• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.3
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• pp.470-486
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• 1995

Mammary epithelial cells contain a subpopulation of cells with a large proliferativ potential which are responsible for the maintenance of glandular cellularity and are the progenitor cells of mammary cancer. These clonogens give rise to multicellular clonal alveolar or ductal units(AU or DU) on transplantation and hormonal stimulation. To isolate putative mammary clonogens, enzymatically monodispersed rat mammary epithelial cells from organoid cultures and from intact glands are sorted by flow cytometry according to their affinity for FITC labeled peanut lectin(PNA) and PE labeled anti-Thy-1.1 antibody(Thy-1.1) into four subpopulations : cells negative to both PNA and Thy-1.1(B-), PNA+cells, Thy-1.1+cells, and cells positive to both reagents(B+). The in vivo transplantation assays indicate that the clonogenic fractions of PNA+cells from out-growths of organoids in primary cultures for three days in complete hormone medium(CHM) are significantly higher than those of cells from other subpopulations derived from cultrues or from intact glands. Extracellular matrix(ECM) is a complex of several proteins that regulated cell function ; its role in cell growth and differentiation and tissue-specific gene expression. It can act as a positive as well as a negative regulator of cellular differentiation depending on the cell type and the genes studied. Regulation by ECM is closely interrelated with the action of other regulators of cellular function, such as growth factors and hormones. Matrigel supports the growth and development of several different multicellular colonies from mammary organoids and from monodispersed epithelial cells in culture. Several types of colonies are observed including stellate colonies, duct-like structures, two- and three-dimensional web structures, squamous organoids, and lobulo-duct colonies. Organoids have the greatest proliferative potential and formation of multi-cellular structures. Phase contrast micrographs demonstrate extensive intracellular lipid accumulation within the web structures and some of duct-like colonies. At the immunocytochemical and electron micrograph level, casein proteins are predominantly localized near the apical surface of the cells or in the lumen of duct-like or lobulo-duct colonies. Squamous colonies are comprised of several layers of squamous epithelium surrounding keratin pearls as is typical fo squamous metaplasia(SM). All-trans retinoic acid(RA) inhibits the growth of SM. The frequency of lobulo-ductal colony formation increased with the augmentation of RA concentration in these culture conditions. The current study models could provide powerful tools not only for understanding cell growth and differentiation of epithelial cells, but also for the isolation and characterization of mammary clonogenic stem cells.

• 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.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.274-283
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• 2020

This study focused on the in vitro investigation of antioxidant and anti-diabetic activities, along with neuroprotection against high glucose-induced cytotoxicity, in order to evaluate the physiological effects of Zanthoxylum piperitum and Zanthoxylum schinifolium. The highest total phenolic content was measured in the 40% ethanolic extracts of Zanthoxylum piperitum (EZP) and Zanthoxylum schinifolium (EZS). The in vitro EZP antioxidant activity showed a relatively higher ABTS/DPPH radical scavenging activity and malondialdehyde inhibitory effect than that of EZS. The EZP inhibited carbohydrate hydrolysis (α-glucosidase and α-amylase) more efficiently than EZS in anti-diabetic tests. However, EZS showed a more efficient inhibition of advanced glycation end-products formation than EZP. In addition, both EZP and EZS effectively protected human-derived neuronal cells from high glucose-induced cytotoxicity. Finally, the physiological compounds were analyzed using UPLC IMS-QTOF/MS^E, and the main EZP (quercetin-3-O-glucoside and 3-caffeoylquinic acid) and EZS (5-caffeoylquinic acid) compounds were identified as phenolic compounds.

• Journal of Korean Public Health Nursing
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• v.4 no.1
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• pp.57-74
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• 1990

