C57BL/6J 생쥐에서의 불안과 조건화된 공포에 대한 행동 분석

학위논문 (석사)-- 서울대학교 대학원 : 뇌인지과학과, 2013. 2. 강봉균.Fear conditioning has been used to study pathogenic mechanisms underlying anxiety disorders. Several studies have shown that humans with anxiety disorders exhibit strong fear responses during the acquisition of conditioned fear. However, there have been no studies investigating whether basal anxiety within the normal range is related to conditioned fear. We hypothesized that individual differences in conditioned fear are correlated to the basal anxiety level of each individual. To test this hypothesis, we measured the basal anxiety of mice by using the elevated-plus maze (EPM) and open field test (OFT) and correlated these data with contextual freezing during contextual fear conditioning (CFC). Strong correlation was found between the basal anxiety level measured in the OFT and contextual freezing in the CFC. Baseline freezing was also strongly correlated with the freezing level during the retrieval phase of CFC. However, the basal anxiety level measured in the EPM was correlated neither with conditioned fear nor with baseline freezing in the CFC. These results suggest that both basal anxiety in the OFT and baseline freezing are related to contextually conditioned fear.Contents Page List of Figures…...…………………………………….…... 1 Abstract…...…………...………….…………………….…... 3 Introduction……………………………..…………….…... 5 Methods…...……………….…….….……….……………... 14 Results………....…………………….……..….………….... 17 Figures……………………….……………..….……...….... 20 Discussion…..…………………...………...……………….. 38 References…..……………….…………………………….. 40 국문초록…..…………………..........…...……………….... 47Maste

Effects of APHACHE II score and initial nutritional status on prognosis of the critically ill patients

의학과/석사목적 : 입원 환자에서 영양 불량은 매우 흔하며 특히 중환자실 환자들에게서 사망률과 이환율에 영향을 미친다. 본 연구에서는 중환자에서 영양 상태를 파악하고 질병의 중증도를 측정하여 중증도에 따라 영양 상태가 예후에 미치는 효과에 대해 알아보고자 하였다.방법 : 중환자실에 입실한 3758명의 환자들을 대상으로 serum albumin과 total lymphocyte count(TLC)를 측정하여 영양 상태를 파악하고 APACHE II score로 질병의 중등도를 측정하여 퇴실시까지 추적 관찰하여 중환자실 재원일수, 재원일수, 호흡기 사용일수, 사망률을 측정하였다.결과 : 측정 결과 영양 불량은 68.3%였으며 moderate, severe group에서 well group에 비해 중환자실 재원일수, 재원일수, 호흡기 사용일수가 길었으며 moderate, severe group에서 well group에 비해 사망률이 3-5배 증가하였다.결론 : 영양 공급이 중환자 치료에 있어 중요한 역할을 하고 있음을 확인하였다. 따라서 중환자에서 질병의 중증도가 높지 않더라도 초기에 적극적이고 적절한 영양 공급을 하는 것이 사망률을 감소 시킬 수 있으리라 기대한다.ope

(An) empirical study on payout smoothing using variance decomposition approach

학위논문(석사) - 한국과학기술원 : 금융공학프로그램, 2024.2,[ii, 43 p. :]본 연구는 한국 기업들의 배당 유연화 현상을 부채 및 투자와 같은 주요 재무정책들 간의 상호작용을 고려하여, 당기순이익을 분해하고 정량화하여 분석하였다. 연구기간은 2000년부터 2022년까지로 설정되었으며, 유가증권시장 및 코스닥시장에 상장된 기업들을 대상으로 Hoang and Hoxha (2016)의 분산 분해 접근법을 적용하여 실증분석을 수행하였다. 분석결과, 기업들은 당기순이익에 대한 충격을 흡수하는 과정에서 주로 부채와 투자 정책을 사용하며, 배당정책을 통한 통합 흡수는 상대적으로 적은 것으로 나타났다. 이러한 경향은 분석기간, 차분 간격, 산업, 기업 규모, 상장 단계, 외부 금융 의존도 등 다양한 외생적 조건의 변화에도 불구하고 배당 유연화 현상이 나타나 결과의 강건성이 확인되었다. 본 연구는 한국에서의 배당 유연화 현상을 정량적으로 입증했다는 의의를 가진다. 동시에, 기업이 당기순이익 충격에 대응할 때 전반적인 재무결정 메커니즘을 고려한다는 시사점을 제공한다.한국과학기술원 :금융공학프로그램

