• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.134-137
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• 1977

The most efficient method for reducing the organic content of dilute liquid waste is by aerobic-biological treatment. Basically, the organisms responsible for treatment possess the ability to decompose complex organic compounds and to use the energy so liberated for their bodily functions: reproduction, growth, locomotion and so on. That part of organic matter used to produce energy is converted to the essentially stable end products of carbon dioxide, water and ammonia, while the remainder is converted to new cells which can be settled and thus removed from the liquid before the waste is discharged to the receiving body water. Oxygen must be supplied continuously during the aerobic process. In the field of sewage treatment the Warburg respirometer is used mainly for the measurement of the oxygen uptake of samples. In this experiment the Warburg constant volume respirometer was used to determine the oxygen uptake by bacteria in the presence of various glucose concentrations. The rate of oxygen uptake by the bacteria was expressed as the respiratory quotient. The result indicated that the oxygen uptake was proportional to the glucose concentration. The expecting equation of the regression line was Y=7.7+0.12X where Y: respiratory quotient, ${\mu}l.\;O_2$ taken up/mg. dry wt. bacterium/hr. X: concentration of glucose, mg/l

• Metals and materials international
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• v.24 no.6
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• pp.1232-1240
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• 2018

Corrosion properties of dissimilar friction stir welded 6061 aluminum and HT590 steel were investigated to understand effects of galvanic corrosion. As cathode when coupled, HT590 was cathodically protected. However, the passivation of AA6061 made the aluminum alloy cathode temporarily, which leaded to corrosion of HT590. From the EIS analysis showing Warburg diffusion plot in Nyquist plots, it can be inferred that the stable passivation layer was formed on AA6061. However, the weld as well as HT590 did not show Warburg diffusion plot in Nyquist plots, suggesting that there was no barrier for corrosion or even if it exists, the barrier had no function for preventing and/or retarding charge transport through the passivation layer. The open circuit potential measurements showed that the potential of the weld was similar to that of HT590, which lied in the pitting region for AA6061, making the aluminum alloy part of the weld keep corrosion state. That resulted in the cracked oxide film on AA6061 of the weld, which could not play a role of corrosion barrier.

• BMB Reports
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• v.56 no.11
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• pp.618-623
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• 2023

Most cancer cells utilize glucose at a high rate to produce energy and precursors for the biosynthesis of macromolecules such as lipids, proteins, and nucleic acids. This phenomenon is called the Warburg effect or aerobic glycolysis- this distinct characteristic is an attractive target for developing anticancer drugs. Here, we found that Phosphofructokinase-1 (PFK-1) is a substrate of the Protein Phosphatase 4 catalytic subunit (PP4C)/PP4 regulatory subunit 1 (PP4R1) complex by using immunoprecipitation and in vitro assay. While manipulation of PP4C/PP4R1 does not have a critical impact on PFK-1 expression, the absence of the PP4C/PP4R1 complex increases PFK-1 activity. Although PP4C depletion or overexpression does not cause a dramatic change in the overall glycolytic rate, PP4R1 depletion induces a considerable increase in both basal and compensatory glycolytic rates, as well as the oxygen consumption rate, indicating oxidative phosphorylation. Collectively, the PP4C/PP4R1 complex regulates PFK-1 activity by reversing its phosphorylation and is a promising candidate for treating glycolytic disorders and cancers. Targeting PP4R1 could be a more efficient and safer strategy to avoid pleiotropic effects than targeting PP4C directly.

• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.131-135
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• 2000

In order to investigate the origin of capacity fading with charge/discharge cycling in $LiMn_2O_4$ thin film battery, impedance studies have been performed with increasing cycling in $LiMn_2O_4/1M\;LiClO_4-PC/Li$ cells. The fitted values obtained from impedance data show good agreements with the experimental results. Especially, the element of charge transfer resistance of $LiMn_2O_4/liquid$ electrolyte interface initially increased, and then saturated with increasing the charge/discharge cycles, which could explain the cause of initial abrupt capacity fading of $LiMn_2O_4$ thin film with cycling due to interfacial reaction. The steady capacity fading is caused by the increasing of Warburg resistance. The chemical diffusion coefficient of Li ions decreased from $5.15\times10^{-11}cm^2/sec$ at 1st cycles to $6.3\times10^{-12}cm^2/sec$ at 800th cycles, which attributed to the Jahn-Teller distortion/Mn dissolution which diminishes tetra hedral sites necessary for Li diffusion in $LiMn_2O_4$.

• Journal of Life Science
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• v.28 no.12
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• pp.1469-1476
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• 2018

Occurrence of the Warburg effect in solid tumors causes resistance to cancer chemotherapy, and targeting energy metabolisms such as aerobic glycolysis is a potential strategy for alternative treatment. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), shifts glucose metabolism from aerobic glycolysis to oxidative phosphorylation (OxPhos) in many cancers. In this study, we investigated the anticancer effect of DCA on a human anaplastic thyroid cancer (ATC) cell line, 8505C. We found that DCA selectively inhibits cell proliferation of the 8505C line but not of a normal thyroid line. In 8505C, the cell cycle was arrested at the G1/S phase with DCA treatment as a result of decreased antiapoptotic proteins such as $HIF1{\alpha}$, PDK1, and Bcl-2 and increased proapoptotic proteins such as Bax and p21. DCA treatment enhanced the production of reactive oxygen species which consequently induced cell cycle arrest and apoptosis. Interestingly, DCA treatment not only reduced lactate production but also increased the expression of sodium-iodine symporter, indicating that it restores the OxPhos of glucose metabolism and the iodine metabolism of the ATC. Taken together, our findings suggest that PDK inhibitors such as DCA could be useful anticancer drugs for the treatment of ATC and may also be helpful in combination with chemotherapy and radiotherapy.

• YAKHAK HOEJI
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• v.25 no.2
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• pp.75-81
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• 1981

Polypenol oxidase activity in the petals of Chysanthemum indicum var. indica Max. (f.sin-dong-a) and the leaves of Artemisia vulgaris var. indica Max was estimated by means of Warburg's manometric method. The browning reaction in owing to the oxidation of chlorogenic acid with polyphenol oxidase.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.664-671
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• 1998

Poly pyrrole polymer(ppy) has an excellent electrical conductivity and can be easily polymerized on anode to give various morophology according to doped anion on electroactive sites. To improve the properties of brittleness, ageing and hydrophobisity, poly furan polymer(pfu) having a high initiation potential was anodically implanted in this porous ppy film matrix to get the Pt/ppy/pfu(x)type of polymer composite electrode. Cyclic voltammetry and electrochemical impedance methods were used to these electrode, where $PF_6^-,\; BF_4^-$, and $ClO_4^-$ ions were employed as dopants. The composition of the pfu(x) at the electrode was changed from 0 to 1.10, but the range was useful only at 0.1 to 0.2 as the redox electrode. The polymer composite electrode doped with $PF_6^-$ was better in charge transfer resistance by a factor of 40 times and in double layer capacitance by a factor of 20 times than others. The charge transfer in the polymer film of the electrode was influenced on frequency change and equivalent circuit of this electrode had Warburg impedance including mass transfer.

• The Korean Journal of Zoology
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• v.12 no.2
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• pp.60-66
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• 1969

Changes in the protein concentration in the hemolymph and the oxidation of respiratory substrates at various developmental stages in cabbage worm, Pieris rapae Linne were measured using Biuret method and Warburg manometric method, respectively. The results are summarized as follows: 1. The hemolymph protein contentration decreased gradually until the six-day pupa and increased thereafter. In the fifth larval instar the concentration reached a maximum and was about two times the value for the six-day pupa. 2. Endogenous respiration was very high at the prepupal stage, decreasing at two-day pupa, followed by an increase at the late pupal stage. 3. Glucose showed the marked activity throughout the whole stages, and had the striking influence on both the prepupal and adult stages. 4. The changes in protein concentration and the rate of oxygen consumption exhibited a general pattern of U-shaped curve through the process of life cycle according to histogenesis of the adult organ and histolysis of the larval organ.

• Corrosion Science and Technology
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• v.2 no.6
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• pp.289-295
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• 2003

The corrosion behavior of Cr-N coated steels with different phases (${\alpha}-Cr$, CrN and $Cr_2N$) deposited by cathodic arc deposition on Hl3 steel was investigated in 3.5% NaCl solution at ambient temperature. Potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were the techniques applied to characterize the corrosion behavior. It was found that the CrN coating had a lower current density from potentiodynamic polarization test than others. The porosity, corresponding to the ratio of the polarization resistance of the uncoated and the coated substrate, was higher in the $Cr_2N$ coating than in the other Cr-N coated steels. EIS measurements showed, for the most of Cr-N coated steels, that the Bode plot presented two time constants. Also, the $Cr_2N$ coating represents the characteristic of Warburg behavior after 72hr of immersion. The coating morphologies were examined in planar view and cross-section by SEM analyses and the results were compared with those of the electrochemical measurement. The CrN coating had a dense, columnar grain-sized microstructure with minor intergranular porosity. From the above results, the CrN coating provided a better corrosion protection than the other Cr-N coated steels.

• The Journal of the Korean Society for Microbiology
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• v.5 no.1
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• pp.33-39
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• 1970

정상혈청과 면역혈청의 존재하에 있어서 균의 생존율이 호흡율과 어떠한 관계가 있는가 Brucella 균을 사용하여 실험해보았다. 혈청의 원액에 균을 $37^{\circ}C$ 3시간 방치했다가 흔히 쓰는 평판주입법에 의하여 생존균수를 측정했고, 균호흡은 Warburg 장치를 사용하여 측정했다. 그 결과를 요약하면 다음과 같다. 혈청의 살균작용과 균호흡억제작용 간에는 극히 대조적인 현상을 엿볼 수 있었는데, 그것은 균호흡이 억제되면 될 수록 생존균수는 그만큼 증가되었다는 사실이다. Brucella 면역혈청의 살균계수가 $1.4{\sim}1.6$이었는데 반해 정상혈청은 2.7나 되었으며, 그 차는 무려 $log_{10}$ 일단위 이상이나 되었다. 그러나 면역혈청내에서의 균호흡율은 정상혈청중에서의 호흡율의 반도 안되었다. 면역체가 보체와 더불어 이러한 호흡억제 작용을 나타낸 것 같으며 이렇게 호흡이 억제된 상태에 있는 균은 혈청의 살균인자에 보다 무감각한 것 같다. 즉 in vitro에서 Brucella 면역체는 어느 일정량 이상 존재하면 균호흡을 억제하고 동시에 혈청의 살균인자로부터 균을 보호해 준 역할을 한다고 볼 수 있다.