• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1205-1212
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• 2000

The effect of temperature on the sources of organic acids and sludge when phosphorus was biologically released was evaluated in this study. The sludge used in this study was obtained from sequencing batch reactor processing the swine wastewater. Temperature is one of the most important parameters influencing the phosphorus release. As a result, the rate of phosphorus released was increased as the temperatures were increased from 5 to $30^{\circ}C$ regardless of the sources of organic acids used. Under anaerobic conditions, as acetate, propionate, glucose, and domestic wastewater were used as the sources of organic acids, the corresponding activation energy($E_a$) values were 49.83, 55.82, 54.61, and 45.44 KJ/mol, respectively. Temperature coefficient($\theta$) values were 1.0676, 1.0826, 1.0748, and 1.0698, respectively. Therefore, the rate of phosphorus released was increased as temperature was increased, whereas, the effect, of the sources of organic acids and temperature on the activation energy and temperature coefficient values were minimal. When the sludge previously adapted to acetate as external organic source was used, the activation energy and temperature coefficient values were 44.94 KJ/mol and 1.0570 respectively. The effect of temperature was minimal. These values obtained from the sludge previously adapted to acetate were smaller than those from the sludge not previously adapted to the same organic acid. This suggest that the sludge previously adapted to acetate was less dependent on temperature than that not adapted to the acetate.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.1
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• pp.61-70
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• 2009

We have examined the effects of certain mutations of the selectivity filter and of the membrane helix M2 on $Ba^{2+}$ blockage of the inward rectifier potassium channel, Kir 2.1. We expressed mutant and wild type murine Kir 2.1 in Chinese hamster ovary(CHO) cells and used the whole cell patch-clamp technique to record $K^+$ currents in the absence and presence of externally applied $Ba^{2+}$. Wild type Kir2.1 was blocked by externally applied $Ba^{2+}$ in a voltage and concentration dependent manner. Mutants of Y145 in the selectivity filter showed little change in the kinetics of $Ba^{2+}$ blockage. The estimated $K_d(0)$ was 108 ${\mu}M$ for Kir2.1 wild type, 124 ${\mu}M$ for a concatameric WT-Y145V dimer, 109 ${\mu}M$ for a WT-Y145L dimer, and 267 ${\mu}M$ for Y145F. Mutant channels T141A and S165L exhibit a reduced affinity together with a large reduction in the rate of blockage. In S165L, blockage proceeds with a double exponential time course, suggestive of more than one blocking site. The double mutation T141A/S165L dramatically reduced affinity for $Ba^{2+}$, also showing two components with very different time courses. Mutants D172K and D172R(lining the central, aqueous cavity of the channel) showed both a decreased affinity to $Ba^{2+}$ and a decrease in the on transition rate constant(${\kappa}_{on}$). These results imply that residues stabilising the cytoplasmic end of the selectivity filter(T141, S165) and in the central cavity(D172) are major determinants of high affinity $Ba^{2+}$ blockage in Kir 2.1.

• Journal of Korea Technology Innovation Society
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• v.10 no.1
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• pp.47-72
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• 2007

Ideas do not become exhausted, and there are no diminishing returns in the creation of knowledge. Nonetheless, growth ultimately ceases in this simplest model of endogeneous innovation. The reasons are similar to those that are discussed in the context of the neoclassical model of capital accumulation. Even if the resource cost of creating new goods does not rise, the economic return to invention may decline as the number of available products increases. When the rate of return to R&D falls to the level of the discount rate, private agents cease to be willing to defer consumption in order to invest in product development. But, if we treat knowledge capital as a public capital considering of its non-appropriable benefits, economic growth can be sustained in the economy. Romer(1986) has pointed out that growth might be sustainable if the accumulation of knowledge is not subject to long-run diminishing returns. Actually Romer assumed diminishing returns in the production of private knowledge from available resources, but increasing returns in the production of output from labor and total (public and private) knowledge. His condition for the sustainability of long-run growth amounts to an assumption that the diminishing returns in the former activity do not outweigh the increasing returns in the latter. The Johansen(1988) cointegration test method is used for finding long-run equilibrium relationship between R&D input and the product innovation. Test results indicate the existence of cointegrating equation between each pair of regression variables including dependent variable in the knowledge production function. And, the signs of cointegrating vectors are well accord to the prediction of sustainable growth. In the empirical analysis, from all cases of the form for the knowledge production function, we could not reject the null hypothesis that R&D spillover effect is significant($H_{0}:\;{\gamma}=1$). In summary, we showed that considering goodness of fit of regression model, we can see that the empirical evidence is strongly in favor of the character of knowledge as the public knowledge capital. So, we can expect that by product innovation, economic growth can be sustained in the Korean economy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.692-699
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• 2017

