• 제목/요약/키워드: Glucose

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Polypyrrole-Glucose oxidase 효소전극의 Ethanol 첨가효과 (An Effect of Ethanol on Polypyrrole-Glucose Oxidase Enzyme Electrode)

  • 김현철;구할본;사공건
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.147-150
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    • 1999
  • In the case of immobilizing of glucose oxidase in organic polymer using electrosynthesis, the glucose oxidase obstructs charge transfer and mass transport during the film growth. This may lead to short chained polymer and/or make charge-coupling weak between the glucose oxidase and the backbone of the polymer. That is mainly due to insulating property and net chain of the glucose oxidase. Since being the case, it is useless to increase in amount of glucose oxidase more than reasonable in the synthetic solution. We establish qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. As ethanol was added by 0.1 rnol dm" in the synthetic solution, Michaelis-Menten constants of the resulting enzyme electrode decreased from 30.7 mmol $dm^{-3}$ to about 2 mmol $dm^{-3}$. That suggests increase in affinity of the enzyme electrode for glucose and in amount of the immobilized enzyme.zyme.

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Glucose Diffusion Limiting Membrane Based on Polyethyleneimine (PEI) Hydrogel for the Stabilization of Glucose Sensor

  • Kim, Suk-Joon;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • 제12권2호
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    • pp.225-229
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    • 2021
  • Commercially available continuous glucose sensors require the operation stability for more than two weeks. Typically, the sensor comprises a sensing layer and an over-coating layer for the stable operation inside the body. In the sensing layer, enzymes and mediators are cross-linked together for the effective sensing of the glucose. The over-coating layer limits the flux of glucose and works as a biocompatible layer to the body fluids. Here, we report the simple preparation of the flux-limiting layer by the condensation of polyethyleneimine (PEI), tri-epoxide linker, and trimethylolpropane triglycidyl ether (PTGE). The sensor is constructed by a layer-by-layer drop-coating of the sensing layer containing glucose dehydrogenase and the PEI-derived blocking layer. It is stable for more than 14 days, which is enough for the sensor in the continuous monitor glucose monitoring (CGM) system.

헤마토크릿 영향을 최소화한 종이 혈당센서 개발 (Development of Paper Blood Glucose Sensor with Minimal Hematocrit Effect)

  • 이영태
    • 반도체디스플레이기술학회지
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    • 제21권4호
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    • pp.116-120
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    • 2022
  • In this paper, we developed a paper blood glucose sensor that can minimize the effect of hematocrit. The paper blood glucose sensor has the advantage of being very simple in its production process as it is manufactured with only three printing processes on the top of the paper substrate. This glucose sensor consists of a total of six electrodes, including blood glucose measurement electrodes, hematocrit measurement electrodes, strip detection electrodes, and blood detection electrodes. A paper blood glucose sensor measures hematocrit with electrodes formed on the same sensor substrate when measuring blood glucose concentration, and compensates for the effect of hematocrit in real time to enable accurate blood glucose measurement.

신생아 구강분비물의 당과 pH 및 영향 요인 탐색 (Glucose and pH of Oral Secretions in Newborns)

  • 김남희;안영미
    • Child Health Nursing Research
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    • 제23권3호
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    • pp.353-363
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    • 2017
  • Purpose: Oral glucose and pH are known as critical indicators for the growth of microorganism inside the oral cavity. This study was performed to identify oral glucose and pH variances in the early postnatal days of newborns. Methods: An explorative study which included 67 newborns was conducted to measure the oral glucose and pH during the first three days of life. Oral secretions were collected every 8 hours for three days or 6 to 9 times immediately after birth up to discharge. Oral glucose and pH variances during the three days were analyzed using the SPSS 22.0. Results: Oral glucose was $30.66{\pm}22.01mg/dl$ at birth then increased to $54.77{\pm}27.96mg/dl$ at the third day of life (F=8.04, p<.001) while oral pH decreased from $7.35{\pm}0.36$ to $5.53{\pm}0.39$ during the three days (F=113.35, p<.001). Oral glucose and pH were related to gestational age, regurgitation, and maternal diabetic mellitus. A negative correlation was found between oral glucose and pH (r=-.34, p<.001). Conclusion: Oral glucose and pH can be utilized for oral health assessment in newborns. Further study is needed to explore the factors which influence oral glucose and pH in high-risk newborns.

