• Korean Journal of Veterinary Service
• /
• v.42 no.1
• /
• pp.25-30
• /
• 2019

The objective of this study was to assess the possibility of detecting Foot-and-Mouth Disease Virus (FMDV) from the herd-based oral fluids specimens collected by the cotton ropes from pig farms that were found as FMDV nonstructural protein (NSP) antibodies positive. The cotton ropes were applied to detect FMDV in the selected pig farms which NSP antibodies were continuously detected in 2016, including the one pig farm which FMDV antigen were detected at the specimens from the pigsty environment. As the result, FMDV antigen were not detected in the oral fluid specimens collected by the cotton ropes. Theoretically, to detect FMDV antigen from the pigs with NSP antibodies has very low possibility because FMDV antigen disappeared at the time when NSP antibodies were produced by FMDV. Therefore, in order to detect FMDV antigen from the oral fluids using the cotton rope, it would be more effective to be applied to target the FMDV infected pigs rather than the NSP antibodies positive pigs. The collected oral fluids using cotton rope could be useful test specimens to monitor high-density pig populations for FMDV infection. Then, oral fluids sampling using cotton rope will be used for the efficient FMDV surveillance to detect FMDV antigen.

• Applied Chemistry for Engineering
• /
• v.22 no.6
• /
• pp.631-635
• /
• 2011

Spherical and non-spherical silica particles prepared by the direct oxidation were studied for the effect of the particle size and shape of these particles on oxide CMP removal rate. Spherical silica particles, which have 10~100 nm in size, were prepared by the direct oxidation process from silicon in the presence of alkali catalyst. The 10 nm silica particles were aggregated by addition of an acid, an alcohol, or a silane as an aggregation inducer between the particles. Two or more aggregated silica particles were used as a seed to grow non spherical silica particles in the direct oxidation process of silicon in the presence of alkali catalyst. The oxide removal rate of spherical silica particles increased with increasing an average particle size for spherical silica abrasives in the oxide CMP. It further increased non-spherical particles, compared with the spherical particles in the similar average particle size.

• Journal of the Korean Institute of Gas
• /
• v.25 no.6
• /
• pp.35-44
• /
• 2021

The PR (Photo Resist) process in the semiconductor process is a process that uses a mixture of flammable substances. Due to the process equipment is installed in a clean room and when flammable substances leak, there is a high risk of suffocation, fire, and explosion. It is necessary to analyze the impact of accidents that may occur during operation and to evaluate whether the safety of workers can be guaranteed. In this study, the value of radiant heat and temperature change at the monitor point set up virtual inside the clean room was confirmed through CFD simulation of 10 leak and fire scenarios using the FLACS CFD - Fire Module. A fire that occurs inside a clean room transfers high radiant heat to the inter-story structure, but its scope is quite limited, and it is unlikely that it will collapse in a single fire accident. There was no scenario in which two stairs leading to the exit were exposed to high radiant heat at the same time due to a fire accident, therefore workers were able to escape in case of a fire. In addition, it was confirmed that the level of radiant heat and temperature rise rapidly decreased as they moved downstairs. According to the API 520 standard, workers exposed to 6.31 kW/m² of radiant heat that workers can withstand for 30 seconds were confirmed that it was possible to sufficiently escape from the inside.

• Korean Journal of Environmental Biology
• /
• v.40 no.3
• /
• pp.307-315
• /
• 2022

In terms of habitat conservation, it is essential to develop a habitat assessment system that can evaluate not only the suitability of the current habitat, but also the health and stability of the habitat. This study aimed to develop a methodology of habitat quality assessment for endangered species by analyzing various existing habitat assessment methods. The habitat quality assessment consisted of selecting targeted species, planning of assessment, selecting targeted sites, assessing performance, calculating grade, and expert verification. Target sites were selected separately from core and potential habitats using a species distribution model or habitat suitability index. Habitat assessment factors were classified into ecological characteristic, landscape characteristic, and species-habitat characteristic. Ecological characteristic consisted of thirteen factors related to health of tree, vegetation, and soil. Landscape characteristic consisted of five factors related to fragment and connectivity of habitat. Species-habitat characteristic consisted of factors for evaluating habitat suitability depending on target species. Since meanings are different depending on characteristics, habitat quality assessment of this study could be used by classifying results for each characteristic according to various assessment purposes, such as designation of alternative habitats, assessment of restoration project, and protected area valuation for endangered species. Forest habitat quality assessment is expected to play an important role in conservation acts of endangered species in the future through continuous supplementation of this system in regard to quantitative assessment criteria and weighting for each factor with an influence.