The purpose of this study is to investigate the display fatigue quantitatively when operating 2D and HMD-based 3D VR bicycles. Though it is generally accepted that the display fatigue induced by 3D VR is greater than that induced by 2D VR, there have been few studies which attempted to measure the display fatigue scientifically. The subjective degree of cybersickness and quantitative flicker fusion frequency (FFF) were measured in twenty subjects (Male 10, Female 10) before and after they operated 2D and 3D VR bicycles for 5 min. Two dependent variables affected by the 2D and 3D VR displays were analyzed and compared statistically based on scientific evidence and research. This study showed that 3D VR resulted in a significantly higher cybersickness rate and a significant lower FFF rate than 2D VR. Given the current propensity to couple VR techniques with exercise equipment, it seems appropriate to verify the general beliefs through scientific methods and experimental measures such as the FFF and cybersickness questionnaires.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3971-3977
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• 2016

Background: Breast cancer, the commonest cancer among women in the world, ranks top in India with an incidence rate of 1,45,000 new cases and mortality rate of 70,000 women every year. Chemotherapy outcome for breast cancer is hampered due to poor response and irreversible dose-dependent cardiotoxicity which is determined by genetic variations in drug metabolizing enzymes and transporters. Pregnane X receptor (PXR), a member of the nuclear receptor superfamily, induces expression of drug metabolizing enzymes (DMEs) and transporters leading to regulation of xenobiotic metabolism. Materials and Methods: A genomic region spanning PXR 3' UTR was amplified and sequenced using genomic DNA isolated from 96 South Indian breast cancer patients. Genetic variants observed in our study subjects were queried in miRSNP to establish SNPs that alter miRNA binding sites in PXR 3' UTR. In addition, enrichment analysis was carried out to understand the network of miRNAs and PXR in drug metabolism using DIANA miRpath and miRwalk pathway prediction tools. Results: In this study, we identified SNPs rs3732359, rs3732360, rs1054190, rs1054191 and rs6438550 in the PXR 3; UTR region. The SNPs rs3732360, rs1054190 and rs1054191 were located in the binding site of miR-500a-3p, miR-532-3p and miR-374a-3p resulting in the altered PXR level due to the deregulation of post-transcriptional control and this leads to poor treatment response and toxicity. Conclusions: Genetic variants identified in PXR 3' UTR and their effects on PXR levels through post-transcriptional regulation provide a genetic basis for interindividual variability in treatment response and toxicity associated with chemotherapy.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.3-14
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• 1986

A stud has been carried out for figuring out real photon spectrum from an observed gamma-ray spectrum by means of response matrix method, which is known one of the relatively convenient method for the estimation of exposure rate of a complex gamma ray field in comparison with graphical analysis and least square fitting of the measured spectrum. A 3'${\times}$3' cylindrical Nal(T1) scintillation detector in association with multichannel pulse height analyzer and six reference gamma ray sources covering the photon energy range of 0.05 to 2.0 MeV were used. In dividing the energy region for the construction of response matrix, two different approaches were attempted. One is dividing the entire energy region of interest into 20 bins, one of which corresponds to a width of 0.1 MeV to form $20{\times}20$ matrix, and another is dividing the 2 MeV region into 14 bins to form $14{\times}14$ matrix consists of $0.1(MeV)^{1/2}$ intervals assuming the resolution of the detector is dependent on square root of the incident photon energy. Inversion of thus constructed matrices was performed by a computor(P-E8/32) using the program attached to the end of this paper. The resultant exposure rates obtained by this method were in good agreement, within 10% with those calculated by ordinary formula widely used for a gamma-ray field of known energy and flux. It is concluded that the photen flux obtained by the response matrix constructed under the assumption of $E^{1/2}$ dependence is more realistic than that obtained by the matrix consist of identical energy bins in dosimetrical point of view.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.2
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• pp.43-49
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• 2010

Autonomic nervous system (ANS) acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The activity of the ANS has been assessed by means of the heart rate variability (HRV). It has been reported that HRV is dependent on sex, age, body mass index, and smoking, etc. However, the effects of posture and sleep deprivation on HRV have rarely been reported. Objective of our work was to find out which posture is appropriate for stable HRV. We measured the number of sleep deprivation and HRV using power spectrum in six stages for 30 minutes. Increased low frequency (LF) power and high frequency (HF) power indicate enhanced sympathetic and parasympathetic activity, respectively. We determined the LF/HF ratio to minimize individual difference. It was found that sleep deprivation by awakening up subjects was affected by posture, which resulted in changes of LF/HF. Although LF/HF varied with time, it was more stable in sitting than in supine. In conclusion, we recommend sitting posture when measuring HRV because of less sleep deprivation resulting in less variation in LF/HF.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.1-6
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• 2014