Ticagrelor versus prasugrel in patients with acute myocardial infarction

Background: Ticagrelor and prasugrel are the mainstay of antithrombotic therapy for patients with acute myocardial infarction (MI). However, direct comparative data on clinical outcomes of potent P2Y12 inhibitors are limited, especially in East Asian populations. We aimed to evaluate the effect of ticagrelor versus prasugrel on clinical outcomes in patients with acute MI. Methods: From the Korean nationwide National Health Insurance database, 10,797 patients with acute MI who received either ticagrelor or prasugrel in combination with aspirin after percutaneous coronary intervention (PCI) were enrolled. The primary outcome was net clinical benefit, defined as a composite of death, MI, stroke, or major bleeding. Secondary outcomes included the individual components of the primary outcome as effectiveness and safety measures. Results: Among 10,797 patients, 9591 (88.8%) received ticagrelor and 1206 (11.2%) received prasugrel. During a median follow-up of 1.8 years, the primary outcome occurred in 1051 (16.6%) and 131 (14.4%) patients in the ticagrelor and prasugrel groups, respectively. In the propensity score matched cohort (n = 5979), the risk for the primary outcome was similar between the two groups (hazard ratio [HR] 0.949 for prasugrel; 95% confidence interval [CI]: 0.780-1.154). The risks for the composite of death, MI, or stroke (HR 0.938; 95% CI: 0.752-1.169) and major bleeding (HR 1.022; 95% CI: 0.709-1.472) were also comparable. Conclusions: In patients with acute MI undergoing PCI, ticagrelor and prasugrel appeared to have similar net clinical benefits. The risks for death, MI, or stroke and major bleeding were not significantly different between the two groups

Angiotensin-Converting Enzyme Inhibitor-based Versus Angiotensin Receptor Blocker-based Optimal Medical Therapy After Percutaneous Coronary Intervention: A Nationwide Cohort Study

Optimal medical therapy (OMT) plays a crucial role in the secondary prevention of established coronary artery disease. The renin-angiotensin system (RAS) is an important target of OMT. However, there is limited evidence on whether there is any difference in the combined effect of OMT according to the classes of RAS blockade [angiotensin-converting enzyme inhibitor (ACEI) vs. angiotensin receptor blocker (ARB)]. Based on the nationwide National Health Insurance database in South Korea, 39,096 patients who received OMT after percutaneous coronary intervention between July 2013 and June 2017 were enrolled. Patients were stratified into either acute myocardial infarction (AMI) or angina cohort and analyzed according to the class of RAS blockade included in OMT at discharge (ACEI vs. ARB). The primary end point was all-cause mortality. The study population had a median follow-up of 2.3 years (interquartile range, 1.3-3.3 years). In the propensity score-matched AMI cohort (8219 pairs), the risk for all-cause mortality was significantly lower in patients with ACEI-based OMT than in those with ARB-based OMT (hazard ratio 0.83 of ACEI, 95% confidence interval 0.73-0.94, P = 0.003). However, in the propensity score-matched angina cohort (6693 pairs), the mortality risk was comparable, regardless of the class of RAS blockade (hazard ratio 1.13, 95 confidence interval 0.99-1.29, P = 0.08). In conclusion, in this nationwide cohort study involving patients receiving OMT after percutaneous coronary intervention, ACEI-based OMT was associated with a significantly lower risk of all-cause mortality in patients with AMI in comparison with ARB, but not in those with angina

Pre-existing depression in patients with coronary artery disease undergoing percutaneous coronary intervention

