리튬 이온 이차전지를 위한 부극용 Si 특성에 관한 연구

김성호,이상헌,박일현,김민철,우태욱,손영국 부산대학교 생산기술연구소 2000 生産技術硏究所論文集 Vol.59 No.-

리튬이온이차전지의 부극으로 Si를 사용하였다. 부극용 Si전극을 1회 충방전 시 Li이온이 탈 삽입될 때 각각의 전압에서 XRD 회절분석을 통하여 Li이온이 이동하여 Si와 반응하는 것을 조사하였다. 순환전압전류 및 충방전 시험을 통하여 전기 화학적 특성을 측정해본 결과 부극으로써 Si의 산화환원 반응이 양호하게 이루어졌으며 충방전에 대한 cycle number가 증가할수록 비가역적인 산화환원반응 및 부피변화로 인해 싸이클 특성 감소함을 나타내었다. Si with anode is used Li ion secondary batteries During Li ion intercalating at first cycle, XRD analysis studies at others voltages showed that Li ions are moved and reacted to Si The electrochemical properties of Si anode materials were evaluated by cyclic voltammetry and charge/discharge test. With cycle number increasing, cyclic characteristics are decreased for irreversible reduction/oxidation and volume change.

Application of Geographically Weighted Regression (GWR) to Investigate the Spatial Distribution of Highly Pathogenic Avian Influenza in Korea

Son Il Pak,Kwang Nyeong Lee,Ki Hyun Cho,Gyeong Ju Lee 대한수의학회 2017 대한수의학회 학술대회발표집 Vol.2017 No.-

Mapping the Global Movement Patterns of Migratory Birds with Special Reference to Potential Risk of HPAI Transmission

Son Il Pak,Weon Hwa Jheong,Han Soo Lee 대한수의학회 2017 대한수의학회 학술대회발표집 Vol.2017 No.-

Analysis of changes in social awareness in livestock stamping out using newspaper articles

Son-Il Pak,Sunhak Bae 한국예방수의학회 2020 예방수의학회지 Vol.44 No.1

The purpose of this study was to find the change in social awareness in livestock stamping out over time. We used the text data mining method for this study. The data used in this analysis comprised approximately 5,600 newspaper articles. The data were sourced using the keywords livestock stamping out 2010-2017, and classified into two-year intervals. The analysis showed a change in perspective on livestock disease and prevention activities over time. Additionally, it was confirmed that problems related to ethics were continuously raised during the entire period. Prevention activities cannot succeed without the support and participation of people. Thus, the results of this study can be used to establish and implement livestock disease prevention policies.

Evaluation of Diagnostic Performance of a Polymerase Chain Reaction for Detection of Canine Dirofilaria immitis

Son-Il Pak,Doo Kim 한국임상수의학회 2007 한국임상수의학회지 Vol.24 No.2

Diagnostic performance of polymerase chain reaction (PCR) for detecting Dirofilaria immitis in dogs wasevaluated when no gold standard test was employed. An enzyme-linked immunosorbent assay test kit (SnapTM, IDEXX,USA) with unknown parameters was also employed. The sensitivity and specificity of the PCR from two-populationmodel were estimated by using both maximum likelihood using expectation-maximization (EM) algorithm and Bayesianmethod, assuming conditional independence between the two tests. A total of 266 samples, 133 samples in each trial,were randomly retrieved from the heartworm database records during the year 2002-2004 in a university animal hospital.for heartworm infection. When combined 2 trials, sensitivity and specificity of the PCR was 96.4-96.7% and 97.6-98.8%in EM and 94.4-94.8% and 97.1-98% in Bayesian. There were no statistical diferences between estimates. This findingindicates that the PCR assay could be useful screening tool for detecting heartworm antigen in dogs. This study wasprovided further evidences that Bayesian approach is an alternative approach to draw better inference about theperformance of a new diagnostic test in case when either gold test is not available.

Molecular typing of epidemiologically unrelated Staphylococcus epidermidis recovered from dogs by pulsed-field gel electrophoresis

Pak, Son-il The Korean Society of Veterinary Science 1999 大韓獸醫學會誌 Vol.39 No.4

A total of 16 Staphylococcus epidermidis isolates collected from 14 dogs admitted to the Veterinary Medicial Teaching Hospital in Seoul National University over eleven months were examined for in vitro antibiotic susceptibility pattern with minimum inhibitory concentration (MIC) and slime production, a virulence-associated phenotype, and were genetically characterized by pulsed-field gel electrophoresis (PFGE). The frequency of resistance to antimicrobial agents tested was not high, with a susceptibility ranging from 56.3% to 100%. Three strains exhibited multiple drug resistance against amikacin (MIC, $32-64{\mu}g/ml$), ampicillin ($32{\mu}g/ml$), fosfomycin ($32-128{\mu}g/ml$) and gentamicin ($16{\mu}g/ml$). Vancomycin, ciprofloxacin and rifampin were effective antibiotics against the isolates. All isolates were slime producers ; strains isolated from dogs which died of bacteremia were more likely to produce slime than those isolated from dogs which survived. Chromosomal DNA fingerprinting of the isolates yielded 16 different genomic types with few common bands, indicating a variety of clones of S epidermidis were prevalent in the hospital. This study revealed that PFGE is an useful method for the genotype characterization of S epidermidis strains and this organism could probably be pathogenic in some dogs with severe disorders. Further works on a larger number of epidemiologically defined strains are required to assess these results.