Investigation of the Nature of the Endogenous Glucose Transporter(s) in Insect Cells

  • Lee, Chong-Kee
    • BMB Reports
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    • 제32권5호
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    • pp.429-435
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    • 1999
  • Unlike the mammalian glucose transporter GLUT1, little is known about the nature of the endogenous sugar transporter(s) in insect cells. In order to establish the transport characteristics and other properties of the sugar transport proteins of Sf9 cells, a series of kinetic analyses was performed. A saturable transport system for hexose uptake has been revealed in the insect cells. The apparent affinity of this transport system(s) for 2-deoxy-D-glucose was relatively high, the $K_m$ for uptake being <0.5 mM. To further investigate the substrate and inhibitor recognition properties of the insect cell transporter, the ability of other sugars or drugs to inhibit 2-deoxy-D-glucose transport was examined by measuring inhibition constants ($K_j$). Transport was inhibited by D-mannose, D-glucose, and D-fructose. However, the apparent affinity of the C-4 epimer, D-galactose, for the Spodoptera transporter was relatively low, implying that the hydroxyl group at the C-4 position may play a role in the strong binding of glucose and mannose to the transporter. The results also showed that transport was stereoselective, being inhibited by D-glucose but not by L-glucose. It is therefore concluded that insect cells contain an endogenous glucose transport activity that in several aspects resembles the human erythrocyte glucose transporter. However, the mammalian and insect transporters were different in some of their kinetic properties, namely, their affinities for fructose and for cytochalasin B.

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Prediction of Glucose Concentration in a Glucose-Lactose Mixture Based on the Reflective Optical Power at Dual Probe Wavelengths

  • Gao, Song;Yue, Wenjing;Lee, Sang-Shin
    • Journal of the Optical Society of Korea
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    • 제20권1호
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    • pp.199-203
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    • 2016
  • An enzyme-free optical method is proposed for estimating high concentrations of glucose in a glucose-lactose mixture, based on a predictive equation that takes advantage of the reflective optical power observed at two discrete wavelengths. Compared to the conventional absorption spectroscopy method based on Beer's Law, which is mainly valid for concentrations below hundreds of mg/dL, the proposed scheme, which relies on reflection signals, can be applied to measure higher glucose concentrations, of even several g/dL in a glucose-lactose mixture. Two probe wavelengths of 1160 and 1300 nm were selected to provide a linear relationship between the reflective power and pure glucose/lactose concentration, where the relevant linear coefficients were derived to complete the predictive equation. Glucose concentrations from 2 to 7 g/dL in a glucose-lactose mixture were efficiently estimated, using the established predictive equation based on monitored reflective powers. The standard error of prediction was 1.17 g/dL.

Polypyrrole-Glucose Oxidase 효소전극에 대한 효소 고정화의 정성적 평가 (Qualitative Analyses of Porypyrrole-Glucose Oxidase Enzyme Electrode for Immobilization)

  • 김현철;구할본;사공건
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.984-986
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    • 1999
  • In the case of immobilizing of glucose oxidase in organic polymer using electrosynthesis, the glucose oxidase obstructs charge transfer and mass transport during the film growth. This may lead to short chained polymer and make charge-coupling weak between the glucose oxidase and the backbone of the polymer. That is mainly due to insulating property and net chain of the glucose oxidase. Such being the case, it is useless to increase in amount of glucose oxidase more than reasonable in the synthetic solution. We establish by means of qualitative analysis that amount of immobilized glucose oxidase can be improved by adding a hole ethyl alcohol in the synthetic solution. As ethyl alcohol was added by 0.1mol $dm^{-3}$ in the synthetic solution, the faradic impedance of resultant electrode was increased about five times as much as the case of ethyl alcohol free in the solution, and mass transport was limited more than over. That is due to insulating property and net chain of the glucose oxidase. Moreover, in ultraviolet spectra of the synthetic solution, the adsorption peak at 285nm corresponding to glucose oxidase was decreased. It suggests increase in amount of immobilized glucose oxidase.

