• BMB Reports
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• v.50 no.4
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• pp.214-219
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• 2017

Mitochondria play pivotal roles in the ATP production, apoptosis and generation of reactive oxygen species. Although dynamic regulation of mitochondria morphology is a critical step to maintain cellular homeostasis, the regulatory mechanisms are not yet fully elucidated. In this study, we identified miR-200a-3p as a novel regulator of mitochondrial dynamics by targeting mitochondrial fission factor (MFF). We demonstrated that the ectopic expression of miR-200a-3p enhanced mitochondrial elongation, mitochondrial ATP synthesis, mitochondrial membrane potential and oxygen consumption rate. These results indicate that miR-200a-3p positively regulates mitochondrial elongation by downregulating MFF expression.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.266-269
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• 1995

In order to measure alcohol contents with speed and accuracy, alcohol sensor was prepared. Alcohol sensor was made by connecting with oxygen electrode after immobilized alcohol oxidase on nylon net with glutaraldehyde. Alcohol was determined by changing the rate of dissolved oxygen consumption using D.O. analyzer. Alcohol contents in alcoholic beverages were determined under the optimum conditions. The results were 0.71% in low-alcohol beverage, $4{\sim}5%$ in beers, 10.06% in wine, 16.12% in chungju, 25.71% in soju, and 6.18% in takju, respectively. The values by alcohol sensor showed an excellent correlation(r=0.999) with GC method.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.275-284
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• 2017

Purpose: This study was performed to evaluate the effects of sannamul or herb extract addition to a soybean oil-in-water emulsion during photooxidation in the presence of chlorophyll. Methods: The emulsion mainly consisted of purified soybean oil and citric acid buffer (pH 4.0) at a weight ratio of 4 to 6, with chlorophyll a addition at 6 mg/kg. Ethanol extract of daraesoon, samnamul, basil, or peppermint was selectively added to the emulsion at 400 mg/kg, and emulsions in glass serum bottles were oxidized at $5^{\circ}C$ under 2,600 lux light for 48 hours. Lipid oxidation of the emulsions was evaluated based on determination of headspace oxygen content, peroxide value, and p-anisidine value. Pigments and antioxidants were also monitored. Results: The emulsion with added samnamul extract with high contents of polyphenols and low chlorophyll content showed lower oxygen consumption, peroxide values, and p-anisidine values, whereas basil and peppermint extracts with high chlorophyll contents increased photooxidation. Chlorophylls were degraded during photooxidation of the emulsions, and the degradation rate was highest in the emulsion with added samnamul extract. Conclusion: The high antioxidant activity of samnamul extract in the photooxidation of soybean oil-in-water emulsion could be due to low chlorophyll content, high concentrations of polyphenol compounds in the extract, as well as rapid degradation of chlorophylls during oxidation.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.446-453
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• 2000

The closed cycle diesel system is operated in closed circuit system where there is non air breathing with working fluid consisted of the combination of oxygen, argon and recycled exhaust gas for obtaining underwater or underground power sources. this study has been carried out to analysis the performance of closed cycle system by means of investigation on the combustion characteristics of diesel engine MTU8V183TE52 operating in open, semi-closed, and closed cycle modes. The combustion in closed mode starts a little bit earlier than in open cycle mode. The oxygen concentration and fuel consumption at 240kW closed cycle running are 21∼24% by volume and 77∼79kg/h, respectively. The maximum cylinder pressure and ignition delay time are investigated 110bar and 8.9degree. Also, The combustion simulation program has been studied to predict whether or not combustion. The results from numerical prediction for the basic, cylinder averaged quantities such as the cylinder pressure and the heat release showed excellent with the experimental data.

• Journal of Chest Surgery
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• v.16 no.3
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• pp.272-280
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• 1983

With respect to controversial opinions concerning the nitroglycerin effects on cardiac muscle the direct nitroglycerin actions were thoroughly studied in isolated papillary muscles, atrial preparations and coronary strips of rabbits. Isometric active tension of papillary muscles developed at $35^{\circ}C$ upon electric stimulation at a rate of 60/min, was not affected by nitroglycerin up to a concentration of 10mg/L Higher concentrations of nitroglycerin, however, reduced action tension progressively. This depression of mechanical activity is accompanied by a decrease in oxygen consumption as measured by means of a flow respirometer. Resting oxygen uptake, on the other hand, remained unchanged. Similarly active tension of spontaneously beating atrial preparations also declined at a nitroglycerin concentration of more than 10 mg/L, whereas the sinus frequency did not change up to 40 mg/L. In contrast, rabbit coronary strips are much more sensitive to nitroglycerin and relax in a range of 10-100 ug/L of nitroglycerin concentration. The results indicate that the pharmacologic effects of nitroglycerin in coronary disease are due to vascular actions, because the plasma levels of nitroglycerin attainable in human therapy are not sufficiently high to directly influence the myocardium.

