• Korean Journal of Ophthalmology
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• v.32 no.6
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• pp.470-477
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• 2018

Purpose: To investigate the relationship between the progression of visual field (VF) loss and changes in lamina cribrosa depth (LCD) as determined by spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging in patients with primary open angle glaucoma (POAG). Methods: Data from 60 POAG patients (mean follow-up, $3.5{\pm}0.7$ years) were included in this retrospective study. The LCD was measured in the optic disc image using SD-OCT enhanced depth imaging scanning at each visit. Change in the LCD was considered to either 'increase' or 'decrease' when the differences between baseline and the latest two consecutive follow-up visits were greater than the corresponding reproducibility coefficient value ($23.08{\mu}m$, as determined in a preliminary reproducibility study). All participants were divided into three groups: increased LCD (ILCD), decreased LCD (DLCD), and no LCD change (NLCD). The Early Manifest Glaucoma Trial criteria were used to define VF deterioration. Kaplan-Meier survival analysis and Cox's proportional hazard models were performed to explore the relationship between VF progression and LCD change. Results: Of the 60 eyes examined, 35.0% (21 eyes), 28.3% (17 eyes), and 36.7% (22 eyes) were classified as the ILCD, DLCD, and NLCD groups, respectively. Kaplan-Meier survival analysis showed a greater cumulative probability of VF progression in the ILCD group than in the NLCD (p < 0.001) or DLCD groups (p = 0.018). Increased LCD was identified as the only risk factor for VF progression in the Cox proportional hazard models (hazard ratio, 1.008; 95% confidence interval, 1.000 to 1.015; p = 0.047). Conclusions: Increased LCD was associated with a greater possibility of VF progression. The quantitative measurement of LCD changes, determined by SD-OCT, is a potential biomarker for the prediction of VF deterioration in patients with POAG.

• The Korean journal of internal medicine
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• v.39 no.1
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• pp.110-122
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• 2024

Background/Aims: Due to limited real-world evidence on the association between time to presentation (T2P) and outcomes following acute myocardial infarction and diabetes (AMI-DM), we investigated the characteristics of patients with AMI-DM and their outcomes based on their T2P. Methods: 4,455 patients with AMI-DM from a Korean nationwide observational cohort (2011-2015) were divided into early and late presenters according to symptom-to-door time. The effects of T2P on three-year all-cause mortality were estimated using inverse probability of treatment weighting (IPTW) and survival analysis. Results: The incidence of all-cause mortality was consistently higher in late presenters than in early presenters (11.4 vs. 17.2%; p < 0.001). In the IPTW-adjusted dataset, the incidence of all-cause mortality was numerically higher in late presenters than in early presenters (9.1 vs. 12.4%; p = 0.072). In the survival analysis, the cumulative incidence of all-cause mortality was significantly higher in late presenters than in early presenters before and after IPTW. In the subgroup with ST-elevation myocardial infarction, late presenters had a higher incidence of cardiac death than early presenters before (4.8 vs. 10.5%; p < 0.001) and after IPTW (4.2 vs. 9.7%; p = 0.034). In the initial glycated hemoglobin (HbA1c)-stratified analysis, these effects were attenuated in patients with HbA1c ≥ 9.0% before (adjusted hazard ratio [HR]: 1.45, 95% confidence interval [CI]: 0.80-2.64) and after IPTW (adjusted HR: 0.82, 95% CI: 0.40-1.67). Conclusions: Late presentation was associated with higher mortality in patients with AMI-DM; therefore, multifaceted and systematic interventions are needed to decrease pre-hospital delays.

• Journal of Biomedical Engineering Research
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• v.38 no.5
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• pp.227-231
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• 2017

Early diagnosis of pancreatic cancer had been considered one of the important barrier for successful therapy since the five year survival rate after treatment of pancreatic cancer was critically low. Nonetheless, patients often miss the golden time of treatment because they rarely visit the hospital until their symptoms are severe. To overcome these problems, a lot of information about the patient's symptoms should be applied as biomarkers for early diagnosis. For this reason, a biomarker for early detection of pancreatic cancer (CA19-9) has been developed as a diagnostic kit. However, since the diagnosis is not accurate enough, pancreatic symptoms (abdominal pain, jaundice, anorexia, diabetes, etc.) and biomarkers (CA19-9) should be considered together. We develop an intelligent diagnostic system that considers CA19-9 and the incidence of pancreatic cancer for pancreatic symptoms that was determined by studying a large number of patient information. It shows a higher accuracy than one using CA19-9 alone. It may increase the survival rate of pancreatic cancer because it can diagnose pancreatic cancer early.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.432-436
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• 2016

The cooler, which is the main part in a Thermal Observation Device (TOD), makes the TOD function by reducing the temperature. As the cooler is imported, overseas enterprises presented 20,000 hours as the operation time and the military have used the cooler as presented. However, failures have occurred occasionally after mass production stage. Therefore, we need to analyze the MTBF of the TOD cooler. So, military and defense industry companies collected the failure data of the TOD cooler. We analyze the MTBF of the TOD cooler using survival probability function and failure data. We find the optimal distribution by applying parametric method and estimate parameters. We determine that the Log-logistic distribution is the most appropriate for this data. Also, we analyze the reliability per hour of the TOD cooler. The result of MTBF of the TOD cooler was higher than that of presented by oversee enterprises.

