• Journal of Preventive Medicine and Public Health
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• v.33 no.1
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• pp.1-9
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• 2000

Objectives : This study was carried out to investigate the sources of infection and modes of transmission of an outbreak of shigellosis that occurred among pupils of 'M' primary school and residents near the school in Kyongju from Sept. 24 to Oct. 24, 1998. Methods : The subjects who completed a questionnaire and a rectal swab for microbiologic examinations were 1,534 persons (781 males, 753 females), including 469 pupils of 'M' primary school (268 males, 201 females). Bacteriological examinations of underground water and simple piped water were done. Results : The attack rate of diarrhea was 28.7% in the subjects from Sept.24 to Oct. 24, 1958. There was no difference in attack rate of diarrhea by gender, but it was significantly higher in the pupils of 'M' primary school than others (p<0.01). The attack rate of diarrhea by resident areas was no different to the pupils of 'M' primary school, but was significantly higher in the residents of Mohwa 2 Ri except pupils that 'M' primary school is located in (p<0.01). The distribution of date of onset revealed the exposure date to be Sept, 22 and 23 in consideration of incubation periods and common source outbreak followed propagative spread in the epidemic curve. The major characteristics of diarrhea were watery (89.1%) in nature, $1\sim3$ days (72.5%) in duration, $2\sim3$ times (63.9%) in frequency. The clinical symptoms among the diarrheal cases included abdominal pain (74.1%), fever (56.4%), headache (55.9%), chill (40.4%) and tenesmus (31.4%). Conclusions : The source of infection was estimated to be contaminated underground water and simple piped water caused by leakage from the cess pool. It is highly necessary that the management of drinking water and cess fools should be done thoroughly.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.176-182
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• 2006

Purpose: The aim of this study was to investigate the spectrum of gastrointestinal mucosal lesions in the children presenting with short-term abdominal pain. Methods: Thirty one children with short term abdominal pain for less than 1 month from January 1995 to May 2004 who were examined using gastrointestinal (GI) endoscopy were reviewed retrospectively. Children presenting with acute abdominal pain unrelated to proper GI were excluded from this study. Results: Male patients were 16 and female were 15. Three patients were 1~5 years old, 15 were 6~10 years old, and 13 were 11~15 years old. The duration of the abdominal pain was less than 7 days in 23 patients, 10 days in 1, 20 days in 2, and 30 days in 4. The major accompanying symptoms were vomiting (15), diarrhea (4), melena (1), hematemesis (1), and fever (2). Using endoscopy, 6 patients were found to have hemorrhagic gastritis, 5 nodular gastritis, 4 duodenal ulcer, 3 gastric ulcer, 3 reflux esophagitis, 2 nodular duodenitis, 2 superficial gastritis, 2 erosive hemorrhagic duodenitis, 2 ulcerative colitis, 1 duodenogastric reflux, and 1 esophageal polyp. Helicobacter pylori (H. pylori) infection was positive in 10 patients. The age and sex ratio, duration of abdominal pain, site of abdominal pain, and duration of abdominal pain between H. pylori- positive and negative children were different. However, only the site of abdominal pain (epigastric) showed statistical significance. All symptoms improved with medication for the GI mucosal lesions noted by the endoscopic findings. Conclusion: The author suggests that GI endoscopy be one of the important first steps in examinations to find out diverse GI mucosal lesions in the patients with short-term abdominal pain. Additionally, the examinations for H. pylori infection are important for these patients, also.

• Tuberculosis and Respiratory Diseases
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• v.41 no.6
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• pp.624-631
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• 1994

Background: Genus of Aspergilli are ubiquitous saprophytic molds in nature, but its change from a saprophytic fungus to a pathogenic organism has occurred since the use of various antibiotics. The fungus affects the chronically ill and debilitated population. Recently frequency of the fungal infection is increasing in Korea with abuse of antibiotics and glucocorticoids. Method: We analyzed medical records of 52 patients with pulmonary aspergillosis seen at Hanyang University Hospital from 1980 to 1994. The results were as follows; Results: 1) Ages ranged between second to eighth decades with majority(50%) in the fourth to fifth decades. The male to female ratio was 1.1:1. 2) Hemoptysis and productive cough, the leading symptoms, occurred in 42.3% and 25% respectively. 3) On chest X-ray fingings, the characteristic "fungus ball" pattern were observed in 53.8% of the 52cases. 4) Sputum culture for aspergilli were positive in 21.6% of the cases. We performed fine needle aspiration in 22 patients and the diagnostic yield was 100%. 5) Thirty-six patients had history of treatment with antituberculous drugs under diagnosis of pulmonary tuberculosis for an average of 27.3 months. But sputum analysis for acid-fast bacilli were positive in 5.6%(2cases of 36cases), and postoperative pathologic findings showed that 38.9%(12 cases of 28cases) were combined with tuberculosis. 6) Right upper and left upper lobes were predominantly involved(34.6% and 19.2% respectively) and lobectomies were performed in 21 cases. 7) Underlying diseases were present in 47 cases and 48.9% of them were pulmonary tuberculosis. Conclusion: These results showed that pulmonary aspergillosis usually develops in patients with open cavitary pulmonary tuberculosis. And we must consider the possibility of pulmonary aspergillosis in a patient with hemoptysis and cavitary lung lesion.

• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.609-614
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• 2013

This study investigated the spontaneous combustion behavior of solvent-treated low rank coals. Indonesian lignite (a KBB and SM coal) and sub-bituminous (a Roto coal) were mixed with non-polar 1-methyl naphthalene (1MN) either by mechanical agitation or ultrasonication. The property change associated with 1MN treatment was then analyzed using proximate analysis, calorific value analysis, Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy and moisture re-adsorption test. Susceptibility to spontaneous combustion was evaluated using crossingpoint temperature (CPT) measurement along with gas analysis by GC. A FT-IR profile showed that oxygen functional groups and C-H bonding became weaker when treated by 1 MN. XPS results also indicated a decrease of the oxygen groups (C-O-, C=O and COO-). Increased hydrophobicity was found in the 1MN treated coals during moisture readsorption test. A CPT of the treated coals was ${\sim}20^{\circ}C$ higher than that of the corresponding raw coals and the ultrasonication was more effective way to enhance the stability against spontaneous combustion than the agitation. In the gas analysis less CO and $CO_2$ were emitted from 1MN treated coals, also indicating inhibition of pyrophoric behavior. The surface functional groups participating in the oxidation reaction seemed to be removed by the ultrasonication more effectively than by the simple mechanical agitation.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.154-162
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• 2011

Purpose : The aim of this study was to identify the clinical characteristics of lower respiratory tract infection due to respiratory syncytial virus (RSV) in young children and to provide information for an effective guideline for palivizumab administration in Korea. Methods : We reviewed medical charts of 167 patients under 3 years of age who were hospitalized in Dongguk University Ilsan Hospital for lower respiratory tract infection between January 2007 and February 2011. Diagnosis of the virus was made based on the multiplex real time polymerase chain reaction. Results : There were 113 patients who were infected by respiratory syncytial virus. 90 patients were term infants and 23 patients were preterm infants. No difference was shown between term and preterm infants except the days of admission which was 9.0${\pm}$6.0 days and 12.6${\pm}$21.0 days respectively. In the preterm group their mean age at the time of admission was 5.21${\pm}$4.9 months and the mean gestational age was 33.1${\pm}$4.3 weeks, and the mean birth weight was 2,152${\pm}$950 g. Only 4 patients were born under 28 weeks gestational age and were candidates for palivizumab administration. Conclusion : Most of the patients with severe RSV lower respiratory tract infection were term or near term infants who were not candidates for palivizumab prophylaxis. A nationwide study is needed to make a new risk stratified guideline for RSV prophylaxis for our country.

• Resources Recycling
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• v.32 no.1
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• pp.50-59
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• 2023

The amount of dust generated during the dissolution of scrap in an electric arc furnace is approximately 1.5% of the scrap metal input, and it is primarily collected in a bag filter. Electric arc furnace dust primarily consists of zinc and ion. The processing of zinc starts with its conversion into pellet form by the addition of a carbon-based reducing agent(coke, anthracite) and limestone (C/S control). These pellets then undergo reduction, volatilization, and re-oxidation in rotary kiln or RHF reactor to recover crude zinc oxide (60%w/w). Next, iron is discharged from the electric arc furnace dust as a solid called Fe clinker (secondary by-product of the Fe-base). Several methods are then used to treat the Fe clinker, which vary depending on the country, including landfilling and recycling (e.g., subbase course material, aggregate for concrete, Fe-source for cement manufacturing). However, landfilling has several drawbacks, including environmental pollution due to leaching, high landfill costs, and wastage of iron resources. To improve Fe recovery in the clinker, we pulverized it into optimal -sized particles and employed specific gravity and magnetic force selection methods to isolate this metal. A carbon-based reducing agent and a binding material were added to the separated coarse powder (>10㎛) to prepare briquette clinker. A small amount (1-3%w/w) of the briquette clinker was charged with the scrap in an electric arc furnace to evaluate its feasibility as an additives (carbonaceous material, heat-generating material, and Fe source).

