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EFFECTS OF HYDROQUINONE ON NEOPLASTIC TRANSFORMATION OF HUMAN EPITHELIAL CELLS IN CULTURE (Hydroquinone이 인체 상피세포의 발암화에 미치는 영향)

  • Sohn, Jung-Hee;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.3
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    • pp.218-228
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    • 2010
  • Components of dental resin-based restorative materials are reported to leach from the filling materials even after polymerization. Hydroquinone (HQ) is one of the major monomers used in the dental resin and is known as a carcinogen. Thus, carcinogenic risk of HQ leaching from the dental resin becomes a public health concern. The present study attempted to examine the carcinogenic potentials of HQ on the human epithelial cell, which is the target cell origin of the most of oral cancers. Cytotoxicity of HQ was observed above 50${\mu}M$ as measured by LDH assay, indicating a relatively low toxicity of this substance in human epithelial cells. The parameters of neoplastic cellular transformation such as cell saturation density, soft agar colony formation and cell aggregation were analyzed to examine the carcinogenic potential of HQ. The study showed that 2-week exposure of HQ showed the tendency of increase in the saturation density and the significant enhancement of soft agar colony formation at the highest dose, 50 ${\mu}M$ only. It is suggested that HQ has a weak potential of carcinogenicity. When cells were treated with HQ and TPA, a well-known tumor promoter, the parameters of neoplastic cellular transformation was significantly increased. This result indicates that the potential risk of carcinogenicity from HQ is largely dependent upon the presence of promoter. Exposure of 50 ${\mu}M$ HQ increased the time-dependent apoptosis as measured by the ELISA kit. This concentration coincides with a dose of neoplastic transformation, indicating a possible link between apoptosis and HQ-induced cellular transformation. Hydroquinone generated Reactive Oxygen Species (ROS) which was evidenced by the treatment of antioxidants such as trolox and N-acetyl cysteine and the GSH depleting agent, BSO. Antioxidants blocked the generation of ROS and the GSH depleting agent, BSO dramatically increased the ROS production. Since HQ is known to increase ROS production thru activation of transcriptional factor such as c-Myb and Pim-1, it is speculated that ROS generation by HQ plays a role in the activation of oncogene, which may lead to neoplastic transformation. In addition, ROS is involved in the alteration of signal transduction, which regulates the apoptosis in many cellular systems. Thus, ROS-mediated apoptosis may be involved in the HQ-induced carcinogenic processes. Protein kinase C (PKC) is known to play pivotal roles in neoplastic transformation of cells and its high expression is often found in a variety of types of tumors including oral cancer. PKC translocation of PKC-${\alpha}$ was observed following HQ exposure. Altered signaling system may also play a role in the transformation process. Taken together, HQ leached from the dental resin does not pose a significant threat as a cancer causing agent, but its carcinogenic potential can be significantly elevated in the presence of promoter. The mechanism of HQ-induced carcinogenesis involved ROS generation, apoptosis and altered signaling pathway. The present study will provide a valuable data to estimate the potential risk of HQ as a carcinogen and understand mechanism of HQ-induced carcinogenesis in human epithelial cells.

A Study on the Improvement Plan through Analyzing the Perception of Expert Group about Landscape Construction Defects (조경공사 하자에 관한 전문가 집단간 인식분석을 통한 개선방안 연구)

  • Lee, Sang-Suk;Yu, Joo-Eun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.4
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    • pp.104-113
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    • 2012
  • This study aimed to find out the improvement plan through analyzing the perception of the expert group engaged in landscape architectural construction and to focus on analyzing the expert groups' experience on Landscape Construction Defects (LCD), defect liability, warranty period, and implementation of the defect liability. The results are as follows: 1. Regarding the experience on the LCD, landscape construction contractors were an awareness of the LCD issue at a serious level, while public-sector clients recognize moderately the LCD issue; and on the first priority in defect implementation, landscape construction contractors considered repair cost while public-sector clients value the identifying causes of defects. 2. In disagreement on the defect liability, landscape construction contractors attributed it to client's lack of responsibility for maintenance while public-sector clients ascribed it to the absence of dealing a criteria with LCD, and regarding the appropriate defect implementation, public-sector clients preferred the following objective by dealing the criteria with LCD while landscape construction contractors advocates by sharing the responsibilities for dealing with LCD based on the identified causes of construction defects. 3. Regarding the warranty period, the public-sector clients considered the 2-year warranty period as appropriate while landscape construction contractors considered it comparatively long, and concerning the commencement of defect warranty period, the public-sector clients viewed it as it should commence to cover the overall completion of the construction while landscape construction contractors perceived it to start on the completion of each work. 4. As for the improvement of the defect implementation system, public-sector clients considered it necessary to establish the objective dealing the criteria with LCD while landscape construction contractors viewed the legislation of maintenance duty. Also, with regard to the important value in establishing and dealing the criteria with LCD, public-sector clients pointed out the objective of the criteria for determining the defects per work type while landscape construction contractors suggested client (user)'s maintenance duty. Because of research, because the system in dealing with LCD is an absence of LCD management agency and dealing the criteria with LCD, it is needed to establish an LCD management agency and make the system in dealing with LCD.

