아동의 한글 해득 수준에 따른 비교

학위논문(석사) -- 서울대학교대학원 : 사범대학 협동과정 유아교육전공, 2023. 2. 최나야.The aim of this study is to investigate the Hangeul acquisition levels of 5-year-old children and children in the first grade of the Korean education system, and to compare how the teachers of the aforementioned children and their parents differ in their opinions toward literacy guidance and Intensive Hangeul Education Policy (IHEP), a policy sponsored by the Korean ministry of education. In order to complete such tasks, the study examined whether or not the Hangeul acquisition level of children who are in the transitional period between kindergarten and elementary school showed any correlation with the way in which teachers and parents view literacy guidance and IHEP, and the differences between the four groups were compared based on their attitudes toward literacy guidance and the IHEP. Samples were collected from the Seoul metropolitan area in Korea and included the following: 156 5-year-old class kindergarten teachers, 177 parents of the 5-year-old children, 155 grade 1 elementary school teachers, and 184 parents of the 1st graders, which amounts to 4 distinct groups and 672 samples total. The participants were asked to record their responses on an online questionnaire, answering questions about the childrens Hangeul acquisition levels, literacy guidance (emergent and conventional), and IHEP (awareness, understanding of the program and its benefits, and openness). Regarding the Hangeul acquisition level, the teachers recorded their responses based on the mean level of Hangeul acquisition amongst their students, and parents responded in accordance with the level of Hangeul acquisition of their children. The collected data were analyzed using the SPSS Statistics 26.0 package, and descriptive statistics, independent sample t-test, one-way analysis of variance, and Scheffés test. The major finding of the study are as follows: First, according to the data collected from the teachers and the parents, the Hangeul acquisition level of first graders was statistically higher than that of 5 year olds. However, the 5 year olds also scored high on the Hangeul acquisition level, and there were first graders who scored low on the level. Second, depending on the level (high·middle·low) of a childs Hangeul acquisition level, there was a difference in how each of the aforementioned sample groups perceived literacy guidance and IHEP. As for the parents of 5 year olds and first graders, both groups showed that when a child belongs to the high level group, they gave more literacy—both emergent and conventional—guidance to the child. The kindergarten teachers, on the other hand, did not show any significant differences in emergent literacy guidance. They, however, did give more conventional literacy guidance to the high level children. The elementary school teachers exhibited the opposite result from the kindergarten teachers. There was no significant difference in the frequency of conventional literacy guidance depending on the childs Hangeul acquisition level, but for high level