• Title/Summary/Keyword: alpha curve

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Bioavailability Studies on Suspension of Inclusion Complexes of Piroxicam with Cyclodextrins (Piroxicam-Cyclodextrin 포접화합물의 현탁제에 대한 생체내 이용율의 연구)

  • Park, Sun Hee;Lee, Chang Hoon;Choi, Young Wook;Park, Gee Bae;Kim, Johng Kap
    • Korean Journal of Clinical Pharmacy
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    • v.1 no.1
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    • pp.9-14
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    • 1991
  • Inclusion complexes of piroxicam with $\alpha,\;\beta\;and\;\gamma- cyclodextrins$ were prepared and suspended to enhance the bioavailability of piroxicam. A quantitative analysis was employed HPLC for the determination of piroxicam in the rabbit serum after a single oral dose in suspension of piroxicam and each of inclusion complexes of piroxicam with $\alpha,\;\beta\;and\;\gamma- cyclodextrins$, respectively. The bioavailability and serum level of piroxicam exhibited the highest in piroxicam clathrated $\beta-cyclodextrin$ than both piroxicam and the other complexes administered. and the total area under the curve of serum concentration versus time for their inclusion complexes were larger than that of piroxicam.

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Development of a One-step Two-site Enzyme Immunoassay for Measuring Human Alpha-fetoprotein by Eliminating Hook-effect

  • Kim, Se-Ho
    • BMB Reports
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    • v.34 no.1
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    • pp.47-50
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    • 2001
  • A one-step, two-site enzyme immunoassay was developed for measuring human alpha-fetoprotein (AFP) in serum and amniotic fluid using monoclonal antibodies (McAb) by eliminating the high-dose hook effect. Three McAbs that recognize different epitopes were selected among 16 different clones on the basis of epitope mapping, two for immobilization and one for horseradish peroxidase conjugation. This one-step immunoassay system is more convenient and rapid compared to a conventional two-step sandwich immunoassay system. It did not exhibit the hook effect to around 2.7 mg/ml of AFP, which is probably one of the highest concentrations of AFP in the serum. The dose-response curve of the system was linear to 500 mg/ml of AFP and the system could differentiate as low as 1 mg/ml of AFP The intra- and inter-assay variations were in an acceptable range; 95~104% and 97~105% respectively Its correlation with other commercial systems was around 95%.

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Hypoglycemic Effect of the Methanol Extract of Soybean Sprout in Streptozotocin-Induced Diabetic Rats (Streptozotocin 유발 당뇨쥐에 있어서 콩나물 메탄올 추출물의 헐당강하효과)

  • 김정인;강민정;배세연
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.6
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    • pp.921-925
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    • 2003
  • To control blood glucose level as close to normal is the major goal of treatment of diabetes mellitus. $\alpha$-glucosidase is the enzyme to digest dietary carbohydrate and inhibition of $\alpha$-glucosidase could suppress postprandial hyperglycemia. The methanol extract of soybean sprout was tested for the inhibitory activities against $\alpha$-glucosidase in vitro. Soybean sprout extract inhibited yeast $\alpha$-glucosidase activity by 24.5% at the concentration of 5 mg/mL. The methanol extract of soybean sprout was subsequently subjected to sequential fractionation with hexane, ethyl acetate, butanol and water. Among the fractions tested ethyl acetate-soluble fraction showed relatively strong inhibition against $\alpha$-glucosidase by 36.3% at the concentration of 5 mg/mL. Acarbose, standard $\alpha$-glucosidase inhibitor, inhibited $\alpha$-glucosidase activity by 40.1%. The ability of soybean sprout extract to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. Starch solution (1 g/kg) with and without the methanol extract of soybean sprout (500 mg/kg) was administered to diabetic rats after an overnight-fast by gastric intubation. A single oral dose of soybean sprout extract inhibited the increase in blood glucose levels significantly at 60, 90, 120, 180 min (p<0.05) and decreased incremental response areas under the glycemic response curve significantly (p<0.05). These results suggest that soybean sprout might exert hypoglycemic effect by inhibiting $\alpha$-glucosidase activity.

Kinetics of Oil-Proof Agent Adsorption onto Cellulose Fibers

  • Zhu, Hongxiang;Honghu, Zeng;Wang, Shuangfei;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.5
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    • pp.59-65
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    • 2009
  • Adsorption of an oil-proof agent (OPA)onto cellulose fibers during the papermaking process was investigated using UV-Vis spectrophotometry by measuring the OPA concentration decrease in the solution. From the calibration curve, the spectrum were converted to chemical concentrations in solution, from which the amount adsorbed onto the fiber surface could be determined. Thus, it was possible to determine the total amount adsorbed onto the fibers and in solution. Using this approach, we studied the adsorption behavior of the OPA onto the fiber surface and derived its, ${\Gamma}^s_t={\Gamma}^s_{\infty}(1-e^{-k_{\alpha}t})$. The values of the parameters kaand ${\Gamma}^s_{\infty}$ were determined using a mathematic model based on a mass transfer equation. Ultimately, a complete was derived: $Q={\alpha}{\cdot}\sum\limits_{i-1}^m{\pi}d_il_i{\cdot}M_A{\cdot}(1-e^{-k_{\alpha}t})/A_N$.