Korean Perspectives on Parks during the Port Opening Period (개항기 한국인의 공원관 형성)

  • Woo, Yun-Joo;Pae, Jeong-Hann
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.6
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    • pp.76-85
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    • 2011
  • This research explores the Korean perspective on parks and the beginning of urban parks in the port opening period. The purpose of the study is to understand how Koreans viewed and accepted the idea of a park as imported from western culture and with what attitudes. Analyzed sources included: "Susinsa's Record"(修信使記錄) by Susinsa(修信使) who wrote the inspection records of foreign modern cultures for the first time after the port opening, "Seoyukyunmun"(西遊見聞) by Yu Kil-jun(兪吉濬) and "Yun Chi-ho's Diary"(尹致昊日記) by Yun Chi-ho(尹致昊), which are representative works by students sent abroad, as well as some records of Seo Jae-pil(徐載弼) and The Independence Club(獨立協會) such as "The Independent"(獨立新聞), which contains the records of 'IndependencePark'. This research is focused on the literature that reexamins and interprets the related data from primary sources. As a result, it was found that the people who led the modern reformation in the Port Opening period adopted and developed social thinking regarding parks. Indeed, it was possible to witness the gradual sophistication of the concept of a park from the time of Susina's thoughts on parks to that of Yu Kil-jun's support for the need and importance of parks and Yun Chi-ho's cultural and artistic interest in parks. Also, Seo Jae-pil and the Independence Club drove the development of Independence Park, which was designed to incorporate social values and symbols while also serving to meet the needs of recreation, leisure, hygiene, and enlightenment. The Independence Club consistently advocated for the necessity of open spaces and delivered this message to the public via article writing. In short, even prior to the Japanese colonial period, Koreans shared thoughts and exchanged opinions on parks. Parks were to be created not just as a copy or transplant of western parks, but were constructed based on social demands and necessity. As few studies have taken the approach of identifying this origin of Korean parks, thus, this research which traces back the origin of Korean parks, is significant.

Studies on the Construction Characteristics of Rear Garden Farmland at Joseon Palace (조선시대 궁궐 후원 농경지(農耕地) 조영의 특성)