children, the elementary school teachers gave more guidance regarding emergent literacy. In addition, when a child belonged to the high level group, the parents of both 5 year olds and first graders and the elementary school teachers all showed positive attitudes toward IHEP, whereas if the child belonged to the middle or low group, they showed dissatisfaction with the policy. Third, the chosen method utilized by each sample group regarding literacy guidance was different. In terms of emergent literacy guidance, and the frequency at which it happens, kindergarten teachers scored the highest and the parents of 5 year olds scored the lowest. For conventional literacy guidance and its frequency, the elementary school teachers and the parents of first graders scored the highest, followed by the parents of 5 year olds, with the kindergarten teachers scoring the lowest. Fourth, there was a big distinction between the four sample groups in the way they perceived IHEP. With regard to awareness (of the policy), the elementary school teachers scored the highest, and the kindergarten teachers did the lowest. Understanding of the policy itself was shown to be the most present in the elementary school teacher group, compared to the rest. Understanding of the benefits of the policy was best done by the parents of the first graders, as opposed to the elementary school teachers, who showed low scores on this particular subcategory. Concerning the openness(toward the policy), the elementary school teachers demonstrated the highest levels of openness, compared to the parents of 5 year olds. In sum, this study has discovered that first graders score higher than 5 year olds on the level of Hangeul acquisition, that many 5 year olds have already acquired Hangeul, and that there are large individual differences within the same age group. The study also emphasizes the importance of preventing children from studying way too ahead of their levels, and the need for intervention programs for students who are slow learners. This study has also shown that there is a difference in the way in which the four sample groups—kindergarten teachers, parents of 5 year olds, elementary school teachers, and parents of first graders—perceive and understand literacy guidance and IHEP, depending on the level of Hangeul Acquisition(high·middle·low) of the children. Such a discordance was corroborated by the results of the analyses, which showed that each group gave children literacy guidance in unalike ways and had different views and attitudes toward IHEP. In conclusion, this study compared the objective status of the Hangeul acquisition level of children who are in the transitional period between kindergarten and elementary school, and provided educational implications for children's literacy development, the basis for establishing appropriate literacy guidance methods for kindergarten and elementary teachers, parents, and policymakers, and proposed a possible future direction for IHEP.본 연구는 5세 유아와 1학년 아동의 한글 해득 수준을 알아보고, 유치원과 초등학교 교사와 부모의 문해지도와 교육부 한글책임교육제에 대한 인식을 비교하고자 하였다. 