• Title/Summary/Keyword: partition coefficient

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Numerical Simulation of PFOA in Tokyo Bay using EMT-3D (EMT-3D 모델을 이용한 동경만의 PFOA 시뮬레이션)

  • Kim, Dong-Myung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.3
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    • pp.173-181
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    • 2007
  • A three-dimensional ecological model (EMT-3D) was applied to Tokyo Bay for the simulation of PFOA. EMT-3D was calibrated with seawater analysis data obtained from the study area in 2004. The simulated results of dissolved PFOA were in good agreement with the observed values, with a correlation coefficient(R) of 0.7115${\sim}$0.8759 and a coefficient of determination $(R^2)$ of 0.5062${\sim}$0.7672. The results of sensitivity analysis showed that partition rate, adsorption rate and settling rate were important factors for PFOA in particulate organic matter. In the case of PFOA in phytoplankton, bioconcentration factor, uptake rate and partition rate were important factors. Therefore, the parameters must be carefully considered in the modeling. In the case of 50% and 80% total loads reduction, concentration of dissolved PFOA was shown to be lower than 20ng/L and 10ng/L, respectively. In the case of reduction of loads from rivers in each prefecture, Tokyo prefecture was found to have the most influence on the change of dissolved PFOA in surface water while Chiba prefecture was found to have the most influnce on the change of dissolved PFOA in bottom water.

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Ecological Risk Assessment for Cadmium in Environmental Media (환경매체별 카드뮴의 생태위해성평가)

  • Lee, Byeongwoo;Lee, Byoungcheun;Yoon, Hyojung;Park, Kyunghwa;Kim, Pilje
    • Journal of Environmental Health Sciences
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    • v.44 no.6
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    • pp.548-555
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    • 2018
  • Objectives: We conducted ecological risk assessment for cadmium, a heavy metal and carcinogen, to identify safety standards by environmental media and to determine its impact on ecosystems by estimating and evaluating exposure levels. Methods: Species sensitivity distributions (SSDs) were generated using ECOTOX DB. A hazardous concentration of 5% (HC5) protective of most species (95%) in the environment was estimated. Using this estimate, predicted no effect concentrations (PNECs) were calculated for aquatic organisms. Based on the calculated PNECs for aquatic organisms, PNEC values for soil and sediment were calculated using the partition coefficient. Predicted exposure concentrations (PECs) were also calculated from environmental monitoring data with hazard quotients (HQs) calculated using PNECs for environmental media. Results: Chronic toxicity data were categorized into four groups and 11 species. In species sensitivity distribution (SSD) analysis, HC5 was $0.340{\mu}g/L$. Based on this value, the PNEC value for aquatic organisms was calculated as $0.113{\mu}g/L$. PNEC values for soil and sediments using a partition coefficient were calculated as 15.02 mg/kg and 90.61 mg/kg, respectively. In an analysis of environmental monitoring data, PEC values were calculated as $0.017{\mu}g/L$ for water, 1.01 mg/kg for soil, and 0.521 mg/kg for sediment. Conclusions: HQs were 0.150, 0.067 and 0.006 for water, soil and sediment, respectively. HQs of secondary toxicity were 0.365 for birds and 0.024 for mammals. In principle, it is judged that an HQ above 1 indicates a high level of risk concern while an HQ less than 1 indicates an extremely low level of risk concern. Therefore, with HQs of cadmium in the environment being <1, its risk levels can be considered low for each media.

In vitro and in vivo pharmacokinetic characterization of LMT-28 as a novel small molecular interleukin-6 inhibitor

  • Ahn, Sung-Hoon;Heo, Tae-Hwe;Jun, Hyun-Sik;Choi, Yongseok
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.4
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    • pp.670-677
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    • 2020
  • Objective: Interleukin-6 (IL-6) is a T cell-derived B cell stimulating factor which plays an important role in inflammatory diseases. In this study, the pharmacokinetic properties of LMT-28 including physicochemical property, in vitro liver microsomal stability and an in vivo pharmacokinetic study using BALB/c mice were characterized. Methods: LMT-28 has been synthesized and is being developed as a novel therapeutic IL-6 inhibitor. The physicochemical properties and in vitro pharmacokinetic profiles such as liver microsomal stability and Madin-Darby canine kidney (MDCK) cell permeability assay were examined. For in vivo pharmacokinetic studies, pharmacokinetic parameters using BALB/c mice were calculated. Results: The logarithm of the partition coefficient value (LogP; 3.65) and the apparent permeability coefficient values (Papp; 9.7×10-6 cm/s) showed that LMT-28 possesses a moderate-high cell permeability property across MDCK cell monolayers. The plasma protein binding rate of LMT-28 was 92.4% and mostly bound to serum albumin. The metabolic half-life (t1/2) values of LMT-28 were 15.3 min for rat and 21.9 min for human at the concentration 1 μM. The area under the plasma drug concentration-time curve and Cmax after oral administration (5 mg/kg) of LMT-28 were 302±209 h·ng/mL and 137±100 ng/mL, respectively. Conclusion: These data suggest that LMT-28 may have good physicochemical and pharmacokinetic properties and may be a novel oral drug candidate as the first synthetic IL-6 inhibitor to ameliorate mammalian inflammation.

