• Journal of the Korea Society for Simulation
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• v.30 no.3
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• pp.19-29
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• 2021

To explain the interregional infections in COVID-19, we designed a multi-group compartmental model by applying the SEIQRD model, a compartmental model of a single group. The model is segmented by compartments to account for hidden infections, such as latent periods and asymptomatic cases, and is capable of comparing infection indices and test rates between regions. Through this, it estimated which region was centered during the second wave in August 2020 and the third wave in November 2020. Subgroups were set up in Seoul, Gyeonggi (including Incheon), and a non-metropolitan area. We fit the model to the Ministry of Health and Welfare's data to estimate the average infection index between regions, average rate of rT-PCR test by region, and the expected number of hidden infections by region.

• The Journal of Korean Medicine
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• v.42 no.1
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• pp.99-109
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• 2021

Objectives: Objective: The purpose of this study is to investigate the treatment of herbal medicine for patients with COVID-19 asymptomatic infections. Method: In English, search engines such as 'PubMed', 'Science Direct', and 'Cumulative Index to Nursing and Allied Health Literature (CINAHL)' were used. In Chinese, search engines such as 'China National Knowledge Infrastructure (CNKI)' and Wanfang were used. The keywords for the search engines were 'COVID-19', 'asymptomatic infection', 'Korean Medicine', 'traditional Chinese medicine', 'herbal medicine', and etc. Only clinical studies using herbal medicine for patients without fever or respiratory symptoms were selected. We excluded the cases that do not fit the research topic. Results: A total of 5 studies were finally selected. Among them, four of them used integrated herbal medicine and Western medicine, and one of the studies treated exclusively for herbal medicine. There were a total of seven prescriptions for herbal medicine used in the study. Outcome variables were used as following: lab test, nucleic acid conversion time, hospitalization period, chest CT, and etc. In the RCT study, herbal medicine and Western medicine decreased nucleic acid conversion time, average hospitalization time compared to the control group, but it was not statistically significant. No other adverse reactions were reported in all studies. Conclusion: According to the results, integrated herbal medicine and Western medicine might be an effective treatment for patients with COVID-19 asymptomatic infection reducing hospitalization period, time of nucleic acid turning negative. No severe adverse effects were reported. However, it is thought that better-designed research will be needed in the future.

• Tuberculosis and Respiratory Diseases
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• v.69 no.1
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• pp.24-30
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• 2010

Background: A novel 2009 influenza A (H1N1) virus emerged and disseminated to all over the world. There are few reports on the clinical characteristics of patients with complications. We describe the clinical features of pneumonia in adult patients hospitalized, who have novel influenza infection. Methods: There were 43 adult patients enrolled into the study with pneumonia of 528 hospitalized patients confirmed influenza A (H1N1) virus infection by real-time reverse transcriptase polymerase chain reaction testing, between 24 August 2009 and 31 January 2010. The clinical data of patients with pneumonia were collected retrospectively. Results: There were 22 of 43 (51.2%) influenza patients with pneumonia that had higher risk factors for complications. Compared to 28 patients with influenza A (H1N1) viral pneumonia and 15 patients, who had isolated bacteria from cultures, those with mixed viral and bacterial pneumonia were significantly more likely to have unilobar consolidations on chest radiographs (53.3 vs. 10.7%, p<0.01) and higher scores of pneumonia severity index (PSI; 90 [66~100] vs. 53 [28~90], p=0.04). Six patients required mechanical ventilation support in an Intensive Care Unit and were more likely to have dyspnea (83.3 vs. 29.3%, p=0.02) and low levels of $PaO_2$ (48.3 [37.0~70.5] vs 64.0 [60.0~74.5] mm Hg, p=0.02) and high levels of pneumonia severity index (PSI) score (108.0 [74.5~142.8] vs. 56.0 [40.5~91.0], p=0.03). Conclusion: The majority of pneumonia patients infected with novel influenza improved. Chest radiographic findings of unilobar consolidations suggest that mixed pneumonia is more likely. Initial dyspnea, hypoxemia, and high levels of PSI score are associated with undergoing mechanical ventilation support.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.293-300
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• 2018