• Economic and Environmental Geology
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• v.57 no.3
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• pp.281-292
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• 2024

North Korea relies heavily on coal as the primary energy source, playing an important role in all energy demand sectors except for the transportation sector. Approximately half of the total electricity is generated through coal-fired power plants, and coal is used to produce heat and power for all industrial facilities. Furthermore, coal has been a significant contributor to earning foreign currency through long-term exports to China. Nevertheless, since the 1980s, indiscriminate mining activities have led to rapid depletion of coal production in most coal mines. Aging mine facilities, lack of investment in new equipment, shortages of fuel and electricity, difficulties in material supply, and frequent damage from flooding have collectively contributed to a noticeable decline in coal production since the late 1980s. North Korea's coal deposits are distributed in various geological formations from the Proterozoic to the Cenozoic, but the most critical coal-bearing formations are Ripsok and Sadong formations distributed in the Pyeongnam Basin of the Late Paleozoic from Carboniferous to Permian, which are called as Pyeongnam North and South Coal Fields. Over 90% of North Korea's coal is produced in these coal fields. The classification of coal in North Korea differs from the international classification based on coalification (peat, lignite, sub-bituminous coal, bituminous coal, and anthracite). North Korean classification based on industrial aspect is classified into bituminous coal, anthracite, and low-grade coal (Chomuyeontan). Based on the energy factor, it is classified into high-calorie coal, medium calorie coal, and low-calorie coal. In North Korea, the term "Chomuyeontan" refers to a type of coal that is not classified globally and is unique to North Korea. It is a low-grade coal exclusively used in North Korea and is not found or used in any other country worldwide. This article compares North Korea's coal classification and the international coal classification of coal and provides insights into the geological characteristics, reserves, utilization, and research trends of North Korean coal resources. This study could serve as a guide for preparing scientific and industrial agendas related to coal collaboration between North Korea and South Korea.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.64-72
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• 1997

Purpose : The incidence of tuberculous meningitis in Korean children has been markedly decreased after 1980s, but this disease has still occurred with low rate. Therefore, it may be suspected that delayed diagnosis and treatment will be happened because of lacking of clinical experiences and indistinguishable other meningitis, so it is important to make early diagnosis and treatment of tuberculous meningitis concerning with the prognosis. In this aspect, we conducted study to concern and investigate sustainly about the diagnostic criteria, clinical characteristics, radiological findings, complications, and prognosis of typical or atypical tuberculous meningitis in children. Methods : Forty four children who were hospitalized and treated due to tuberculous meningitis in pediatric wards of Our Lady of Mercy Hospital, St. Holy Hospital, St. Vincent Hospital and Uijungbu St. Mary Hospital from January 1985 to June 1996 were included in this study. We reviewed medical records of these patients retrospectively. Results : 1) The tuberculous meningitis has occured continuosly since mid-1980s. The highest 2) The diagnosis was made by contact history of active tuberculous patients, positive tuberculin test, responses of antituberculous antibiotics and discovery of Mycobacterium tuberculosis from CSF or other specimens. Among patients, 7 children(16%) were not vaccinated with BCG, and only 18 children(40%) were positive in tuberculin test. 3) The symptoms and signs of our patients on initial examinations were fever, vomiting, headache, lethargy, poor feeding, weight loss, neck stiffness, convulsion, abdominal pain and motor deficits. 4) The findings of initial CSF samples revealed leukocyte $239.5/mm^3$(mean) with lymphocyte predominant, elevated protein levels(mean;259.5mg%) and low sugar level(mean;40.7mg%). And the ratio of CSF/blood sugar was 0.407. But, atypical CSF findings were seen in 31.8% patients. 5) On brain imaging study, 34 out of 39 children had findings of hydrocephalus, basilar meningeal enhancement, infarction and subarachnoidal inflammations etc. On chest X-ray, the findings of miliary tuberculosis(34.1%), normal finding(29.5%), parenchymal infiltrations (11.4%) and calcifications(9.1%) were showed. 6) In neurological clinical stage, there were twenty-six children(59%) in stage 1, fourteen children(32%) in stage 2 and four children(9%) in stage 3. The late sequeles were encountered by 29.5% with mild and 4.6% with severe neurological injury. The most common neurological injury was quadriplegia and the mortality rate was 6.8%. 7) The SIADH was developed in 20 children(45.5%) after the 4th hospital day. Half of all SIADH patients were symptomatic. Conclusion : Tuberculosis meningitis is still an important extrapulmonary disease with high morbidity and mortality. Early diagnosis with clinical contact history of active tuberculosis and radiological imaging examinations and early treatments are essential in order to prevent and decrase the rate of late sequeles and death.

