in order to reduce surgery cancellation. Methods: We analyzed the association of surgery cancellation with patient characteristics, surgical characteristics and surgery schedule related characteristics, using electronic medical record (EMR) data on surgeries conducted at a university hospital in Korea over 10 years. Additionally, we examined the reasons for surgery cancellation based on patient and hospital characteristics. We used chi-square tests to analyze the distribution of various characteristics according to reasons for surgery cancellation. Multivariate logistic regression analyses were conducted to evaluate the factors associated with surgery cancellation. Results: Among 60,333 cases, surgery cancellation rate was 8.0%. The results of the logistic regression indicated a high probability of surgery cancellation when the patient was too old (odds ratio [OR]: 1.35, 95% confidence interval [CI]: 1.14⁻1.59), when it was a neurosurgery case (OR: 1.39, 95% CI: 1.21⁻1.59), when local anesthesia was used (OR: 1.15, 95% CI: 1.07⁻1.24) or when it was a planned surgery (OR: 2.45, 95% CI: 2.21⁻2.73). The surgery cancellation rate was lower when the patient was female (OR: 0.87, 95% CI: 0.82⁻0.93) or when the surgery was related to Obstetrics & Gynecology (OR: 0.53, 95% CI: 0.46⁻0.60) or Ophthalmology (OR: 0.66, 95% CI: 0.56⁻0.79). Among the canceled 4834 cases, the surgery cancellation rate for the reasons of patients was 93.2% and the surgery cancellation rate for the reasons of a hospital was 6.8%. Conclusions: This study found that there are related various causes to cancel operations, including patient characteristics, surgery related characteristics and surgery schedule related characteristics and it means that it would be possible for some reasons to be prevented. Every medical institution should consider the operation cancellation as an important issue and systematic monitoring should be needed.ope

한국 애기털보부채게상과와 부채게상과의 계통분류학적 연구

학위논문 (박사)-- 서울대학교 대학원 : 생명과학부, 2013. 2. 김원.A systematic study was conducted on the Korean pilumnoid and xanthoid crabs. The specimens, deposited in the Laboratory of Systematics and Molecular Evolution in Seoul National University since 1950, were examined for the present study. They have been collected from the intertidal and shallow subtidal zones in Republic of Korea. As a result, 18 species of 12 genera and 28 species of 24 genera were identified in the superfamily Pilumnoidea and the superfamily Xanthoidea, respectively. The updated checklist and the key to species of Korean pilumnoids and xanthoids were provided herein. A total of 46 speceis have been recorded with the specific characters including the pictures, the illustrations. Moreover, their distribution in Korean peninsular and the worldwide was displayed on the map, and their habitats were investigated. Of these, one pilumnoid and 8 xanthoids were first recorded from Korea: Actaea polyacantha (Heller, 1861), Actaeodes hirsutissimus (Rüppell, 1830), Atergatopsis germaini A. Milne-Edwards, 1865, Danielea noelensis (Ward, 1934), Etisus anaglyptus H. Milne Edwards, 1834, Gaillardiellus rueppelli (Krauss, 1843), Lybia caestifera (Alcock, 1898), Neoactumnus convexus Sakai, 1965, and Platypodia tomentosa (De Man, 1902). The mtCOI sequences from 26 species of the Korean pilumnoids and xanthoids were obtained, and examined by DNA barcoding method. The some suspected cryptic species or misidentified specimens were discovered, and then molecular taxonomic relationship among them was inferred by Baysian inferences and Maximum likelihood. According to Baysian inferences tree, a significant taxonomic relationship was found as follows: 1) Neoliomera insularis would be questioned their taxonomic status, 2) Based on the relationship between Leptodius nigromaculatus and L. affinis, the two species were the same species, 3) Actaea bocki (Odhner, 1925) would be considered to examined their taxonomic status, 4) Korean Medaeops granulosus would be not real M. granulosus or a cryptic species. Zehntneriana villosa (Zehntner, 1894) were examined and redescribed with illustrations herein with the illustration. Zehntneriana villosa from Japan, used to establish the genus Zehntneriana, was found out to be a new species. As a result of the revision of the genus Leptodius A. Milne-Edward, 1863, the genus Leptodius are consisting 10 speices: L. acutidens (Stimpson, 1907), L. affinis (De Haan, 1835), L. australis Ward, 1936, L. davaoensis Ward, 1941, L. exaratus A. Milne-Edwards, 1834, L. gracilis Dana, 1852, L. planus Ward, 1834, L. sanguineus A. Milne-Edwards, 1834, and L. nudipes (Dana, 1853). As regards recorded five species of recent checklist, Leptodius nigromaculatus Serène, 1962 would be synonymized as L. affinis (De Haan, 1835). Leptodius philippinensis Ward, 1941 and L. hombronii (Lucas, in Jacquinot & Lucas, 1853) would be synonymized as L. sanguineus. Leptodius efference Rathbun, 1907 and L. waialuanus Rathbun, 1906 would be considered to transfer to the genus Liocarpilodes Klunzinger, 1913 and the genus Etisus H. Milne Edwards, 1834, respectively.ABSTRACT iii CONTENTS iv GENERAL INTRODUCTION 1 MATERIALS AND METHODS 4 Chapter 1. Faunal and molecular taxonomic study 8 1-1. Faunal study of Korean pilumnoids and xanthoids 9 1-2. Molecular taxonomic study of Korean pilumnoids and xanthoids using DNA barcoding 192 Chapter 2. Taxonomic revision 204 2-1. Redescrtiption of Zehntneriana villosa (Zehntner, 1894), with new record of Zehntneriana n. sp. 205 2-2. A revision of the genus Leptodius A. Milne-Edwards, 1863 222 CONCLUSION 305 REFERENCES 314 ABSTRACT (Korean) 343Docto