Objectives. The current study aims to determine the correlation between nutritional status upon presentation and disease severity, as well as treatment and survival outcomes. Methods. Patients who were diagnosed with deep neck infection, underwent at least one surgical drainage/debridement, and had more than 1 week of hospitalization at a tertiary medical center from 2007 to 2015 were retrospectively included. Thereafter, initial serum albumin, C-reactive protein (CRP), and body mass index (BMI) were reviewed. Results. A total of 135 patients were included in the final analysis. Accordingly, the proportion of patients with simultaneous mediastinitis (21.0%), necrotizing fasciitis (12.9%), disease extent >1 cervical level (72.6%), mean CRP (22.4 mg/dL), mean length of hospitalization (25.0 days), and mean 1-week follow-up CRP (7.2 mg/dL) was significantly higher in the hypoalbuminemia group (initial serum albumin <3.0 g/dL) than in the normoalbuminemia group (all P<0.05). No significant correlations had been observed according to BMI status. After adjusting for age and Charlson comorbidity index, odds ratios for the following outcomes were calculated in patients initially presenting with hypoalbuminemia: simultaneous mediastinitis (3.07), necrotizing fasciitis (7.89), disease extent >1 cervical level (2.12), initial serum CRP over 20 mg/dL (3.79), hospitalization of more than 14 days (4.10), 1-week follow-up CRP over 5 mg/dL (3.78), and increased duration for an over 50% decrease in initial CRP (2.70) (all P<0.05). Although intravascular albumin replenishment decreased the proportion of patients with hypoalbuminemia after 2 weeks (P<0.05), it did not significantly predict better treatment outcomes. Conclusion. Among the markers reflecting an individual's nutritional state, an initial serum albumin of less than 3.0 g/dL was an independent serologic marker predicting increased disease severity and complications in patients with deep neck infection.

• Journal of Chest Surgery
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• v.31 no.3
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• pp.286-290
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• 1998

The pectus excavatum is the most common deformity of chest wall. The most common cause of surgical correction is cosmetic problem. From January 1981 to July 1996, 24 patients had undergone surgery for pectus excavatum and they were corrected by Ravitch operation(n=4) or modified Wada operation(n=20) respectively. We analyzed each surgical cases according to age, sex, chief complaint, degree of deformity, EKG findings, complications and satisfaction degree of patient. In some cases, we measured Welch index preoperatively and postoperatively. The postoperative complications were wound infection in two, pneumothorax in two and reccurrence in one. The average value of Welch index was significantly improved from 5.86$\pm$0.51 preoperatively to 4.10$\pm$0.51 postoperatively(P<0.05). The results by Humphreys' criteria were satisfiable in 88%(excellent 71%, good 17%). The findings of this study suggest that surgical correction of pectus excavatum with modified Wada rocedure and submammary s in incision is effective method in physical and psychiatric aspect.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.561-564
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• 2008

Pinus densiflora(red pine) stands in Korea have been faced with the serious threat by pine wilt disease caused by Bursaphelenchus xylophilus (nematodes). It is not easy to early detect and prevent the infected trees because those cannot be visually identified during the initial phase of infection. Red pine is usually infected by B. xylophilus from May to July and can be just visually detected in October or November. While the infected trees are wilted, the spectral value of Near Infrared (NIR) is supposed to be decreased. Based on this phenomena, in this paper, the vegetation vitality change of infected trees was analyzed using vegetation indices. Spectral values of Red, Green and NIR had been acquired monthly by a portable NIR camera in the same place of red pine stands infected by pine wilt disease. It could be proven that the vegetation index, or vegetation vitality of damaged trees starts to decrease from June, in the early infecting phase.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.117-123
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• 2011

Purpose : We investigated the change of antibody titer to measles, mumps and rubella according to age after vaccination. Methods : The IgG antibody titers to measles, mumps and rubella were tested on the residual serum from patients aged 7-20 years old after routine laboratory testing in the hospital with informed consent from the parents. Results : Antibody to measles was present in 275 cases out of 408 cases with a positive rate of 67.4%, the mean IgG titer was 2.77${\pm}$1.18 Index. Antibody to mumps was present in 112 cases out of 408 cases with a positive rate of 27.5%, the mean IgG titer was 2.08${\pm}$1.29 Index. Antibody to rubella was present in 367 cases out of 408 cases with a positive rate of 90.0%, the mean IgG titer was 60.46${\pm}$63.47 IU/mL. Conclusion : It is important to maintain a high rate of vaccination coverage in order to prevent an outbreak of measles, mumps, or rubella. It is also important to stress the maintenance of vaccination records for further reference.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.224-233
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• 1983

