• 한국양식학회지
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• 제19권2호
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• pp.90-94
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• 2006

The effects of formalin on mixed function oxygenase (MFO) system and stress-response were investigated in olive flounder (Paralichthys olivaceus). Olive flounder was exposed to formalin at the concentration of 300 ppm for 1, 2, 4 and 16 h. Levels of stress-response enzymes together with total protein, glucose and osmolality were quantitatively determined in blood, and the activities of phase I (cytochrome P450, ethoxyresorufin deethylase) and phase II (glutathione S-transferase) hepatic enzymes were also determined. Since the formalin-exposure for 16 h resulted no significant changes in aspartate aminotransferase and alanine aminotransferase, specific enzymes for liver damage, it was thought that it did not cause hepatic tissue damage at the concentration of 300 ppm. However, hepatic MFO system was induced at 1 to 4 h, and stress response was induced after 16 h of exposure. Moreover, it is considered that the depression of MFO activity after 16 h of exposure may not be adaptation to formalin, but toxic response. These results suggest that low concentration of formalin does not cause hepatic tissue damage of fish, but could induce MFO and stress response.

• 멤브레인
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• 제20권3호
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• pp.197-202
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• 2010

당뇨병 환자의 혈당치 측정을 위하여 폴리우레탄으로 만들어진 진단막을 제조하였다. 혈액 속의 글루코우즈의 농도를 변화시켜가며 폴리우레탄 진단막을 가지고 680 nm에서의 최종흡광도를 측정하였다. 시간에 따른 흡광도 변화량(K/S)의 최종 결과치가 글루코우즈의 농도가 증가함에 따라 직선적으로 증가하였다. 헤마토크릿이 글루코우즈의 농도 측정에 미치는 영향을 조사하였다. 낮은 헤마토크릿에서는 글루코우즈의 농도와 K/S와의 기울기 값(Dose-Response Slope : DRS)이 플라즈마와 비교해 큰 차이를 보이지 않았다. 그러나 높은 헤마토크릿(40% 이상)에서는 상당히 감소함을 알 수 있었다.

• 멤브레인
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• 제21권4호
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• pp.329-335
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• 2011

당뇨병 환자의 혈당치 측정을 위하여 메톡시에톡시기와 트라이플루오르에톡시기가 함께 치환된 포스파젠 고분자를 기초로 한 새로운 형태의 진단막을 제조하였다. 플라즈마와 혈액속의 글루코우즈의 농도를 변화시켜가며 활성화 된 폴리포스파젠 진단막을 가지고 680 nm에서의 최종흡광도를 측정하였다. 시간에 따른 흡광도 변화량(K/S)의 최종 결과치가 글루코우즈의 농도가 증가함에 따라 직선적으로 증가하였다. 친수성기와 소수성기의 치환율이 글루코우즈의 농도 측정에 미치는 영향을 조사하였다. 친수성기의 치환율이 증가함에 따라 글루코우즈의 농도와 K/S와의 기울기 값(Dose-Response Slope : DRS)이 점차 증가하였다. 그러나 친수성기의 치환율이 30% 이상일 경우에는 DRS가 급격히 증가하여 정확한 글루코우즈의 농도 측정이 어려웠다.

• 한국약용작물학회지
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• 제24권4호
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• pp.263-270
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• 2016

Background: In this study, microwave extraction was used, which is an effective method to extract useful bioactive substances as it requires low quantities of solvent and short time periods. The aim of this study was to determine the optimal extraction conditions for Agrimonia pilosa Ledeb. Methods and Results: The independent variables were ethanol concentration, microwave power, and extraction time, each of which had five levels. The dependent variables were total polyphenol and total flavonoid content, and DPPH radical scavenging activity. To determine the optimal extraction conditions for bioactive compounds, a response surface methodology was employed. Contour maps were generated from polynomial equations. The optimal conditions were then assumed by superimposing these contour maps. Based on the resulting graph, the optimal microwave extraction conditions for Agrimonia pilosa Ledeb were determined as 42 - 48% ethanol concentration, 240 - 280W microwave power, and 13 - 20 min of extraction time. Conclusions: Ethanol concentration had a significant effect on microwave extraction, in terms of total polyphenol and total flavonoid content, as well as DPPH radical scavenging activity. Microwave power and extraction time influenced the total polyphenol content, but not the total flavonoid content or the DPPH radical scavenging activity.

• 한국물환경학회지
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• 제25권6호
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• pp.943-950
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• 2009

Cadmium (Cd) adsorption onto the activated carbon containing hydroxyapatite (HAP) was investigated in batch experiments and response surface methodology (RSM) using the Box-Behnken methods were applied to the experimental results. Cd adsorption with different HAP mass ratio of from 10% to 30%. With more HAP, Cd was more adsorbed. These results suggest that the higher HAP mass causes an increase of the ion exchange potential of the HAP sorbent. Equilibrium experimental results from Cd adsorption was fitted to Langmuir and Freundlich isotherm models. Cd adsorption on HAP sorbent were found to follow the Freundlich isotherm model well in the initial adsorbate concentration range. Also, Cd adsorption was a function of the HAP mass ratio ($x_1$), initial Cd concentration ($x_2$), and initial pH ($x_3$) from the application of the RSM. Statistical results showed the order of significance of the independent variables to be initial Cd concentration > HAP mass ratio > initial pH.

