• Title/Summary/Keyword: 선택과 제거

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Development of Preliminary Quality Assurance Software for $GafChromic^{(R)}$ EBT2 Film Dosimetry ($GafChromic^{(R)}$ EBT2 Film Dosimetry를 위한 품질 관리용 초기 프로그램 개발)

  • Park, Ji-Yeon;Lee, Jeong-Woo;Choi, Kyoung-Sik;Hong, Semie;Park, Byung-Moon;Bae, Yong-Ki;Jung, Won-Gyun;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.21 no.1
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    • pp.113-119
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    • 2010
  • Software for GafChromic EBT2 film dosimetry was developed in this study. The software provides film calibration functions based on color channels, which are categorized depending on the colors red, green, blue, and gray. Evaluations of the correction effects for light scattering of a flat-bed scanner and thickness differences of the active layer are available. Dosimetric results from EBT2 films can be compared with those from the treatment planning system ECLIPSE or the two-dimensional ionization chamber array MatriXX. Dose verification using EBT2 films is implemented by carrying out the following procedures: file import, noise filtering, background correction and active layer correction, dose calculation, and evaluation. The relative and absolute background corrections are selectively applied. The calibration results and fitting equation for the sensitometric curve are exported to files. After two different types of dose matrixes are aligned through the interpolation of spatial pixel spacing, interactive translation, and rotation, profiles and isodose curves are compared. In addition, the gamma index and gamma histogram are analyzed according to the determined criteria of distance-to-agreement and dose difference. The performance evaluations were achieved by dose verification in the $60^{\circ}$-enhanced dynamic wedged field and intensity-modulated (IM) beams for prostate cancer. All pass ratios for the two types of tests showed more than 99% in the evaluation, and a gamma histogram with 3 mm and 3% criteria was used. The software was developed for use in routine periodic quality assurance and complex IM beam verification. It can also be used as a dedicated radiochromic film software tool for analyzing dose distribution.

Biocompatibility and Histopathologic Change of the Acellular Xenogenic Pulmonary Valved Conduit Grafted in the Right Ventricular Outflow Tract (우심실 유출로에 이식한 무세포화 이종 폐동맥 판막도관의 생체 적합성 및 조직병리학적 변화양상에 대한 연구)

  • 허재학;김용진;박현정;김원곤
    • Journal of Chest Surgery
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    • v.37 no.6
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    • pp.482-491
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    • 2004
  • Background: The xenogenic or allogenic valves after in Vitro repopulation with autologous cells or in vivo repo-pulation after acellularization treatment to remove the antigenicity could used as an alternative to synthetic polymer scaffold. In the present study, we evaluated the process of repopulation by recipient cell to the acellu-larized xenograft treated with NaCl-SDS solution and grafted in the right ventricular outflow tract. Material and Method: Porcine pulmonary valved conduit were treated with. NaCl-SDS solution to make the grafts acellularized and implanted in the right ventricular outflow tract of the goats under cardiopulmonary bypass. After evaluating the functions of pulmonary valves by echocardiography, goats were sacrificed at 1 week, 1 month, 3 months, 6 months, and 12 months after implantation, respectively. After retrieving the implanted valved conduits, histopathologic examination with Hematoxylin-Eosin, Masson' trichrome staining and immunohistochemical staining was performed. Result: Among the six goats, which had been implanted with acellularized pulmonary valved conduits, five survived the expected time period. Echocardiographic examinations for pulmonary valves revealed good function except mild regurgitation and stenosis. Microscopic analysis of the leaflets showed progressive cellular in-growth, composed of fibroblasts, myofibroblasts, and endothelial cells, into the acellularized leaflets over time. Severe inflammatory respon-se was detected in early phase, though it gradually decreased afterwards. The extracellular matrices were regenerated by repopulated cells on the recellularized portion of the acellularized leaflet. Conclusion: The acellularized xenogenic pulmonary valved conuits were repopulated with fibroblasts, myofibroblasts, and endothelial cells of the recipient and extracellullar matrices were regenerated by repopulted cells 12 months after the implantation. The functional integrity of pulmonary valves was well preserved. This study showed that the acellularized porcine xenogenic valved conduits could be used as an ideal valve prosthesis with long term durability.

Transaortic Mitral Commissuroplasty with a Bentall Procedure or Artic Valve Replacement (대동맥 판막 치환술과 벤탈 수술 환자에서 대동맥 근부를 통한 승모판막 교련 성형술)

