• Ocean and Polar Research
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• 제34권1호
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• pp.85-91
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• 2012

Physical properties such as sound speed contrast (h) and density contrast (g) of the interested target are key parameters to understand acoustic characteristics by using theoretical scattering models. The density and sound speed of moon jellyfish (common jellyfish, Aurelia aurita s.l.) were measured. Sound speed contrast (h) was measured from travel time difference (time-of-flight method) of an acoustic signal in a water tank for APOP studies (Acoustic Properties Of zooplankton). Density contrast (g) was measured by the displacement volume and wet weight (dual-density method). The sound speed remained almost constant as the moon jellyfish increased in bell length. The mean values${\pm}$standard deviation of h and g were $1.0005{\pm}0.0012$ and $0.9808{\pm}0.0195$), respectively. These results will provide important input for use in theoretical scattering models for estimating the acoustic target strength of jellyfish.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.509-516
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• 2003

A model system for the immnunochemical detection of Escherichia coli O157:H7 using a combined immunomagnetic separation (IMS) and test-strip liposome immunoassay (LIA) procedure was developed. Immunomagnetic beads coated with anti-E. coli O157 IgG antibodies were used to separate the E. coli O157 (including the H7 serotype) from culture. Immunoliposomes, whose surface was conjugated to goat anti-E. coli O157:H7 IgG and which encapsulated the marker dye, sulforhodamine B, were used as a detection label. The test strip, onto which antibodies to goat IgG were immobilized, was the immunosensor capturing immunoliposomes that did not bind to E. coli O157:H7 on the immunomagnetic bead-E. coli O157:H7 complexes. In experiments, pure cell culture suspensions of $10^5 E.$ coli O157:H7 organisms per ml produced a measurable signal inhibition, whereas a weak yet detectable signal inhibition occurred with $10^3CFU/ml$. The inhibition signals increased, when the incubation time for IMS was extended to 90 min and higher IgG-tag density (0.4mol%) was used on the liposomes. With 0.2 and 0.4mol% IgG-tagged liposomes, the IMS-LIA procedure showed more improved signal inhibitions than those of a direct (no IMS) LIA. The combined assay, which measures the instantaneous signal from immunoliposomes, can be completed within 90 min, making it significantly faster than conventional plating methods and enzyme-linked immunosorbent assay (ELISA). Accordingly, it is quite feasible to use the combined immunoassay format of IMS and dye-loaded immunoliposomes for the detection of E. coli O157:H7.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.65-66
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• 2007

현재 수립된 3차전력수급기본계획의 전원구성을 WADE Economic Model을 사용하여 친환경적이며, 경제적이고 기존 대형발전소의 보완 역할이 기대되는 분산형전원으로 우리나라의 전원을 구성하였다. 즉, WADE Economic Model로서 신규수요를 CG(Centralized Generation) 및 DE(Decentralized Energy)의 담당비율에 따라 시나리오를 구성하여 3차전력수급기본계획의 전원구성을 WADE Economic Model에 의한 시나리오로 전원을 구성한 경우와 비교 분석하였다.

• Archives of Pharmacal Research
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• 제27권7호
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• pp.806-810
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• 2004

Metformin is a biguanide antihyperglycemic agent often used for the treatment of non-insulin dependent diabetics (NIDDM). In this study, the pharmacokinetics and pharmacodynamics of metformin were investigated in Korean healthy volunteers during a fasting state for over 10 h. In order to evaluate the amount of glucose-lowering effect of metformin, the plasma concentrations of glucose were measured for a period of 10 h followed by the administration of metformin (oral 500 mg) or placebo. In addition, the concentration of metformin in blood samples was determined by HPLC assay for the drug. All volunteers were consumed with 12 g of white sugar 10 minutes after drug intake to maintain initial plasma glucose concentration. The time courses of the plasma concentration of metformin and the glucose-lowering effect were analyzed by nonlinear regression analysis. The estimated $C_{max}$, $T_{max}$, $CL_{t}$/F (apparent clearance), V/F(apparent volume of distribution), and half-life of metformin were 1.42$\{pm}$0.07 $\mu\textrm{g}$/mL, 2.59$\{pm}$0.18h, 66.12$\{pm}$4.6 L/h, 26.63 L, and 1.54 h respectively. Since a significant counterclock-wise hysteresis was found for the metformin concentration in the plasma-effect relationship, indirect response model was used to evaluate pharmacodynamic parameters for metformin. The mean concentration at half-maximum inhibition $IC_{50}$, $k_{in}$, $k_{out}$ were 2.26 $\mu\textrm{g}$/mL, 83.26 $H^{-1}$, and 0.68 $H^{-1}$, respectively. Therefore, the pharmacokinetic-pharmacodynamic model may be useful in the description for the relationship between plasma concentration of metformin and its glucose-lowering effect.