The impact of pre-existing depression on mortality in individuals with established coronary artery disease (CAD) remains unclear. We evaluate the clinical implications of pre-existing depression in patients who underwent percutaneous coronary intervention (PCI). Based on National Health Insurance claims data in Korea, patients without a known history of CAD who underwent PCI between 2013 and 2017 were enrolled. The study population was divided into patients with angina (n=50,256) or acute myocardial infarction (AMI; n=40,049). The primary endpoint, defined as all-cause death, was compared between the non-depression and depression groups using propensity score matching analysis. After propensity score matching, there were 4262 and 2346 matched pairs of patients with angina and AMI, respectively. During the follow-up period, there was no significant difference in the incidence of all-cause death in the angina (hazard ratio [HR] of depression, 1.013; 95% confidence interval [CI] 0.893-1.151) and AMI (HR, 0.991; 95% CI 0.865-1.136) groups. However, angina patients less than 65 years of age with depression had higher all-cause mortality (HR, 1.769; 95% CI 1.240-2.525). In Korean patients undergoing PCI, pre-existing depression is not associated with poorer clinical outcomes. However, in younger patients with angina, depression is associated with higher all-cause mortality

Frequency and Significance of Right Bundle Branch Block and Subclinical Coronary Atherosclerosis in Asymptomatic Individuals

Limited data exist regarding the association between right bundle branch block (RBBB) and subclinical coronary atherosclerosis. This study investigated the influence of RBBB on subclinical coronary atherosclerosis detected by coronary computed tomographic angiography (CCTA) in an asymptomatic population. We retrospectively analyzed 7,205 asymptomatic individuals (mean age 54.4 ± 7.9 years and 4,695 men [65.2%]) with no prior history of coronary artery disease who voluntarily underwent CCTA and 12-lead electrocardiographic evaluation as part of a general health examination. The degree and extent of subclinical coronary atherosclerosis were evaluated by CCTA, and ≥50% diameter stenosis was defined as significant. The association between RBBB and subclinical coronary atherosclerosis was determined by logistic regression and propensity score matching analyses. Of study participants, 116 (1.6%) had RBBB. After adjustment for cardiovascular risk factors, there were no statistically significant differences in the adjusted odds ratios of RBBB for any atherosclerotic plaque (0.87, 95% confidence interval [CI] 0.57 to 1.32), calcified plaque (0.78, 95% CI 0.51 to 1.19), noncalcified plaque (1.44, 95% CI 0.77 to 2.69), mixed plaque (1.12, 95% CI 0.52 to 2.39), and significant coronary artery stenosis (0.92, 95% CI 0.48 to 1.74). Similarly, in the 5: 1 propensity score-matched population (n = 696), there were no statistically significant differences in the odds ratios for any subclinical coronary atherosclerosis between participants with and without RBBB (p for all >0.05). In conclusion, through this large cross-sectional study of asymptomatic individuals who underwent CCTA and electrocardiography evaluation, individuals with RBBB were not associated with an increased risk of subclinical coronary atherosclerosis compared with those without RBBB

Comparison of new implantation of cardiac implantable electronic device between tertiary and non-tertiary hospitals: a Korean nationwide study

This study compared the characteristics and mortality of new implantation of cardiac implantable electronic device (CIED) between tertiary and non-tertiary hospitals. From national health insurance claims data in Korea, 17,655 patients, who underwent first and new implantation of CIED between 2013 and 2017, were enrolled. Patients were categorized into the tertiary hospital group (n=11,560) and non-tertiary hospital group (n=6095). Clinical outcomes including in-hospital death and all-cause death were compared between the two groups using propensity-score matched analysis. Patients in non-tertiary hospitals were older and had more comorbidities than those in tertiary hospitals. The study population had a mean follow-up of 2.1 +/- 1.2 years. In the propensity-score matched permanent pacemaker group (n=5076 pairs), the incidence of in-hospital death (odds ratio [OR]: 0.76, 95% confidence interval [CI]: 0.43-1.32, p=0.33) and all-cause death (hazard ratio [HR]: 0.92, 95% CI 0.81-1.05, p=0.24) were not significantly different between tertiary and non-tertiary hospitals. These findings were consistently observed in the propensity-score matched implantable cardioverter-defibrillator group (n=992 pairs, OR for in-hospital death: 1.76, 95% CI 0.51-6.02, p=0.37; HR for all-cause death: 0.95, 95% CI 0.72-1.24, p=0.70). In patients undergoing first and new implantation of CIED in Korea, mortality was not different between tertiary and non-tertiary hospitals