• Journal of Food Hygiene and Safety
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• v.10 no.3
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• pp.133-138
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• 1995

In vitro antimutagenic activity of methanol extract from brrwn rice and its physico-chemical characteristics were investigated using Salmonella typhimurium reversion assay and SOS chromotest. Methanol extracts of brown rice were not mutagenic compared with direct and indirect, mutagenicities of 4NQO (4-nitroquinoline oxide), 2NF(2-nitrofluorene), Trp-p-1(3-Amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole), and Trp-p-2(3-Amino-1-methy-5H-pyrido-[4,3-b]indole). Antimutagenic activity against the indirect mutagenicties induced by Trp-p-1, Trp-p-2 and AFB1 (aflatoxin B1) was found in methanol extract. Even though antimutagenic activity showed dose-dependent, it remained constant at inhibition rate ranging 60~90% when the concentration was abov 3mg/plate in the S. typhimurium reversion assay and 0.2~0.6 mg/assay in the SOS chromotest. The antimutagenic activity of the methanol extracts was stable at various pH (2, 7 and 10), temperatures (60, 80 and 10$0^{\circ}C$)and heation times (2, 4, 6, 8, 10 min at 10$0^{\circ}C$).

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.701-707
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• 2006

Disinfectant residual should be maintained to achieve biological stability during distribution of treated water. The wide distribution of retention times associated with storage and transport of water in a network and the reactivity of disinfectants make it difficult to maintain adequate residuals at critical locations. Rechlorination at some intermediate locations may reduce the total disinfectant dose while keeping residuals within specified limits throughout the water distribution system. In order to select the adequate location of rechlorination for achieving to maintain of residual chlorine throughout the distribution system, EPANET was used in this study. EPANET was well predicted chlorine transport and residual loss in the distribution system. Location of rechlorination was selected to maintain 0.4mg/L of residual chlorine throughout a water distribution system by field investigation and model simulation. The quantity of chlorine may reduced 36.7% and provided smooth residual between 0.42 and 0.60mg/L, when rechlorination would be used continuously at strategic location within the distribution system.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.559-571
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• 2006

The overall objective of this research was to find out the interrelation of coagulant and organic matter during rapid mixing process and to identify the change of organic matter by mixing condition and to evaluate the effect of coagulation pH. During the coagulation, substantial changes in dissolved organics must be occurred by coagulation due to the simultaneous formation of microflocs and NOM precipitates. Increase in the organic removal efficiency should be mainly caused by the removal of microflocs formed during coagulant injection. That is, during the mixing period, substantial amount of dissolved organics were transformed into microflocs due to the simultaneous formation of microflocs and NOM precipitates. The results also showed that 40 to 80% of dissolved organic matter was converted into particulate material after rapid mixing process of coagulation. During the rapid mixing period, for purewater, formation of dissolved Al(III) (monomer and polymer) constant by rapid mixing condition, but for raw water, the species of Al hydrolysis showed different result. During the rapid mixing period, for high coagulant dose, Al-ferron reaction increases rapidly. At A/D(Adsorption and Destabilization) and sweep condition, both $Al(OH)_3(s)$ and dissolved Al(III) (monomer and polymer) exist, concurrent reactions by both mechanism appear to cause simultaneous precipitation.

• Korean Journal of Clinical Pharmacy
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• v.16 no.1
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• pp.57-62
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• 2006

The purpose of this study was to investigate the effect of naringenin, one of flavonoids, on the pharmacokinetics and bioavailability of diltiazem (15 mg/kg) after oral administration of diltiazem with or without naringenin (2.0, 10 and 20 mg/kg) in rabbits. Coadministration of naringenin increased the absorption rate constant $(K_a)$, the area under the plasma concentration-time curve (AUC) and peak concentration $(C_{max})$ of diltiazem compared to the control group, but only significantly (p<0.05) by 10mg/kg of naringenin coadministration. The absolute bioavailability (AB%) of diltiazem by coadministration ranges from 7.8% to 10.3%, increased more than control (7.2%), and relative bioavailability (RB%) of diltiazem is increased from 1.08- to 1.43-fold. Coadministration caused on significant changes in the terminal half-lives $(t_{1/2})$ and the time to reach the peak concentration $(T_{max})$ of diltiazem. On the other hand, coadministration of naringenin increased the AUC desacetyldiltiazem, significantly at the dose of 10mg/kg. But the metabolite ratio (MR) was decreased, significantly at 10mg/kg of naringenin. Based on these results, we can make a conclusion that the increased bioavailability and the significant changes of these pharmacokinetic parameters might be due to naringenin, which possess the potency to inhibit the metabolizing enzyme (CYP3A4) in the liver and intestinal mucosa, and also inhibit the P-glycoprotein efflux pump in the intestinal mucosa.

• BMB Reports
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• v.38 no.4
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• pp.407-413
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• 2005

Calcium and zinc binding protein, calprotectin is a multifunctional protein with broad spectrum antimicrobial and antitumoural activity. It was purified from human neutrophil, using a two-step ion exchange chromatography. Since surface hydrophobicity of calprotectin may be important in membrane anchoring, membrane penetration, subunits oligomerization and some biological roles of protein, in this study attempted to explore the effect of calcium in physiological range on the calprotectin lipophilicity. Incubation of human calprotectin ($50\;{\mu}g/ml$) with different calcium concentrations showed that 1-anilino-8-naphthalene sulfonic acid (ANS) fluorescence intensity of the protein significantly elevates with calcium in a dose dependent manner, suggesting an increase in calprotectin surface hydrophobicity upon calcium binding. Our study also indicates that calcium at higher concentrations (6, 8 and 10 mM) induces aggregation of human calprotectin. Our finding demonstrates that the starting time and the rate constant of calprotectin aggregation depend on the calcium concentration.

