• Korean Journal of Environmental Agriculture
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• v.2 no.1
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• pp.1-5
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• 1983

A study was undertaken to investigate the persistence of diazinon in two different soils under field conditions. Half-life of diazinon granule(5%) incorporated into soils at a rate of 0.15 ㎏ a.i./l0a was 11 and $9{\sim}12$ days in Suweon and Iri soil under field conditions, respectively. Diazinon residues in brown rice and rice straw harvested from Suweon field were also evaluated by scheduled application intervals. On the basis of maximum residue limit of diazinon in brown rice, it is recommended that the insecticide could be applied upto 15 days before harvest at the limit of 4 spraying times.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.130-135
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• 2000

Photodegradation rate of flupyrazofos in aqueous solution were measured under various test conditions mainly following the guidelines of U.S. EPA and OECD. It was observed that the flupyrazofos was degraded by simple hydrolysis but not degraded by light in pure water. Using acetone as a known photosensitizer, the minimal concentration of acetone needed to photo-degrade the flupyrazofos in % and molar terms were 0.047% and 0.006, respectively. When treated with acetone, it was also found that the ringlet oxygen is a very effective photo oxidant in the degradation of flupyrazofos, but the effect of hydroxyl radical was not observed at the treatment level of hydroxyl radical, isopropylbenzene. In an actinometer experiment, quantum yield of flupyrazofos (0.4 ppm with 2% acetone) was $17.66{\times}10^{-5}$ and degradation rate and half-life were 0.038/hr and 18.2 hours, respectively.

• Journal of Information Management
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• v.36 no.2
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• pp.1-24
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• 2005

This study is aimed at investigating if there were the differences on citing behavior of researchers among different fields of engineering, in terms of five items, such as types of resources cited, the average number of documents cited, the demand of current documents, languages used in cited documents, and the life decrease phenomena of information. 29,160 cited references in 2,333 articles from 4 major selected journals, published in the year of 1999, 2001, and 2003 were analyzed. The result of this study shows that there were the differences on citing behavior of researchers among different fields of engineering on all 5 items. And also, some suggestions were given the priority of library collection and shelf arrangement for the library.

• Journal of Veterinary Clinics
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• v.24 no.1
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• pp.5-9
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• 2007

The purpose of this study was to examine the allometric analysis of roxithromycin using pharmacokinetic data. The pharmacokinetic parameters used were $half-life(t_{1/2})$, mean residence time (MRT), clearance (Cl) and volume of distribution at steady state $(V_{ss})$. Relationships between body weight and the pharmacokinetic parameter were based on the empirical formula $Y=aW^b$, where 'Y' is $t_{1/2}$, MRT, Cl, or $V_{ss}$, W the body weight and 'a' is an allometric coefficient (intercept) that is constant for a given drug. The exponential term, 'b', is a proportionality constant that describes the relationship between the pharmacokinetic parameter of interest and body weight. As results of the allometric analyses, the logarithms of $t_{1/2}$, MRT, Cl, and $V_{ss}$ were linearly related to the logarithms of body weight. Results of the current analyses could provide information on appropriate doses of roxithromycin for all species.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.150.1-150
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• 2003

열무의 안전한 생산을 위한 생산단계에서의 각 농약 잔류량 변화 추이와 최종 소비단계에서의 농산물 안전성 평가자료로 활용하기 위하여 실제 시험포장에 열무를 파종한 후 수확 10일 전에 4 종(diazinon, endosulfan, cypermethrin, cyhalothrin)의 살충제를 각 성분별로 안전사용 기준에 따라 기준량 및 배량의 처리구에 직접 살포하여 열무의 포장상태에서의 잔류량 감소(생물학적 반감기) 변화를 조사하였다. 각 농약별로 2 수준 농도의 표준물질을 첨가하여 실험한 결과 평균회수율은 diazinon 98.7∼99.9%, endosulfan 97.6∼98.5%, cypermethrin 98.3∼99.6%, cyhalothrin 98.4∼99.1%이였고, 검출한계는 diazinon 및 cypermethrin은 0.04 mg/kg, endosulfan은 0.012 mg/kg, cyhalothrin은 0.01 mg/kg 이었다. 약제 살포 후 분해속도가 빠른 성분은 diazinon ＞ endosulfan ＞ cypermethrin ＞cyhalothrin 순이었다. 작물체(열무)내에서 시간의 경과에 따른 잔류량의 변화를 1차 반응으로 표현하여 농약 4종의 살포농도별 생물학적 반감기를 산출한 결과, 기준량 살포의 경우 diazinon 0.9일, endosulfan 2.0일, cypermethrin 2.2일, cyhalothrin 2.5일 그리고 배량 살포의 경우에는 diazinon 1.1일, endosulfan 2.0일, cypermethrin 2.1일, cyhalothrin 2.2일로 나타났다. 안전한 농산물 생산을 위한 열무 중 약제 살포 후 수확일은 잔류허용기준(MRL)을 적용시킬 경우 기준량으로 볼 때 diazinon은 6일 후, endosulfan은 10일 후에 수확하는 것이 바람직한 것으로 나타났으며 합성 피레스로이드계인 cypermethrin과 cyhalothrin은 농약살포 후 2 시간 후에 농약 잔류량이 잔류허용기준 미만으로 나타났다.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.85-96
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• 2006