이를 통해 유·초 전이기 아동의 한글 해득 수준이 유·초등 교사 및 부모의 문해지도와 한글책임교육제에 대한 인식과 관련이 있는지 살펴보고, 문해지도와 한글책임교육제에 대한 인식에 대해 네 집단 간의 차이를 비교하였다. 이를 위해, 수도권의 유치원 5세반 담임교사 156명, 5세아 부모 177명, 초등학교 1학년 담임교사 155명, 1학년 부모 184명, 총 672명의 자료를 수집하였다. 교사와 부모는 온라인 설문조사에 참여하여 아동의 한글 해득 수준, 문해지도(발현적 문해지도, 관습적 문해지도), 한글책임교육제에 대한 인식(정책인지도, 정책이해도, 정책이점인식, 정책수용도)을 측정하는 질문에 응답하였다. 이 중 아동의 한글 해득 수준에 대하여 교사는 학급 아동들의 평균 수준으로 보고했고, 부모는 자신의 자녀를 기준으로 평가하였다. 수집한 자료는 SPSS Statistics 26.0을 이용하여 기술통계분석, 독립표본 t-검정, 일원분산분석, Scheffé 사후검정으로 분석하였다. 본 연구의 주요 결과는 다음과 같다. 첫째, 교사와 부모의 평가에 의하면 5세 유아들보다 1학년 아동의 한글 해득 수준이 유의하게 높았다. 그러나 5세 유아의 한글 해득 수준도 상당히 높은 경향을 보인 반면, 1학년 아동 중에도 낮은 경우가 있는 것으로 나타났다. 둘째, 아동의 한글 해득 수준(상·중·하)에 따라 5세반 교사, 5세아 부모, 1학년 교사, 1학년 부모의 문해지도와 한글책임교육제에 대한 인식에 각각 차이가 있었다. 먼저 유·초등 부모들은 자녀가 한글 해득 수준 상집단일 때 발현적·관습적 문해지도를 동시에 더 많이 하는 것으로 나타났다. 반면 유치원 교사는 한글 해득 수준에 따라 발현적 문해지도에는 차이가 없었지만, 한글 해득 수준 상집단에 대해 관습적 문해지도를 유의하게 더 많이 하는 것으로 나타났다. 이와 반대로 1학년 교사는 아동의 한글 해득 수준에 따라 관습적 문해지도에는 차이가 없었지만, 상집단에 대해 발현적 문해지도를 더 많이 하는 것으로 나타났다. 다음으로 아동의 한글 해득 수준이 상집단일 때 5세아 부모, 1학년 교사, 1학년 부모의 한글책임교육제에 대한 인식은 긍정적인 반면, 중집단 또는 하집단인 경우 이 정책에 만족하지 못하는 경향을 보였다. 셋째, 5세반 교사, 5세아 부모, 1학년 교사, 1학년 부모의 문해지도는 다른 방식으로 이루어진다. 우선 발현적 문해지도는 5세반 교사가 가장 많이 하고, 5세아 부모가 가장 적게 하는 것으로 나타났다. 관습적 문해지도는 1학년 교사와 1학년 부모가 가장 많이 하고, 그다음으로 5세아 부모의 순이며, 5세반 교사는 비교적 적게 하는 것으로 확인되었다. 넷째, 한글책임교육제에 대한 5세반 교사, 5세아 부모, 1학년 교사, 1학년 부모의 인식에 큰 차이가 발견되었다. 정책인지도는 1학년 교사가 가장 높았고, 5세반 교사가 가장 낮았다. 정책이해도는 1학년 교사들이 다른 세 집단에 비해 유의하게 높은 수준이었다. 정책이점인식은 1학년 부모 집단이 가장 높은 수준을, 1학년 교사 집단이 가장 낮은 수준을 보였다. 정책수용도는 1학년 교사집단이 5세아 부모 집단에 비해 유의하게 높은 것으로 나타났다. 본 연구의 결과는 한글 해득 수준에서 5세 유아보다 초등 1학년생들이 더 높은 수준인 동시에, 5세아들의 상당수가 이미 한글을 해득하고, 동일연령집단 내에서 개인차가 큼을 증명하여, 누리과정에 맞게 취학 전에 무리한 한글 선행교육을 방지하는 동시에, 느린 학습자들을 위한 빠른 개입이 요구됨을 역설하였다. 또한 아동의 한글 해득 수준(상·중·하)에 따라 부모와 교사 네 집단의 문해지도와 한글책임교육제에 대한 인식에도 차이가 있음이 나타났다. 이와 함께 네 집단의 문해지도가 각기 다른 방식으로 이루어짐과 한글책임교육제에 대한 인식의 하위요인별로 차별성을 확인하여, 네 집단 간의 동상이몽을 분명하게 보여준다. 결론적으로 본 연구는 취학 전후 아동의 한글 해득 수준에 대한 객관적인 실태를 비교하여 함께 파악하며 아동의 문해발달을 둘러싼 교육적 함의를 제공하고, 유·초등 교사-부모-정책 입안자들이 적절한 문해지도 방식을 정립해야 할 근거를 제시하며, 한글책임교육제가 나아갈 올바른 방향에 대해 제안하였다.Ⅰ. 문제제기 1 Ⅱ. 이론적 배경 및 선행연구 고찰 5 1. 아동의 한글 해득 5 1) 한글 해득의 개념 5 2) 아동의 문해 발달과 한글 해득 8 3) 유·초등 한글 해득의 현황 10 2. 아동 문해지도 11 1) 문해지도의 개념 11 2) 문해지도의 유형 14 3) 부모·교사 파트너십과 문해지도 16 3. 한글책임교육제 19 1) 한글책임교육제의 내용과 시행 19 2) 유·초연계와 한글책임교육제 21 3) 한글책임교육제에 대한 부모와 교사의 인식 23 Ⅲ. 연구문제와 용어 정의 26 1. 연구문제 26 2. 용어의 정의 27 1) 아동의 한글 해득 수준 27 2) 문해지도 28 3) 한글책임교육제에 대한 인식 28 Ⅳ. 연구 방법 및 절차 29 1. 연구 대상 29 2. 연구 도구 32 1) 아동의 한글 해득 수준 32 2) 문해지도 32 3) 한글책임교육제에 대한 인식 33 3. 연구 절차 34 1) 예비조사 34 2) 본조사 35 4. 자료 분석 36 Ⅴ. 연구 결과 및 해석 37 1. 5세 유아와 1학년 아동의 한글 해득 수준 비교 37 1) 교사가 평가한 5세 유아와 1학년 아동의 한글 해득 수준 비교 37 2) 부모가 평가한 5세 유아와 1학년 아동의 한글 해득 수준 비교 40 3) 아동의 한글 해득 수준(상·중·하) 구분 43 2. 유치원 5세반 교사, 5세아 부모, 초등 1학년 교사, 1학년 부모의 문해지도 비교 45 1) 유·초등 교사와 부모의 문해지도에서 아동의 한글 해득 수준(상·중·하)에 따른 차이 비교 45 2) 유치원 5세반 교사, 5세아 부모, 초등 1학년 교사, 1학년 부모 간의 문해지도 비교 49 3. 유치원 5세반 교사, 5세아 부모, 초등 1학년 교사, 1학년 부모의 한글책임교육제에 대한 인식 비교 52 1) 유·초등 교사와 부모의 한글책임교육제에 대한 인식에서 아동의 한글 해득 수준(상·중·하)에 따른 차이 비교 52 2) 한글책임교육제에 대한 유치원 5세반 교사, 5세아 부모, 초등 1학년 교사, 1학년 부모 간의 인식 비교 57 Ⅵ. 결론 및 논의 62 참고문헌 71 부록 87 Abstract 94석

