• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.669-675
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• 2001

The objective of this study was to examine the effects of antioxidant vitamins on the formation of $AFB_{1}-DNA$ adduct and $AFB_{1}-inducing$ cellular oxidative damage. Intraperitoneal(i.p.)injections of 10 mg/kg vitamin C(VC) and 63.8 mg/kg vitamin E(VE) were repeatedly administrated 4 times with 2 days interval to 6 week old male ICR mice. After one hour of vitamin treatments, 0.4 mg/kg $AFB_1$ was injected in $AFB_1$ plus vitamin treated groups by same way. On the other hands, $AFB_1$ treated group was only injected with $AFB_1$ by the same method described above without vitamins. According to quantitative analysis of the $AFB_1$ in mice serum by indirect competitive ELISA, 12.28 and 18.78 ng/mL were detected in $AFB_1-treated$ groups, but 7.60 and 4.85 ng/mL in $AFB_1$ plus VC and VE treated groups, respectively. 23.78, 25.48 ng/mL of $AFB_1-DNA$ adduct were detected in mice liver of $AFB_1$treated groups, while 5.26, 7.81 ng/mL in $AFB_1$ plus VC and VE treated groups, respectively. Consequently, the differences in the concentrations of $AFB_1$ related materials between vitamin treated and non-treated groups were significant. Immunohistochemistry revealed brownish infiltration of $AFB_1$ around central vein and sinusoid in $AFB_1-treated$ group. This manifestation was distinctly reduced in $AFB_1$ plus VC and VE treated groups.

• Tuberculosis and Respiratory Diseases
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• v.64 no.5
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• pp.362-368
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• 2008

Background: LKB1(STK11) is a serine/threonine kinase that functions as a tumor growth suppressor. The functions of LKB1 in lung cancer are not completely understood. This study evaluated the relationship between LKB1 protein expression and the clinicopathological features in lung cancer tissues. Methods: The expression of LKB1 was studied in paraffin-embedded tumor blocks, which were obtained from 77 patients who had undergone surgery at Wonkwang University Hospital. The expression of the LKB1 protein was considered positive if the staining intensity in the tumor tissue adjacent to the normal airway epithelium was >30%. Results: The LKB1 expression was positive in 31 (40%) of samples. Loss of LKB1 expression was significantly associated with being male, smoking history, and squamous cell carcinoma. In the peripheral sites, the loss of LKB1 expression was strongly associated with a smoking history. A loss of LKB1 expression was more frequently associated with progression according to TNM staging, particularly more than T2, N progression. Conclusion: There was a significant relationship between the loss of the LKB1 protein and gender, smoking history, and histological type in primary lung cancer. Although LKB1 expression was not found to be a significant prognostic factor, further studies with a larger cohort of patient's lung cancer tissue samples will be needed to confirm this.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.929-936
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• 2005

The purpose of this study was to examine the ability of alkaline phosphatase (ALP) synthesis of MC3T3-E1 cells when above edible sources, Solidago virga-aurea var. gigantea Miq. root (SVR) extracts, were supplimented. MC3T3-E1 cells were cultured with $\alpha-MEM$(vehicle control), dexamethasone and genestein (positive control), and SVR extracts for 27 days. The effects of SVR MeOH extracts and its fractions on cell proliferation were measured by MTT assay. At 10, 100${\mu}g/mL$ of SVR methanol extract treated, that were elevated of cell proliferation to 140 and $120\%$ via vehicle control, respectively. And then ALP synthesis was measured by spectrophotometer for enzyme activity and by naphthol AS-BI staining for morphometry at 3, 9, 18, and 27th day. As the results, every extracts and fractions were promoted ALP activity by time course at 1, 10, 100${\mu}g/mL$, except n-hexane and chloroform fractions. Remarkably, the MeOH extracts were increased ALP activity more than 4.4 times compared with vehicle control, 2.2 times via positive control at 27th day (p<0.05). The SVR MeOH extracts treated cells, especially at a concentration of 10${\mu}g/mL$, showed remarkably higher than vehicle-treated control cells of mineralization which were checked by Alizarin red staining. These results indicate that SVR methanol extract have an induction ability of proliferation and differentiation on osteoblast.

• Journal of dental hygiene science
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• v.17 no.2
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• pp.142-149
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• 2017

This study targeted 123 dental hygienists working at the university and dental hospital as well as the dental clinic in Busan. The study ran for 5 months beginning July 23, 2016. The purpose of the study was to understand the relationship between core competencies and job performance for dental hygienists. The major core competencies of dental hygienists were interpersonal relation competency (3.61) was the highest, followed by management and educational competency (3.59), organizational relation competency (3.57), and basic dental hygiene management competency (3.56). Regarding the subjects' job performance, 'the task requested by a boss could be finished by the deadline' (3.93) was the highest, followed by 'there has been no case where others were harmed owing to carelessness' (3.76). 'The performance exceeding the targets set by the boss' (3.11) was relatively low. The group working for dental hospitals showed higher job performance than the group working for dental clinics (p=0.009) while there were high correlations between core competencies and job performance (p=0.733). Also, analysis for understanding relevant variables of core competencies that affected job performance revealed that the interpersonal relation competency (p=0.25), self-control competency (p=0.32), and basic dental hygiene competency (p=0.15) were significant. In summary, reinforcement of the dental hygienists' core competencies has a positive effect on job performance. Improved job performance in turn should improve patient care as well as the performance of the healthcare organization overall which will be eventually helpful to the provision of high-quality medical service to patients, and helpful for the hospital organization Helpful in making their performance better. Therefore, it would be necessary to establish administrative/educational support to facilitate dental hygiene education to develop major competencies and vocational basic abilities, as well as reinforce diverse competency educational programs for the current dental hygienists.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1395-1401
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• 2012

This study investigated the cognition-related effects on antioxidant activities, ${\gamma}$-aminobutyric acid (GABA) contents, and AChE inhibitory activities in ethanol extracts from Zingiber officinale Rosc. (Korea), Curcuma longa L. (Korea), Curcuma longa L. (Myanmar), and Curcuma aromatica Salisb. (India). These extracts were investigated to determine the relationships among total polyphenols as well as DPPH and ABTS radical scavenging activities, GABA contents, and acetylcholinestrase (AChE) inhibitory activity. For the results, C. longa L. from Myanmar exhibited the highest contents of curcumin (97.1 ${\mu}g/mg$), total polyphenols (98.4 ${\mu}g/mg$), and GABA (1.31 ${\mu}g/mg$), as well as the strongest radical scavenging activities and AChE inhibitory activity. In addition, C. aromatica Salisb from India, which had the highest total polyphenol content (98.4 ${\mu}g/mg$) and strongest radical scavenging activities, exhibited relatively high AChE inhibitory activity similar to that of C. longa L. from Myanmar. On the other hand, Z. officinale Rosc. and C. longa L. from Korea showed low contents of curcumin (12.2 ${\mu}g/mg$) and polyphenols (85.7 ${\mu}g/mg$), as well as low AChE inhibitory activities. However, we could detect 1.11 ${\mu}g/mg$ of GABA in these extracts, which was similar to that of C. longa L. from Myanmar. Therefore, GABA content was not correlated with AChE inhibitory activity. Based on the results, AChE inhibitory activity is highly correlated with polyphenol contents in Zingibearceae family. Overall, among the Zingiberaceae tested, C. longa L. from Myanmar might be a strong candidate as a cognitive-enhancing ingredient.

• Korean Journal of Remote Sensing
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• v.38 no.2
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• pp.189-198
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• 2022

In this present study, we investigated the effect of the offset correction factor calculation method on the sulfur dioxide (SO₂) column density in the SO₂ retrieval algorithm of the Geostationary Environment Monitoring Spectrometer (GEMS) launched in February 2020. The GEMS operational SO₂ retrieval algorithm is the Differential Optical Absorption Spectroscopy (DOAS) - Principal Component Analysis (PCA) Hybrid algorithm. In the GEMS Hybrid algorithm, the offset correction process is essential to correct the absorption effect of ozone appearing in the SO₂ slant column density (SCD) obtained after spectral fitting using DOAS. Since the SO₂ column density may depend on the conditions for calculating the offset correction factor, it is necessary to apply an appropriate offset correction value. In this present study, the offset correction values were calculated for days with many cloud pixels and few cloud pixels, respectively. And a comparison of the SO₂ column density retrieved by applying each offset correction factor to the GEMS operational SO₂ retrieval algorithm was performed. When the offset correction value was calculated using radiance data of GEMS on a day with many cloud pixels was used, the standard deviation of the SO₂ column density around India and the Korean Peninsula, which are the edges of the GEMS observation area, was 1.27 DU, and 0.58 DU, respectively. And around Hong Kong, where there were many cloud pixels, the SO₂ standard deviation was 0.77 DU. On the other hand, when the offset correction value calculated using the GEMS data on the day with few cloud pixels was used, the standard deviation of the SO₂ column density slightly decreased around India (0.72 DU), Korean Peninsula (0.38 DU), and Hong Kong (0.44 DU). We found that the SO₂ retrieval was relatively stable compared to the SO₂ retrieval case using the offset correction value on the day with many cloud pixels. Accordingly, to minimize the uncertainty of the GEMS SO₂ retrieval algorithm and to obtain a stable retrieval, it is necessary to calculate the offset correction factor under appropriate conditions.

• Clean Technology
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• v.29 no.1
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• pp.10-21
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• 2023

Hydrogels that are made of natural polymer-based double networks have excellent biocompatibility, low cytotoxicity, and high water content, assuring that the material has the properties required for a variety of biomedical applications. However, hydrogels also have limitations due to their relatively weak mechanical properties. In this study, hydrogels based on an alginate di-aldehyde (ADA) and gelatin (Gel) double network that is reinforced with additional hydrogen bonds formed between the hydroxyl (-OH) groups of the hyperbranched polymer (HPG) and the functional groups present inside of the hydrogels were successfully synthesized. The enhanced mechanical properties of these synthesized hydrogels were evaluated by varying the amount of HPG added during the hydrogel synthesis from 0 to 25%. In addition, magnetite nanoparticles (Fe₃O₄ NPs) were synthesized within the hydrogels and the structures and the magnetic properties of the hydrogels were also characterized. The hydrogels that contained 15% HPG and Fe₃O₄ NPs exhibited superparamagnetic behaviors with a saturation magnetization value of 3.8 emu g^-1. These particular hydrogels also had strengthened mechanical properties with a maximum compressive stress of 1.1 MPa at a strain of 67.4%. Magnetic hydrogels made with natural polymer-based double networks provide improved mechanical properties and have a significant potential for drug delivery and biomaterial application.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.163-172
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• 2016

Four growing Hanwoo cattle weighing 200±11.7kg were used within 4×4 Latin square design to establish nutrient requirements for Hanwoo growing steers under severe heat stress. The steers were fed four different energy level diets; 100%(control), 100%(E100), 115%(E115) and 130%(E130) of energy levels of growing Hanwoo steers based on total digestible nutrient level suggested by the Korea Feeding Standard for Hanwoo using timothy hay and commercial concentrate. The steers in the control were housed with no stress, whereas the steers in the other groups were under severe heat stress. The severe heat stress significantly decreased(p<0.05) true digestibility of dry matter(i.e. control 81.5% vs E100 79.1, E115 77.0 and E130 76.0, respectively). The severe heat stress and different energy intake levels did not affect blood physiological metabolites and body temperature of the growing steers. Based on changes in average daily gain by different energy intake level, the equation(Y=0.235X+115.03) of energy requirement of growing Hanwoo steers without changes in body weight was calculated, indicating that, compared with the present energy intake suggested by Korean feeding standard, 15.03% of dietary energy for maintenance of growing Hanwoo steers under severe heat stress should be increased.