Matrix metalloproteinases (MMPs)는 치주조직내에 존재하는 세포외기질의 유지와 분해에 중요한 역할을 담당하고 있으며 이중 MMP-13은 치주질환의 진행과 깊은 관계가 있다고 알려져 있다. 이번 연구는 치주질환의 진행에 있어서 MMP-13의 활성에 대한 mitogen activated protein(MAP) Kinase의 역할을 구명하기 위해 시행되었다. 백서 치주인대세포에서의 MMP-13 mRNA의 발현은 RT-PCR에 의하여, 그리고 MAP Kinase의 발현은 Western blot에 의하여 측정하였다. $Interleukin-1{\beta}$(IL $-1{\beta}$), Tumor necrosis $factora(TNF-{\alpha})$와 parathyroid hormon(PTH)는 MMP- 13 mRNA 발현을 각각 320%, 180%, 380% 증가시켰으나 bone morphogenetic protein-7(BMP-7)은 MMP-13 mRNA의 발현을 증가시키지 않았다. p38 MAP Kinase 억제제인 SB203580은 IL $-1{\beta}$ 유도 MMP-13의 발현을 약 40% 정도 억제시켰으나, PTH-유도 MMP-13 mRNA의 발현은 억제하지 못했다. IL $-1{\beta}$는 MMP- 13 mRNA의 반감기를 약 2시간 정도로 증가시켰으나, p38 MAP Kinase 억제제로 전처치한 경우에는 반감기가 60분으로 줄어들었다. $IL-1{\beta}$는 p38 MAP kinase와 JNK의 인산화 활성을 증가시켰으나 PTH, $TNF-{\alpha}$와 BMP-7은 p38, JNK, ERK의 활성을 증가시키지 못했다. 이상의 연구결과는 p38 MAP Kinase가 백서 치주인대세포에서의 MMP-13 mRNA 발현을 조절하는데 중요한 역할을 담당함을 시사하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1147-1151
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• 2001

We investigated stabilities of blue pigment extracted from Gardenia jasminoides at various conditions to check its applicability for beverages. Gardenia blue pigment with maximum absorption at 587 nm was obtained from the reaction of glycine and genipin (aglycone of geniposide). The blue pigment was found to be relatively unstable at acidic pH but very stable at alkaline conditions with half-life values of 102 days and 126 days at PH 9.0 and PH 11.0, respectively. The pigment also showed high thermal stability with half-life value of 55, 18, and 2 days at 50, 70, and 9$0^{\circ}C$, respectively. The addition of inorganic ions, sugars, and amino acids to model beverage containing this blue pigment increased retention rate at room temperature while addition of vitamin C decreased the stability. The sensory evaluation of the model beverage showed that inorganic ions and amino acids increased overall acceptability, indicating that the blue pigments of Gardenia jasminoides can be used as a natural colorant for leverage.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.31-37
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• 1987

A study has been conducted to investigate the behavior of carbofuran in a miniature paddy agrosystem simulated for paddy field. Carbofuran applied onto the paddy water was rapidly absorbed and translocated into rice plants. Carbofuran concentration in rice plant reached its maximum level between 1 to 3 days after treatment and gradually decreased thereafter. Half life of carbofuran concentration in paddy water was 4 days in both application rates of 0.12 and 0.24Kg a.i./10a. Carbofuran residue in paddy soil was gradually dissipated with the half life of 8 and 12 days in 0.12 and 0.24㎏ a.i./l0a respectively. Range of carbofuran residue in brown rice and rice straw harvested from the paddy agrosystem was 0.01∼0.02 ppm and 0.37∼0.57 ppm irrespective of the two application rates respectively.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.733-738
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• 1998

Tannic acid (TA), chlorogenic acid (GA) and caffeic acid (CA) as copigments were added in anthocyanin solutions (pH 3.0) to test their effects on the stability against temperatures, metal ions, and light. Absorbance of anthocyanins increased with the increase of copigment concentrations. Tannic acid showed the highest absorbance increase with bathochromic shift of 14 nm (from 514 nm to 528 nm). Copigmentation resulted in higher storage stability of anthocyanins for 21 days at room temperature $925^{\circ}C)$ but lower thermal stability at higher temperatures more than $70^{\circ}C. Addition of metal ions to TA caused the enhanced stability as well as increased absorbance of anthocyanins. Copigmentation also caused a significant increase of light stablilty of anthocyanins at room temperature, so that addition of TA showed 2.3 times showed photodegradation of anthocyanins under 20,000 lux-light dosage in pH 3.0 solution at $25^{\circ}C$.

• Journal of Information Management
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• v.36 no.3
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• pp.51-70
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• 2005

It is meaningful to develop the scholarly digital archives in a respect that it could preserve the research papers using digital media. The scholarly digital archives provide scientists with the information source with which scientists could actively accomplish research. This study measured based on the citation analysis to what extent PMC, which is life science scholarly digital archives, has an effect on the scholarly communication in the same subject field. The findings are as follows. First, the three citation indicators, impact factor, immediacy index, and half-life, have no remarkable difference in between pre and post-digital archives era. Second, there were more cases that the major citation indicators increased rather than ones decreased with the appearance of the scholarly digital archives, as a result of ranking the scholarly journals after classifying according to subjects.