• Journal of Korean Neurosurgical Society
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• v.52 no.2
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• pp.80-84
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• 2012

Objective : This study analyzed the relationship between prognosis and multiple clinical factors of ruptured middle cerebral artery (MCA) aneurysm with intracerebral hemorrhage (ICH), to aid in predicting the results of surgical treatment. Methods : Enrolled subjects were 41 patients with ruptured MCA aneurysm with ICH who were treated with surgical clipping. Clinical factors such as gender, age, and initial Glasgow coma scale were assessed while radiological factors such as the volume and location of hematoma, the degree of a midline shift, and aneurysm size were considered retrospectively. Prognosis was evaluated postoperatively by Glasgow outcome scale. Results : Age and prognosis were correlated only in the groups with ICH over 31 mL or ICH at the frontal lobe or sylvian fissure. When initial mental status was good, only patients with ICH on the temporal lobe had a better prognosis. If the midline shift was less than 4.5 mm, the probability of better prognosis was 95.5% (21 of 22). If the midline shift was more than 4.5 mm, the probability of poor prognosis was 42.1% (8 of 19). Patients with ICH less than 31 mL had higher survival rates, whereas if the ICH was more than 31 mL, 41.2% (7 of 17) had a poor clinical pathway. Conclusion : Even if the initial clinical condition of the patient was not promising, by carefully examining and taking into account all factors, neurosurgeons can confidently recommend surgical treatment for these patients.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.565-575
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• 2019

This study evaluated Campylobacter jejuni risk in ground meat products. The C. jejuni prevalence in ground meat products was investigated. To develop the predictive model, survival data of C. jejuni were collected at $4^{\circ}C-30^{\circ}C$ during storage, and the data were fitted using the Weibull model. In addition, the storage temperature and time of ground meat products were investigated during distribution. The consumption amount and frequency of ground meat products were investigated by interviewing 1,500 adults. The prevalence, temperature, time, and consumption data were analyzed by @RISK to generate probabilistic distributions. In 224 samples of ground meat products, there were no C. jejuni-contaminated samples. A scenario with a series of probabilistic distributions, a predictive model and a dose-response model was prepared to calculate the probability of illness, and it showed that the probability of foodborne illness caused by C. jejuni per person per day from ground meat products was $5.68{\times}10^{-10}$, which can be considered low risk.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.2
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• pp.158-164
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• 2014

LEO(Low Earth Orbit) Satellite which is discarded should be reentered to atmosphere in 25 years by '25 years rule' of IADC(Inter-Agency Space Debris Coordination Committee) Guidelines. If the parts of satellite are survived from severe aerothermodynamic condition, it could damage to human and property. South Korea operates KOMPSAT-2 and STSAT series as LEO satellite. It is necessary to dispose of them by reentering atmosphere. Therefore this paper analyze the trajectory, survivability, casualty area and casualty probability of a virtual LEO satellite using ESA(European Space Agency)'s DRAMA(Debris Risk Assesment and Mitigation Analysis) tool. As a result, it is noted that casuality area is $15.2742m^2$ and casualty probability is 5.9614E-03 then will be survived 198.831kg.

• Radiation Oncology Journal
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• v.37 no.3
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• pp.176-184
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• 2019

Purpose: It is unclear whether adding concurrent chemotherapy (CT) to definitive radiotherapy (RT) following induction CT is a tolerable and cost effective treatment for non-small-cell lung cancer (NSCLC) patients aged 70 years or older with comorbidities. This study evaluated the actual clinical outcomes between concurrent chemoradiotherapy (CCRT) and RT alone following induction CT or not in patients (≥70 years) in a single institution's clinical practice. Materials and Methods: A total of 82 patients with unresectable stage III NSCLC between 2004 and 2016 were retrospectively analyzed. Their treatment tolerance and clinical outcomes such as overall survival (OS), locoregional recurrence (LRR), treatment toxicities and distant metastasis (DM) were evaluated. Early mortality rates were also evaluated as 4-month mortality after RT. Results: Fifty-four patients received CCRT and 28 patients received RT alone. Induction CT before RT was performed for 68.5% and 50.0% in CCRT and RT alone groups. Treatment tolerance was significantly worse in CCRT (p = 0.046). The median survival was 21.1 and 18.1 months for CCRT and RT alone, which was not statistically significant. LRR and DM were also not different. Most early deaths after CCRT were attributed to non-cancer-related mortality. Acute esophagitis of grade ≥2 occurred more following CCRT (p = 0.017). In multivariate analysis, a Charlson Comorbidity Index (CCI) of ≥5 and a weight loss of ≥5% after RT were associated with poor OS. The factors adversely affecting 4-month survival were a CCI of ≥5 and CCRT. Conclusion: There were no significant differences in OS, LRR, and DM between CCRT and RT alone treatment in elderly patients. However, there was a poorer tolerance and higher incidence of acute esophagitis in the CCRT group. Specifically, when the patients had a CCI of ≥5, RT alone seems to be reasonable with a low probability of early death.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.19-32
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• 2016

Due to the increasing fiscal burden and structural unbalanced premium/benefit costs, the new reform on the government employees pension system (GEPS) was considered even after the recent reform in 2009. This article examines the various effects of recent amendment in 2015 on GEPS using a simple probabilistic model. We consider effects on both sides, the pensioners and the government. First of all, the expected net value of pension payment for an individual employee was calculated based on the supposed survival distribution. The fairness of individual pension holders was compared using the benefit-cost ratio. Secondly, from pension system users' point of view, the default probability and the government subsidy were examined by Monte-carlo simulation. From the simulation experiment, we could see that the 2015 reform plan indeed reduces the default probability and the size of the fiscal burden of government by increasing the premium and decreasing the benefit. However, the size of the effect is not very standout at this moment because the number of new employees who are fully subject to the reform will be much smaller than the number of previous employees for a while. Thus, the effect of the reform is expected to appear in a slow manner.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.199-204
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• 2016

The dependence of cell survival on exposure dose and the duration of the liquid-holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage.