• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.194-201
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• 2014

Clitocybin A is a novel anti-wrinkle cosmetic agent produced by the strain from a Korean native mushroom Clitocybe aurantiaca. In this study, fermentation, extraction, and purification conditions for a large scale production of clitocybin A were optimized, and its cytotoxicity and inhibition activity on the expression of matrix metalloproteinase-1 (MMP-1) were characterized. The mass production of anti-wrinkle agent was achieved according to the 300 L fermentation process with a fed-batch cultivation using the modified yeast-maltose (YM) broth, and a total of 12.5 kg of cell mass was obtained in a 120 L culture broth for 14 days. After extraction and purification, clitocybin A was identified by HPLC. The cytotoxicity of clitocybin A was examined by the MTT assay. When assayed at 100 and 200 ${\mu}g/ml$ concentrations, clitocybin A showed no cytotoxicity, demonstrating safety. The inhibition activity of clitocybin A on the expression of MMP-1 was examined against UV irradiation. Oleanolic acid (control group) showed a relatively low MMP-1 inhibiting activity (ca. 16.7%) at 10 ${\mu}g/ml$ and showed increased cytotoxicity at higher concentrations. In contrast, clitocybin A showed no cytotoxicity at 100 ${\mu}g/ml$, and exhibited a relatively high MMP-1-inhibiting activity (33.1%). These findings indicate that clitocybin A may be a safe and effective anti-wrinkle agent for use in functional cosmetics.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.323-328
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• 2016

Pressurized membrane used for side-stream MBR process requires fouling control strategy both for normal and abnormal operation conditions for stable operation of the facilities. In this study, $85m^3/day$ of pilot-scale side-stream MBR process was constructed for the evaluation of fouling mitigation by air bubble injection into the membrane module. In addition, fouling phenomena at abnormal operation conditions of low influent and/or loading rate were also investigated. Injection of air bubble was found to be effective in delaying transmembrane pressure (TMP) increase mainly due to scouring effect on the membrane surface, resulting in expanded filtration cycle at a high flux of $40L/m^2{\cdot}h$ (LMH). At abnormal operation condition, injection of PACl (53 mg/L as Al) into the bioreactor showed 19% reduction of TMP increase. However, inhibition of nitrifying bacteria by continuous PACl injection was observed from batch experiments. In contrast, injection of powdered activated carbon (PAC, 0.6 g/L) was able to maintain the initial TMP of $0.2kg/cm^2$ for 5 days at the abnormal conditions. It may have been caused from the adsorption of extracellular polymeric substances (EPS), which was known to be excessively released during growth inhibition condition and act as the major foulants in MBR operations.

• Molecules and Cells
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• v.38 no.1
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• pp.1-13
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• 2015

Recent technical developments have transformed how neuroscientists can probe brain function. What was once thought to be difficult and perhaps impossible, stimulating a single set of long range inputs among many, is now relatively straight-forward using optogenetic approaches. This has provided an avalanche of data demonstrating causal roles for circuits in a variety of behaviors. However, despite the critical role that neuropeptide signaling plays in the regulation of behavior and physiology of the brain, there have been remarkably few studies demonstrating how peptide release is causally linked to behaviors. This is likely due to both the different time scale by which peptides act on and the modulatory nature of their actions. For example, while glutamate release can effectively transmit information between synapses in milliseconds, peptide release is potentially slower [See the excellent review by Van Den Pol on the time scales and mechanisms of release (van den Pol, 2012)] and it can only tune the existing signals via modulation. And while there have been some studies exploring mechanisms of release, it is still not as clearly known what is required for efficient peptide release. Furthermore, this analysis could be complicated by the fact that there are multiple peptides released, some of which may act in contrast. Despite these limitations, there are a number of groups making progress in this area. The goal of this review is to explore the role of peptide signaling in one specific structure, the bed nucleus of the stria terminalis, that has proven to be a fertile ground for peptide action.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.487-496
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• 2009

This paper addresses an indexing scheme capable of efficiently processing range queries in a large-scale trajectory database. After discussing the drawbacks of previous indexing schemes, we propose a new scheme that divides the temporal dimension into multiple time intervals and then, by this interval, builds an index for the line segments. Additionally, a supplementary index is built for the line segments within each time interval. This scheme can make a dramatic improvement in the performance of insert and search operations using a main memory index, particularly for the time interval consisting of the segments taken by those objects which are currently moving or have just completed their movements, as contrast to the previous schemes that store the index totally on the disk. Each time interval index is built as follows: First, the extent of the spatial dimension is divided onto multiple spatial cells to which the line segments are assigned evenly. We use a 2D-tree to maintain information on those cells. Then, for each cell, an additional 3D $R^*$-tree is created on the spatio-temporal space (x, y, t). Such a multi-level indexing strategy can cure the shortcomings of the legacy schemes. Performance results obtained from intensive experiments show that our scheme enhances the performance of retrieve operations by 3$\sim$10 times, with much less storage space.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.353-363
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• 2019

This study is for the use of color recommendation system for the color combination of mobile application. For this study, color combination methods of a material design color system that recommends harmonized colors automatically and of a mobile web application were applied to a mobile application design and a color combination experiment was carried out. Then for a survey on the experiment using the two methods, color combinations, selected colors and satisfaction with outputs were investigated on a 7-point Likert scale. And color combination characteristics of outputs were compared. It was found that the material design color palette made it easy to select colors by systematizing the regular coloring stages of fixed colors automatically, but there were differences in color compositions and color scopes of dominant color, assort color and accent colors, which are three-color combinations of mobile web application and accent color selection function was required for each design, since only primary colors and secondary colors could be selected. Moreover, chromatic colors were used a lot in the material system because of the fixed color scopes and color combination scopes and images of color combination outcomes varied depending on the color combination scopes, even when tones with a big contrast or complementary colors were selected. The role of color composition was important according to the color combination scopes.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.140-145
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• 2016

Objectives : Parental behavior is related to personality development and ego resilience in the childhood. The objective of this study was to identify the influence of parental behavior on ego resilience in Korean middle school student. Methods : Subjects were selected based on stratified multi-stage cluster sampling in Korea youth panel study 2013(Boy : N=1,075, Girl : N=1,033). We used Parental behavior inventory(PBI) to estimate parental behavior and the Ego resilience scale to estimate ego resilience. The data were statistically analyzed using a Pearson correlation analysis and regression analysis with the statistical package for the social sciences(SPSS). We considered differences to be significant when p<0.05. Results : A regression analysis showed that rational explanation, affection, Interest and inconsistency of the parental behavior domains influence ego resilience. Also rational explanation, affection and Interest of the parental behavior domains showed a significant positive correlation with ego resilience(r=0.24, r=0.31, r=0.22, p<0.01). In contrast to early childhood studies, inconsistency showed no significant correlation. Conclusions : Adolescents who had taken more rational explanation, interest and affection from their parents were more likely to have higher ego resilience. However, inconsistency of parental behavior showed no correlation with ego resilience of adolescents, which means that they are affected by several other factors than parental behavior. This study would be a basic research that could be a help to psychosocial approach in pediatric psychiatry.

• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.891-900
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• 2021

Objective : Vertebral artery dissecting aneurysm (VADA) is a very rare subtype of intracranial aneurysms; when ruptured, it is associated with significantly high rates of morbidity and mortality. Despite several discussions and debates, the optimal treatment for VADA has not yet been established. In the last 10 years, flow diverter devices (FDD) have emerged as a challenging and new treatment method, and various clinical and radiological results have been reported about their safety and effectiveness. The aim of our study was to evaluate the clinical and radiological results with the use of FDD in the treatment of unruptured VADA. Methods : We retrospectively evaluated the data of all patients with unruptured VADA treated with FDD between January 2018 and February 2021 at our hybrid operating room. Nine patients with unruptured VADA, deemed hemodynamically unstable, were treated with FDD. Among other parameters, the technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcomes were evaluated. Results : Successful FDD deployment was achieved in all cases, and the immediate follow-up angiography showed intra-aneurysmal contrast stasis with parent artery preservation. A temporary episode of facial numbness and palsy was noted in one patient; however, the symptoms had completely disappeared when followed up at the outpatient clinic 2 weeks after the procedure. The 3-6 months follow-up angiography (n=9) demonstrated complete/near-complete obliteration of the aneurysm in seven patients, and partial obliteration and segmental occlusion in one patient each. In the patient who achieved only partial obliteration, there was a sac 13 mm in size, and there was no change in the 1-year follow-up angiography. In the patient with segmental occlusion, the cause could not be determined. The clinical outcome was modified Rankin Scale 0 in all patients. Conclusion : Our preliminary study using FDD to treat hemodynamically unstable unruptured VADA showed that FDD is safe and effective. Our study has limitations in that the number of cases is small, and it is not a prospective study. However, we believe that the study contributes to evidence regarding the safety and effectiveness of FDD in the treatment of unruptured VADA.