As the whole world took on the tendency to be highly industrialized, it became necessary for each field of occupation to require professional man power. Especially, since the World War n, the participation of woman power in economic activities has been continually increasing. In our country also, because of the rapid economic growth, change in the way of thinking of women as well as their participation in economic activities are increasing. Thus, woman power is being utilized in various occupational fields from simple physical labor to those that require high-professional skill. Also, continued economic development policies, by setting the establishment of welfare society as the ideology to be fulfilled, brought expansion of medical facilities in the field of public health and increase in man power in that field. As for the nursing specialists, more than 6000 have been being produced per year and as of the end of 1988, the total number of nursing specialists, reached 123, 115. Therefore, this study is done to recognize the professional knowledge and ability of nursing specialists, who take up $40\%$ of the total public-health related man power in our country, through evaluating their working environment and their disposition of character. This study, which was done from September 18th to September 30th 1989, took on the method of using formed questionnaires that had been amended and supplemented during two preparatory investigations, 322 of such questionnaires were used as an analytical material. In the formation of questionnaires, 12 questions were related to the working environment, and 26 in fortotal were related to the disposition of character, 5 for wise-disposition, 11 for activedisposition and 10 for open-disposition. The measuring method, which used 5-point-standard, allowed 5 points for affirmative recognition of the working environment, also 5 points for showing wise, active and open disposition of character and only point in opposite cases. Collected materials were analyzed, through an electronic calculation, into the average value, the standard deflection percentage, pearson corelative number and stepwise multiple regression. Summarizing the results from this study is as follows: 1. It was shown that the nursing specialists with the average of 3.07 have affirmative recognition of their working environment. The questions which drew most affirmative reaction were those concerning finance-management system such as hand, the questions that received negative reaction were those concerning communication method with the average of 2.49. Such reaction seems to have resulted from the cramming regulation by the superior authorities. Concerning the recognition of working environment in relation to employment conditions, more affirmative recognition is shown with the average of 3.14. at hospitals where injection job is not performed. The nursing specialists working at regular hospitals show more affirmative recognition than those at general hospitals, the averages being respectiely 3.16 and 3.03. 2. As for the disposition of character of the nursing specialists, active-disposition was highest with the average of 3.38, next was wise-disposition with 3.20 and the lowest was open-diposition with 2.98. Variable-wise disposition of character shows that wise-disposition and academic background are beneficially correlated by 0.12. Ative-disposition and open-disposition show correlation to the office term by respectively 0.16 and 0.21. In other words. better academic background leads to higher wise-disposition and more - experience results in higher active and open disposition. Also, the class that performs the injection job, in relation to the working environment, might cause change in the self-conceit that identify those in that class with the nurses; however, as far as professional judgment and action, in dealing with nursing job, being wise, active and open is concerned, not much effect is made. 3. The relation between the recognition of the working environment and the disposition of character is that more afirmative recognition- a nursing specialist has about her working environment, the higher the active-disposition becomes by 0.13. The degrees of the relation between recongnition of environment and wise and open dispositions show respectively 0.06 and -0.06 and -0.06. That is to say that when having more affirmative recognition of the working environment, a nursing specialist shows wise but closed disposition of character. This, howerver, didn't mean much statistically. When observing the results mentioned above, it is conspicuous that the nursing specialists, working as substitutes for the nurse at medical institutions of various sizes, get the feeling of being somewhat equal to the nurses and to some extent, fulfill their desire to accomplish their ego; however, as far as professional ability expansion if concerned. they lack wise and open dispositions. Therefore, considiering upon the results of this study, in medical institutions where the work of nursing specialists is regaded equal to that of the nurses, as a medical member who deals with human lives, it is desirable to make the nursing specialists work under the supervision of the nurses and to offer them continuous education to strengthen and improve their natural dispositions.

• Journal of Nutrition and Health
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• v.35 no.3
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• pp.291-295
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• 2002

This study was designed to investigate the effects of a butanol (BuOH) fraction from an extract of pine (Pinus densiflora Sieb et Zucc.) needles, on oxygen radicals and their scavenger enzymes in the liver membranes of rats. Twenty-eight male Sprague-Dawley (SD) rats were divided into four groups over a 45 days study period: the control group on a basic diet, and three experimental groups on three different dietary levels of the butanol fraction, specifically 25 mg (BuOH-25), 50 mg (BuOH-50), and 100 mg (BuOH-100) butanol fraction/kg body weight/day, thereby 0.025%, 0.05%, 0.1% of butanol extract of pine needles was added to basil diet respectively. At the end of the experimental period, body weights and food intakes were not different among the four groups. The results showed that cholesterol accumulation in the mitochondria and microsomes of liver cells was significantly inhibited in the BuOH-50 and BuOH-100 groups: by 11.6% and 20.1% in the mitochondria of the BuOH-50 and BuOH-100 groups, respectively; and by 10.5%, and 13.5% in the microsomes of the BuOH-50 and BuOH-100 groups, respectively, compared with the control group. The levels of hydroxyl radicals (.OH) were significantly) lower in the liver mitochondria of the BuOH-50 and BuOH-100 groups (by 13.3% and 18.5%, respectively), while OH radicals were significantly lower in the microsomes or all three experimental groups (by 15.7% in the BuOH-25 group, 20.0% in the BuOH-50 group, and 20.6% in the BuOH-100group), compared with the control group. Superoxide radical (O$_2$) formation was also significantly inhibited in the liver cytosol of both BuOH-50 and BuOH-100 groups; the levels of these radicals were 8.0% lower for the BuOH-50 group and 11.1% lower for the BuOH-100 group, compared to the control group. Copper/Zinc - superoxide dismutase (Cu/Zn-SOD) activities were significantly increased (by 10.3% and 15.9%, respectively) in the liver cytosols of the BuOH-50 and BuOH-100 groups, but Mn-SOD activities were almost identical in the three RuOH groups, compared with the control group. Glutathione peroxidase (GPx) activities were significantly increased in the three experimental groups (by 9.0% in the BuOH-25 group, 19.4% in the BuOH-50 group, and by 25.6% in the BuOH-100 group), compared with the control group. These results suggest that the butanol extract of pine needles may play an effective role in attenuating oxygen radicals and activating scavenger enzymes; consequently, aging may be very effectively modulated and/or inhibited.