Calcium chloride enhances the delivery of exosomes

Exosomes might have an unimproved potential to serve as effective delivery vehicles. However, when exosomes are developed for therapeutic applications, a method to enhance their delivery is important. This study aimed to evaluate wheather calcium chloride (CaCl2) or other chloride compounds could enhance exosome delivery to various cells without causing toxicity. Exosomes were purified from human serum by using the ExoQuick exosome precipitation kit. Isolated exosomes were mixed with CaCl2 at concentrations ranging from 100 μM to 1 mM, and then washed using Amicon filter for treating the cells. The delivery efficiency of exosomes and the viability of the cells [HEK 293 (human kidney cells) and H9C2 (rat cardiomyocytes)] were evaluated. Cellular uptake of exosomes was observed using a confocal microscope based on PKH26 labeling of exosomes. CaCl2 increased the delivery of exosomes in a dose- and treatment time-dependent manner. In HEK 293 cells, a CaCl2 concentration of 400 μM and exposure time of 12 h increased the delivery of exosomes by >20 times compared with controls. In H9C2 cells, a CaCl2 concentration of 400 μM and exposure time of >24 h increased the delivery of exosomes by >400 times compared with controls. The viability of both cell lines was maintained up to a CaCl2 concentration of 1 mM. However, cobalt chloride, cupric chloride, and magnesium chloride did not change the delivery of exosomes in both cell lines. These results suggest that the use of CaCl2 treatment might be a useful method for enhancing the delivery of exosomes.ope

항레트로바이러스 감염 역학에 관한 모델링연구.

학위논문 (박사)-- 서울대학교 대학원 : 자연과학대학 협동과정 계산과학전공, 2018. 2. 신동우.A focus of this thesis is to develop a mathematical modeling approach to analyze the clinical data of Human immunodeficiency virus(HIV) acute infection. From the several studies, a remarkable stability of the HIV latent reservoir is detected despite the long-term treatment and advances in anti–retroviral therapy, and it has been recognized as a major barrier to HIV cure. We analyze several nonlinear mathematical models including the one that contains latent reservoir effect which provides consecutive viral replication and derive reproductive number (R0) which is a key index on HIV dynamics. For a quantitative analysis, we estimated parameters best describe time-series viral load measurements, obtained from published clinical study. We implement an efficient estimation method for the relevant parameters and numerical algorithm to solve the HIV infection dynamics. By using a nonlinear least square method for parameter estimation, analysis on the sensitivity parameters are performed for each model. In addition, we can obtain the total contribution of the reservoir processes to the productively infected T lymphocyte cells is also examined. We also propose a new model for HIV infection dynamics. There has been some researches that some influencing fractions on the dynamics of blood flow have been associated with the severity of HIV infection. In order to explain the rheological behavior of HIV infection in T lymphocyte populations we attempt to modify Latent cell model with fractional order differentiation of order α ∈ (0, 1]. The hemorheological parameters and fractional-order derivative in HIV system embody essential features of influencing fractions on the dynamics of blood flow associated with the severity of HIV infection. We show that the modified model has non-negative, bounded solutions and stable equilibrium points. Optimal fractional order and kinetic parameters are estimated by using the nonlinear weighted least-square method, the Levenberg-Marquardt algorithm, and Adams-type predictor-corrector method is employed for the numerical solution. The numerical results confirm that a value of fractional order (α) representing the rheological behavior in plasma is significantly related with a density of lymphocyte population.Chapter 1 Introduction 1 1.1 Infection mechanism of HIV and Antiretroviral treatment 2 1.2 Latent reservoir and drug-resistant mutant in HIV infection 6 1.3 Modeling HIV infection dynamics in lymphocyte 9 1.4 Thesis overview 12 Chapter 2 Mathematical models for HIV infection dynamics 14 2.1 Models and their analysis 14 2.1.1 Three-component model 16 2.1.2 Chronical infection model 39 2.1.3 Latent infection model 46 2.2 Parameter estimation 52 2.2.1 Description of measurement data and their clinical result 53 2.2.2 An algorithm for parameter estimation 56 2.2.3 Initial guess for initial state density and model parameters 60 2.2.4 Analysis of parameter sensitivity 61 2.3 Numerical result 64 2.3.1 Sensitivity equations 64 2.3.2 Numerical simulation 66 2.4 Conclusion 70 Chapter 3 A fractional-order model for HIV infection 77 3.1 The fractional calculus 78 3.2 Motivation 80 3.3 Model derivation 83 3.4 Numerical methods 93 3.4.1 The fractional Adams method 94 3.4.2 Sensitivity equations 99 3.4.3 Initial guess for paramters and the fractional order 102 3.5 Numerical results: model fits and sample predictions 102 3.6 Conclusion 107Docto

