• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.407-415
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• 2019

The biological half-life of pesticides applied on crops is the key indicator for ensuring the safety of agricultural products. The biological half-life is affected by the several factors like growing conditions of the crop, climate, application method, and physicochemical properties of pesticides. In this study, the biological half-life was calculated and the degradation rates of six triazole fungicides sprayed on perilla leaves were evaluated. Moreover, the statistical analysis confirmed the correlation between the biological half-life and physicochemical properties of six triazole pesticides. The recoveries of the six pesticides were between 84.8-104.9%, which satisfied the residual pesticide analysis criteria. The biological half-life of six pesticides sprayed on perilla leaves, calculated using the first-order kinetics model, ranged between 6.4-15.1 days. When the biological half-life and the physicochemical properties were correlated using the principal component analysis: pKa and Log P, the biological half-life was found to be affected by PC1. The correlation coefficient between biological half-life and physicochemical properties (pKa), calculated by Spearman rank-order correlation, was R² = -0.928 (p <0.01). Biological half-life has been shown to correlate with pKa. In conclusion, it can be used as a database for the relationship between biological half-life and physicochemical properties and will contribute to ensure safe supply of agricultural products.

• Journal of Information Management
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• v.18 no.4
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• pp.22-50
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• 1985

본(本) 연구(硏究)는 정보이용가치(情報利用價値)의 반감기(半減期)가 (1)그 정보(情報)를 이용(利用)하는 지역(地域)에 따라 차이(差異)가 있으며, (2)같은 지역(地域)에서는 이용자(利用者) 대부분(大部分)의 개인적 유학지(留學地), 언어(言語) 등 배경으로 형성된 지역별(地域別) 친소(親疏)관계에 따라 그 정보(情報)의 생산지(生産地)에 따른 차이(差異)가 있을 것이라는 가설(假說)을 입증(立證)하기 위하여 계획, 수행되었다. 이 가설(假說)을 입증(立證)하기 위하여 구체적(具體的)으로 우리나라 경제학자(經濟學者)들이 연구성과(硏究成果)를 발표(發表)하고 있는 3종(種)의 주요(主要) 국내(國內) 경제학전문지(經濟學專門誌), 즉, $\ulcorner$경제논집(經濟論集)$\lrcorner$, $\ulcorner$한국개발연구(韓國開發硏究)$\lrcorner$ 및 $\ulcorner$경제학연구(經濟學硏究)$\lrcorner$를 조사대상지(調査對象誌)로 선정(選定)하고, 그 속에 게재된 논문(論文)들이 인용(引用)하고 있는 문헌(文獻)들을 처리(處理)하며, (1)경제학문헌(經濟學文獻)의 형태별(形態別), 생산지별(生産地別) 반감기(半減期)를 측정(測定)하고, (2)그렇게 측정(測定)된 반감기(半減期)를 다른 나라에서 측정(測定)되어 이미 발표(發表)되어 있는 경제학문헌(經濟學文獻) 반감기(半減期)와 비교(比較)하였다.

• Journal of Information Management
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• v.24 no.4
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• pp.24-42
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• 1993

This study examines the obsolescence of library and information science literature published in Korea, analysing citations appeared in major periodicals of 1992. Periodicals, languages, and forms of cited literatures are analyzed to find the half-life and the annual aging factors of Korean library and information science literature and then synthesized.

• 대한방사선방어학회:학술대회논문집
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• 2010.04a
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• pp.164-165
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• 2010

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.34-42
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• 2008