• The Journal of Engineering Geology
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• v.33 no.3
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• pp.371-388
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• 2023

A stratum with a complex composition and a distributed low-permeability soil layer is difficult to remediate quickly because the soil remediation does not proceed easily. For efficient purification, the permeability should be improved and the soil remediation agent (H₂O₂) should be injected into the contaminated section to make sufficient contact with the TPH (Total petroleum hydrocarbons). This study analyzed a method for crack formation and effective delivery of the soil remediation agent based on pneumatic fracturing, plasma blasting, and vacuum suction (the PPV method) and compared its improvement effect relative to chemical oxidation. A demonstration test confirmed the effective delivery of the soil remediation agent to a site contaminated with TPH. The injection amount and injection time were monitored to calculate the delivery characteristics and the range of influence, and electrical resistivity surveying qualitatively confirmed changes in the underground environment. Permeability tests also evaluated and compared the permeability changes for each method. The amount of soil remediation agent injected was increased by about 4.74 to 7.48 times in the experimental group (PPV method) compared with the control group (chemical oxidation); the PPV method allowed injection rates per unit time (L/min) about 5.00 to 7.54 times quicker than the control method. Electrical resistivity measurements assessed that in the PPV method, the diffusion of H₂O₂2 and other fluids to the surface soil layer reduced the low resistivity change ratio: the horizontal change ratio between the injection well and the extraction well decreased the resistivity by about 1.12 to 2.38 times. Quantitative evaluation of hydraulic conductivity at the end of the test found that the control group had 21.1% of the original hydraulic conductivity and the experimental group retained 81.3% of the initial value, close to the initial permeability coefficient. Calculated radii of influence based on the survey results showed that the results of the PPV method were improved by 220% on average compared with those of the control group.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.420-428
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• 2015

The majority of cultivated varieties of grape have perfect flowers that are clustered in an individual inflorescence. Grape flower has a single pistil, five stamens, a protective flower cap (calyptra), and a calyx. After fertilization, an individual flower develops into a single berry. Although there are a number of reported studies focusing on berry formation, berry enlargement, and sugar accumulation in grape, the morphological studies of flower, including gametophyte morphogenesis and structural change in floral organs, have not yet been studied in detail. In this study, we investigated the flower structure and development characteristics of grape using microscopy and defined the floral development stages 9 to 13 based on microspore or male gametophyte development stage from tetrad to mature pollen. We used seeded diploid table grapes 'Campbell Early' (Vitis labruscana) and 'Tamnara' (V. spp.) as plant materials. At floral development stage 9, pollen mother cells develop to tetrads. During floral development stages 10 to 11, unicellular microspore develop to mid bicellular pollen. At the end of floral stage 12, male gametophyte develops to mature tricelluar pollen. In floral stage 13, the flower cap falls off and flower bud opens. During floral development stages 9 to 12, there were no major changes in calyx length, whereas the length of the flower cap continuously increased. The flower cap-to-calyx length ratio was 2.0, 3.0, 4.5, and 6.5 at floral stages 9, 10, 11, and 12, respectively. The flower cap-to-calyx length ratio was consistent in the two grape cultivars, suggesting that the ratio is a morphological character representing floral development stage. This study provides a reference for determining floral development stage of the two grape cultivars. It will be useful for the determination of optimum time for microspore culture needed to generate doubled haploid lines and appropriate gibberellic acid treatment needed to induce parthenocarpic fruit development in 'Tamnara' grape.