  • Jung, Woo-Jin;Sim, Woo-Kyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.4
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    • pp.62-77
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    • 2012
  • This study aimed to investigate the Confucian-oriented agriculture phase of the Joseon Dynasty, which was reflected at the palaces, by analyzing constructional aspects and spatial characteristics of farmlands at the palace rear gardens. The objective sites were the rear gardens of Gyeongbok Palace, Changkyung Palace, and the outside of Sinmoomoon(神武門) This study was based on literature reviews. The farmlands at the palace rear garden were constructed to self-estimate the year's harvest condition within the palaces. It was a part of the agriculture encouragement policy on governing the group of Joseon like publishing the Nongsajiksul(農事直說) and establishing the Chingyeongnye(親耕禮: king's own cultivation ceremony) and Kikokje(祈穀祭: the rite of praying for grain). In addition, farmlands of the rear garden were operated from the beginning of the state almost until the Japanese colonial era. The results were summarized as follows: First, Gyeongbok Palace rear garden's farmland which begin at the reign of Sejong(世宗) existed at the present Hyangwonji(香遠池) area. It was constructed in order to check the advanced agricultural technologies. The rear garden's farmland in Changkyung Palace, which was executed during the reign of Seongjong(成宗), was constructed right after the initial Chingyeongnye of the Joseon Dynasty. Therefore, it might be understood as the context of the king's own cultivation of the Jeokjeonchinkyung(籍田親耕). Injo(仁祖) dug for farmland in the ground of the Gyemgdeok Palace(慶德宮) though there was some stay palace, when his stay dragged out for too long. This bespeaks that those farmlands at the palace rear gardens were of great importance in the Joseon political history. The farmland near Gyeongnongjae(耕農齋), which was made during the reign of Gojong(高宗), inherited predecessor's walks of the promoting agriculture and exhibited spatial compositions such as the rear garden's farmland at Changkyung Palace. Secondly, irrigation, its water systems, the name of observatory to study farming[觀耕臺] and location requirements for farmland had something in common. It was assumed as universal forms of physiocracy-space in the Joseon Dynasty. In this study, by considering aspects of operating about vegetable garden managed by eunuchs and of the orchard in palace to cultivate fruits for national ceremonies, it could be assumed that landscape architecture of royal palace in the Joseon Dynasty did not only focus on solemnity, orderliness and fanciness but also on the practical and productive which was helpful in life. In addition, the diverse activities of productive landscape architecture led by the royal family in palaces, and the initiatively tested advanced agricultural technologies by the king were considered as an aspect of the Korean traditional specific royal palace landscape architecture. That is considered sole landscape not only to love of the people but also the 'agriculture-first' principle which were absent from other nations.

Comparative Evaluation of Neighborhood Parks in Korea and China based on the Place Attachment Model (장소애착 모델에 근거한 한국·중국 근린공원의 비교평가)

  • Yang, Lei;Lee, Shiyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.3
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    • pp.21-29
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    • 2017
  • In this study of visitor place attachment to parks, Scannel and Gilford considered the dimensions of place attachment, and proposed the theoretical framework of PPP(Place, Person, Process) that should be systematically studied from the perspective of person, place and psychological processes. According to Scannel's theoretical basis, this paper puts forward the hypothesis of a structure model of place attachment. In the model, the five independent variables of people, places, cognition, emotion, and behavior have influenced the dependent variable of place attachment. The questionnaire was conducted on 18 neighborhood parks in Kunming, China, and the residents of the 5 neighborhood parks in Daejeon, South Korea. A total of 1,645 valid samples of the questionnaire survey were collected. Through confirmatory factor analysis(CFA) results of the inspection of the various elements, it was shown that the reliabilities of 6 latent variables, such as people, places, cognition, affection, behavior and place attachment, which were composed with the observed variables(30 observed variables in Daejeon, 19 observed variables in Kunming), were all above 0.7 and the data were fit for this study. The hypothesis test results found that the physical environment of the neighborhood parks such as a comfortable environment, pleasant road and convenient facilities would increase the rate of visitors coming back. From the park management perspective, to increase the amount of visitors to the park, the park should increase visibility, provide more organized, varied activities and meetings, or special exhibitions according to the particular characteristics of the individual park, to increase awareness of the park. From the park visitors' psychological perspective, visitors are seeking to enjoy the park facilities and environment not only to bring physical relaxation, but also to bring about a psychological cure. With the commonality of attachment structure between the two countries, to improve the place attachment of neighborhood park visitors, collecting regularly visitor feedback will facilitate the sustainable development of neighborhood park attachment.

A Study on the Recognition of Modern Cultural Heritage Value of Japanese-style Building Groups Using Q Methodology - Focusing on Huam-dong, Seoul - (Q 방법론을 이용한 일본식 건물군의 근대문화유산 가치에 관한 인식 연구 - 서울시 후암동을 중심으로 -)

  • Park, Han-Sol;Sung, Jong-Sang
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.6
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    • pp.115-128
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    • 2019
  • Huam-dong is a representative area from the Japanese colonial period and is the space where most Japanese-style buildings remain in Seoul. Interest in modern cultural heritage continues to increase, including the registration of cultural properties in 2001, building assets in 2015, and the registration of cultural property units in 2018. As the debate continues over the necessity of preserving cultural heritage that reminds us of the Japanese colonial, there is a need for research to grasp the perceptions of stakeholders along with the perceived value of such spaces. This study identified the subjective perception types of the stakeholders concerned with the Japanese-style building group in Huam-dong, analyzed characteristics by types, and debated the issues. For this purpose, Q methodology, which is a statistical technique for measuring human self-subjectivity and extracting common human perspectives, was used. A literature study on the values of Huam-dong and modern cultural heritage was conducted, and a Q questionnaire based on five aspects of modern cultural heritage values (historical, architectural, sociocultural, landscape, and economic) was applied. The results of the study depicted three types of cognition and showed different attitudes toward the Japanese building group. This study found a conflict comparing the perceptional differences between the types of cognition. This study is meaningful in that it provides an in-depth approach to the perspectives of the stakeholders concerned with the Japanese-style buildings clustered in central Seoul. It is also meant to present a theoretical framework that can be applied to the use area as sustainable cultural heritage through the establishment of preservation and utilization of Japanese-style areas and conflict resolution.

Locational Analysis and Classification of the Eup-Settlements in the Joseon Dynasty Period from Feng-Shui's Point of View (조선시대 지방도시의 풍수적 입지분석과 경관유형- 경상도 71개 읍치를 대상으로 -)

  • Choi, Won-Suk
    • Journal of the Korean Geographical Society
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    • v.42 no.4
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    • pp.540-559
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    • 2007
  • The purpose of this paper is to analyse the locations and to interpret the landscapes of the local towns in Joseon Dynasty from Feng-shui's point of view. As a result of analysing the locations of towns in Gyeongsang Province, the towns which have typical Feng-shui landscapes make up to 58% of the total. Historically, the local towns that were established in the early period of the Joseon Dynasty didn't reveal Feng-shui's landscape, but those that were established in the late period of the Joseon Dynasty revealed the Feng-shui's landscape clearly. In this article, I classify the local towns of the Gyeongsang Province into 3 types: 1. Non Feng-shui type These towns are located near the seashore. The main reason that these towns were located at the seashore was defense against an enemy. 2. Semi Feng-shui type. These towns don't have natural location but have a man-made landscape, based on the principles of Feng-shui. 3. Typical Feng-shui type. These towns were typically administrational towns which were located at the center of a local region.

Consumer expectation and consumer satisfaction before and after health care service (의료이용 전.후 기대와 만족수준 비교)

  • Park, Jang-Soon;Yu, Seung-Hum;Sohn, Tae-Yong;Park, Eun-Cheol
    • Korea Journal of Hospital Management
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    • v.8 no.1
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    • pp.112-134
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    • 2003
  • The purpose of this study is to analyze the consumer's expectation before the health care service and the consumer's satisfaction after it. The participants of the study are inpatients in a general hospital located in Seoul. The resources were collected from the self-administration questionnaire survey run parallel with face to face interview. In order to measure the degree of the consumer's expectation, 349 samples were collected from the first questionnaire survey on the date of admission to the hospital. The second questionnaire survey was carried out on the date of discharge to the hospital with the participants responding to the first questionnaire survey. There are 154 samples collected from this survey. The results from the analysis of these resources are as follow. First, the survey shows that one of the highest consumers' expectations was about the generosity, kindliness and sincerity from the staff at the hospital, specially from doctors. Second, according to the analysis of the factors affecting the expectations of the consumers, with regard to path of admission to a hospital relating to patient's features, outpatient who gets into a hospital expected good medical care much more than the other patients. In regard of doctor's features, patients usually and highly expect good medical care from doctors who have good carrier and much experience. Third, according to the second questionnaire survey, what patients are satisfied most with is about the generosity and sincerity from staff at a hospital, especially from doctors and their gem attitudes. The results from survey show that the differences among the degree of consumers' satisfaction are very variable, depending on surrounding environments and facilities. The only fact that expectation didn't meet with satisfaction appeared to the case about technology and skill of medical care and the case about updated medical skills and equipments. Fourth, comparing the degree of expectation with the degree of satisfaction of consumers, correlative analysis was concerned significantly and specifically about the part of overall cleanliness relating to facilities and surrounding environments, the items about medical examination and test plan procedure relating to skill of medical care, professional specialties and convenience for procedure, and the items about satisfying explanations and concern about patients from doctors relating to staff's generosity and sincerity. Fifth, the analysis of the factors affecting the degree of how much patients are satisfied with shows that relating to sociodemographical features, patients are not satisfied with the case when the time and process of medical treatment are getting longer. It is surveyed that consumer were satisfied with the motivation to visit a hospital and the insurance type in patient's feature and so were the medical department and the factor of the degree of the expectation in disease's feature. Sixth, according to analysis based on the survey, patients would join again a hospital when they get satisfaction from the medical care and also they want to come again regarding to doctor's capability. For example, when doctors are old, have a good carrier and much experience, patients would come again. As seen from the above, consumers are usually satisfied with the medical treatment more than that they expected before. They would intend to use again when they get satisfaction from the medical care provided at a hospital. Patients and consumers highly expect good attitude as well as capacity from medical doctors and they are also generally satisfied with those things. Therefore, in order to increase the degree of consumer's satisfaction and their intention to come again, the hospital staff would have to commit themselves to achieve high quality service continuously and would have to make an effort to offer the finest quality service.