• Pediatric Infection and Vaccine
• /
• v.14 no.1
• /
• pp.75-82
• /
• 2007

Purpose : Human metapneumovirus (hMPV) is a newly identified paramyxovirus that causes a variety of clinical syndromes in children, including upper and lower respiratory tract illnesses. hMPV is considered an ubiquitous virus causing respiratory tract diseases among children especially during late winter and spring seasons. We report clinical features of human metapneumovirus infection in Korean children. Methods : hMPV infection was diagnosed by reverse transcriptase-polymerase chain reaction (RT-PCR) in respiratory specimens obtained from patients with acute respiratory tract infections from October, 2004 to May, 2005. Medical records of all hMPV-positive patients were reviewed, retrospectively. Results : A total of 15 hMPV were identified from 443 nasopharyngeal aspirations by RT-PCR (3.4%). The range of age of the patients with hMPV infection was from 1 month to 62 months (median age, 31.5 months), with similar numbers of females (8/15) and males (7/15). Among hMPV-positive children, 53.3% (8/15) were aged less than 24 months. Fever, cough, rhinorrhea, vomiting, diarrhea, tachypnea, and chest wall retractions were common findings. Most common clinical diagnosis was pneumonia (60%). Two of the 15 hMPV-positive patients were also positive for adenovirus. Fever persisted from 0 to 10 days (mean 4.9 days). The duration of hospitalization ranged from 4 to 7 days (mean 5.6 days). Conclusion : hMPV accounted for a small but significant proportion of respiratory tract infection in infants and children. Future development and application of diagnostic tools will determine the burden of disease caused by this newly discovered pathogen.

• Clinical and Experimental Pediatrics
• /
• v.51 no.10
• /
• pp.1065-1070
• /
• 2008

Purpose : This study aims to determine whether early closure (within 7 d) of significant patent ductus arteriosus (PDA) with indomethacin or ligation reduces neonatal morbidity when compared with delayed closure (after 7 d). Methods : Fifty-eight extremely-low-birth-weight infants admitted to the NICU of Seoul National University Hospital from April 2005 to May 2007 with PDA were studied retrospectively. Results : The mean gestational age (GA) was $26{\pm}2weeks$ (range, 23-32 wk), and the birth weight was $782{\pm}146g$ (range, 430-990 g). The delayed closure group was associated with early GA ($25.7{\pm}1.7wk$ vs $27.1{\pm}2.0wk$, P=0.013), in vitro fertilization (IVF) (55% vs 24%, P=0.017), and the absence of preeclampsia (5% vs. 34%, P=0.013). There was no difference in ductal size between the early closure and delayed closure groups. The incidence of bronchopulmonary dysplasia (95% vs 65%, P=0.012) and intraventricular hemorrhage (70% vs. 39%, P=0.027) increased in the delayed closure group. Using regression analysis adjusted for gestational age, delayed closure correlated positively with the duration of ventilator support (P=0.008), hospitalization (P=0.020), time to full enteral feeding (P<0.001), and total parenteral nutrition (P=0.010). Conclusion : Delayed closure of the hemodynamically significant patent ductus arteriosus in extremely-low-birth-weight infants is significantly related to the development of various morbidities. Thus, early closure of PDA is needed within the first week of life.

• Tuberculosis and Respiratory Diseases
• /
• v.55 no.1
• /
• pp.31-40
• /
• 2003

Background : A CT scan is a useful modality for the diagnosis and evaluation of disease activity in patients with pulmonary tuberculosis. However, the CT diagnosis of pulmonary tuberculosis is sometimes difficult in patients with an atypical CT pattern, especially with lobar consolidation mimicking pneumonia. The aim of this study was to evaluate the clinical and CT features of pulmonary tuberculosis, simulating pneumonia, from a CT scan. Materials and Methods : The clinical and CT features in 21 patients, where the CT diagnosis was pneumonia, or the CT differential diagnosis included pneumonia, were retrospectively analyzed. Results : Of the 21 patients, 6 were immunocompromised, 15 presented with fever or leukocytosis and 15 showed positive sputum smear test for acid fast bacilli. Also, 17 of the 21 patients showed a positive sputum culture test. On the CT scan, consolidation was noted in all patients (100%), volume loss of the involved lobe or segment in 12 (57%), bronchogenic spread in 15 (71%), a cavity in 7 (33%) and bronchial wall thickening also in 7 (33%). The location of the consolidation revealed a relatively even distribution, with no specific predilection site. The other associated pulmonary diseases included ARDS, bronchiectasis, severe pulmonary emphysema, idiopathic pulmonary fibrosis and pulmonary alveolar proteinosis. Conclusion : In the immunocompromised patients, or patients with an underlying pulmonary disease, whose CT scans showed pulmonary consolidation, especially in association with findings of bronchogenic spread, a cavity or bronchial wall thickening, meticulous examination for pulmonary tuberculosis is recommended.

