• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.2
• /
• pp.345-352
• /
• 2017

In this paper, a unified potentiostat which can measure the current of both $O_2$-based and $H_2O_2$-based blood glucose sensors with low supply voltage of 1.0V has been designed and verified by simulations and measurements. Potentiostat is composed of low-voltage operational transconductance amplifier, cascode current mirrors and mode-selection circuits. It can measure currents of blood glucose chemical reactions occurred by $O_2$ or $H_2O_2$. The body of PMOS input differentional stage of the operational transconductance amplifier is forward-biased to reduce the threshold voltage for low supply voltage operation. Also, cascode current mirror is used to reduce current measurement error generated by channel length modulation effects. The proposed low-voltage potentiostat is designed and simulated using Cadence SPECTRE and fabricated in Magnachip 0.18um CMOS technology with chip size of $110{\mu}m{\times}60{\mu}m$. The measurement results show that consumption current is maximum $46{\mu}A$ at supply voltage of 1.0V. Using the persian potassium($K_3Fe(CN)_6$) equivalent to glucose, the operation of the fabricated potentiostat was confirmed.

• YAKHAK HOEJI
• /
• v.29 no.3
• /
• pp.117-123
• /
• 1985

A clorimetric determination method of pyruvic acid using hydroxylamine was studied. Hydroxylamine was reacted with pyruvic acid to form complex compound in the presence of Cu(II) ion. Optimal conditions for the quantitative analysis were investigated and the structure of complex was examined spectrometrically. The molar ratio (2:1) and the stability constant ($1.88{\times}10^{4}$) of the complex were measured. It was the characteristic feature of this method that the commonly encountered interfering substances such as fructose, glucose and lactic acid do not infuence the measurement of pyruvic acid.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.250-251
• /
• 2002

혈당의 비침습적인 측정의 필요성은 잦은 채혈로 인한 감염의 우려, 필요할 때마다 채혈의 고통 없이 혈당을 측정할 수 있다는 장점 때문에 지난 20여 년 동안 활발히 연구되어 왔다. 근적외선 및 원적외선 흡수분광법, 라만분광법, Polarization rotation 또는 Stimulated Raman 측정법, 온도측정법, 통계적 분석법, 전처리연구 등 많은 분야에서 접근하고 있지만 아직까지는 in vivo 측정에 성공하고 있지 못하고 있다 [1]. (중략)

• 대한핵의학회:학술대회논문집
• /
• 1970.10a
• /
• pp.95.1-95.1
• /
• 1970

• Bulletin of the Korean Chemical Society
• /
• v.34 no.5
• /
• pp.1571-1574
• /
• 2013

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1179-1182
• /
• 2005

To facilitate the cell based robot research, we presented a micro-mechanical force measurement system for the biological muscle actuators, which utilize glucose as a power source for potential application in a human body or blood vessels. The system is composed of a micro-manipulator, a force transducer with a glass probe, a signal processor, an inverted microscope and video recoding system. Using this measurement system, the contractile force and frequency of the cardiac myocytes were measured in real time and the magnitude of the contractile force of each cardiac myocyte on a different condition was compared. From the quantitative experimental results, we estimated that the force of cardiac myocytes is about $20{\sim}40\;{\mu}$N, and showed that there is difference between the control cells and the micro-patterned cells.

• Bulletin of the Korean Chemical Society
• /
• v.13 no.2
• /
• pp.145-148
• /
• 1992

A microbial sensor for BOD (Biochemical Oxygen Demand) measurement has been developed by immobilizing Hansenula anomala in a polyacrylamide gel. The optimum pH and temperature for BOD measurement using this sensor were pH 7.0 and $30^{\circ}C$, respectively. The response time was 30 min. A linear relationship was observed between the potential and the concentration below 44 ppm BOD. The potential was reproducible within ${\pm}9%$ of the relative error when a sample solution containing 20 mg/l of glucose and 20 mg/l of glutamic acid was employed. The effect of various compounds on BOD estimation was also examined. The potential output of the sensor was almost constant for 30 days. The relative error in BOD estimation was within ${\pm}10%$.