• 한방안이비인후피부과학회지
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• 제12권1호
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• pp.1-17
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• 1999

Shinisan has been used for treatment of allergic disease in Oriental Medicine. However, its effect in experimental models remains unknown. The mast cell plays a pivotal role in initiating allergic response by secreting intracytoplasmic granular mediators such as histamine. The present report describes an inhibitory effect of Shinisan on mast cell-mediated immediate type allergic reactions. Topical application of compound 48/80 can induce an ear swelling response in normal ($WBB6F_1-+/+$) mice but not in the congenic mast cell-deficient $WBB6F_1-W/W^v$ mice. Shinisan inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80. Shinisan inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by topical application. Shinisan also inhibited concentration-dependently the histamine release from the rat peritoneal mast cells by compound 48/80 or anti-DNP IgE. Moreover, Shinisan had a significant inhibitory effect on compound 48/80-induced systemic anaphylactic reaction. These results indicate that Shinisan inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in vivo and in vitro.

• 한방안이비인후피부과학회지
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• 제12권1호
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• pp.36-46
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• 1999

The mast cell plays a pivotal role in initiating allergic response by secreting intracytoplasmic granular mediators such as histamine. Magnoliae flos has been used for treatment of allergic disease in Korea. However, its effect in experimental models remains unknown. The present report describes an inhibitory effect of Magnoliae flos on mast cell-mediated immediate-type allergic reactions. Topical application of compound 48/80 can induce an ear swelling response in normal($WBB6F_1-+/+$) mice but not in the congenic mast cell-deficient $WBB6F_1-W/W^v$ mice. Magnoliae flos inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80 by topical application. Magnoliae flos inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by topical application. Magnoliae flos also inhibited concentration-dependently the histamine release from the rat peritoneal mast cells by compound 48/80 or anti-DNP IgE. Moreover, Magnoliae flos had a significant inhibitory effect on compound 48/80-induced systemic anaphylactic reaction. These results indicate that Magnoliae flos inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in vivo and in vitro.

• 산업식품공학
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• 제21권3호
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• pp.256-266
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• 2017

This study was designed to optimize ethanol extraction process of unfertilized corn silk (UCS) to maximize phytochemical contents and bioactivities. The response surface methodology (RSM) with central composite design (CCD) was employed to obtain the optimal extraction conditions. The influence of ethanol concentration, extraction temperature and extraction time on total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activities and tyrosinase inhibition were analyzed. For all dependable variables, the most significant factor was ethanol concentration followed by extraction temperature and extraction time. The following optimum conditions were determined by simultaneous optimization of several responses with the Derringer's desirability function using the numerical optimization function of the Design-Expert program: ethanol concentration 80.45%, extraction temperature $53.49^{\circ}C$, and extraction time 4.95 h. Under these conditions, the predicted values of total polyphenol contents, total flavonoid contents, maysin contents, DPPH radical scavenging activity and tyrosinase inhibition were $2758.74{\mu}g\;GAE/g$ dried sample, $1520.81{\mu}g\;QUE/g$ dried sample, 810.26 mg/100g dried sample, 56.86% and 43.49%, respectively, and the overall desirability (D) was 0.74.

• 대한조선학회지
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• 제21권1호
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• pp.13-20
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• 1984

As the first step to the dynamic stress analysis of structures, transient responses of a Timoshenko beam with variable section subject to impact load are analyzed. According to the various characteristics of impact load, time histories of the transient response of Timoshenko beam with general boundary conditions are obtained and compared with those of one degree of freedom system. Numerical solutions of the governing equations of motion are calculated by adopting the equivalent lumped-mass system and the finite difference method. It is found that the dynamic responses of Timshenko beam depend on the effect of concentration and location of impact load. As a result, increasing tendency of fluctuation in dynamic response, especially in bending moment, is found according to the increase of load concentration factor in time and space.

• 센서학회지
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• 제21권6호
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• pp.425-428
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• 2012

This paper presents the fabrication and characterization of graphene based hydrogen sensors. Graphene was synthesized by annealing process of Ni/3C-SiC thin films. Graphene was transferred onto oxidized Si substrates for fabrication of chemiresistive type hydrogen sensors. Au electrode on the graphene shows ohmic contact and the resistance is changed with hydrogen concentration. Nanoparticle catalysts of Pd and Pt were decorated. Response factor and response (recovery) time of hydrogen sensors based on the graphene are improved with catalysts. The response factors of pure graphene, Pt and Pd doped graphenes are 0.28, 0.6 and 1.26, respectively, at 50 ppm hydrogen concentration.