Human peripheral blood‑derived exosomes for microRNA delivery

Exosomes serve important functions in cell‑to‑cell communication and biological functions by serving as a delivery cargo shuttle for various molecules. The application of an improved delivery method for microRNAs (miRNAs/miRs) may enhance their potential as a therapeutic tool in cardiac diseases. Thus, the present study investigated whether human peripheral blood‑derived exosomes may be used as a delivery cargo system for miRNAs, and whether the delivery of miR‑21 using a human peripheral blood derived‑exosome may influence the degree of remodeling following myocardial infarction (MI). In H9C2 and HL‑1 cells, miR‑21 expression was successfully regulated by treatment with human peripheral blood derived‑exosomes loaded with an miR‑21 mimic or inhibitor compared with untreated cells. In addition, the mRNA and protein expression levels of SMAD family member 7 (Smad7), phosphatase and tensin homolog (PTEN) and matrix metalloproteinase 2 (MMP2), which are involved in cardiac fibrosis, were associated with the uptake of miR‑21 mimic‑ or inhibitor‑loaded exosomes. Similarly, the in vivo mRNA and protein expression of Smad7, PTEN and MMP2 were altered following treatment with miR‑21 mimic‑ or inhibitor‑loaded exosomes. Furthermore, miR‑21 mimic‑loaded exosomes enhanced fibrosis, whereas miR‑21 inhibitor‑loaded exosomes reduced fibrosis in a mouse MI model. These results suggested that miRNA‑loaded human peripheral blood derived‑exosomes may be used as a therapeutic tool for cardiac diseases.ope

Long-term Clinical Outcomes and Prognostic Factors After Endovascular Treatment in Patients With Chronic Limb Threatening Ischemia

Background and objectives: Endovascular therapy (EVT) first strategy has been widely adopted for the treatment of chronic limb threatening ischemia (CLTI) patients in real-world practice. This study aimed to investigate long-term outcomes of CLTI patients who underwent EVT and identify prognostic factors. Methods: From the retrospective cohorts of a Korean multicenter endovascular therapy registry, 1,036 patients with CLTI (792 men, 68.8 ± 9.5 years) were included. The primary endpoint was amputation-free survival (AFS) defined as the absence of major amputation or death. Secondary endpoints were major adverse limb events (MALE; a composite of major amputation, minor amputation, and reintervention). Results: Five-year AFS and freedom from MALE were 69.8% and 61%, respectively. After multivariate analysis, age (hazard ratio [HR], 1.476; p<0.001), end-stage renal disease (ESRD; HR, 2.340; p<0.001), Rutherford category (RC) 6 (HR, 1.456; p=0.036), and suboptimal EVT (HR, 1.798; p=0.005) were identified as predictors of major amputation or death, whereas smoking (HR, 0.594; p=0.007) was protective. Low body mass index (HR, 1.505; p=0.046), ESRD (HR, 1.648; p=0.001), femoropopliteal lesion (HR, 1.877; p=0.004), RC-6 (HR, 1.471; p=0.008), and suboptimal EVT (HR, 1.847; p=0.001) were predictors of MALE. The highest hazard rates were observed during the first 6 months for both major amputation or death and MALE. After that, the hazard rate decreased and rose again after 3-4 years. Conclusions: In CLTI patients, long-term outcomes of EVT were acceptable. ESRD, RC-6, and suboptimal EVT were common predictors for poor clinical outcomes. Trial registration: ClinicalTrials.gov Identifier: NCT02748226.ope