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Synecological Study of the Naturalized Plant Communities in Old-Andong City (구 안동시역에 분포하는 귀화식물군락의 생태학적 연구)

  • 송종석;안상흥
    • The Korean Journal of Ecology
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    • v.22 no.3
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    • pp.169-179
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    • 1999
  • The present study was undertaken to classify and describe the spring naturalized plant communities in old-Andong city by the methodology of the ZM school of phytosociology. As a result, the vegetation was classified into the six communities and two subcommunities: A. Bromus tectorum community A-a. Bromus japonicus subcommunity, A-b. Melica onoei subcommunity; B. Poa pratensis community; C. Rumex crispus community; D. Oenothera lamarckiana community; E. Ambrosia artemisiifolia var. eiatior community; F. Rumex conglomeratus community. The total taxa of the naturalized plant communities consisted of 31 families, 86 genera, 114 species and 13 varieties. Of which the taxa of the naturalized plant species consisted of 8 families, 21 genera, 25 species and 1 variety. The result of Bray-Curtis ordination revealed that the plots suveyed were arranged according largely to the vegetation units of' the communities. Also the interspecific affinity was examined by an analysis of interspecific association and the main component species in the communities were divided into two groups. The naturalized rate was higher in the communitise affected by strong human impacts, while was lower in the communities affected relatively less by human impacts. On the other hand the seasonal changes of the communities and the naturalized rate between the spring and the autumn were investigated. Many naturalized communities present in Spring were replaced by the other native ruderal communitues in the Autumn. The naturalized rate based on the dominance was largely decreased over from the spring to the Autumn.

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An Analysis of Teachers' Level of Usage and Concern Over the 7th Science Curriculum (제7차 과학 교육과정에 대한 지구과학 교사들의 관심도와 활용도 분석)

  • Lee, Yong-Seob;An, Hyun-Hee;Kim, Sang-Dal;Kim, Jong-Hee
    • Journal of the Korean earth science society
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    • v.24 no.5
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    • pp.378-392
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    • 2003
  • The purpose of this study is to investigate the depth of earth science teachers' concern over the 7th Science Curriculum and levels of their use of it in reality, using the tools "Concern" and "Levels of use" which are two important tools use in CBAM. The results of the study are as follows. How much concern do the earth science teachers have over the 7th Science Curriculum? There are seven stages (from 0 stage to 6 stage) of teachers' concern over the curriculum. o stage represents teachers' indifference to the curriculum and 98% teachers are placed in this stage. According to the study on teachers' teaching experience, teachers having from 10 to 14 years of teaching experience are the most indifferent to the 7th Science Curriculum, compared to other teachers. Which levels of use of the 7th science curriculum do earth science teachers choose in reality? There are five levels of use (from 1 to 5) of the 7th curriculum. 43.97% of teachers are placed in the 3rd level called "Mechanical level", which represents a teacher-concerned learning method with consideration of learners' response. According to the study on teachers' frequency of level of use in the fields of "Instruction objects, Instruction contents, Instruction methods, Instruction materials and Evaluation.", teachers chose high levels of use in the fields of "Instruction objects and Instruction contents" and low levels of use in the other three fields. What factors are barriers for earth science teachers to perform the 7th Science Curriculum in reality? 80.9% of teachers have trouble performing the 7th Science Curriculum in reality because of too much routine work, official papers, and lack of instructional materials, laboratories, training systems and workshops. The two biggest barriers among the above are routine work and of official papers. According to the study on teachers' teaching experience, teachers having from 0 to years of teaching experience have the most trouble in performing the curriculum in reality, compared to other teachers.