The purpose of this study was to investigate the killing effect of Candida albicans on hairless mouse-2 (HRM-2) mouse tissues. We tested the effectiveness of a non-thermal atmospheric pressure plasma in killing C. albicans strains. The viability of C. albicans was determined by counting the colony forming units (CFU), after non-thermal atmospheric pressure plasma treatment. When non-thermal atmospheric pressure plasma was repeatedly treated on mouse skin which inoculated with C. albicans. The C. albicans cells were planted on skin tissue, and then the infected mouse tissue was exposed to non-thermal atmospheric pressure plasma for 0 sec, 60 sec, 180 sec and 300 sec. The death rate of C. albicans was increased in dependent with treatment times. The three times of non-thermal atmospheric pressure plasma at the interval of 10 minutes significantly showed the 6 log CFU/ml reduction of death rate on HRM-2 mouse tissues. Thus, non-thermal atmospheric pressure plasma could be used for the disinfection of C. albicans on oral surface.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.1
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• pp.41-46
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• 2001

Objective: To determine the effects of leukemia inhibitory factor (LIF) on embryonal development in in vitro culture. Methods: This is designed in vitro model using eggs from mouse. The eggs from mouse were assigned 29 for control group, 53 for 20 ng/ml of LIF, 88 for 40 ng/ml of LIF, 68 for 80 ng/ml of LIF respectively for in vitro fertilization. And 26 fertilized eggs at 2 cell stage from mouse also were assigned. The mouse embryos of all groups were cultured in medium supplemented with LIF in different concentrations, whereas the eggs in control group was cultured in medium without supplement of LIF. Results: At 72 hours culture of eggs from in vitro fertilization, there was a slight increas in rate of embryonal development to morula in both LIF-20 and LIF-40 as results of 64.15% and 75% respectively, while 42.65% in inferior rate of LIF-80, compare with 51.72% in control group. But the difference between these each groups were not significant in statistically ($p{\le}0.05$). And after 96 hours culture of eggs, the rates blastocyst formation was significantly higher in both LIF-20 and LIF-40 as 56.6% and 63.63% than those in control and LIF-80 as 44.83% and 35.29% respectively. On culturing eggs from in vivo fertilization, the rates of blastocyst formation was significantly not only higher as 85% and 81.81% respectively in medium supplemented with LIF-40 and LIF-80 than 42.3% in LIF-20 but also embryonal cell viability were remakedly improved at 96 hours after culture. Conclusion: The LIF in low dose is embryotrophic, but LIF in high dose is embryotoxic on eggs from in vitro fertilization. Whereas on culturing eggs from in vivo fertilization, LIF is more beneficial with dose dependent in high concentration.

• Journal of Ginseng Research
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• v.7 no.2
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• pp.102-107
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• 1983

The effects of saponin, one of major components (Panax ginseng C.A. Meyer), on the growth of E. coli K-12 and the formation of siderphore was observed The following results were obtained. 1. When E. coli was grown on medium containing 1${\times}$10-5%-11${\times}$10-1% of the saponin, the rate of growth was stimulated at 10-1% of the saponin significantly compared to that of control. 2. When E. coli K-12 was grown on medium containing 1${\times}$10-1% of the saponin, the amount of siderphore was two times as much as the control. 3. The growth of E. coli was observed to be dependent on the concentration of siderophore when siderophore was added to medium. 4. The effect of saponin on the formation of siderophore in vitro was observed to reach maximum at 1${\times}$10-3% of the saponin. Such results suggest that the growth rate of E. coli K-12 could be enhanced by ginseng saponin fraction through stimulation of siderphore formation. We have described the fast growth of E. coli, K-12 and B. subtilis, rapid uptake of 14C-glucose, and high level of other metabolites such as lipids and proteins of E. coli, and B. subtilis in medium containing saponing fraction compared to that of microorganisms without saponin fraction.1∼3Such differences were claimed to be due to rapid uptake of 14C-glucose by widened periplasmic region throught unknown mechanism in the prescence of saponin fraction in medium3 and have raised a question whether there is another possible factor, siderophore4(Greek for iron bears), since microorganisms must secure a sufficient amount of iron for normal growth. These are known to be synthesized by the cells under iron-deficient condition and in most case, excreted into the medium5, where they can complex and solubilize any iron present there. It is generally believed that these complexes are then taken into the cells presumably by specific transport systems, thus providing iron for cell metabolism. Within the group of enteric bacteria, only three species (E. coli, S. typhimurium, and A. aerogense) have, so far, been studied in a ny detail. The main iron-binding compound produced by these species is enterochelin, and its role in iron transport is now well established. And biosynthesis of enterochelin from 2, 3- dihydroxybenzoate and serine in the prescence of magnesium ions and ATP was reported6. 2, 3-dihydroxybenzoate was also shown to involve isochorismate and 2, 3-dihydro-2, 3-dihydroxybenzoate as intermediate.7∼11 The present paper deals with the effect of ginseng saponin fraction on growth, the level of enterochelin formation in vivo and the conversion of 2, 3-dihydroxybenzoate and serine into entrochelin in vitro, and entrochelin obtained on the growth in relation to possible explanation of ginseng saponin fraction on the rapid growth of E. coli, K-12.