In order to know the residual pattern of some pesticides and predict to the degradation period until below MRL, we experimented chlorothalonil, indoxacarb, lufenuron, metalaxyl and methomyl for Chinese cabbage. They were frequently detected pesticides in Chinese cabbage by NAQS (National Agricultural product Quality management Service) monitoring survey. In this experiment, we sprayed those pesticides 10days before harvest and analyzed 0, 1, 2, 3, 5, 7, 10 day samples to establish logical equation and to calculate $DT_{50}0$. During the cultivating period, the residue amount of chlorothalonil was changed from $55.58\;mg\;kg^{-1}$ (0 day) to $20.08\;mg\;kg^{-1}$ (10 day), $DT_{50}$ was 7.45 days, indoxacarb was $7.85\;mg\;kg^{-1}$ (0 day) to $1.46\;mg\;kg^{-1}$ (10 day), and 4.2 days, lufenuron was $1.57\;mg\;kg^{-1}$ (0 day) to $0.49\;mg\;kg^{-1}$ (10 day), and 5.85 days, metalaxyl was $8.12\;mg\;kg^{-1}$ (0 day) to $0.10\;mg\;kg^{-1}$ (10 day), and 175 days, and methomyl was $11.51\;mg\;kg^{-1}$ (0 day) to $0.80\;mg\;kg^{-1}$ (10 day), and 2.42 days at single dose application, respectively. The $DT_{50}$ of double amount in those pesticides were 9.05 days in chlorothatonil, 7.09 days in indoxacarb, 8.82 days in lufenuron, 3.32 days in metalaxyl, and 2.72 days in methomyl, respectively.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.683-689
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• 1995

임상적으로 건강한 New Zealand White 종인 수컷 토끼에서 항생제 norfloxacin(NFX)의 체내 동태를 조사하기 위하여 체중 kg당 5mg을 정맥 및 경구 투여하였다. 그 결과 빠른 분포기와 소실기를 갖는 2-콤파트먼트 모델 양상으로 나타났다. 혈장에서의 약물분석은 HPLC로 실시하였는데, 이동상은 acetonitrile/0.01M phosphate buffer/ 10% citric acid 1mM heptane sulfonic acid(10/70/20)이었고, 흡수 파장은 274nm에서 실시하였다. 정맥 투여후, 생물학적 반감기는 3.14시간으로 나타났으며, 분포반감기는 0.38시간으로 빠른 분포를 보여주었다. 최고 혈중농도는 $24.27{\mu}g/ml$로 계산되었으며 청소율은 0.68ml/kg/h로 분석되었다. 경구 투여후, 최고 혈중 농도와 최고 혈중 도달 시간은 $0.86{\mu}g/ml$과 0.43시간으로 각각 계산되었다. 이때의 생물학적 반감기는 3.61시간으로 정맥 투여시와 유의성 있는 차이는 없었으며, 흡수 반감기는 0.17시간으로 빠른 흡수를 보여주었다. 생체이용율은 30%로 나타났으며, 0.2-1.6g/ml인 치료혈중 농도 범위에서 혈장 결합율은 26%로 나타나, 토끼에서 항생요법은 구강 투여시 초기 투여량은 2.71mg/kg이며, 유지 투여량은 12시간마다 2.54mg/kg이 적당한 것으로 분석되었다.

• Proceedings of the Korean Society for Information Management Conference
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• 2003.08a
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• pp.233-244
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• 2003

본 연구는 우리나라 디자인학분야 5개 학회(협회)지의 2002년분에 인용된 3,046개 문헌을 인용문헌의 형태별, 발행지별, 발행년도별, 주제별로 분석하여 디자인학분야 연구자의 문헌 이용행태와 문헌의 이용가치 감소현상 즉 반감기를 측정하였다. 연구결과 디자인학분야 연구자들은 단행본(62.5%), 학술잡지기사(21.8%), 논문(10.8%), 보고서(2.9%), 기타(2%)순으로 많이 이용하였으며, 단행본의 인용이 현저히 많은 것으로 자료 형태별 이용에 있어 국내 디자인학분야 연구자의 연구활동이 국내 사회과학, 미술분야와 유사하다고 볼 수 있다. 발행지별로 분석한 결과는 국내 디자인학분야 연구자들이 국내문헌을 해외문헌보다 2.5배정도 많이 이용한 것으로 국내문헌에 많이 의존하는 것으로 분석되었다. 이것은 해외문헌을 국내문헌보다 2배정도 많이 이용한 것으로 분석된 사회과학분야의 선행연구와 비교할 때 디자인학분야에서는 정반대의 현상을 보이는 것이나 4배정도 국내문헌을 많이 이용한 것으로 분석된 미술분야의 선행연구와는 유사한 결과를 나타내는 것이다. 디자인학분야 문헌의 반감기는 5.75년이었으며, 자료형태별 반감기는 단행본(6.64년), 논문(5.97년), 학술잡지기사 (4.55년), 기타(3.73년), 보고서(3.41년) 순으로 분석되었고, 발행지별 반감기는 해외문헌(9.1년), 국내문헌(5.1년)순으로 분석되었다. 또한 타주제와의 관계분석에 있어 경영학, 건축술, 공학 등과 긴밀한 관계를 맺고 있는 것으로 디자인학이 단순히 미를 추구하는 것이 아니라 산업경쟁력 증진의 도구로서 존재한다는 것을 알 수 있다.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.98-103
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• 2014