• KSBB Journal
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• v.10 no.1
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• pp.78-88
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• 1995

The encapsulatpd A. niger grew up inside the capsule and mycelia penetrated through the pore of the capsule membrane. The mycelia on the capsule wall became loose when the carbon source and oxygen were deficient in the medium. On the contrary, the production rate increased and mycelia made a lump tightly when the carbon source and oxygen were sufficient. Namely, number of proper capsule of unit volume in the medium was existed. The phenomenon which was swelled of capsule membrane in cultivation could prevented by adding CaCl2 into the medium. According to the time adding CaCl2 into the medium, the production rate of citric acid was influenced. In case of adding CaCl2 into the medium at 7th day cultivation, the production yield of citric acid was increased about 40 percent higher than that of adding CaCl2 initially. The production yield of citric acid using encapsulated A. niger of flask culture was influenced with oxygen supply. The production yield of citric acid ($\Delta$p/$\Delta$s) of the flask culture was increased 3.88 time by using T-flask instead of parafilm sealed flask. Therefore, the productivity and consumption rate concerning production which was taken carbon source were increased when oxygen supply was sufficient. The production of citric acid using encapsulated A. niger was increased average 30 percent higher than that of bead in between 6th and 13th day cultivation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.31-37
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• 2005

To find out temporal variations of net photosynthetic rate (NPR) of intertidal flats, we measured oxygen microprofiles in sediments with oxygen microsensors 4 times from December 2003 to June 2004. The study areas were the intertidial flats in Janghwa-ri and Dongmak-ri, located on the southwestern and the southern parts of Ganghwa-gun, respectively, and in Incheon North Harbor where the content of organic matter was relatively high. During the investigation, oxygen penetration depths in the tidal flats of Janghwa-ri and Dongmak-ri were high in December (mean values of 4.0-4.1 mm). Thereafter, the oxygen penetration depths declined to mean values of 2.2-2.8 mm and 1.6-1.8 mm in the two tidal flats. Interestingly, the oxygen penetration depths in the Incheon North Harbor tidal flat showed a lower range $(0.8{\pm}0.3\;mm;\;mean{\pm}1SD)$ over the period. The maximum NPR in the Dongmak-ri tidal flat was found in March $(11.1{\pm}2.8\;mmol\;O_2\;m^{-2}\;h^{-1})$, and those In Janghwa-ri $(6.1{\pm}4.1\;mmol\;O_2\;m^{-2}\;h^{-1})$ and Incheon North Harbor $(6.4{\pm}1.4\;mmol\;O_2\;m^{-2}\;h^{-1})$ were observed in May. During the period when NPR was most active, the highest oxygen concentration was found at 0.1-0.5 mm depth below the surface sediment, and was on average 1.8-3.2 times higher than the air-saturated oxygen concentration in the overlying seawater. Although we took into account of low in situ light intensity $(400{\mu}Einst\;m^{-2}\;s^{-1})$ during the investigation in June, NPR in the 3 study areas decreased significantly to less than $0.2\;mmol\;O_2\;m^{-2}\;h^{-1})$. Thus, temporal variations of NPR were somewhat different among the tidal flats. Generally, benthic primary producers inhabiting in the uppermost 0.5 mm of the sediment showed a peak photosynthetic activity in the study areas in spring. This is the first domestic report on photosynthetic rates of benthic microflora in the tidal flats with oxygen microsensors, and the use of the microsensor can be widely applied to measurements of benthic primary production of a tidal flat and the oxygen consumption rate of surficial sediments.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1190-1195
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• 2005

Biomass burning is a source of greenhouse gases, carbon dioxide, methane, and nitrous oxide. Under the ideal conditions of complete combustion, the burning of biomass produces carbon dioxide and water vapor. Since complete combustion is not achieved under any conditions of biomass burning, other carbon species, including carbon monoxide, methane, non-methane hydrocarbons and particulate carbon are produced. In this study, we analyze the combustion characteristics of rice-husk, such as heat release rate, smoke production rate, the percentage variation of CO and $CO_2$, oxygen consumption rate, and mass loss under different heat fluxes (20, 50 and 70kW). As a result, at 20kW incomplete combustion is occurred so that the percentage of CO is high in initial burning and total smoke release is higher than the others. At 50kW and 70kW, the combustion behaviors is very similar except the variation of CO percentage.

• Safety and Health at Work
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• v.9 no.4
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• pp.468-472
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• 2018

Background: Firefighters are required to use self-contained breathing apparatus (SCBA), which impairs ventilatory mechanics. We hypothesized that firefighters have elevated arterial $CO_2$ when using SCBA. Methods: Firefighters and controls performed a maximal exercise test on a cycle ergometer and two graded exercise tests (GXTs) at 25%, 50%, and 70% of their maximal aerobic power, once with a SCBA facemask and once with protective clothing and full SCBA. Results: Respiratory rate increased more in controls than firefighters. Heart rate increased as a function of oxygen consumption ($V_{O_2}$) more in controls than firefighters. End-tidal $CO_2$ ($ETCO_2$) during the GXTs was not affected by work rate in either group for either condition but was higher in firefighters at all work rates in both GXTs. SCBA increased $ETCO_2$ in controls but not firefighters. Conclusions: The present study showed that when compared to controls, firefighters' hypoventilate during a maximal test and GXT. The hypoventilation resulted in increased $ETCO_2$, and presumably increased arterial $CO_2$, during exertion. It is proposed that firefighters have altered $CO_2$ sensitivity due to voluntary hypoventilation during training and work. Confirmation of low $CO_2$ sensitivity and the consequence of this on performance and long-term health remain to be determined.

• 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.