• Korean Journal of Food Science and Technology
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• v.4 no.3
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• pp.206-212
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• 1972

Oxidative changes in the rice lipids under accelerated condition were studied by measuring the changes in weight gain, total carbonyl compound, malonaldehyde, and fatty acid composition. Rice lipids were prepared by extraction with either n-hexane or ethanol from polished rice grain and purified by Folch's method. The lipid preparations were either incubated in dark at $40^{\circ}C$ or irradiated with ultra-violet light for a period of 55 days. Weight gain by oxygen absorbed sharply increased within 3 days in the rice lipids under UV light irradiation. However, with the rice lipids at $40^{\circ}C$ incubation a moderate increase in weight was observed only after 45 days storage. Their induction periods were one day (hexane extracted, under UV light), 2 days (ethanol extracted, under UV light), 30 days (hexane extracted, at $40^{\circ}C$), and 40 days (ethanol extracted, at $40^{\circ}C$) respectively. Oxidative rancid odor appeared at the end of the induction period. Total carbonyl compound and malonaldehyde markedly increased within 7 days, and decreased in the rice lipids under ultra violet light irradiation, while at $40^{\circ}C$ incubation they were continued to increase slowly through out the storage. The hexane extracted lipid were less stable than ethanol extracted lipid on the basis of oxygen absorption, malonaldehyde and other carbonyl compound formation. With the hexane extracted lipid during 55 days incubation at $40^{\circ}C$, the contents of linoleic and linolenic acids decreased, while the oleic, stearic, and palmitic acids increased.

• Journal of the Korean Chemical Society
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• v.67 no.2
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• pp.81-88
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• 2023

The contribution of hydrophobic residues to the protein folding reaction was studied by using HubWA variant proteins with I and L to V mutation. Folding kinetics of all V variant proteins was observed to be satisfied by a three-state on-pathway mechanism, U ⇌ I ⇌ N, where U, I, and N represent unfolded, intermediate, and native state, respectively. Three-state folding reaction was quantitatively analyzed and the free energy of folding of each elementary reactions and overall folding reaction, ΔG^o_UI, ΔG^o_IN, and ΔG^o_UN, were obtained. From the ratio of free energy difference between the variant protein and HubWA, ΔΔG^o_UI/ΔΔG^o_UN (ΔΔG^o_UI = ΔG^o_UI (variant protein) - ΔG^o_UI (HubWA) and ΔΔG^o_UN = ΔG^o_UN (variant protein) - ΔG^o_UN(HubWA)), the contribution of hydrophobic residues to HubWA folding was analyzed. The residues which are located in the hydrophobic core between α-helix and β-sheet, I3, I13, L15, I30, L43, I61 and L67, showed ΔΔG^o_UI/ΔΔG^o_UN value of ~0.5 when each of these residues was mutated to V, indicating that these residues form relatively solid hydrophobic core in the intermediate state. Residues located at the end of secondary structures and loop, I23, L69 and I36 showed ΔΔG^o_UI/ΔΔG^o_UN value below 0.4 when each of these residues was mutated to V, indicating that the region containing these residues are loosely formed in the intermediate state. V17A, L50V and L56V showed fairly high ΔΔG^o_UI/ΔΔG^o_UN value of ~0.8. Since L50 and L56 are located in the region containing long loop (residue 46 to 62), it is suggested that the high ΔΔG^o_UI/ΔΔG^o_UN value of these residues prevents the formation of aggregate at the early stage of folding reaction.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.109-114
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• 1999

Purpose : The importance of meniscal repair is well recognized. But transeciton of the posterior horn of the medial meniscus at the posterior tibial attachment is rarely documented and known irreparable. We experienced 9 cases of transection, and present clinical features and pull out suture technique. Methods and Materials : There were 9cases of transection of the posterior horn of medial meniscus from September 1998 to July 1999 in our hospital. Age was 59.3 years in average and ranged from 38 to 70years. Clinical features and MRI made diagnosis in all cases. We confirmed the diagnosis with arthroscopy and repaired the transection with pullout suture technique. Clinical features : Transection of the posterior horn of the medial meniscus at the posterior tibia attachment occurred frequently in middle aged people. They complained posterior knee pain, but they have no history of definitive trauma. Characteristically they had difficulty in full flexion of the knee and in having a squatting position. MRI is very important in diagnosis of transection, especially in coronal view, there is separation of the posterior horn of the meniscus from the posterior tibial attachment. Surgical technique : Pullout suture technique includes debridement of fibrous or scar tissue, exposure of the subchondral bone of the posterior tibial attachment site, suture the transected end of the meniscus with PDS suture, bone tunnel formation from the anteromedial aspect of the proximal tibia, insertion of wire loop through the tibia tunnel, pull the PDS suture through the tibia tunnel out of the joint and stabilize the PDS with post-tie technique to the proximal tibia. Conclusion : Transection of the posterior horn of the medial meniscus at the posterior tibial attachment is not common clinically and rarely documented. Clinical features and MRI are very important in diagnosis of this type tear. Arthroscopic pullout sutures is useful for treatment of this type tear of the meniscus.