Association between diabetes-related factors and clinical periodontal parameters in type-2 diabetes mellitus

BACKGROUND: Evidence consistently shows that diabetes is a risk factor for increased prevalence of gingivitis and periodontitis. But there is a controversy about the relationship between diabetes related factors and periodontal health. The aim of the present study is to explore the relationship between diabetes related factors such as glycosylated hemoglobin, fasting blood glucose, duration of diabetes and compliance to diabetes self management and periodontal health status. METHODS: Periodontal health of 125 participants with type-2 diabetes mellitus was measured by the number of missing teeth, community periodontal index (CPI), Russell's periodontal index and papillary bleeding index. Information on sociodemographic factors, oral hygiene behavior, duration and compliance to self management of diabetes, levels of glycosylated hemoglobin(HbA1c) and fasting blood glucose(FBG) were collected by interview and hospital medical records. Statistically, independent t-test, an analysis of variance (ANOVA), chi-squared test and multiple regression analyses were used to assess the association between diabetes-related factors and periodontal health. RESULTS: Periodontal parameters including the number of missing teeth and papillary bleeding index were significantly influenced by duration of diabetes, FBG and compliance to self management of diabetes. CPI was significantly influenced by duration of diabetes, FBG and HbA1C. And Russell's periodontal index was significantly influenced by duration of diabetes, FBG, HbA1C and compliance to self management of diabetes. Results of multiple linear regression analysis showed that the duration of diabetes showed significant positive correlation with all of the periodontal health parameters, except for missing teeth. HbA1c was correlated with Russell's periodontal and papillary bleeding index. FBG and compliance to self management of diabetes were correlated with missing teeth and papillary bleeding index respectively. CONCLUSIONS: Diabetes-related factors such as duration of diabetes, FBG, HbA1c and compliance to self management of diabetes were significantly correlated with periodontal health among individuals with type-2 diabetes.ope

Implementation and Evaluation of Active Biasing Circuit for Temperature Compensation of RF Power Amplifier

In this paper, the power amplifier using active bias circuits for LDMOS(Lateral Diffused Metal Oxide Semiconductor) MRF-21060 is designed and fabricated. According to change the temperature, the gate voltage of LDMOS is controlled by the fabricated active bias circuits, which is made of PNP transistor to suppress drain current. The driving amplifier using AH1 and parallel power amplifier AH11 is made to drive the LDMOS MRF-21060 power amplifier. The variation of current consumption in the fabricated 5 Watt power amplifier has an excellent characteristics of less than 0.1 A, whereas passive biasing circuit dissipate more than 0.5 A. The implemented power amplifier has the gain over 12 dB, the gain flatness of less than ±0.09 dB and input and output return loss of less than -19 dB over the frequency range 2.11 ~ 2.17 GHz. The DC operation point of this power amplifier at temperature variation from 0 ℃ to 60 ℃ is fixed by active bias circuit.제 1 장 서론 = 1 1.1 연구 배경 = 1 1.2 연구 목적 = 2 제 2 장 초고주파 전력증폭기의 기본이론 = 4 2.1 전력이득 = 4 2.2 안정성 = 8 2.3 증폭기의 잡음 = 12 2.4 비선형 특성 = 15 제 3 장 온도 보상용 능동 바이어스 회로 설계 = 18 3.1 MRF-21060 소자의 특성 = 18 3.2 LDMOS FET 전력증폭기의 바이어스 = 20 3.3 능동 바이어스 회로 설계 = 23 3.4 구동 증폭단의 설계 = 26 3.5 5 Watt 단위 이득 증폭기 = 31 제 4 장 전력증폭기용 온도 보상회로의 제작 및 측정 = 34 4.1 온도 보상용 능동 바이어스 회로의 제작 = 34 4.2 특성 측정 및 평가 = 35 제 5 장 결론 = 39 참고 문헌 = 4

The Role of Hospital Transfer in Reexamination Computed Tomography Scans: A Nationwide Cohort Study of Gastric Cancer Patients Undergoing Surgery

