• Tuberculosis and Respiratory Diseases
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• v.83 no.4
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• pp.303-311
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• 2020

Background: If the duration of mechanical ventilation (MV) is related with the intensive care unit (ICU) readmission must be clarified. The purpose of this study was to elucidate if prolonged MV duration increases ICU readmission rate. Methods: The present observational cohort study analyzed national healthcare claims data from 2006 to 2015. Critically ill patients who received MV in the ICU were classified into five groups according to the MV duration: MV for <7 days, 7-13 days, 14-20 days, 21-27 days, and ≥28 days. The rate and risk of the ICU readmission were estimated according to the MV duration using the unadjusted and adjusted analyses. Results: We found that 12,929 patients had at least one episode of MV in the ICU. There was a significant linear relationship between the MV duration and the ICU readmission (R²=0.85, p=0.025). The total readmission rate was significantly higher as the MV duration is prolonged (MV for <7 days, 13.9%; for 7-13 days, 16.7%; for 14-20 days, 19.4%; for 21-27 days, 20.4%; for ≥28 days, 35.7%; p<0.001). The analyses adjusted by covariables and weighted with the multinomial propensity scores showed similar results. In the adjusted regression analysis with a Cox proportional hazards model, the MV duration was significantly related to the ICU readmission (hazard ratio, 1.058 [95% confidence interval, 1.047-1.069], p<0.001). Conclusion: The rate of readmission to the ICU was significantly higher in patients who received longer durations of the MV in the ICU. In the clinical setting, closer observation of patients discharged from the ICU after prolonged periods of MV is required.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.683-694
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• 2016

Sensitivity analysis of the WRF model according to the impact of nudging (e.g., nudging techniques and application domains) was conducted during high nocturnal ozone episode to improve the prediction of the regional ozone concentration in the southeastern coastal area of the Korean peninsula. The analysis was performed by six simulation experiments: (1) without nudging (e.g., CNTL case), (2) with observation nudging (ONE case) to all domains (domain 1~4), (3) with grid nudging (GNE case) to all domains, (4)~(6) with grid nudging to domain 1, domain 1~2 and domain 1~3, respectively (GNE-1, GNE-2, GNE-3 case). The results for nudging techniques showed that the GNE case was in very good agreement with those observed during all analysis periods (e.g., daytime, nighttime, and total), as compared to the ONE case. In particular, the large effect of grid nudging on the near-surface meteorological factors (temperature, relative humidity, and wind fields) was predicted at the coastline and nearby sea during daytime. The results for application domains showed that the effects of nudging were distinguished between the meteorological factors and between the time periods. When applied grid nudging until subdomain, the improvement effects of temperature and relative humidity had differential tendencies. Temperature was increased for all time, but relative humidity was increased in daytime and was decreased in nighttime. Thus, GNE case showed better result than other cases.

• Journal of Genetic Medicine
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• v.7 no.1
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• pp.87-90
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• 2010

Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea Hyperammonemia in the newborn often leads to severe fatal illness associated with hyperammonemic encephalopathy. Transient hyperammonemia in newborns (THAN) is characterized by self-limiting, transient hyperammonemia during the neonatal period. THAN may have favorable long-term outcomes if it is diagnosed early and appropriately managed. However, severe hyperammonemia can develop even in newborns with THAN, which may require emergent management. Here we report a case of THAN with severe hyperammonemia during the neonatal period that was successfully treated with continuous renal replacement therapy and nitrogen-scavenging medications. Our patient went on to develop normally and has not re-experienced a hyperammonemic episode until 9 months of age without the administration of a protein restricted diet or medications.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.395-404
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• 2011

Asian dust evens took place in Seoul on 27~28 March and 31 March~1 April 2007, during which the mass and chemical compositions of $PM_{10}$ were measured at urban area in Seoul, Korea. In conjunction with $PM_{10}$ compositions, the behaviors of gas precursors such as CO, $O_3$, $SO_2$, and $NO_2$ and meteorological parameters and air mass trajectories were thoroughly examined. The earlier case was a weak dust incidence which was characterized by elevated concentrations of CO, $SO_2$ and $NO_2$ as well as secondary aerosols. In contrast, the later showed the trait of the dust aerosols associated with high $PM_{10}$ mass and $Ca^{2+}$ concentrations. In general, the fractions of ionic species against mass decreased with increase in dust loading. The ratios of ${SO_4}^{2-}$ to ${NO_3}^-$ and $SO_2$ to $NO_2$ were similar in temporal variations, suggesting the concentrations of secondary aerosols were sensitive to the level of precursor gases. In this study, $Na^+$ and $Cl^-$ were also highly elevated during the heavy dust episode, which is thought to have originated from alkaline soils spreading through the northeast regions of China.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.3
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• pp.190-197
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• 2004