Purpose: The effective half life of I-131 is useful to calculate radiation dose, period of hospitalization, and exposure dose of surrounding people from patient. However, it is difficult to measure. This study estimates the effective half life in whole body and thyroid in using of value of residual radioactivity obtained from the early and delay images of Dual time I-131 whole body scan. Also, the correlations between the effective half life and serum creatinine, GFR, and administration dose were investigated in this study. Materials and Methods: The targets were 50 patients administration high dose of I-131 from February to August in 2013, having normal range of serum creatinine and over $30{\mu}IU/mL$ of TSH levels. After administration radioactive I-131, the early scan in the 3rd day and the delay scan in the 5-6th days were performed. To measure the residual radioactivity in the whole body and thyroid, ROI was set and then background radioactivity was corrected to estimate. The effective half life was estimated by calculating the ratio of measured values between the early and delay images. To compare the effective half lives of the whole body and thyroid, it was analyzed by Independent t-test, and each correlation of the effective half life, GFR, serum creatinine, and the dose of administration were analyzed by calculating the pearson's correlation coefficient. All of the analysis were determined to be statistically significant when P<0.05. Results: The effective half life of the whole body was $17.06{\pm}5.50$ hours and of the thyroid was $17.22{\pm}5.41$ hours. The two effective half life did not show significant difference (P=0.887). As the value of GFR was increased, the effective half life of whole body (r=-0.407, P=0.003) and of thyroid (r=-0.473, P=0.001) were significantly decreased; as the value of serum creatinine was increased, the effective half life of whole body (r=0.309, P=0.029) and of thyroid (r=0.371, P=0.008) were significantly increased. In the administration dose, effective half life did not have correlations. Conclusion: The effective half life of I-131 of patients treated for their thyroids were estimated only by using the images of Dual time I-131 whole body scan. Also, the correlations with the effective life, GFR, and serum creatinine were examined. This study might be utilized for a study on optimization for the period of hospitalization of patients treated by high dose of I-131 and on evaluation for internal absorbed dose of MIRD schema in application of the effective half life.

• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.379-408
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• 2005

The purpose of this study is to investigate the research trends of library and information science in Korea by means of the subject analysis of the Korean journal articles published during the last sixty years and by means of the ciation analysis of the literatures cited in the journal articles. The results of this study are as follows. First, the subjects of the journal articles are difference from the articles by publication period. The core subjects of the research have been changed over the years. Second, the subjects of library and information science literatures in foreign languages cited in the journal articles are difference from the literatures by citation period and by literature age. Third, the subjects of other disciplinary literatures in foreign langauges cited in the journal articles is difference from the literatures by citation period and by literature age. Fourth, although the half-life of library and information science literatures cited in the journal articles is difference from the literatures by subject, the half-life of the literatures of this discipline is 10-year.

• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.85-102
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• 2005

The purpose of this study is to analysis the type of cited materials, dependence ratio of foreign information of domestic researchers, and to predicts half-life of life science for the collection development of libraries and user friendly information services. The journal articles was extracted from five subjects-medical science, pharmacy, food science, agricultural science, microbiology. In result, it was found that it citing the scholarly journal most plentifully, and dependence ratio of foreign information of domestic researchers was high most the microbiology. And then, half-life of life science was found 8.98 in agricultural science, and 7.11 in food science, and 6.96 in pharmacy, and so on.