Scenario Analysis of Dioxins Behaviors In Ulsan Bay of Korea using EMT-3D Model (EMT-3D 모델을 이용한 울산만 Dioxins 거동에 관한 시나리오 분석)

  • Kim, Dong-Myung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.2
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    • pp.89-96
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    • 2011
  • A three dimensional ecological model(EMT-3D) was applied to Ulsan Bay for the simulation of Dioxins. The simulated results of dissolved Dioxins were in agreement with the observed values, with a correlation coefficient(R) of 0.7951 and a coefficient of determination($R^2$) of 0.6265. The results of sensitivity analysis showed that partition rate, adsorption rate and bioconcentration factor were important factors. Therefore, the parameters must be carefully considered in the modeling. In the case of 50% and 80% total loads reduction, concentration of dissolved Dioxins was shown to be lower than 0.150 and 0.250 pg WHD-TEQ/L, respectively.

Partitioning Behavior of Selected Printing Ink Solvents between Headspace and Chocolate Cookie Samples

  • An, Duek-Jun
    • Preventive Nutrition and Food Science
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    • v.16 no.3
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    • pp.267-271
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    • 2011
  • Static Headspace Gas Chromatographic analysis was used to study the partitioning behavior of five organic printing ink solvents between chocolate cookie/air systems. Three cookie sample formulations varied with respect to chocolate type and overall percentage of constituents. Major considerations involved differences in fat content and type and resulting variability in chemical and physical structure. Each of the solvents studied (ethyl acetate, hexane, isopropanol, methyl ethyl ketone, toluene) represents a general class of printing ink solvents based on predominate functional group. Values of the partitioning coefficient (Kp) were determined at equilibrium using measured quantities of both solvent and cookie sample in closed systems at temperature of 25, 35, and $45^{\circ}C$. In each of the three cookies at the three test temperatures, toluene always exhibited the greatest value of partitioning to cookie and hexane always exhibited the least. Results also showed that the partitioning behavior of solvents is generally inversely related to temperature and that solvent affinity, though constant for a particular cookie type over all test temperatures, varies significantly among the three cookie types. The preference of each of the five solvents for each cookie sample was also found to vary with temperature. No correlation was found between the extent of partitioning and cookie formulation or physical characteristic of solvent. The Hildebrand parameter, related to ${\Delta}Hmix$ (heat of mixing), may be used to describe differences in partitioning based on the overall potential of a solvent/cookie interaction to occur. The potential for interaction is dependent upon the chemical structure of the cookie sample and thus the availability of 'active-sites' required for a given solvent.

Interactive Effect of Food Compositions on the Migration Behavior of Printing Ink Solvent

  • An, Duek-Jun
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.310-315
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    • 2009
  • The partitioning behavior of the five printing ink solvents in nine lab-made cookies with various sugar and water content at 25${^{\circ}C}$ was studied to find out the presence and effects of interaction between the two ingredients on partitioning behavior in cookies. Solvents were ethyl acetate, hexane, isopropanol, methyl ethyl ketone and hexane. It was observed that the partition coefficient (the solvent concentration in food compared to that in air, Kp) decreased as sugar increased in all case and increased as water content increased for all compounds except toluene. Statistical analysis by the F-test method was used to determine the significance of sugar-water interactions, as well as other single factors on partitioning behavior of each solvent. Sugar content alone had no significant effects, but the crystallinity of sugar, as changed by water content, affected the partitioning behavior of the five solvents significantly. Parameter estimation for each significant factor by SAS program yielded a regression equation, which was used to predict the partitioning behavior in the finished cookie. Kp values from the regression equation could be determined more precisely by applying a correction term for the interaction between sugar and water to the Kp values of each ingredient after baking.

