• Title/Summary/Keyword: pH dependant

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Effect of Antioxidants on the Preparation of $^{99m}Tc-MDP$ ($^{99m}Tc-MDP$ 제조시 산화방지제 첨가영향)

  • Awh, Ok-Doo;Park, Kyung-Bae;Kim, Jae-Rok
    • The Korean Journal of Nuclear Medicine
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    • v.26 no.1
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    • pp.133-139
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    • 1992
  • To improve the quality of $^{99m}Tc-methylenediphonate$ $(^{99m}Tc-MDP)$ for skeletal imaging, different composed $^{99m}Tc-MDP$ complexes were prepared with addition of antioxidants such as ascorbic acid, getisic acid, and p-aminobenzoic acid. To characterize the different $^{99m}Tc-MDP$ preparations, some physical and biochemical properties of $^{99m}Tc-MDP$ such as thermal stability, lipophilicity and bindability to serum protein were studied and organ distribution pattern of these complexes also compared. The thermal stabilities of $^{99m}Tc-MDP$ contained antioxidants were dependant mainly on pH, temperature, and elapsed time after the preparation. $^{99m}Tc-MDP$ complex contained gentisic acid as antioxidant was extremely unstable at alkaline condition. The most stable $^{99m}Tc-MDP$ was found in the presence of p-aminobenzoic acid. $^{99m}Tc-MDP$ complexes with antioxidants were very lipophilic but lipophilicity differences in antioxidants were not observed. The bindability of $^{99m}Tc-MDP$ to serum protein was not affect at pH $5.0\sim9.0$ by the different antioxidants. However, protein binding percentage of $^{99m}Tc-MDP$ with ascorbic acid was relatively low (22.7%) at pH 9.0. In biodistribution studies in mice, bone to muscle ratios of $^{99m}Tc-MDP$ preparations containing ascorbic acid, gentisic acid, and p-aminobenzoic acid were 15.3, 24.5, and 30.1, respectively. Im to our results, p-aminobenzoic acid is fond to be the most promising antioxidant.

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Optimization of Tyrosinase Inhibitory Activity in the Fermented Milk by Lactobacillus plantarum M23 (Lactobacillus plantarum M23 균주를 이용한 Tyrosinase 저해 활성 발효유 생산의 최적화)

  • Lim, Sang-Dong;Kim, Kee-Sung
    • Food Science of Animal Resources
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    • v.32 no.5
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    • pp.678-684
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    • 2012
  • The melanin pigment in human skin is a major defense mechanism against ultraviolet light to the skin, but darken skin color. Tyrosinase is mainly responsible for melanin biosynthesis (melanogenesis) in animals and enzymatic browning (melanosis) in plants. The purpose of this study was to optimize the fermented milk process for the melanin formation inhibition by using Lactobacillus plantarum M23 with tyrosinase inhibitory activity. We used 4-factor-3-level central composite design combining with response surface methodology. Yeast extract concentration (%, $X_1$), addition of grape (%, $X_2$), incubation temperature ($^{\circ}C$, $X_3$) and incubation time (h, $X_4$) was used as an independent factor, on the other hand, pH (pH, $Y_1$), overall palatability (score, $Y_2$) and tyrosinase inhibitory activity (%, $Y_3$) was used as a dependant factor. Based on the optimization for the highest tyrosinase inhibitory activity with pH 4.4, the expected data of pH, palatability and tyrosinase inhibitory activity with 14.8 h incubation at $37.1^{\circ}C$ by the addition of 0.127% of yeast extract, 2.95% of grape was 4.42, 7.06 and 86.65%, but the real data was 4.35, 6.86 and 84.05%, respectively. Based on the previous results, fermented milk using Lactobacillus plantarum M23 with the tyrosinase inhibitory activity could contribute for the whitening and antiaging of human skin.

A Study of antibacterial effect on pseudomonas aeruginosa of soft contact lens multi-purpose solution (MPS) (Pseudomonas aeruginosa에 대한 soft contact lens 다목적 용액의 항균효과)

  • Yoon, Min-Hwa;Park, Hyun-Ju;Lee, Ki-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.353-359
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    • 2004
  • This study was performed to examine the pseudomonas aeruginosa, antibacterial effect of a soft contact lens multi-purpose solution (MPS). Pseudomonas aeruginosa was incubated in the Muller Hinton Broth culture, and treated with 5 MPSs. TO investigate the antibacterial efficiency of MPSs, UV spectrometer was used for measuring optical density of pseudomonas aeruginosa. The antibacterial effect of 4 MPSs was significant except for one MPS. This result suggested that the antibacterial effect of MPSs is dependant on their components, pH. Therefore they had antibacterial effect of the pseudomonas aeruginosa.