Associates and Prognosis of Giant Left Atrium; Single Center Experience

Background: Left atrial (LA) remodeling develops as a result of longstanding pressure overload. However, determinants and clinical outcome of excessive remodeling, so called giant left atrium (GLA), are not clear. Methods: Clinical characteristics of patients with GLA (antero-posterior diameter higher than 65 mm), including echo-Doppler parameters, and follow-up clinical outcomes from a tertiary referral hospital were investigated. Results: Among 68519 consecutive primary patients who underwent echocardiography over a period of 10 years, data from 163 GLA cases (0.24%) were analyzed. Main causes were significant rheumatic mitral stenosis (n = 58, 36%); other causes comprised significant rheumatic mitral regurgitation (MR; n = 10, 6%), mitral valve (MV) prolapse or congenital mitral valvular disease (MVD) (n = 20, 12%), and functional MR (n = 25, 15%). However, mild rheumatic MV disease (n = 4, 3%) or left ventricular (LV) systolic or diastolic dysfunction without significant MR (n = 46, 28%) were also causes of GLA. During median follow-up of 22 months, 42 cases (26%) underwent composite events. MV surgery was related to lower rate of composite events. In multivariate analysis, MV surgery, elevated pulmonary arterial systolic pressure, and increased LA volume index were independent predictors of future events (p < 0.05) regardless of underlying diseases or history of MV surgery. Conclusion: Although rheumatic MVD with atrial fibrillation is the main contributor to GLA, longstanding atrial fibrillation with LV dysfunction but without MVD also could be related to GLA. Even in GLA state, accurate measurement of LA volume is crucial for risk stratification for future events, regardless of underlying disease.ope

Coronary Artery Aneurysm after Second-Generation Drug-Eluting Stent Implantation

PURPOSE: We evaluated the incidence, predictors, and prognosis of coronary artery aneurysm (CAA) after second-generation drug-eluting stent (DES) implantation. MATERIALS AND METHODS: A total of 976 consecutive patients (1245 lesions) who underwent follow-up angiography after second-generation DES implantation were analyzed. Incidence and predictors of CAA were assessed, and clinical prognosis was compared with 34 cases of CAA after first-generation DES implantation using previous CAA registry data. RESULTS: All 10 cases of CAA (0.80% per lesion) in 10 patients (1.02% per patient) were detected at follow up. Compared to lesions without CAA, those with CAA had greater involvement of the proximal segment (90% vs. 51%, p=0.014), a higher proportion of pre-intervention, a Thrombolysis in Myocardial Infarction score of 0 or 1 flow (80% vs. 16%, p<0.001), more chronic total occlusions (40% vs. 10%, p<0.001), and longer implanted stents (41.9±23.2 mm vs. 28.8±14.8 mm, p=0.006). As for CAA morphology, instances of CAA after second-generation DES were predominantly the single fusiform type (90%), whereas instances of CAA after first-generation DES were multiple saccular (47%) and single saccular (35%) types (p<0.001). Myocardial infarction with stent thrombosis occurred in 5 patients with CAA after first-generation DES (15%), and no adverse events were observed in patients with CAA after second-generation DES over a median follow-up duration of 4.3 years (p=0.047, log-rank). CONCLUSION: Although CAAs after second-generation DES implantation were detected at a similar incidence to that for CAAs after first-generation DES implantation, second-generation DES-related CAAs had different morphologies and more benign clinical outcomes versus first-generation DES-related CAAs.ope

