• The Korean Journal of Mycology
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• v.35 no.1
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• pp.1-10
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• 2007

The cell wall is essential for the survival and osmotic integrity of fungal cells. It is the framework to which biologically active proteins such as cell adhesion molecules and hydrolytic enzymes are attached or within which they act. Recently it was shown that mutations in ${\alpha}-COP$, a subunit of COPI vesicle, is responsible for the thermo-sensitive osmo-fragile phenotype of fungi, such as Saccharomyces cerevisiae and Aspergillus nidulans, and suggested that ${\alpha}-COP$ may play a crucial role in translocation of protein(s) of the ${\beta}-1,3-gulcan$ synthase complex and cell wall proteins, thus may contribute to the maintenance of cell wall integrity. In this review, we summarized the relationship between the intra-cellular protein translocation machinery, especially the ${\alpha}-COP$ of COPI vesicle, and cell wall biogenesis in fungi. We also discussed potential use of secretory mutants in basic and applied research of the fungal cell walls.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.4
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• pp.67-74
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• 2020

PURPOSE: The progression of the center of pressure (COP) velocity of the stance phase may have important roles for predicting gait speed in older adults with cognitive decline. This study was conducted to identify the correlation between gait speed and the velocity of COP progression during the stance phase in older adults with cognitive decline. METHODS: Forty adults aged 65 years or older (twenty participants without cognitive decline, 20 participants with cognitive decline) were recruited. The COP progression velocity was measured using an F-scan pressure-sensitive insole system. The stance phase was divided into four sub-stages. (loading response, mid-stance, terminal stance, and pre-swing). Gait speed, double support phase, and cadence were also measured. Correlations and multiple regression analyses were performed. RESULTS: Gait speed was associated with the COP progression velocity in midstance (r = .719, p < .05), cadence (r = .719, p < .05) and the COP progression velocity in loading response velocity (r = .515, p < .05) in older adults with cognitive decline. However, no correlation was found in older adults without cognitive decline. In multiple regression analysis using gait speed as a dependent variable, the COP progression velocity in midstance and cadence were significant predictors of gait speed, with the COP progression velocity being the most significant predictor. CONCLUSION: The COP progression velocity is an important factor for predicting gait speed in older adults with cognitive decline, suggesting that the cognitive function influences gait speed and the velocity of COP progression.

• Journal of the Korean Institute of Gas
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• v.16 no.3
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• pp.42-47
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• 2012

In this paper, alternative natural refrigerant R290(Propane), R600(Butane), R717(Ammonia), R1270(Propylene) for freon refrigerant R22 were used working fluids for 2-stage compression and 1-stage expansion refrigeration system. The operating parameters considered in this study included evaporation temperature, condensation temperature, subcooling degree, superheating degree, mass flow rate ratio of inter-cooler. The main results were summarized as follows : The COP of 2-stage compression and 1-stage expansion refrigeration system increases with the increasing subcooling degree and mass flow rate ration of inter-cooler, but decreases with the increasing evaporating temperature, condensing temperature and superheating degree. Therefore, subcooling degree, mass flow rate ratio of inter-cooler of 2-stage compression and 1-stage expansion refrigeration system using natural refrigerants have an effect on COP of this system. The COP of natural refrigerants was higher than the COP of freon R22 in this study, so points to be considered are the security, the attached facilities for natural refrigerants than COP.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.30-36
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• 2019

Numerous studies have reported that enteric neurons involved in controlling neurotransmitter secretion and motility in the gut critically contribute to the progression of gut inflammation. Clostridium difficile toxins, which cause severe colonic inflammation, are also known to affect enteric neurons. Our previous study showed that C. difficile toxin A directly induces neural cell toxicities, such as viability loss and apoptosis. In the current study, we attempted to identify a potent inhibitor of toxin A-induced neural cell toxicity that may aid in managing toxin A-induced gut inflammation. In our recent study, we found that the Korea dung beetle-derived antimicrobial peptide CopA3 completely blocked neural cell apoptosis caused by okadaic acid or 6-OHDA. Here, we examined whether the antimicrobial peptide CopA3 inhibited toxin A-induced neural cell damage. In neuroblastoma SH-SY5Y cells, CopA3 treatment protected against both apoptosis and viability loss caused by toxin A. CopA3 also completely inhibited activation of the pro-apoptotic factor, caspase-3. Additionally, CopA3 rescued toxin A-induced downregulation of neural cell proliferation. However, CopA3 had no effect on signaling through ROS/p38 $MAPK/p27^{kip1}$, suggesting that CopA3 inhibits toxin A-induced neural cell toxicity independent of this well-characterized toxin A pathway. Our data further suggest that ability of CopA3 to rescue toxin A-induced neural cell damage may also ameliorate the gut inflammation caused by toxin A.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.3
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• pp.19-30
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• 2022

In this study, comparative analysis of energy performance in Taebaek city, a test area, by applying hydrothermal, geothermal source and hybrid heat pump system to office, school and smart farms with different internal heat loads. The conclusion is as follows. In the load characteristics by use of buildings, it was found that office had a large cooling load compared to heating load, school had a large heating load compared to cooling load, and smart farm had only cooling load year-round. Performance analysis of the heat pump system in office shows that the cooling COP of the hydrothermal source is 5.12% and the heating COP is 3.22% lower based on the geothermal source, the cooling COP of the hybrid is 0.41% higher, and the heating COP is the difference in performance appeared sparsely. The performance analysis of the heat pump system in school showed that the cooling COP of the hydrothermal source was 10.44% and the heating COP 3.22% lower based on the geothermal source, and the performance difference between the hybrid cooling and heating COP was insignificant. Heat pump system performance analysis in smart farm only occurred with cooling load. Based on geothermal sources, the cooling COP of the hydrothermal source was 46% and the cooling COP of the hybrid was 19.65%, respectively.