• 한국미생물·생명공학회지
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• 제20권5호
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• pp.597-606
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• 1992

Alcaligenes eutrophus 균주로 poly-Beta-hydroxybutyrate(PHB) 생산을 위한 연속배양 공정의 성능에 미치는 희석비율, 주입 포도당 및 염화암모늄농도의 영향에 대하여 연구하였다. 주입 기질농도가 일정할때( 주입 포도당농도=20g/l, 주입 염화암모늄농도=2g/l), 생체성장속도와 PHB생성속도는 희석비율이 각각 0.1, $0.06h^{-1}$에서 최고 값을 나타냈고, $0.13h^{-1}$에서 세포가 전부 배출되었다. 희석비율이 증가함에 따라 비PHB 생성속도는 계속 증가하였지만 PHB 축적비는 50%에서 25%로 감소하였다. 세포농도는 주입 염화암모늄농도가 2g/l일 때 최고값을 나타내었고, 그 이상의 농도에서는 감소하였다. 이 실험결과로 암모늄에 의한 기질저해가 있음을 알 수 있었다. 주입 포도당농도가 30g/l에서 세포농도는 최고값을 나타냈지만 PHB 농도는 계속 증가하였따. 모델속도식에 대한 매개변수는 도식적 방법과 매개변수 추정으로 구하였고 희석비율, 주입 포도당농도, 주입 염화암모늄농도의영향에 대하여 모사한 결과 실험데이타와 잘 일치하였다.

• Carbon letters
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• 제19권
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• pp.12-22
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• 2016

Date palm leaflets were used as a precursor to prepare dehydrated carbon (DC) via phosphoric acid treatment at 150℃. DC, acidified with H₃PO₄, was converted to activated carbon (AC) at 500℃ under a nitrogen atmosphere. DC shows very low surface area (6.1 m²/g) while AC possesses very high surface area (829 m²/g). The removal of lisinopril (LIS) and chlorpheniramine (CP) from an aqueous solution was tested at different pH, contact time, concentration, and temperature on both carbons. The optimal initial pH for LIS removal was 4.0 and 5.0 for DC and AC, respectively. However, for CP, initial pH 9.0 showed maximum adsorption on both carbons. Adsorption kinetics showed faster removal on AC than DC with adsorption data closely following the pseudo second order kinetic model. Adsorption increases with temperature (25℃–45℃) and activation energy (E_a) is in a range of 19–25 kJ mol/L. Equilibrium studies show higher adsorption on AC than DC. Thermodynamic parameters show that drug removal is endothermic and spontaneous with physical adsorption dominating the adsorption process. Column adsorption data show good fitting to the Thomas model. Despite its very low surface area, DC shows ~70% of AC drug adsorption capacity in addition of being inexpensive and easily prepared.

• 생약학회지
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• 제43권1호
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• pp.72-78
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• 2012