Clinical evidence of initiating a very low dose of sacubitril/valsartan: a prospective observational analysis

Sacubitril/valsartan is superior to enalapril in reducing the risks of cardiovascular death and preventing hospitalization in patients with heart failure and reduced ejection fraction (HFrEF). However, patients often do not receive sacubitril/valsartan because of concerns about hypotension. We examined the feasibility of initiating sacubitril/valsartan at a very low dose (VLD) in potentially intolerant patients with HFrEF and subsequent dose up-titration, treatment persistence and outcomes. We analyzed 206 patients with HFrEF grouped according to starting sacubitril/valsartan dose. The VLD group (n = 106) commenced 25 mg twice daily, and the standard-dose (SD) group (n = 100) started on ≥ 50 mg twice daily. Baseline systolic blood pressure was 103 ± 12 mmHg vs. 119 ± 14 mmHg in the SD group (P < 0.001). The maximal target dose achievement rate was higher in the SD group (27.0% vs 9.4%, p = 0.001) and the VLD group experienced more dose up-titrations and fewer down-titrations than the SD group. The VLD group had a decrease in N-terminal prohormone of brain natriuretic peptide (NT-proBNP) similar to the SD group and a similar increase in left ventricular ejection fraction. There were no significant differences in symptomatic hypotension, worsening renal function, hyperkalemia, cardiovascular mortality, and rehospitalization due to HF between the two groups during follow-up period. In patients considered by the treating physician likely to be intolerant of sacubitril/valsartan, initiation with 25 mg twice daily was generally possible and patients remained in therapy, with similar decreases in NT-proBNP and increases in left ventricular ejection fraction to those observed in patients receiving SD sacubitril/valsartan.ope

치주질환에서 Toll-like receptor 역할에 대한 고찰

학위논문 (석사)-- 서울대학교 대학원 : 치의학과, 2012. 2. 이성중.Inflammation is an excessive immune response that destroys host tissues and periodontitis is caused by inflammation. The development of the disease can be classified into the initial, early, established and advanced lesions. Toll-like receptors(TLRs) are pattern-recognition receptors that recognize specific pathogen-associated molecular patterns and initiate appropriate immune responses against them. TLRs facilitate expression of pro-inflammatory mediators such as cytokines by MyD88-dependent pathway and MyD88-independent pathway. TLRs are mainly expressed on the immune cells such as macrophage, neutrophil and monocyte, but it turns out that the cells in periodontal tissue also express TLRs and the interaction between TLR and their specific ligand has an important role in progression of periodontal disease. It seems that TLRs on epithelial cells make a protective barrier and become tolerized during sustained exposure to bacterial structures such as LPS. But once pathogens or opportunists invade and destroy the epithelial barriers, it is possible that TLRs on the cells in underlying connective tissues directly contact with bacterial products. It causes hyper-inflammatory responses because these TLRs are not tolerized unlike TLRs on gingival epithelial cells. There are lots of attempts to target TLRs as treatment of inflammatory diseases. It could be helpful to study the role of TLRs in periodontal disease to make use of TLRs in therapies of periodontal disease.염증반응은 host의 면역반응의 하나로써 이것이 과도하여 반응이 일어나는 주변의 host tissue를 파괴하는 현상이며 치주염은 이러한 염증반응에 의한 질환이라고 하겠다. 치주질환의 진행은 초기, 조기, 확립기, 진행기로 나누어질 수 있다. Toll-like receptor는 미생물의 pathogen-associated molecular patterns이라고 하는 구조를 인식하므로써 면역반응의 개시에서 중요한 역할을 한다고 알려져 있다. Toll-like receptor는 MyD88-dependent pathway, MyD88-independent pathway를 통해서 pro-inflammatory mediators의 발현을 촉진하는 것으로 알려져 있다. 이러한 Toll-like receptor는 macrophage, neutrophil, monocyte와 같은 immune cell에 주로 발현되지만 치주조직에서 epithelial cell, gingival fibroblast, periodontal fibroblast, cementoblast, osteoblast, osteoclast 등에서도 Toll-like receptor가 발현됨이 확인되었으며 이러한 세포들에 존재하는 Toll-like receptor와 ligand의 상호작용이 치주질환의 진행에 중요한 역할을 한다. steady state에서는 치은의 상피에서 발현되는 Toll-like receptor가 작용하여 barrier를 먼저 형성하고 그 이후에 지속적인 자극에 대해서는 tolerance를 나타내어 더 이상의 inflammation이 진행되지 않게 제한하여 protection 작용을 하지만 virulence factor를 가지는 pathogen이나 기회감염균 등이 이러한 상피장벽을 파괴시켜 치주조직의 더 깊은 층으로 침투하게 되면 tolerance를 나타내지 않은 Toll-like receptor와 직접적으로 접촉하게 되어 pro-inflammatory cytokine의 분비가 증가되어 치주질환이 진행되는 것으로 생각된다. 면역반응에서 Toll-like receptor의 역할이 밝혀지기 시작하면서 Toll-like receptor를 target으로 한 염증성 질환에 대한 치료에 관한 연구가 활발히 이루어지고 있으며 이에 따라 치주질환에서도 Toll-like receptor signaling pathway를 이용한 치료법에 대한 가능성이 제시되고 있다Maste