An experimental study was carried out to observe the susceptibility of several kinds of laboratory animals to Fibricola seoulensis infection, a diplostomatid fluke of mammals. The metacercariae were obtained from the viscera of the snakes, Natrix tigrina lateralis and 50~2,000 in number each was artificially fed to a total of 127 animals; albino rats, mice, dogs, cats, rabbits and chickens. After 3 days to 8 weeks the animals were sacrificed and the recovery rate of worms as well as their maturity was observed. The results are as follows: 1. The overall worm recovery rates throughout the experimental period was highest in albino rats (40.0%) followed by mice (33.9%), cats (20.9%), dogs (11.4%), rabbits (0.05%) and chickens (0%). However, the recovery rates in the same host decreased as infection progressed longer and variable by the amount of metacercariae given. 2. From albino rats and mice, the highest recovery rates were obtained in 1,000 and 200-metacercariae infection groups respectively, and it is considered that such amount should be the optimum dose for experimental infection of these animals. 3. The main location of F. seoulensis in experimental animals was small intestine especially the duodenum. 4. The maturity index (No. mature worms/ No. examined) was 100% in albino rats and mice, while only 22.7% or 0% in dogs or cats respectively. From the results, it is concluded that albino rats and mice are the most susceptible hosts for F. seoulensis infection among six kinds of laboratory animals examined.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.8-16
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• 2018

Purpose: In this study, the clinical and epidemiological characteristics of patients admitted for viral croup were analyzed to evaluate disease severity based on the organism that caused the infection. Methods: We retrospectively reviewed the medical records of 302 patients who were admitted to the Department of Pediatrics at the Wonju Severance Hospital between May 2013 and December 2016 for viral croup. Patients who showed positive results on multiplex polymerase chain reaction were subsequently diagnosed with respiratory virus infection. The Westley scoring system was used to evaluate the severity of viral croup. Results: Of the 302 patients, 149 were admitted due to severe viral croup, including 88 boys and 61 girls, with a boy-to-girl ratio of 1.44:1. About 110 cases of parainfluenza virus infection have been reported, which accounted for almost half of the total cases. The other identified viruses included influenza virus, human rhinovirus, and respiratory syncytial virus. Analysis of the association between severe viral croup and causative pathogen revealed that only parainfluenza type 2 virus showed a significantly high risk. Parainfluenza type 2 virus did not show an age-based difference in frequency but showed relatively a higher frequency of infections during the summer and fall. Conclusions: In this study, parainfluenza virus type 2 was the only virus associated with severe viral croup. To facilitate proper preventive management, treatment, and prognosis evaluation of viral croup, prospective and multicenter studies should assess the additional variables and the severity of the virus. Additionally, further studies should be conducted to assess age-dependent influences, as well as the regional and seasonal incidence of viral infection.

• Clinical and Molecular Hepatology
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• v.24 no.4
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• pp.384-391
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• 2018

Backgrounds/Aims: The objective of our study was to determine the epidemiological, laboratory, and serological characteristics of patients with chronic hepatitis B virus (HBV) infection and normal transaminases. The study also aimed to evaluate liver damage by measuring the liver fibrosis (LF) grade and to identify possible factors associated with the presence of fibrosis. Methods: A retrospective observational study was conducted in patients with chronic HBV infection and classified as inactive carriers or immune-tolerant. Epidemiological variables of age, sex, immigrant, alcohol consumption, and body mass index (BMI), as well as virological variables (HBV DNA) and transaminase level were collected throughout the follow-up. The LF grade was evaluated by transient elastography. The cutoff value for significant fibrosis (SF) was liver stiffness ${\geq}7.9kPa$. Results: A total of 214 patients were included in the analysis, and 62% of them had a BMI ${\geq}25kg/m^2$. During follow-up, 4% of patients showed transaminase elevation (<1.5 times normal). Most patients had a viral DNA level <2,000 IU/mL (83%). Data on LF were available in 160 patients; of these, 14% had SF, 9% F3, and 6% F4. The variables associated with the presence of SF were transaminase alteration during follow-up, as 23% of patients with SF had elevated transaminases versus 3% of patients without SF (P<0.005), and BMI, as the vast majority of patients with SF (88%) had a BMI ${\geq}25kg/m^2$ versus 56% of patients without SF (P<0.05). Conclusions: In patients with chronic HBV infection and normal transaminases, liver damage does not seem to be related to DNA levels, alcohol consumption, or immigrant status. SF seems to be associated with transaminase alteration during follow-up and elevated BMI. It is therefore recommended to measure LF grade with validated non-invasive methods in such patients.