• Pediatric Infection and Vaccine
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• v.6 no.1
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• pp.78-85
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• 1999

Purpose : Mycoplasma pneumoniae pneumonia has been to be developed frequently in school age children and adolescence and hard to see under 3 year-old children. But it seems to be increased in number of patients with Mycoplasma pneumoniae pneumonia under 3-year old in clinical practice in these days. We have aimed to examine the characteristics of clinical findings of Mycoplasma pneumonia under 3 year-old children. Methods : We had performed retrospective review of medical records of 30 patients with Mycoplasmal pneumonia under 3-year old children who admitted to Department of Pediatrics, Kyunghee University Hospital from Jan. 1994 to Dec. 1997. The diagnostic criteriae was Cold agglutinin titer>1:64 or Mycoplasma antibody titer>1:80. Results : Mycoplasmal pneumonia was 30 out of 235 cases(12.7%) of total pneumonia under 3 year old children. Male female ratio was 1.3 : 1 and age distributions were 0~1y : 0, 1~2y : 8, 2~3y : 22 cases. Clinical symptoms and signs were cough(100.0%), sputum(83.3%), fever(80.0%) rhinorrhea(33.3%), vomiting(33.3%), moist rale(86.7%), decreased breathing sound(26.7%), wheezing(20.0%), and pharyngeal injection(30.0%). Thirteen out of 30 cases(43.3%) had unilateral infiltration, 10 cases(33.4%) had bilateral infiltration, 1 case(3.3%) had pleural effusion, and 6 cases(20.0%) had negative findings on chest radiography and there was no cases of atelectasis. On laboratory findings, 6 out of 30 cases(20.0%) had leukocytosis, 1 case(3.3%) had neutrophilia, 10 cases(30.0%) had eosinophilia, 17 cases(56.7%) had increased ESR, and 18 cases(60.6%) had positive CRP. Positive cold agglutinin titers(>1 : 64) were 19 cases(63.3%), and positive mycoplasma antibody(M-ab) titers(>1 : 80) were 27 cases(93.3%). Mycoplasma antibody test was more valuable than cold agglutinin test for the diagnosis of Mycoplasmal pneumonia and there was no correlation between cold agglutinin titer and mycoplasma antibody titer. Mycoplasma-polymerase chain reaction(M-PCR) was done with 13 cases, 12 out of 13 cases(92.3%) were positive. M-PCR test was valuable to the diagnosis of Mycoplasmal pneumonia but it will be needed to further study for their clinical application. Among 30 cases, 5 cases(16.7%) had complications, 3 cases(10.0%) had skin rash, 1 case(3.3%) had pleural effusion, 1 case(3.3%) had arthralgia, but all complications were mild and recovered without residual sequelae. Conclusion : The occurrence of Mycoplasmal pneumonia under 3 year-old children was not rare from this study. Clinical characteristics of Mycoplasmal pneumonia under 3-year old were normal radiologic findings in many cases, low complication rate, mild clinical course, and tend to rapid recovery compared with general manifestations of Mycoplasmal infectionsin children and adolescence. There were likely to be missed patients with Mycoplasmal pneumonia which did not diagnose by conventional serologic tests that had low sensitivity and specificity. We have to pay attention to the Mycoplasmal infection of the young children with pneumonia during epidemic periods of Mycoplasmal infection.

• Pediatric Infection and Vaccine
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• v.11 no.2
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• pp.158-169
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• 2004

Purpose : Although influenza is one of the most important cause of acute respiratory tract infections in children, virus isolation is not popular and there are only a few clinical studies on influenza and diagnostic methods. We evaluated the epidemiological and clinical features of influenza in children and rapid antigen detection test(QuickVue influenza test) on fist half of the year 2004 in Busan. Methods : From January 2004 to June 2004, throat swab and nasal secretion were obtained and cultured for the isolation of influenza virus and tested by rapid antigen detection test(QuickVue influenza test) in children with suspected influenza infections. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Influenza viruses were isolated in 79(17.2%) out of 621 patients examined. Influenza virus was isolated mainly from March to April 2004. The ratio of male and female with influenza virus infection was 1.2 : 1 with median age of 4 years 6month. The most common clinical diagnosis of influenza virus infection was bronchitis. There was no difference between influenza A and B infection in clinical diagnosis and symptoms. All patients recovered without severe complication. The sensitivity obtained for rapid antigen detection test (QuickVue influenza test) was 93.6% and the specificity was 80.2%, the positive predictive value 40.8%, the negative predictive value 98.8%. Conclusion : With rapid antigen detection test, it is possible early detection of influenza in children. reduction in use of antimicrobial agent and early use of antiviral agent.