Alnus japonica Steud (A. japonica) have long been used in the traditional medicine for gastric disorder, hepatitis and fatty liver in Korea. Antiulcer effects of A. japonica hot water extract (AJ ext) were evaluated by in vitro antibacterial activity against H. pylori, by the inhibitory action against the in vitro gastric $H^+/K^+$-ATPase and using rat models of gastric mucosal damage and gastric ulcer induced by HCl-ethanol, indomethacin, and restraint and water-immersion stress. For the determination of antibacterial activity of AJ ext against H. pylori, the activity of urease which released from H. pylori was measured in culture. AJ ext showed weak antibacterial activity against H. pylori with the growth inhibitions of 37% and 61% by adding final concentrations of 500 and $1000{\mu}g/ml$ culture, respectively at 24 h. To observe the inhibitory activity of AJ ext against the $H^+/K^+$-ATPase in hog gastric membrane vesicle, $IC_{50}$ value of AJ ext was $806.3{\mu}g/ml$. Pretreatment of AJ ext (200, 500 mg/kg, p.o.) prevented in a dose-dependent manner the acute gastritis in HCl-ethanol model and the formation of gastric ulcer in indomethacin model and restraint and water-immersion stress model. These results suggest that the AJ ext can be used for prevention and treatment of gastric mucosal damage and ulcers induced by various stress.

• 한국물환경학회지
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• 제33권4호
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• pp.441-448
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• 2017

Microcystis aeruginosa (M. aeruginosa) is a cyanobacterium species that can form harmful algal blooms in freshwater bodies worldwide. The use of Artemisia asiatica extracts to control M. aeruginosa inhibition will be environmentally friendly and promising. Artemisia asiatica extracts removed successfully upto 88% of M. aeruginosa pH 8 at $25^{\circ}C$ of temperature. These results was indicated that the amount of 2.24 g/L Artemisia asiatica extracts was removed 1g dryweight/L of M. aeruginosa. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the M. aeruginosa was grown in medium containing 2.5 g/L of initial concentration of Artemisia asiatica extracts. In the various growth control models, Luong model showed the highest correlation coefficient of 0.9916. Therefore, the Luong model was the most suitable control model for the growth control of M. aruginosa using Artemisia asiatica extracts. In conclusion, the growth control of M. aruginosa using Artemisia asiatica extracts can be applied in the field without controlling the temperature and pH of rivers and streams, and it is possible to control the growth of M. aruginosa efficiently in a short time. The natural extract, Artemisia asiatica extracts, can be a promising inhibition due to its high efficiency and low dose requirements.

• Membrane and Water Treatment
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• 제15권2호
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• pp.89-98
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• 2024

The ability of Zizyphus lotus stem powder (ZLSP) to remove Pb (II) and Cd (II) ions from an aqueous solution was evaluated. The present phenomenon of biosorption was revealed to depend on pH, biosorbent dosage, temperature, initial ionic concentration, time of contact and biosorbent's particle size. The sorption process was exothermic (∆H°<0), and showing a strong Pb(II)/Cd(II)-ZLSP affinity (∆S°>0). Gibbs free energy data (∆G°<0, and decreases as temperature increase) reveals that the process studied is characterized by its feasibility and spontaneous nature. The best fits of the equilibrium data were obtained by the Temkin model and the Langmuir model. The maximum Pb(II)/Cd(II)-ZLSP biosorption capacities were 33.02 mg/g for Pb (II) and 20.73 mg/g for Cd (II). The pseudo-second order model was the most appropriate for fitting the kinetic data. The characterization of the biochemical groups essentially involved in the sorption phenomenon was made possible by FTIR spectral analysis. The capacity of ZLSP as an effective and ecofriendly biosorbent is confirmed through this study.

• 한국식품영양과학회지
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• 제30권3호
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• pp.500-504
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• 2001

Gamma irradiation was applied to reduce egg allergy. Ovalbumin (OVA), an egg white protein, was used as model allergen and was gamma-irradiated at 3, 5, or 10 kGy in an aqueous state (2.0 mg/mL). The changes in allergenic and antigenic properties of OVA resulted from gamma irradiation were monitored by ELISA with serum from egg-hypersensitive patients (H-IgE), and mouse monoclonal IgG (M-IgG) or rabbit polyclonal IgG (R-IgG). The binding ability of H-IgE to irradiated OVA was dose-dependently reduced. However, IgGs from animal did better recognize 3 or 5 kGy-irradiated OVA. In the evaluation of immune reactivity using blind test, the reactivity of H-IgE rapidly decreased depending upon the irradiation dose. However, the reactivities of M-IgG and R-IgG was higher at 5 and 3 kGy-irradiated OVA than non-irradiated control. The results provide a new possibility to use irradiation process for reducing the allergenicity of egg white.