This paper presents automated prediction of transient ischemic episodes using neural networks(NN) based pattern matching method. The learning algorithm used to train the multilayer networks is a modified backpropagation algorithm. The algorithm updates parameters of nonlinear function in a neuron as well as connecting weights between neurons to improve learning speed. The performance of the method was evaluated using ECG signals of the MIT/BIH long-term database. Experimental results for 15 records(237 ischemic episodes) show that the average sensitivity and specificity of ischemic episode prediction are 85.71% and 71.11%, respectively. It is also found that the proposed method predicts an average of 45.53［sec］ ahead real ischemia. These results indicate that the NN approach as the pattern matching classifier can be a useful tool for the prediction of transient ischemic episodes.

• School Mathematics
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• v.18 no.3
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• pp.457-478
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• 2016

The purpose of this study is to investigate middle school students' understanding and development of function graphs. We collected the data from the teaching experiment with two middle school students who had not yet received instruction on linear function in school. The students participated in a 15-day teaching experiment(Steffe, & Thompson, 2000). Each teaching episode lasted one or two hours. The students initially focused on numerical values rather than the overall relationship between the variables in functional situations. This study described meaning, role of and students' responses for the given tasks, which revealed the students' understanding and development of function graphs. Especially we analyzed students' responses based on their methods to solve the tasks, reasoning that derived from those methods, and their solutions. The results indicate that their continuous reasoning played a significant role in their understanding of function graphs.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.813-820
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• 2009

On Dec 22, 1909, a young patriot called Lee Jae-Myung (1986~1910) attempted to assassinate Lee Wan-Yong, the prime minister of the last Yi Choseon cabinet and he later signed the annexation treaty with imperial Japan. Despite that Lee Jae-Myung failed in this assassination attempt, his heroic deed motivated national pride thereafter. After this attempted assassination, a medical record was prepared about stab wound that was inflicted upon Lee Wan-Yong during the trial of Lee Jae-Myung, and this record included many significant specific descriptions that were concerned with thoracic surgery. They included an intercostal stab wound and intercostal arterial hemorrhage, lung injury, chest contusion, traumatic pleuritis and supposedly pneumo-and hemothorax. Thoracentesis for drainage of the serosanguinous pleural effusion was also mentioned. This medical record is judged to be the first written medical record on thoracic surgery in Korean history. The aim of this study is to analyze the content of the record as it is related with a well known episode in modern Korean history.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.414-418
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• 2007

A 2.8-year-old intact female Beagle dog (weighing 11kg) was referred with the primary complaint of exercise intolerance with occasional syncope. Physical examination revealed irregularly irregular heart rhythm with persistent pulse deficits. The 12-lead surface ECG showed a third degree heart block. Permanent transvenous cardiac pacing with a bipolar implantable pacemaker was performed in the right ventricle. After pacemaker implantation, the dog did not show syncopal episode and is currently able to take a walk with an owner. No side effects associated with permanent pacemaker implantation has been observed to date.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.1
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• pp.85-91
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• 2006

PFAPA syndrome is characterized by periodic fevers associated with aphthous stomatitis, pharyngitis, and cervical adenitis and is unusual in infants and children. We report on a case of PFAPA syndrome mimicking cyclic vomiting syndrome in a 42-month-old girl. She had experienced multiple episodes of cyclic vomiting with abdominal pain from age 20 to 30 months. When she was 30 months old, periodic fever with pharyngitis was combined with cyclic vomiting, and when 40 months old, aphthous stomatitis and cervical adenitis were added. These periodic symptoms and signs were not treated with prokinetics or antibiotics. Symptom duration of an episode was 3 days. After cimetidine therapy (150 mg three times daily for 6 months), her febrile and cyclic vomiting episodes ceased. At the time of writing she had not received therapy for 10 months and has remained well without periodic attack.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.564-568
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• 2000

The authors present a rare case of subependymal giant cell astrocytoma which successfully treated with endoscopic tumor resection. A 15-year-old boy was presented with multiple episode of generalized seizure and intermittent headache for 5 years. The patient had facial adenoma sebaceum, multiple nevi on his back, and mental retardation. Cerebral MRI scans showed a round tumor located at the frontal horn of right ventricle near the foramen monro. The tumor was totally removed with endoscopic procedure and histologically confirmed as a subependymal giant cell astrocytoma. Subependymal giant cell astrocytomas can cause all the clinical problems that are associated with other types of intracranial tumor. However, surgical indication is not well standardized, because of the lack of basic knowledge about the tumor and the likelihood of surgical morbidity. We believe that endoscopic surgery, a minimally invasive technique, can circumvent the surgical disadvantage while achieving the surgical goal.