• Cross-Cultural Studies
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• v.45
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• pp.109-143
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• 2016

This article examines distinctive linguistic shifts of translational English in an effort to verify the validity of the translation universals hypotheses, including simplification, explicitation, normalization and leveling-out, which have been most heavily explored to date. A large-scale study involving comparable corpora of translated and non-translated English newspaper texts has been carried out to typify particular linguistic attributes inherent in translated texts. The main findings are as follows. First, by employing the parameters of STTR, top-to-bottom frequency words, and mean values of sentence lengths, the translational instances of simplification have been detected across the translated English newspaper corpora. In contrast, the portion of function words produced contrary results, which in turn suggests that this feature might not constitute an effective test of the hypothesis. Second, it was found that the use of connectives was more salient in original English newspaper texts than translated English texts, being incompatible with the explicitation hypothesis. Third, as an indicator of translational normalization, lexical bundles were found to be more pervasive in translated texts than in non-translated texts, which is expected from and therefore support the normalization hypothesis. Finally, the standard deviations of both STTR and mean sentence lengths turned out to be higher in translated texts, indicating that the translated English newspaper texts were less leveled out within the same corpus group, which is opposed to what the leveling-out hypothesis postulates. Overall, the results suggest that not all four hypotheses may qualify for the label translation universals, or at least that some translational predictors are not feasible enough to evaluate the effectiveness of the translation universals hypotheses.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.89-95
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• 2019

Mooring observations of water temperature and salinity were conducted to investigate the effects of freshwater discharge patterns on the mouth of Nakdong River from April 2017 to March 2018. More than $500-1000m^3\;s^{-1}\;d^{-1}$ of freshwater was frequently discharged into the estuary throughout the rainy season, but less than $200m^3\;s^{-1}\;d^{-1}$ was discharged through the normal season. Sluice gates of the estuarine barrage operated depending on the tide level during spring tide, but they were constantly open during neap tide. Water temperature and salinity fluctuated regularly with intermittent discharges of freshwater, whereas they were stable while freshwater discharge was continuous. Mean salinity was 29 during the study period. Salinity exceeded the mean value in the normal season and rapidly recovered after a temporary reduction. In contrast, water with salinity below the mean value prevailed in the estuary for three months over the rainy season. These results indicate that water temperature and salinity were affected by the amount of freshwater discharge, as well as the frequency of discharge on a large scale and the time over which the freshwater discharge continued.

• International Area Studies Review
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• v.21 no.1
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• pp.25-57
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• 2017

In this study, we analyzed the information asymmetry and the agency problem in major affiliated companies on the basis of the R&D investment. As a result of comparing how the R&D investment effects on major affiliated companies and the independent companies, even the achievement of R&D investment effects in a positive way to the firm value, the positive effect appears much lower on major affiliated companies comparing independent companies. In order to analyze the case, we investigated in a separate way according to the shareholding ratio and the affiliated market using the sample of the independent company and the group affiliated company. As a result of such analysis, the cause of this comes from the agency problem in major affiliated company, not the asymmetry information of affiliated company. After we analyzed the sample of the research depending on the affiliation market, we could observe there is a little impact of the asymmetry information in the outcome of the R&D investment of the major affiliated companies. In contrast, the companies which rated lower in the ratio of the shareholding appears much less in the positive effect of R&D investment compared to the companies which rated at a higher level. This phenomenon was also consistently observed when changing the research method or further subdividing the sample of companies belonging to the group based on the ownership share of major shareholders.