Color Experience and Reductive Explanation —A Defense of Dispositional Higher-order Theory—

의식적 경험에 관한 성향적 고차 이론은 경쟁 이론인 일차이론과 고차적 사고이론의 난점을 극복하려는 시도에서 제시되었다. 성향적 고차이론은 단순히 일차 이론의 난점 뿐만 아니라 일차 이론과 고차 이론이 정작 여러 형태의 무의식적 지각 상태에 대한 설명이 어렵다는 점 또한 극복할 수 있다. 반면, 일차 이론의 설명이 보이는 강점이었던 지각 경험의 본래성에 대한 설명에 대하여는 성향적 고차 이론이 취약한 것처럼 보이기도 한다. 하지만, 필자는 우리 지각 경험이 본래적이라는 당연시 여겨졌던 가정 자체가 오히려 우리의 지각 경험에 있어서 임의로 짧게 상정된 관찰시간에 기인한다고 방어하였다. 이런 점에서 성향적 고차 이론은 지각 경험에 대해 아무런 반성 없이 가정했던 전제들을 비판적으로 성찰하게끔하는 기회를 제공한다. 또한, 성향적 고차 이론은 색깔의 물리적 속성이 본래 성향적 속성을 가지고 있음을 전적으로 부정하지 않으면서 색깔이 지각되는 인과 과정 또한 과학적 성과와도 일관적임을 밝히면서 다양한 지각 경험들의 차이를 밝혀준다는 점에서 보다 세련된 설명이라고 할 수 있다. This paper argues for a form of representational theory of color and Peter Carruthers dispositionalist version of the higher-order thought theory. The dispositionalist account is a higher-order thought theory, yet overcomes the shortcomings of both the first-order theory and the higher-order thought theory. The theory I embrace explains conscious states such as color perception as available to a higher-order of thought. The difficulty with the account lies in its non-categorical and its non-actual characteristics that become its strength in explicating the different forms of non-phenomenally conscious perceptual states. On the downside, the account seems to have difficulty in explaining the non-dispositional nature of our perceptual experience. Rosenthal criticizes that the theory has difficulty explaining our phenomenal aspects of mental states because disposition alone has no causal role in making the information actual. I argue against this criticism by raising the question of the received assumption that our perceptual experience is intrinsic. The impression that our color experience is intrinsic might be misleading due to the short time slot in observation. Unlike the traditional characteristic of color, our color experience can be dispositional depending on the duration of observation. In conclusion, Carruthers dispositional account of higher-order thought theory is a more refined account that it is consistent with scientific facts of color and that it specifies different kinds of nonconscious color perception.이 논문은 2007년도 정부재원(교육과학기술부 인문사회 연구역량강화사업)으로 한국연구재단의 지원을 받아 연구되었음. [KRF-354-2007-1-A00052