• Health Policy and Management
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• v.33 no.2
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• pp.185-193
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• 2023

Background: This study focuses on the establishment and operation of a stroke patient hotline program to help patients and their caregivers determine when acute neurological changes require emergency attention. Method: The stroke hotline was established at the Gyeonggi Regional Cerebrovascular Center, Seoul National University Bundang Hospital, in June 2016. Patients diagnosed with stroke during admission or in outpatient clinics were registered and provided with stroke education. Consulting nurses managed hotline calls and made decisions about outpatient schedules or emergency room referrals, consulting physicians when necessary. The study analyzed consultation records from June 2016 to December 2020, assessing consultation volumes and types. Outcomes and hotline satisfaction were also evaluated. Results: Over this period, 6,851 patients were registered, with 1,173 patients (18%) undergoing 3,356 hotline consultations. The average monthly consultation volume increased from 29.2 cases in 2016 to 92.3 cases in 2020. Common consultation types included stroke symptoms (22.3%), blood pressure/glucose inquiries (12.8%), and surgery/procedure questions (12.6%). Unexpected outpatient visits decreased from 103 cases before the hotline to 81 cases after. Among the 2,244 consultations between January 2019 and December 2020, 9.6% were recommended hospital visits, with two cases requiring intra-arterial thrombectomy. Patient satisfaction ratings of 9-10 points increased from 64% in 2019 to 69% in 2020. Conclusion: The stroke hotline program effectively reduced unexpected outpatient visits and achieved high patient satisfaction. Expanding the program could enhance the management of stroke-related neurological symptoms and minimize unnecessary healthcare resource utilization.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.51-76
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• 2022

Identifying the factors that influence the formation of the entrepreneurial intention is important in cultivating entrepreneurs and inducing entrepreneurial innovation in the country. Previous studies have mainly examined the direct effects of social cognition attributes as predictors on entrepreneurial intentions or entrepreneurial activities. However, the fundamental factors that these social cognition attributes are derived from have not been sufficiently addressed in the field of entrepreneurship. Based on social cognitive theory and schema theory, this study assumes that an individual's entrepreneurial experience is an important antecedent factor in forming social cognitive attributes, and reveals the mechanism for how experience forms entrepreneurial intention. To this end, this study analyzes the influence of entrepreneurs' prior experience of entrepreneurial activities on entrepreneurial self-efficacy, opportunity recognition, and fear of failure which are considered to be the main variables that shape entrepreneurial intention. And it analyzes how these factors have a significant effect on entrepreneurship intention. Along with this, the mediating role of these social cognitive attributes is analyzed in order to understand the path that leads from entrepreneurial experience to entrepreneurial intention. This study also suggests how gender moderates the effect of entrepreneurship experience on social cognitive attributes. As a result of the analysis, it was found that entrepreneurial experience increase entrepreneurial self-efficacy and opportunity recognition of entrepreneurs, and decrease the fear of failure. These social perception attribute significantly mediate the relationship between entrepreneurial experience and entrepreneurial intention. This study also found that there are significant moderating effects of gender on the relationship of entrepreneurial experience and both of entrepreneurial self-efficacy and fear of failure. This study also analyzed the impact of the entrepreneurial experience of failure, which corresponds to the detailed experience. Similar to the results of entrepreneurial experience analysis, entrepreneurial experience of failure plays a role in enhancing entrepreneurial self-efficacy. However, its effect on opportunity recognition and fear of failure were not significant. An empirical analysis of data related to 25,047 entrepreneurs from 87 countries, using the Global Entrepreneurship Monitor (GEM), shows the differences in the formation of individuals' entrepreneurial intentions according to entrepreneurial experience and the mediating role of social cognitive attributes. The study has embodied the social cognitive theory on entrepreneurial intention by shedding light on the variables that are important but alienated for increasing entrepreneurial intention. Moreover, the study enhances the understanding of cognitive processes leading from individual experiences to entrepreneurial intentions. This study also emphasizes the importance of differentiated approach by gender for boosting entrepreneurial intention through analysis of moderating effect of gender.