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Current Status and Future Perspective of PET (PET 이용 현황 및 전망)

  • Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.1
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    • pp.1-7
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    • 2002
  • Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) defecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3,015 and 4,414 in 1996,1997,1998,1999 and 2000, respectively. The application in cardiac disorders is minimal, and among various neuropsychiatric diseases, patients with epilepsy or dementia can benefit from PET studios. Recently, we investigated brain mapping and neuroreceptor works. PET is not a key application for evaluation of the cardiac patients in Korea because of the relatively low incidence of cardiac disease and less costly procedures such as SPECT can now be performed. The changes in the application of PET studios indicate that, initially, brain PET occupied almost 60% in 1995, followed by a gradual decrease in brain application. However, overall PET use in the diagnosis and management of patients with cancer was up to 63% in 2000. The current medicare coverage policy in the USA is very important because reimbursement policy is critical for the promotion of PET. In May 1995, the Health Care Financing Administration (HCFA) began covering the PET perfusion study using Rubidium-82, evaluation of a solitary pulmonary nodule and pathologically proven non-small cell lung cancer. As of July 1999, Medicare's coverage policy expanded to include additional indications: evaluation of recurrent colorectal cancer with a rising CEA level, staging of lymphoma and detection of recurrent or metastatic melanoma. In December of 2001, National Coverage decided to expand Medicare reimbursement for broad use in 6 cancers: lung, colorecctal, lymphoma, melanoma, head and neck, and esophageal cancers; for determining revascularization in heart diseases; and for identifying epilepsy patients. In addition, PET coverage is expected to further expand to diseases affecting women, such as breast, ovarian, uterine and vaginal cancers as well as diseases like prostate cancer and Alzheimer's disease.

A Study on the Model Regulation's Improvement for Control of Aeronautical Obstacles in Korea (항공장애물관리규정 개선을 위한 연구)

  • Lee, Kang-Seok
    • Journal of Korean Society of Transportation
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    • v.23 no.3 s.81
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    • pp.21-34
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    • 2005
  • To control the obstacles surrounding aerodrome is significant for preventing air accident and ensuring the long sustaining of aerodromes. On the other hand, within a scope of ensuring safe flight operations, the application of Shielding is one of the issues to be importantly considered to manage efficiently the obstacles limitation around aerodromes, to dissolute the private asset privilege limitation from regulation on aerodrome circumference, and to decrease the pains to manage the obstacles, in terms of not only operating safely but also utilizing efficiently the airspace around aerodromes. The ICAO and other aviation-advanced states mitigate the construction limitation or exempt the obligation of obstacle sign by applying the shielding theory that the obstacles are not regarded as obstacles where are below the shadow surface. The Republic of Korea inserted the new regulation including the applying shielding similar to ICAO on Aviation Act and regulations. It is, however, hard to manage the aviation obstacles around aerodrome efficiently with these new regulation. Particularly, there exists much rooms to dispute because it cannot suggest the specific standard which is necessary to apply shielding theory at airspace of aerodromes. Therefore, in this study, the international standards on aviation obstacles were reviewed, analyzed and compared with those of domestic status. The direction of which guideline for control of aeronautical obstacles applicable within domestic circumstances as well as correspondent with international standard was suggested. Particularly, as far as the disputable application of shielding theory is concerned, the alternatives for aviation safety and efficient airspace operation by suggesting the clear standards alternatives were suggested.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2008 (설비공학 분야의 최근 연구 동향: 2008년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il;Choi, Jong-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.12
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    • pp.715-732
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    • 2009
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

Quantitative evaluation of collapse hazard levels of tunnel faces by interlinked consideration of face mapping, design and construction data: focused on adaptive weights (막장관찰 및 설계/시공자료가 연계 고려된 터널막장 붕괴 위험도의 정량적 산정: 가변형 가중치 중심으로)

  • Shin, Hyu-Soung;Lee, Seung-Soo;Kim, Kwang-Yeom;Bae, Gyu-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.5
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    • pp.505-522
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    • 2013
  • Previously, a new concept of indexing methodology has been proposed for quantitative assessment of tunnel collapse hazard level at each tunnel face with respect to the given geological data, design condition and the corresponding construction activity (Shin et al, 2009a). In this paper, 'linear' model, in which weights of influence factors are invariable, and 'non-linear' model, in which weights of influence factors are variable, are taken into account with some examples. Then, the 'non-linear' model is validated by using 100 tunnel collapse cases. It appears that 'non-linear' model allows us to have adapted weight values of influence factors to characteristics of given tunnel site. In order to make a better understanding and help for an effective use of the system, a series of operating processes of the system are built up. Then, by following the processes, the system is applied to a real-life tunnel project in very weak and varying ground conditions. Through this approach, it would be quite apparent that the tunnel collapse hazard indices are determined by well interlinked consideration of face mapping data as well as design/construction data. The calculated indices seem to be in good agreement with available electric resistivity distribution and design/construction status. In addition, This approach could enhance effective usage of face mapping data and lead timely and well corresponding field reactions to situation of weak tunnel faces.