• Pediatric Infection and Vaccine
• /
• v.17 no.2
• /
• pp.74-82
• /
• 2010

Purpose : The Dipslide culture test is a rapid method for diagnosis of urinary tract infection (UTI). The aim of this study is to determine the diagnostic availability of a urine Dipslide test for evaluation of UTI in febrile children. Methods : Urine specimens from 151 febrile infants were inoculated by a routine blood agar urine culture method and the Dipslide test at the same time. Following incubation for 16-24 hours, the results of the Dipslide test were read at the next visit. Both results of Dipslide and those of routine culture were compared. Results : The mean age of subjects was 15${\pm}$10.6 months. There were 150 infants (99.3%) who had fever with a mean duration of 2.6${\pm}$2.6 days. Thirty two infants (21.2%) were diagnosed as having UTI. Sensitivity and specificity of Uricult Trio CLED medium were 59.4% and 84.8%, respectively. Sensitivity and specificity of Uricult Trio E. coli medium were 60.0% and 96.2%, respectively. The Pearson correlation coefficient between results of Uricult Trio CLED medium and urine culture was 0.438 (P=0.01). Correlation between results of Uricult Trio E. coli medium and urine culture was 0.617 (P=0.01). Conclusion : The Dipslide test requires only 16-24 hours with high specificity in terms of UTI caused by E. coli without the problems associated with specimen delay. This test seems to be helpful for exclusion of UTI in febrile infants and it may reduce unnecessary hospitalization and antibiotic use. However, further studies are required before the product can be recommended as a routine diagnostic tool.

• Neonatal Medicine
• /
• v.15 no.1
• /
• pp.44-53
• /
• 2008

Purpose : Epidemic keratoconjunctivitis (EKC) caused by adenovirus is a highly contagious disease, which has been reported as outbreaks involving adults in the community. However, there has been no report on EKC outbreak by adenovirus in a neonatal intensive care unit (NICU) in Korea. Aims of this study were to investigate the EKC outbreak by adenovirus type 8 in NICU and to confirm an effectiveness of polymerase chain reaction (PCR) for diagnosis. Methods : Conjunctival swab or nasopharyngeal aspirate specimens were taken from all patients and tested by viral culture and PCR. Adenovirus serotype was determined by sequencing of PCR product of selected region of hexon gene using the virus isolates or specimens. Results : An outbreak of EKC occurred which was involving 12 preterm infants in the NICU of the Seoul National University Children's Hospital between July 12th and August 1st, 2005. Three hospital staffs and one family member of the neonate were also affected. Adenovirus was detected in 12/12 (100%), 6/11 (54.5%) by PCR and virus culture, respectively. Eleven PCR-positive neonates were identified as serotype 8 by sequencing. The first affected 4 babies have had routine ROP (retinopathy of prematurity) examinations one week ago. While previous outbreaks were sustained for a few months, the event in our unit was controlled without complications in 3 weeks. Conclusion : We analyzed the EKC outbreak by adenovirus type 8 in NICU. Adenovirus serotype was identified by PCR and sequencing with high sensitivity for the first time in Korea, so we suggest this method can be very useful for rapid diagnosis and infection control.

• Pediatric Infection and Vaccine
• /
• v.26 no.1
• /
• pp.1-10
• /
• 2019

Purpose: We investigated the distribution and antimicrobial resistance of pneumococcal isolates from hospitalized children at Asan Medical Center for recent 4 years, and aimed to recommend proper choice of empirical antibiotics for pneumococcal infection. Methods: From March 2014 to May 2018, children admitted to Asan Medical Center Childrens' Hospital with pneumococcal infection were subjected for evaluation of minimal inhibitory concentration (MIC) for ${\beta}-lactams$ and macrolide antibiotics. Patient's age, underlying disease, gender were retrospectively collected. Using Monte Carlo simulation model and MIC from our study, we predicted the rate of treatment success with amoxicillin treatment. Results: Sixty-three isolates were analyzed including 20.6% (n=13) of invasive isolates, and 79.4% (n=50) of non-invasive isolates; median age were 3.3 years old, and 87.3% of the pneumococcal infections occurred to children with underlying disease. Overall susceptibility rate was 49.2%, 68.2%, and 74.6% for amoxicillin, parenteral penicillin, and cefotaxime respectively. 23.8% and 9.5% of the isolates showed high resistance for amoxicillin, and cefotaxime. Only 4.8% (n=3) were susceptible to erythromycin. Monte Carlo simulation model revealed the likelihood of treatment success was 46.0% at the dosage of 90 mg/kg/day of amoxicillin. Conclusions: Recent pneumococcal isolates from pediatric patients with underlying disease revealed high resistance for amoxicillin and cefotaxime, and high resistance for erythromycin. Prudent choice of antibiotics based on the local data of resistance cannot be emphasized enough, especially in high risk patients with underlying disease, and timely vaccination should be implemented for prevention of the spread of resistant strains.