Because the high-cost of medical imaging can cause a tremendous economic burden across the health care system, we investigated factors associated with taking additional computed tomography (CT) scans. Data of gastric cancer patients were eligible for analysis if the patient underwent a gastrectomy during the study period (2002-2013). We defined initial CT scans as those taken within 90 days from the surgery date. If there was an additional CT scan between the date of an initial CT scan and the surgery date, we regarded it as a reexamination. We used multivariate logistic regression analysis for reexamination CT scans. Among 3342 gastrectomy patients, 1165 participants underwent second CT scans. Transfer experience (adjusted odds ratio (OR) = 23.87, 95% confidence interval (CI) = 18.15-31.39) was associated with higher OR for reexamination. Among transferred patients, an increased number per 100 beds at the initial CT hospital was associated with a decreased OR for reexamination (OR = 0.88, 95% CI = 0.83-0.94), but increased beds in surgery hospitals was related to an increased OR for reexamination (OR = 1.29, 95% CI = 1.20-1.36). In our study, transfer experience, initial CT scan in a low-volume hospital, and surgical treatment in a high-volume hospital were associated with reexamination CT scans.ope

Prevalence of Attention-Deficit/Hyperactivity Disorder and its Comorbidity among Korean Children in a Community Population

The aim of this study was to determine the prevalence of attention deficit hyperactivity disorders (ADHD) in children according to socio-demographic factors and the distribution of ADHD subtypes in a community in Korea. A screening survey using the Korean version of ADHD Rating Scale (K-ARS) was conducted between 2007 and 2008, and clinical interviews by a pediatric psychiatrist were performed for selected children between 2009 and 2010. A total of 49,573 elementary school students, between ages of 7 and 12, constituted the target population, among which 38,365 students (77.2%) and respective parents gave consent to participate. Of the participants, 200 screened children were clinically examined to confirm the diagnosis of ADHD. We estimated the prevalence of ADHD and its comorbidity in the population, after adjusting for nonresponse and nonparticipation. The prevalence of ADHD was 11.7% in boys and 5.2% in girls, with an overall prevalence of 8.5%. The combined type of inattentive and hyperactive was the most frequent at 4.7% of the whole population. Children were more likely to have ADHD if their parents were separated and had less education. Most commonly combined comorbidity was autism spectrum disorder (ASD) (10.1%). The prevalence of ADHD in the school-aged population is an essential information for improving the quality of public health mental services for evaluation and treatment of ADHD.ope

Quality of Life of Family Members Living with Cancer Patients

BACKGROUND: Due to the rapid progress of industrialization, the expansion of the nuclear family, and an increase in women's social activities, the burden of care of cancer patients has increased, so that all family members are now involved in care. We compared the health-related quality of life (HRQOL) between members of families of cancer patients (hereafter, cancer families) and members of cancer-free families (non-cancer families). MATERIALS AND METHODS: The data were from the Community Health Survey (2012). The study population included respondents at least 30 years of age. Data were adjusted for the following covariates: sex, age, education, marital status, household income, economic activity, household type, chronic disease, and perceived health status. Frequency analysis, analyses of variance, and multiple linear regression analysis were performed. RESULTS: Among 163,495 respondents, 3,406 (2.1%) were part of a cancer family and 160,089 (97.9%) were part of a non-cancer family. Cancer families had lower EQ-5D scores than non-cancer families. However, by subgroup, the scores had significant association between cancer and non-cancer families only for females and for those who worked. CONCLUSIONS: There was a significant relationship between HRQOL scores and being a family member of a cancer patient. This indicates that the responsibility for care has been extended to the entire family, not only the primary caregiver.ope

Effects of Hospital Workers' Friendship Networks on Job Stress

BACKGROUND: This study attempted to identify the sources of job stress according to job position and investigate how friendship networks affect job stress. METHODS: Questionnaires based on The Health Professions Stress Inventory (HPSI) developed by Wolfgang experienced by healthcare providers were collected from 420 nurses, doctors and radiological technologists in two general hospitals in Korea by a multistage cluster sampling method. Multiple regression analysis was used to examine the effects of friendship networks on job stress after controlling for other factors. RESULTS: The severity of job stress differed according to level of job demands (p = .006); radiologic technologists experienced the least stress (45.4), nurses experienced moderate stress (52.4), and doctors experienced the most stress (53.6). Those with long-term friendships characterized by strong connections reported lower levels of stress than did those with weak ties to friends among nurses (1.3, p < .05) and radiological technologists (11.4, p < .01). The degree of cohesion among friends had a positive impact on the level of job stress experienced by nurses (8.2, p < .001) and radiological technologists (14.6, p < .1). Doctors who participated in workplace alumni meetings scored higher than those who did not. However, those who participated in alumni meetings outside the workplace showed the opposite tendency, scoring 9.4 (p < .05) lower than those who did not. The resources from their friendship network include both information and instrumental support. As most radiological technologists were male, their instrumental support positively affected their job stress (9.2, p < .05). Life information support was the primary positive contributor to control of nurses' (4.1, p < .05), radiological technologists' (8.0, p < .05) job stress. CONCLUSION: The strength and density of such friendship networks were related to job stress. Life information support from their friendship network was the primary positive contributor to control of job stress.ope