Reduction of Skin Irritation by the Control of Skin Permeation of Methyl Paraben

  • Seong-Hoon Jeong;Mun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.23 no.3
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    • pp.108-114
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    • 1997
  • The skin permeation study has two meanings in cosmetics. One is how to promote the skin permeation of active meterials for improving their bioavailabilities and the other is how to decrease it of irritants for reducing their skin side effects. In this study, we selected methyl paraben, one of the preservatives, as a model irritant and tried to reduce the skin irritation by the decrease of skin permeation. Furthermore, the relationship between skin permeation and skin primary irritation was discussed. For in vitro skin permeation experiments, Franz type diffusion cells and the excised skin of female hairless mouse from 8 weeks old were used. The donor compartment was charged with oil only or O/W emulsion containing 0.3% MP. We selected 19 oils, including esters, triglycerides, plant oils, hydrocarbons, and alchols, which are broadly used in cosmetics. We evaluated with female guinea pig. The skin permeahility of MP from the oils showed following order: ester oils > triglycerides > plant oils > hydrocarbons > alcohols. We considered that this result was based on the different effect of each oil on the barrier function of stratum corneum. In O/W emulsion containing each oil, the skin permeability of MP decreased as the oil/water partition coefficient of MP increased. The skin primary irritation increased as the skin permeability of MP increased. In conclusion, we suggest that the skin irritation could be reduced by the decrease of skin permeability of MP, which may be obtained by the good selection of oils in cosmetic preparations.

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A STANDARD METHOD FOR JOINTING CAMEL CARCASSES WITH REFERENCE TO THE EFFECT OF SLAUGHTER AGE ON CARCASS CHARACTERISTICS IN NAJDI CAMELS. 3. PARTITION AND DISTRIBUTION OF CARCASS FAT

  • Abouheif, M.A.;Basmaeil, S.M.;Bakkar, M.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.4 no.3
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    • pp.219-225
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    • 1991
  • The influence of age on the relative growth patterns of subcutaneous, intermuscular, intramuscular, perirenal, channel and hump fat in relation to the total fat weight in carcass sides of 18 Najdi male camels averaging 8, 16 and 26 months of age has been investigated. The total fat weight in a carcass side increased (p<.01) from 17.3% to 27.1% as the camel age increased from 8 to 26 months. However, at all ages studied, intermuscular fat weight was the largest fat depot, followed, in order, by subcutaneous and intramuscular fat. The change in weight of the intramuscular, intermuscular and subcutaneous fat between 8 and 26 months of age was greater, reaching 6.7, 4.3 and 4 times respectively, than the hump, channel and perirenal fat weight which increased by 3.6, 2.5 and 2.3 times, respectively. The allometric growth coefficient (${\beta}$) for intramuscular fat in relation to the total carcass fat weight was the highest, followed, in order, by intermuscular, subcutaneous, hump, channel and perirenal fat.

Comparative Analyses of the Flavors from Hallabong (Citrus sphaerocarpa) with Lemon, Orange and Grapefruit by SPTE and HS-SPME Combined with GC-MS

  • Yoo, Zoo-Won;Kim, Nam-Sun;Lee, Dong-Sun
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.271-279
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    • 2004
  • The aroma component of Hallabong peel has been characterized by GC-MS with two different extraction techniques: solid-phase trapping solvent extraction (SPTE) and headspace solid-phase microextraction (HSSPME). Aroma components emitted from Hallabong peel were compared with those of other citrus varieties: lemon, orange and grapefruit by SPTE and GC-MS. d-Limonene (96.98%) in Hallabong was the main component, and relatively higher peaks of cis- ${\beta}$-ocimene, valencene and -farnesene were observed. Other volatile aromas, such as sabinene, isothujol and ${\delta}$-elemene were observed as small peaks. Also, principal components analysis was employed to distinguish citrus aromas based on their chromatographic data. For HSSPME, the fiber efficiency was evaluated by comparing the partition coefficient ($K_{gs}$Kgs) between the HS gaseous phase and HS-SPME fiber coating, and the relative concentration factors (CF) of the five characteristic compounds of the four citrus varieties. 50/30 ${\mu}$m DVB/CAR/PDMS fiber was verified as the best choice among the four fibers evaluated for all the samples.

Partitioning of Recombinant Human Granulocyte-Macrophage Colony Stimulating Factor (hGM-CSF) from Plant Cell Suspension Culture in PEG/Sodium Phosphate Aqueous Two-phase Systems

  • Lee, Jae-Hwa;Loc, Nguyen-Hoang;Kwon, Tae-Ho;Yang, Moon-Sik
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.1
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    • pp.12-16
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    • 2004
  • Partitioning of human granulocyte-macrophage colony stimulating factor (hGM-CSF) was achieved in the aqueous two-phase systems (ATPSs) using a crude extract of transgenic tobacco cell suspension culture. This study examined the effects of polyethylene glycol (PEG) molecular weight and concentration and the effects of sodium phosphate concentration in different PEG/sodium phosphate systems on the partition coefficient, K. The best ATPS system was 5% PEG 8,000/1.6 M sodium phosphate after 2 h of incubation at room temperature. In this system, hGM-CSF was partitioned in the PEG-rich phase with a yield of 57.99% and K$\_$hGM-CSF/ of 8.12. In another system, 3% PEG 10,000/1.6 M sodium phosphate, hGM-CSF was also partitioned primarily in the top phase with a yield of 45.66% and K$\_$hGM-CSF/ of 7.64 after 2 h of incubation at room temperature.