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Radiation effects of I-V characteristics in MOS structure irradiated under $Co^{60}-{\gamma}$ ray ($Co^{60}-{\gamma}$ ray을 조사시킨 MOS 구조에서의 I-V특성의 방사선 조사 효과)

  • Kwon, S.S.;Jeong, S.H.;Lim, K.J.;Ryu, B.H.;Kim, B.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.123-127
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    • 1992
  • When MOS devices is exposed to radiation, radiation effects of P-type MOS capacitor can cause modulation and/or degradation in devices characteristics and its operating life. The oxide layer is grown in $O_2$+T.C.E. and its thickness ranges from 40 to 80 nm. Irradiations on MOS capacitor were performed by Cobalt-60 gamma ray source and total dose ranges from $10^4$ to $10^8$ rads. The radiation effect on electrical conduction characteristics(I-V) in MOS capacitor was measured as a function of gate oxide thickness and total dose. From the experimental result, I-V characteristics is found to be influenced strongly by total dose in irradiated p-type MOS capacitors. The ohmic current is dependant on of total dose in irradiated P-type MOS capacitors. This results are explained using surface states at interface radiation-induced traps.

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Antipruritic Effects of Ethanol Extracts from Perillae Japonicae Semen leaves and Chaenomelis Fructus (임자잎과 모과 에탄올 추출물의 피부 가려움증 억제 효과)

  • Kim, Hyeon-Soo;Jeon, In-Hwa;Mok, Ji-Ye;Kang, Hyun-Ju;Jang, Seon-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.3
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    • pp.314-319
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    • 2012
  • Itching is one of the major diagnostic criteria of atopic dermatitis (AD) and one of its most troublesome symptoms that provokes the desire to scratch. Effective control of itching is believed to be one of the basic approaches in controlling AD. The purpose of this study was undertaken to investigate the antipruritic effect of ethanol extracts from Perillae Japonicae Semen leaves (PJSL) and Chaenomelis Fructus (CF) on the scratching behavior induced by pruritogen such as compound 48/80 or substance P in hairless mice. PJSL or CF treatment inhibited histamine release in HMC-1 stimulated compound 48/80 or substance P in a dose-dependant manner. In particularly, co-treatment PJSL ($50{\mu}g/mL$) plus CF ($100{\mu}g/mL$) significantly inhibited histamine release in HMC-1 stimulated compound 48/80 or substance P. PJSL, CF or PJSL plus CF was administered orally for 2 h and then compound 48/80 ($50{\mu}g/site$) or substance P ($100{\mu}g/site$) was injected into rostral back, and scratching of the injected site by the hind paw was counted for 1 h. PJSL or CF administration reduced the scratching behavior induced by compound 48/80 as well as substance P in a dose-dependent manner. Furthermore, co-administration of PJSL and CF markedly suppressed the scratching behavior induced by compound 48/80 as well as substance P. These suppressive effects were synergistically increased by their combination. From the preliminary observations, we considered that ethanol extracts from PJSL and CF could be an effective natural materials for itching treatment.

Correlation between Phytoplankton Dynamics and Water Quality in Paldang Reservoir (팔당호에서 식물플랑크톤 군집 동태와 수질과의 상관성)

  • Han, Myung-Soo;Jheong, Weon-Hwa;Park, Jun-Dae;Kim, Jong-Min
    • Korean Journal of Ecology and Environment
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    • v.38 no.2 s.112
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    • pp.217-224
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    • 2005
  • This study was aimed to analyze the long-term fluctuation of water quality and phytoplankton dynamics of Paldang reservoir in Korea and to assess the relationship between algal bloom patterns and hydrological, limnological data. Diatoms in Paldang reservoir occurred continuously through the year. Blue- green algae occurred during the summer season (from June to Sept.), and the highest count was observed in July. Occurrence pattern of green algae was similar to that of blue-green algae. The rest of algae contained a lot of Cryptomonas spp. whose concentration was high from May to Aug. Dominant algal genera (>>7,000 cells $mL^{-1}$) in Paldang reservoir were Aulacoseira, Cyclotella, Microcystis, and Cryptomonas spp. Microcystis and Anabaena occurred during the summer season. Many different green algal genera were found in Paldang reservoir but their abundances were very low. There were some significant correlations (r>0.3, p<0.05) between algal taxa and water quality; diatoms and water temperature, TP:blue-green algae and water temperature, pH, DO saturation, COD, TP; green algae and water temperature, pH, DO saturation, COD, SS, TP. Furthermore, algal genera and water quality was significantly correlated (r>0.3, p<0.05) ; Aulacoseira and TN, TP; Anabaena and water temperature, DO saturation, COD, TP : Microcystisand water temperature, pH, DO saturation, TP; Coelastrum and COD, SS; Scenedesmus and water temperature, COD, TN, TP; Cryptomonas and DO saturation, TN. In Paldang reservoir, the water temperature had relatively big effect on blue-green algal bloom that was also dependant upon its hydrologic condition.