• Journal of the Korean Applied Science and Technology
• /
• v.39 no.1
• /
• pp.52-62
• /
• 2022

The purpose of this study was to find a way to improve the stability and quality of urinalysis by checking the changes in the measurement values of representative clinical chemistry test items according to the repeated freezing and thawing before the urine test and the thawing process. All subjects were 10 healthy males, and the freeze and thaw stability test was performed using their urine samples. In the case of micro-albumin and amylase, there was no statistical significance at 37℃ with time, but at 42℃ and 60℃, there was a statistically significant change in the results with time. There were statistically significant changes in BUN, creatinine, uric acid, and glucose. As a result of long-term stability, after 7 days, glucose mutation increased and amylase decreased at 60℃. In the case of glucose and amylase, there was a statistically significant change in the results over time. To obtain accurate test results, accurate standardization of urinalysis including appropriate collection, storage, and storage methods of urine samples is required and systematic study of conditions for securing stability for each biomaterial is required.

• Journal of Acupuncture Research
• /
• v.24 no.3
• /
• pp.81-97
• /
• 2007

Objectives: The purpose of this study is to investigate the anti-oxidative effect of electroacupuncture at Kokchi($LI_{11}$) in rats. Methods: A study administer AAPH to the abdominal cavity of rats and stimulate Kokchi($LI_{11}$) of the rat that lead to oxidative stress by electropuncture. And the study survey serum albumin, total bilirubin, LDL-cholesterol, LDH, Glucose, GOT, GPT and measure SOD activity, GSH concentration, catalase activity, NO concentration, MDA concentration. Results: 1. At the analysis of blood chemistry Albumin and Glucose significantly increase at $LI_{11}$-NR group, $LI_{11}$-EA group than at control group and holder group. LDL cholesterol, GOT, GPT decrease meaningfully. 2. As results of measurement at liver, SOD, Catalase represnet significantly increase at $LI_{11}$-NR group and $LI_{11}$-EA group than at control group and holder group. 3. Glutathione has some increases at the $LI_{11}$-NR group and $LI_{11}$-EA group than at the control group and the holder group. 4. As a result of measurement of NO and MDA's content, the content of NO decrease at the $LI_{11}$-NR group than at the control group. That reduces more meaningfully at the $LI_{11}$-EA group than at the control group. MDA has a significant decrease at the $LI_{11}$-NR group and the $LI_{11}$-EA group. 5. At the histological analysis, the study confirm that the density of intracellular cytoplasm in the liver tissue decreases at the control group as compared with the Normal group and the size of cell increases. Conclusions : These results suppose that electroacupuncture at $LI_{11}$ has an anti-oxidant effect in human.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.2
• /
• pp.204-211
• /
• 2011

To yield high concentrations of protein expressed by genetically modified Escherichia coli, it is important that the bacterial strains are cultivated to high cell density in industrial bioprocesses. Since the expressed target protein is mostly accumulated inside the E. coli cells, the cellular product formation can be directly correlated to the bacterial biomass concentration. The typical way to determine this concentration is to sample offline. Such manual sampling, however, wastes time and is not efficient for acquiring direct feedback to control a fedbatch fermentation. An E. coli K12-derived strain was cultivated to high cell density in a pressurized stirred bioreactor on a pilot scale, by detecting biomass concentration online using a capacitance probe. This E. coli strain was grown in pure minimal medium using two carbon sources (glucose and glycerol). By applying exponential feeding profiles corresponding to a constant specific growth rate, the E. coli culture grew under carbon-limited conditions to minimize overflow metabolites. A high linearity was found between capacitance and biomass concentration, whereby up to 85 g/L dry cell weight was measured. To validate the viability of the culture, the oxygen transfer rate (OTR) was determined online, yielding maximum values of 0.69 mol/l/h and 0.98mol/l/h by using glucose and glycerol as carbon sources, respectively. Consequently, online monitoring of biomass using a capacitance probe provides direct and fast information about the viable E. coli biomass generated under aerobic fermentation conditions at elevated headspace pressures.