Recent Progress in Air Conditioning and Refrigeration Research - A Review of papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 1998 and 1999 - (공기조화, 냉동 분야의 최근 연구 동향 - 1998년 1999년 학회지 논문에 대한 종합적 고찰 -)

  • 이재헌;김광우;김병주;이재효;김우승;조형희;김민수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.12
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    • pp.1098-1125
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    • 2000
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

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A Study on Advancing Strategy for National Environmental Geographic Informations - Focused on the National Environmental Assessment Map, Ecological Map and Land Cover Map - (국토환경지리정보 고도화 전략 연구 - 국토환경성평가지도, 생태자연도, 토지피복지도를 중심으로 -)

  • Lee, Chong-Soo
    • Journal of Environmental Policy
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    • v.6 no.2
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    • pp.97-122
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    • 2007
  • In 2006, the Ministry of Environment of the Republic of Korea, completed the construction on national environmental geographic informations including National Environmental Assessment Map, Ecological Map, Land Cover Map and so on. At this point of time, it is necessary to establish the advance strategy on national environmental geographic information, considering the complicated characteristics. Therefore, this study suggests the advance strategy on national environmental geographic information, reflecting results of analyzing the given condition and the trend of informatization. National environmental geographic information has spacial quality to be managed dispersedly in a department unit or an operations unit. According to this quality, requirements for users who need the policy based on national environmental geographic information and complex information are not satisfactory. And, the information system centering the process of administrative affairs should be converted to one putting decision supporting first in importance. Therefore, this study sets up "the realization of the sustainable land management system by advancing national environmental geographic information" as the vision of the advancing strategy. In order to accomplish the vision, this study established the purpose as follow; constructing strategic and geographic information based on knowledge, arranging the foundation to open information to the public transparently, building expanded and integrated national environmental geographic information, embodying the environmental administration based on national environmental geographic information, enhancing the efficiency of national environmental geographic information, and supporting efficiently the process of administrative affairs. And this study suggests executive plans to achieve the vision and the purpose as next; developing the quality control program to verify the information confidence, building the system to integrate and to provide environmental information, collecting information, readjusting laws and regimes in parts of the construction, the application and the management of the system, and operating the task process, human power, organization and information technology. This study puts the emphasis on providing the turning opportunity politically which is possible to make sure of the information confidence in quality, advancing from the expansion of one in quantity. However, this improvement strategy doesn't reflect all national environmental geographic information and current status of environmental administrations. Therefore, for applying the result of this study to the actual environmental administration, it is necessary to discuss regularly the systematic categorization of national environmental geographic information, to interview with the contracting parties and so on hereafter.

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The Distribution and Characteristics of Use of Urban Farms - A Case Study of the Siji Region in Daegu Metropolitan City - (도시텃밭의 분포 및 이용 특성 - 대구광역시 시지지역을 사례로 -)

  • Nam, Tae-Ho;Jung, Tae-Yeol
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.6
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    • pp.1-9
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    • 2014
  • Within the urban area, over the past decades unused land and public land such as streams and road sides have given urban residents a space for farming (urban farms). However, because this use is illegal, farming in unused and public lands could cause conflicts between urban farm users and land owners, degrade the quality of the urban landscape and contaminate the environment. Therefore, the purpose of this study is to provide a way of legalizing these farming practices that have been cultivated in unused urban areas and public lands. This study analyzed the status of distribution and use of the urban farms that have been scattered around urban areas in many different forms. The survey was conducted through on-the-spot investigation and in-person interviews with farm users and those who were operating weekend farms in the Siji region of Daegu Metropolitan City. According to the results of this study, urban farms were mainly found in green areas that were easily accessible from residential districts and prohibited from development. It was also revealed that the nearer to the border of the residential districts the sites of urban farms were, the larger the number of urban farms was. When it comes to the type of land use, although the proportion of urban farms located in farmlands was very high, the proportion of those located on state-owned lands such as roads, railroads and streams was also high, over 1/3 of that of the former sites. Among the users of urban farms, the percentage of users who were farming private-owned land for free was highest and that of state-owned land without permission ranked second. Most people who were farming unused lands or state-owned lands without permission, such as streams, roads, railroads, were the elderly. This shows the potential of farms in urban area as leisure activities spaces for the elderly. Even though this study has limitations in that the survey target area was selected in a certain area and the sizes of all urban farms were not measured by surveying apparatus and instruments, it helps to determine the characteristics of use and distribution associated with the spaces of urban farming, and to raise the importance and necessity of legalizing urban farms cultivated illegally in public land.