• The Journal of Korean Physical Therapy
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• v.18 no.4
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• pp.51-60
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• 2006

Purpose: This study was to compare the effect of center of pressure(COP) displacement and muscle activation onset during expected and unexpected sudden limb loading in subjects with low back pain and healthy control subjects. Most studies of COP displacement and muscle activation onset on postural task focused on sudden trunk loading or gross limb movements. Investigation of the COP displacement and muscle activation onset during expected and unexpected sudden upper limb loading deserves similar attention. Methods: For this study, 14 subjects with low back pain and 12 healthy control subjects are participated. Force plate and surface EMG measures were used to determine COP displacement and muscle activation onset under expected and unexpected sudden upper limb loading. Results: COP displacement and muscle activation onset under unexpected sudden upper limb loading were similar in subjects with low back pain and healthy control subjects. However, COP displacement and muscle activation onset under expected sudden upper limb loading were shortened in healthy control subject but not among the subjects with low back pain. Conclusion: The results provide evidence for impaired feed-forward control in subjects with low back pain.

• International Journal of Air-Conditioning and Refrigeration
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• v.7
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• pp.55-68
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• 1999

In this study, computer simulation programs were developed for single-stage, two-stage, and three-stage condensation heat pumps and their performance with CFC11, HCFC123, HCFC141b was examined under the same external conditions. The results showed that the coefficient of performance(COP) of an optimized 'non-split type' three-stage condensation heat pump is 25-42% higher than that of a conventional single-stage heat pump. The increase in COP, however, differed among the fluids tested. The improvement in COP is largely due to the decrease in average LMTDs in condensers, which results in the decrease in thermodynamic irreversibility in heat exchange process. For the three-stage heat pump, the highest COP is achieved when the total condenser area is evenly distributed among the three condensers. For the two-stage heat pump, however, the optimum distribution of the total condenser area varies with an individual working fluid. For the three-stage system, 'splitting the condenser cooling water'for the use of intermediate and high pressure subcoolers helps increase the COP further. When the individual cooling water entering the intermediate and high pressure subcoolers is roughly 10% of the total condenser cooling water, the maximum COP is achieved showing roughly an 11% increase in COP as compared to that of the 'non-split type' heat pump.

• Journal of Power System Engineering
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• v.18 no.1
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• pp.51-56
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• 2014

In this paper, the performance of the $CO_2-C_2H_6-N_2$ cascade liquefaction cycle with respect to temperature differences in the LNG heat exchangers is analyzed theoretically using HYSYS software and then compared the COP(coefficient of performance) of the cascade liquefaction cycles using $C_3H_8-C_2H_4-C_1H_4$ and $CO_2-N_2O-N_2$. In comparison of COP of three cycles, the cascade liquefaction cycles using $C_3H_8-C_2H_4-C_1H_4$ showed the highest COP. And the liquefaction cycle using $CO_2-C_2H_6-N_2$ and $CO_2-N_2O-N_2$ presented the second and third highest COP, respectively. In case of COP, the $C_3H_8-C_2H_4-C_1H_4$ cascade liquefaction cycle yields better COP. But, in terms of the environment and maintain, it is confirmed that the cascade liquefaction cycle using $CO_2-C_2H_6-N_2$ provides favorable characteristics.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.459-463
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• 2014

Purpose: The purpose of this study was to investigate the correlations between functional movement screen (FMS) and ankle dysfunctions in subjects with chronic ankle instability (CAI). Methods: This study was a cross-sectional study of 20 participants with CAI. The ankle dorsiflexion range of motion (ROM), Foot and Ankle Disability Index (FADI), center of pressure (COP) path length, and COP velocity for ankle dysfunction were measured in all the subjects. All the subjects underwent the FMS concerned with ankle functions consisted of deep squats, hurdle steps and in-line lunges. The Spearman rank-order correlation coefficient was used to determine relationship between the ankle ROM, FADI, COP and FMS. Results: The results of the deep squat and in-line lunge exercises revealed a significant correlation with the ankle dorsiflexion ROM, FADI, COP path length, and COP velocity. The hurdle step showed no correlation with the ankle dorsiflexion ROM and FADI but a significant relationship with the COP path length and COP velocity. Conclusion: The results of this study showed that relationship deep squat and in-line lunge and it is suggested that an assessment tool using ankle dorsiflexion ROM and ankle instability would be clinically effective.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.197-202
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• 1996

The effects of erythrosine on the oxidative stability of cholesterol in an aqueous model system were studied by depleted headspace oxygen and cholesterol oxidation products (COP). As the oncentration of erythrosine was increased, headspace oxygen depletion, 7-COP and total COP increased during storage at $25^{\circ}C$ for 50 hours under the fluorescent light. As the intensity of fluorescent light was increased, amounts of headspace oxygen depleted and COP formed in an aqueous cholesterol dispersion containing erythrosine also increased. Addition of ${\alpha}-,\;{\delta}-$, mixed-tocopherol and ${\beta}-carotene$ resulted in the enhanced oxidative stability of an aqueous cholesterol dispersion containing erythrosine during the fluorescent light storage.