• Archives of Pharmacal Research
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• v.26 no.10
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• pp.855-860
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• 2003

The effect of silver sulfadiazine (SSD) on the proliferation of human dermal fibroblast (HDF) was studied to determine the impact of the drug on the wound healing process and dermal mechanical strength. Human dermal fibroblasts were cultured to 80% confluency using DMEM with 10% FBS and viability of the cell was estimated using neutral red assay. In addition, the $2^{nd}$ degree burn wound was prepared on the anterior part of rabbit ear skin and dressings containing SSD were applied for 96 h. Presence of inflammatory cells and degree of re-epithelialization were investigated in the wound. After 15 day of the induction of burn wounds, the treated area was excised and dermal mechanical strength was quantitatively measured with a constant speed tensiometer. SSD was found to be highly cyto-toxic in cultured HDF cells. The topical application of SSD (2%) could control the infection as evidenced by the lack of accumulation of inflammatory cells in histological evaluation. Therefore, these observations suggested that the impairment of dermal regeneration and decreased mechanical strength of dermal tissue was resulted from the cyto-toxic effect of SSD on dermal cells. Since the decreased mechanical strength may lead to reduction in resilience, toughness and maximum extension of the tissue, the identification of optimum dose for SSD that limits infection while minimizes the cyto-toxic effect may be clinically relevant.

• Tuberculosis and Respiratory Diseases
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• v.81 no.1
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• pp.13-18
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• 2018

Bronchodilator therapy is central to the management of chronic obstructive pulmonary disease and are recommended as the preferred treatment by the Global Obstructive Lung Disease Initiative (GOLD). Long acting anti-muscarinics (LAMA) and long acting ${\beta}_2$ agonists (LABA) are both more effective than regular short-acting drugs but many patients remain symptomatic despite monotherapy with these drugs. Combination therapy with LAMA and LABA increases the therapeutic benefit while minimizing dose-dependent side effects of long-acting bronchodilator therapy. The TOviTO programme has investigated the benefits of treatment with a combination of tiotropium and olodaterol administered via a single inhaler. Tiotropium+olodaterol $5/5{\mu}g$ significantly improved forced expiratory volume in 1 second ($FEV_1$) area under the curve from 0 to 3 hours, trough $FEV_1$ health status and breathlessness versus the mono-components and placebo. Tiotropium+olodaterol $5/5{\mu}g$ also increased endurance time and reduced dynamic hyperinflation during constant work rate cycle ergometry. On the basis of these and other studies the 2017 GOLD report recommends escalating to dual bronchodilator therapy in patients in groups B and C if they remain symptomatic or continue to have exacerbations and as initial therapy for patients in group D.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.451-457
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• 2015

In this paper, we consider the observer design problem that truly reflects the nonlinear stiffness of the manipulators. The two key ideas of our design are that (a) estimation error dynamics of the manipulator equipped with accelerometer dose not dependent on nonlinearities at the link part, when the measured signals are the motor position and the output of the accelerometer and (b) the nonlinear stiffness is indeed a Lipschitz function. In order to effectively compensate the nonlinear stiffness, the gain of the proposed observer is carefully chosen from the ARE(algebraic Riccati equations) which depend on Lipschitz constant. Comparative simulation result verifies the effectiveness of the proposed solution.

• Membrane and Water Treatment
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• v.6 no.3
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• pp.189-203
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• 2015

Membrane biofouling impedes wide application of membrane bioreactor (MBR) for wastewater treatment. Recently, quorum sensing (QS) mechanisms are accounted for one of major mechanisms in biofouling of MBRs. In this study, vanillin was applied to investigate reduction of biofouling in MBRs. MBR sludge was analyzed to contain QS signal molecules by cross-feeding biosensor assay and HPLC. In addition, the inhibitory activity of vanillin against bacterial quorum sensing was verified using an indicator strain CV026. The vanillin doses greater than 125 mg/L to 100 mL of MBR sludge showed 25% reduction of biofilm formed on the membrane surfaces. Two MBRs, i.e., a typical MBR as a control and an MBR with vanillin, were operated. The TMP increases of the control MBR were more rapid compared to those of the MBR with the vanillin dose of 250 mg/L. The treatment efficiencies of the two MBRs on organic removal and MLSS were maintained relatively constant. Extracellular polymeric substance concentrations measured at the end of the MBR operation were 173 mg/g biocake for the control MBR and 119 mg/g biocake for the MBR with vanillin. Vanillin shows great potential as an anti-biofouling agent for MBRs without any interference on microbial activity for wastewater treatment.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.2
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• pp.57-72
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• 1995

We have recently developed a novel in vitro SPF evaluation method with a high correlation coefficient (r=0.93) to in vivo SPF values(test sunscreen formulas : cress m, foundation). In this method, the in vitro SPF value was determined by the ratio of the time taken to achieve the minimal erythema dose with and without the sunscreens applied. We also reviewed the dilution and thin-layer methods for in vitro SPF evaluation, and investigated the relationship between irradiance(3$\times$10-3 2.5x 10-5W/cm2) and the degree of erythema. The degree of erythema was similar if t he radiation exposure(40mJ/cm2) was kept constant. It was obtained more than 0.90 correlation coefficient when it was compared the results by our new method with those from SPF-290 analyzer (Optometries, U.S.A.).