A Study on the Tian-Ren relations theory of Wangfu (왕부(王符)의 천인관계론(天人關係論) 연구)

  • Cho, Won il
    • The Journal of Korean Philosophical History
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    • no.57
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    • pp.127-150
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    • 2018
  • Although Wangfu's Tian-Ren relations theory could not be free from the influence of the religious understanding of the Yinyangwuxing theory, which was prevalent in the times of two Hans, due to the limitations of the times, it refers to human status and capabilities here and there of the "Qianfulun" and traces of attempts to enhance humans' ability to preside and attempts to dilute the powers of Tian(heaven) and God can be found. In addition, the fact that the theory shifted the focus of the administration and politics of the state from Tian(heaven) to the people can be also said to be highly worthwhile. Of course, when seen from philosophical, political, social, and economic perspectives, Wangfu's primary concern can be said to have been the stabilization of people's livelihood. The influence and contribution of Wangfu's ?Qianfulun? as such on the aspects of political and philosophical thoughts in the society at the time can be said to be comparable to those of Wangchong. Although there are the limitations of the situations of the times faced by Wangfu that made him unable to surpass the standardized paradigm of the Tian-Ren response theory, when seen from other perspectives, the fact that he severely criticized the confused social conditions at that time unlike other intellectuals in the confused situations at the end of the East Han Dynasty period can be said to be worth affirmation. The fact that Wangfu, who tried to work on the basis, the stabilization of the people's livelihood, concentrated most of his energy on overcoming the situation of national internal and external troubles such as breaking down the bad customs of operating the national administration by religious notions such as natural calamity or superstition instead of trying to solve the problems of the times from the academic and ideological aspects as with Wangchong can be also said to be valuable in itself. In addition, Wangfu naturally became to take the lead in breaking down deeply superstitious notions such as the Yinyangwuxing theory and the Chanwei theory while he was conducting studies on how practical problems could be overcome facing the situations in the turbulent period.

Recent Progress in Air Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 (공기조화, 냉동 분야의 최근 연구 동향: 2006년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Shin, Dong-Sin;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.6
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    • pp.427-446
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    • 2008
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.

Diagnostic Availability of Estrogen Receptor Alpha mRNA on Cervical Cancer Tissue (자궁경부암 조직에서 에스트로겐 수용체 알파 mRNA의 진단적 유용성)

  • Kim, Geehyuk;Yu, Kwangmin;Kim, Jungho;Kim, Seoyong;Park, Sunyoung;Ahn, Sungwoo;Lee, Ji-Young;Kim, Sunghyun;Park, Ho-Hyun;Lee, Dongsup
    • Korean Journal of Clinical Laboratory Science
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    • v.50 no.4
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    • pp.449-456
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    • 2018
  • Cervical cancer is the fourth most frequently diagnosed cancer in women worldwide. In lower Human Development Index countries, it has the second highest incidence and mortality among cancer in women. Therefore, better diagnosis and treatment systems are needed. Among them, estrogen receptor alpha ($ER-{\alpha}$) mRNA expression has been analyzed with RT-qPCR since several studies reported that $ER-{\alpha}$ is necessary in the maturation of the uterus and is related to cervical cancer. In this study, $ER-{\alpha}$ quantitative analysis was performed on various lesions and normal tissue samples. Based on the receiver operating characteristic (ROC) curve, its sensitivity and specificity were 85% and 75%, respectively, showing higher or similar results to those of conventional HPV tests. In addition, its expression level was analyzed with clinical information. With regression analysis, the R square value between the $ER-{\alpha}$ mRNA expression level and menopause status was 0.5041, indicating a strong correlation. This study was performed as part of a pilot study and suggests that $ER-{\alpha}$ is related to carcinogenesis. Future studies will examine other hormones and menopausal factors with a larger sample size.