Parameters Characteristics of Single Work Hardening Model Dependent on the Stress Path (응력경로에 따른 단일항복면구성모델의 토질매개변수 특성)

  • 김찬기
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.38 no.2
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    • pp.133-144
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    • 1996
  • To get accurate results, the realistic stress-strain relationships of soils are dependent on a number of factors such as soil types, density, stress levels and stress path. Such attempts are continuously being made by the developement of analytical models for soils incorporating all such factors. Isotropic compression-expansion test and a series of drained conventional triaxial tests with several stress path for Baekma river sand were performed to investigate parameters characteristics of Lade's single work hardening model dependant on the stress path. Using the computer program based on the regression analysis, the values of parameters for the model were determined. In conclusion, the parameters of Lade's model are little influenced by the stress paths. Though yield criterion parameters ( h, ${\alpha}$a) are much influenced by stress level and stress path, the parameters don't have influence on stress-strain behavior.

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Effect of Dietary Monascus Koji on the Liver Damage Induced by Bromobenzene in Rats (식이성 홍국이 Bromobenzene에 의한 간 손상의 해독에 미치는 영향)

  • 오정대;윤종국;유대식
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.6
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    • pp.965-972
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    • 2004
  • In the present study, it is observed that Monascus diet may have a hepatoprotective effect on the liver damage induced by bromobenzene in rats. By treatment with bromobenzene (400 mg/kg, i.p.) once a day for 3 consecutive days, the liver damage was reduced in rats fed 2% Monascus diet, based on the liver functional and histopathological findings. Furthermore, retreatment of bromobenzene to the animals with damaged liver showed higher decreasing rate of hepatic glutathione content and increasing rate of cytochrome P450 dependent aniline hydroxylase activity at 4 h in rats fed 2% Monascus diet than those fed STD diet, and V$_{max}$ in glutathione S-transferase was higher in liver of rats fed 2% Monascus diet than those fed STD diet. On the other hand, activities of antioxidant enzymes such as hepatic glutathione S-transferase, catalase and superoxide dismutase were generally higher both in bromobenzene and 2% Monascus diet treated group than those fed STD diet. In conclusion, the rats fed 2% Monascus diet showed lower liver damage than those fed STD diet, which may be due to the acceleration of bromobenzene metabolism and detoxication of oxygen free radicals.s.

The Effect of the Water Extracts of Digestive Medicinal Plants on the Shelf-life of Pork Patties

  • Seol, Kuk-Hwan;Seol, Hyun-Chul;Prayad, Thirawong;Kim, Hyoun-Wook;Jang, Ae-Ra;Ham, Jun-Sang;Oh, Mi-Hwa;Kim, Dong-Hun;Lee, Moo-Ha
    • Food Science of Animal Resources
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    • v.31 no.1
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    • pp.54-60
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    • 2011
  • This study was performed to examine the possibility of water extracts of several digestive medicinal plants (DMPEs), such as Amomum tasoko, Alpinia oxyphylla, Citrus unshiu, and Myristica fragrans, as a natural antioxidant. Total phenol contents of each extract were expressed as gallic acid equibalents (GAE) and those were significantly different among A. tasoko ($39.87{\pm}5.77$ mg GAE/g), A. oxyphylla ($30.28{\pm}3.36$ mg GAE/g), C. unshiu ($28.13{\pm}5.01$ mg GAE/g) and M. fragrans ($6.36{\pm}0.30$ mg GAE/g) (p<0.05), and extract of A. tasoko showed significantly higher antioxidative effect than butylated hydroxyanisole (BHA) on linoleic acid peroxidation at 72 h after incubation (p<0.05). Addition of extracts in pork patties did not affect the pH value and total microbes during cold storage. However, thiobarbituric acid reative substances (TBARS) of treated patties were lower in dose dependant manner than that of control as storage period increased (except patties treated with C. unshiu extract), and patties treated with 0.5% A. tasoko extract showed no significant difference with patties treated with 0.5% BHA at day 7.

Effects of Tributyltin in vitro on Hepatic Monooxygenase System in Marine Fishes (유기주석화합물이 해산 어류의 간장 MFO 효소계에 미치는 영향)

  • 전중균;이미희;이지선;심원준;이수형;허형택
    • Korean Journal of Environmental Biology
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    • v.21 no.1
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    • pp.18-25
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    • 2003
  • Effects of tributyltin chloride (TBTC) in vitro on mixed function oxygenase (MFO) system on liver microsome of eight marine fish species were investigated. To determine the effects on MFO system, cytochrome P45O (CYP) and cytochrome b5 con-tents, activities of two reductases (NADH-cytochrome b5 reductase and NADPH-cy-tochrome P450 reductase) and four dealkylation enzymes (EROD, PROD, MROD and ECOD) were measured in fish microsoms exposed to TBTC for 20 min. The WP content was reduced to 10% of the control group in 6 out of 8 species exposed to TBTC, whereas there was no significant change in the cytochrome bs content. the response of NAD(P)H dependant reductases depended on fish species. The dealkylation enzyme activities in microsome were also apparently inhibited by TBTC. The degree of inhibition was different among fish species and four enzymes. The EROD activities in eight species were decreased to the range of 1∼65% of control group.