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심혈관 수술 신생아의 혈당수준에 따른 환아 결과 (Patient Outcomes according to Blood Glucose Level in Neonates with Cardiovascular Surgery)

  • 황정혜;박형숙
    • Child Health Nursing Research
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    • 제18권1호
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    • pp.43-52
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    • 2012
  • Purpose: The purpose of this study was to provide basic data for suitable neonate blood glucose maintenance by investigating and analyzing the blood glucose level of post cardiovascular surgery neonates in the ICU for the effect of blood glucose levels on the following outcomes; ICU stay, hospital stay, mechanical ventilation time, morbidity, and mortality. Methods: The participants were 143 neonates in the ICU after having had cardiovascular surgery. The design for this study was an investigation of the blood glucose levels of the neonates and retrospective analysis of patient outcomes according to blood glucose level. Results: The results for the neonate groups showed that the factors of hospital stay, ICU stay, mechanical ventilation time and mortality, for the group with a blood glucose level over 140 mg/dL were longer and higher than for the group with blood glucose of less than 100 mg/dL or the group between 100-139 mg/dL. Conclusion: The results of this study indicate that when caring for neonates after cardiovascular surgery, it is important to recognize the influence of blood glucose levels on patient outcomes like hospital days, ICU stay, length of time on mechanical ventilation and mortality. Further, care guidelines for neonates' glucose level management need to be developed.

갈락토스-글루코스 혼합당 수소 발효 (Hydrogen Fermentation of the Galactose-Glucose Mixture)

  • 천효창;김상현
    • 한국수소및신에너지학회논문집
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    • 제23권4호
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    • pp.397-403
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    • 2012
  • Galactose, an isomer of glucose with an opposite hydroxyl group at the 4-carbon, is a major fermentable sugar in various promising feedstock for hydrogen production including red algal biomass. In this study, hydrogen production characteristics of galactose-glucose mixture were investigated using batch fermentation experiments with heat-treated digester sludge as inoclua. Galactose showed a hydogen yield compatible with glucose. However, more complicated metabolic steps for galactose utilization caused a slower hydrogen production rate. The existence of glucose aggravated the hydrogen production rate, which would result from the regulation of galactose-utilizing enzymes by glucose. Hydrogen produciton rate at galactose to glucose ratio of 8:2 or 6:4 was 67% of the production rate for galactose and 33% for glucose, which could need approximately 1.5 and 3 times longer hydraulic retention time than galacgtose only condition and glucose only condition, respectively, in continuous fermentation. Hydrogen production rate, Hydrogen yield, and organic acid production at galactose to glucose ratio of 8:2 or 6:4 were 0.14 mL H2/mL/hr, 0.78 mol $H_2$/mol sugar, and 11.89 g COD/L, respectively. Galactose-rich biomass could be usable for hydogen fermenation, however, the fermentation time should be allowed enough.

Association Analysis between Genes' Variants for Regulating Mitochondrial Dynamics and Fasting Blood Glucose Level

  • Jung, Dongju;Jin, Hyun-Seok
    • 대한의생명과학회지
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    • 제22권3호
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    • pp.107-114
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    • 2016
  • Maintenance of fasting blood glucose levels is important for glucose homeostasis. Disruption of feedback mechanisms are a major reason for elevations of glucose level in blood, which is a risk factor for type 2 diabetes mellitus that is mainly caused by malfunction of pancreatic beta-cell and insulin. The fasting blood glucose level has been known to be influenced by genetic and environmental factors. Mitochondria have many functions for cell survival and death: glucose metabolism, fatty acid oxidation, ATP generation, reactive oxygen species (ROS) metabolism, calcium handling, and apoptosis regulation. In addition to these functions, mitochondria change their morphology dynamically in response to multiple signals resulting in fusion and fission. In this study, we aimed to examine association between fasting blood glucose levels and variants of the genes that are reported to have functions in mitochondrial dynamics, fusion and fission, using a cohort study. A total 416 SNPs from 36 mitochondrial dynamics genes were selected to analyze the quantitative association with fasting glucose level. Among the 416 SNPs, 4 SNPs of PRKACB, 13 SNPs of PPP3CA, 6 SNPs of PARK2, and 3 SNPs of GDAP1 were significantly associated. In this study, we were able to confirm an association of mitochondrial dynamics genes with glucose levels. To our knowledge our study is the first to identify specific SNPs related to fasting blood glucose level.