Generation of Klobuchar Coefficients for Ionospheric Error Simulation

  • Lee, Chang-Moon;Park, Kwan-Dong;Ha, Ji-Hyun;Lee, Sang-Uk
    • Journal of Astronomy and Space Sciences
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    • v.27 no.2
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    • pp.117-122
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    • 2010
  • An ionospheric error simulation is needed for creating precise Global Positioning System (GPS) signal using GPS simulator. In this paper we developed Klobuchar coefficients n ${\alpha}_n$ and ${\beta}_n$ (n = 1, 2, 3, 4) generation algorithms for simulator and verified accuracy of the algorithm. The algorithm extract those Klobuchar coefficients from broadcast (BRDC) messages provided by International GNSS Service during three years from 2006 through 2008 and curve-fit them with sinusoidal and linear functions or constant. The generated coefficients from our developed algorithms are referred to as MODL coefficients, while those coefficients from BRDC messages are named as BRDC coefficients. The maximum correlation coefficient between MODL and BRDC coefficients was found for ${\alpha}_2$ and the value was 0.94. On the other hand, the minimum correlation was 0.64 for the case of ${\alpha}_1$. We estimated vertical total electron content using the Klobuchar model with MODL coefficients, and compared the result with those from the BRDC model and global ionosphere maps. As a result, the maximum RMS was 3.92 and 7.90 TECU, respectively.

The Thickness Determination of Silicone Resin on Zinc Electroplated Steels using Compton Scattering (Compton 산란선을 이용한 아연계 전기도금강판 표면의 Slicone Resin Film 두께측정)

  • Jae Chun So;Do Hyung Lee
    • Journal of the Korean Chemical Society
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    • v.35 no.5
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    • pp.539-544
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    • 1991
  • A method to determine the thickness of silicone resin film on zinc eletroplated steel using X-ray compton scattering was investigated. On the basis of the fact that compton scattering process predominates over photoelectric absorption for the light elements such as C, H, O and Si, the compton scattered line of RhK$_{\alpha}$ was used to determine the thickness of silicone resin. In this method, the standard calibration curve for thickness determination of silicone resin film was found to be linear in the range of 0.2~5.0 ${mu}$m film thickness. The analytical results agreed well with those obtained by the gravimetric method and the accuracy was found to be 0.22 ${mu}$m.

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Effects of Sasa Borealis Leaf Extract on the Glucose Tolerance of Major Foods for Carbohydrate (조릿대 잎 추출물이 탄수화물 급원 식품의 당 내성에 미치는 영향)

  • Yun, Eun-Kyoung;Heo, Young-Ran;Lim, Hyeon-Sook
    • Journal of Nutrition and Health
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    • v.43 no.3
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    • pp.215-223
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    • 2010
  • Sasa borealis leaf has been known to have anti-diabetic properties. In this study, we tried to evaluate the effects of Sasa borealis leaf extract (SBE) on the inhibition of $\alpha$-glucosidase activity and postprandial glycemic response following ingestion of four carbohydrate-rich foods; cooked rice, ramen (instant noodle), noodle, and bread. Fourteen healthy female adults consumed 50 g of glucose (control) or one of the four foods containing 50 g of available carbohydrate with or without 2,000 mg of SBE. The activity of $\alpha$-glucosidase was inhibited dose-dependently by SBE. With SBE, blood glucose concentration at 15 min and the positive area under the curve (AUC) of postprandial glycemic response at 15 min and 30 min after consuming each of the four foods were reduced significantly. As the result, total positive AUC during 120 min was decreased in case of taking cooked rice or bread. Glycemic index and glycemic load of the four foods were declined from 13% to 23% with SBE. The results of this study suggest that SBE may be effective for postprandial glucose control by inhibiting $\alpha$-glucosidase activity.

TGA열분석을 이용한 개질된 NR고무의 열화반응

  • An, Won-Sul;Park, Gi-Ho
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2008.11a
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    • pp.488-490
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    • 2008
  • 등온 및 비등온 TGA 열분석을 이용하여 TTSP를 이용하여 실험적으로 Shift factor(Acceleration factor) ${\alpha}_T$를 구하고 이로부터 마스터 커브 (master curve)를 도출할 수 있었고, 실험에 사용된 개질된 NR고무재료는 Arrhenius식을 잘 따르는 것이 확인되었으며, 이로부터 TTSP에 의한 촉진시험 결과의 신빙성을 확인할 수 있었다. 한편, 등온 TGA 실험으로부터 얻은 활성화에너지는 37.70 kJ/mol인 반면, 비등온 TGA로부터 Kissinger plot에 의해 얻은 활성화에너지는 166.20 kJ/mol이었는데, 이는 저온과 고온에서 서로 다른 분해기구에 의해 중량 감소가 일어나기 때문인 것으로 생각 되었다.

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The Program for Teaching on Type I error and Type II error

  • Choi, Hyun-Seok
    • 한국데이터정보과학회:학술대회논문집
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    • 2004.10a
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    • pp.17-23
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    • 2004
  • At the conclusion from the hypothesis testing, there is a possibility of making Type I error and Type II error. The purpose of this article is to use this program in statistics teaching through developing the program for studying on the concept about these two errors, two kinds of the probability of errors by the variation of rejection region, two kinds of the probability of errors by the variation of sample size, the relations of the probability $\alpha$ and $\beta$ by these two errors, and power function, power curve.

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Analysis of Empirical Failure Criteria and Suggestion of New Equation for Intact Rocks (경험적 파괴조건식의 해석과 새로운 수식의 제안)

  • Park, Chul-Whan
    • Tunnel and Underground Space
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    • v.6 no.3
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    • pp.234-238
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    • 1996
  • Three empirical criteria of rock failure are analyzed in order to understand the meaning of coefficients. Transformation of equations is discussed to apply in the numerical analysis. New failure criterion for intact rocks is proposed in this study, which can be used directly in programming. New equation has the form of parabolic curve($\alpha$=0.5~1.0), and is based on Mohr's shear failure using data from triaxial tests. Its validity will be discussed in the next report.

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