Washing Practices of Livestock Transport Vehicles at Ten Selected Slaughterhouses in Korea

Son Il Pak,Sung Hyun Choi 대한수의학회 2016 대한수의학회 학술대회발표집 Vol.2016 No.-

개에서 Helicobacter균 감염을 검출하기 위한 urease 검사와 PCR 검사의 진단적 정확도

Pak, Son-Il,Oh, Tae-Ho 한국임상수의학회 2001 한국임상수의학회지 Vol.18 No.4

새로 개발되거나 혹은 기존의 어떤 진단검사를 다양한 임상상황에 적용하기 위해서는 먼저 이들 검사법의 진단적 정확도를 추정하는 연구가 반드시 선행되어야 한다. 진단의 정확도에 대한 추정치를 모른다면 검사결과를 해석하는 것이 불가능하기 때문이다. 특히 동일한 개체에서 감염부위별로 3개 이상의 시료를 얻어 진단검사를 적용하는 경우 각 시료의 검사결과는 독립적인 측정시료가 아니라 개체내에서 연관성이 매우 높은 종속적인 시료에 해당 한다. 즉 동일한 개체에서 얻은 시료일수록 검사결과에서 유사한 반응을 보이며 이 경우 분석의 단위는 각각의 개체가 아니라 검사부위가 되는데 이는 의학연구에서 매우 흔하다. 본 연구에서는 Helicobacter 균에 의한 감염을 검출하기 위하여 동일한 개로부터 위의 해부학적 구조상 pyloric antrum, body 및 cardia의 생검시료에 대하여 urease 검사와 PCR 검사를 적용하여 각 검사의 진단적 정확도를 추정하였다. urease 검사의 민감도와 특이도는 0.74 (95% 신뢰구간: 0.64-0.84)와 0.87 (95% 신뢰구간: 0.67-1.00)이었으며 PCR 검사의 민감도와 특이도는 0.95 (95% 신뢰구간: 0.89-1.00)와 0.90 (95% 신뢰구간: 0.70-1.00)로 두 검사의 특이도는 높은 것으로 나타났다. 그러나 PCR 검사에 비하여 urease 검사의 경우 가음성 (false negative)의 가능성이 높기 때문에 진단결과에 대한 신중한 해석이 요구된다. Evaluation on the diagnostic performances of urease test and polymerase chain reaction (PCR) for detection of Helicobacter species infection in dogs has rarely been performed in research with site-specific situations, although assessing diagnostic tests is an essential part prior to its practical use in a variety of clinical settings. The clinical value of a diagnostic test may be misjudged and comparisons between different tests may yield misleading conclusions when high within-patient correlations are present. We applied a conceptually simple statistical approach to estimate the sensitivity and specificity of urease test and PCR for detection of Helicobacter species infection in dogs. This approach assumes that responses from three different sampling sites within an animal are correlated where unit for statistical analysis is the site rather than the animal. The sensitivity and specificity of urease test was 0.74% (95% confidence interval, 0.64-0.84) and 0.87 (95% CI, 0.67-1.00), respectively. For PCR, the sensitivity was 0.95(95% CI, 0.89-1.00) and specificity 0.90 (95% CI, 0.70-1.00). Two tests were almost equally specific. Urease test, however, has a lower diagnostic accuracy and thus should only be used after careful validation in terms of sensitivity.

Diagnostic performance of enzyme-linked immnosorbent assays for diagnosing paratuberculosis in cattle: a meta-analysis

Pak, Son-Il The Korean Society of Veterinary Science 2004 大韓獸醫學會誌 Vol.44 No.4

To evaluate the diagnostic accuracy of two commercial ELISA tests (Allied- and CSL-ELISA) for the diagnosis of Mycobacterium paratuberculosis in cattle, Meta-analysis using English language papers published during 1990-2001 was performed. Diagnostic odds ratios (DOR) were analyzed using regression analysis together with summary receiver operating characteristic (ROC) curves. The difference in diagnostic performance between the two ELISA systems was evaluated by using linear regression. Publication bias was assessed by funnel plot and linear regression. The pooled sensitivity and specificity were 44% (95% CI, 38 to 51) and 98% (95% CI, 96 to 99) for the random-effect model. The DOR between studies was heterogeneous. The area under the fitted ROC curve (AUC) was 0.72 for the unweighted and 0.77 for the weighted model. Maximum joint sensitivity and specificity for the unweighted and weighted model from their summary ROC curve were 70% and 75%, respectively. Based on the fitted model, at a specificity of 95%, sensitivity was estimated to be 52% for the unweighted and 57% for the weighted model. From the final multivariable model study characteristic, the country was the only significant variable with an explained component variance of 13.3%. There were no significant differences in discriminatory power, sensitivity, and specificity between the two ELISA tests. The overall diagnostic accuracy of two commercial ELISA tests was moderate, as judged by the AUC, maximum joint sensitivity and specificity, and estimates from the fitted model and clinical usefulness of the tests for screening program is limited because of low sensitivity and heterogeneous of DOR. It is, therefore, recommended to use ELISA tests as a parallel testing with other diagnostic tests together to increase test sensitivity in the screening program.

Spatiotemporal Distribution of Migratory Bird Species with Potential Transmission of Highly Pathogenic Avian Influenza

Son Il Pak,Woo-seog Jeong,Hong Shik Park 대한수의학회 2016 대한수의학회 학술대회발표집 Vol.2016 No.-