  • Kim, Si-Wook;Park, Pyo-Won
    • Journal of Chest Surgery
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    • v.40 no.11
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    • pp.727-732
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    • 2007
  • Background: The reciptents of aortic valve replacement or a Bentall operation usually display various degrees of mitral regurgitation. When deciding whether or not to correct the mitral regurgitation, one must consider its severity, underlying causes and operative risk. Recently, the operation method for correcting the concomitant mitral regurgitation has been done through aortic root to reduce the operation time and the cardiac trauma. We report our experiences that transaortic mitral valve commissuroplasty done with aortic valve replacement or a Bentall operation has been a simple, less invasive, effective method in the operative management of mitral valve regurgitation without significant organic changes. Material and Method: Between June 2002 and June 2005, twenty patients under-went mitral valve commissuroplasty via the aortic root with aortic valve replacement (n=14) or a Bentall operation (n=7). The mitral valve regurgitation of the patients didn't exceed a moderate (grade 2) degree and there was no significant organic disease. The preoperative diagnosis of MR was established by TTE and intraoperative TEE, and the patients were followed postoperatively by TTE. The operative technique was a simple anterolateral commissuroplasty of the mitral valve with a single mattress suture via the transaortic annular approach after excision of the aortic valve leaflets. Result: The mean patient age was 56.2 years and 65% (n=13) were male. The preoperative MR was mild (grade 1) in 9 (45%), mild to moderate in 8 (40%), and moderate (grade 2) in 3 (15%) patients. There were no operative mortalities. The MR improved in all patients (p=0.002) and the left ventricular ejection fraction (LV EF) improved in 14 (70%) patients (p=0.005). The mean cross-clamp time for the patients who under- went aortic valve replacement with transaortic mitral repair was $62.1{\pm}13.9 min$ and this was $137.5{\pm}7.2 min$ for the patients who underwent a Bentall operation with transaortic mitral repair. Conclusion: For selected patients without significant mitral organic disease, transaortic mitral valve commissuroplasty combined with aortic valve replacement or a Bentall operation may be a feasible, effective method without adding significant aortic cross clamping time and more cardiotomy.

Development of 'Carbon Footprint' Concept and Its Utilization Prospects in the Agricultural and Forestry Sector ('탄소발자국' 개념의 발전 과정과 농림 부문에서의 활용 전망)

  • Choi, Sung-Won;Kim, Hakyoung;Kim, Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.358-383
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    • 2015
  • The concept of 'carbon footprint' has been developed as a means of quantifying the specific emissions of the greenhouse gases (GHGs) that cause global warming. Although there are still neither clear definitions of the term nor rules for units or the scope of its estimation, it is broadly accepted that the carbon footprint is the total amount of GHGs, expressed as $CO_2$ equivalents, emitted into the atmosphere directly or indirectly at all processes of the production by an individual or organization. According to the ISO/TS 14067, the carbon footprint of a product is calculated by multiplying the units of activity of processes that emit GHGs by emission factor of the processes, and by summing them up. Based on this, 'carbon labelling' system has been implemented in various ways over the world to provide consumers the opportunities of comparison and choice, and to encourage voluntary activities of producers to reduce GHG emissions. In the agricultural sector, as a judgment basis to help purchaser with ethical consumption, 'low-carbon agricultural and livestock products certification' system is expected to have more utilization value. In this process, the 'cradle to gate' approach (which excludes stages for usage and disposal) is mainly used to set the boundaries of the life cycle assessment for agricultural products. The estimation of carbon footprint for the entire agricultural and forestry sector should take both removals and emissions into account in the "National Greenhouse Gas Inventory Report". The carbon accumulation in the biomass of perennial trees in cropland should be considered also to reduce the total GHG emissions. In order to accomplish this, tower-based flux measurements can be used, which provide a direct quantification of $CO_2$ exchange during the entire life cycle. Carbon footprint information can be combined with other indicators to develop more holistic assessment indicators for sustainable agricultural and forestry ecosystems.

Research on Mobile Wheelchair Lift Design (이동식 휠체어 리프트 디자인 연구)

  • 이명기
    • Archives of design research
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    • v.15 no.4
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    • pp.275-284
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    • 2002
  • To improve the social and economic position of the disabled people and secure their human rights, an integrated society should be buill. To build such a society, an adequate access should be provided to the movement or in using buildings or facilities. The inconveniences from social life on the part of the disabled people might not result from their impairment or disability, but from physical and social barriers in the environment surrounding them. Therefore, it is necessary to reconstruct entire systems of the society as a disabled people-friendly structure in order to remove those barriers, make them stand their own feet in our communities and freely participate in the social activities. This will eventually lead to build a society in which all people including the disabled people can use those facilities in a more convenient way. It is almost impossible for the disabled people to safely and conveniently access to and use facilities and equipments and freely move to their desired places, without any help from others in Korea. Even though, there are currently many disabled people-related convenience facilities, they have been independently built without a connection with other facilities and buildings, thus not greatly useful. Even when convenience facilities have been built, mostly they are superficially set up; therefore, in many cases, the disabled peOple cannot use those facilities. In this. research, I tried a new concept of mobile wheelchair lift design, which the disabled people can operate without restrictions, when using the public facilities. The key to this research was to develop the existing import-oriented simple functional products to a new system with functional safety and high quality orientation. Also, this research aimed at bringing an. import substitution effect, as well as preempting the mobile wheelchair lift market by advancing into overseas markets through application of new image designs in the field of disabled people aid equipments.

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Comparison of Anticancer Activities of Ultrasonification Extracts of Callus and Roots from Rhodiola sachalinensis A. Bor (홍경천 뿌리 및 캘러스 초음파 추출물의 항암활성 비교)

  • Ha, Ji-Hye;Jeong, Hyang-Suk;Jeong, Myoung-Hoon;Kim, Seung-Seop;Jin, Ling;Nam, Jong-Hyun;Hwang, Baik;Ma, Choong-Je;Lee, Hyeon-Yong
    • Korean Journal of Food Science and Technology
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    • v.41 no.5
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    • pp.552-559
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    • 2009
  • In this study, the anticancer activity of the water extract at $100^{\circ}C$ was compared to that of the callus extracts via a ultrasonification extraction process. All the extracts were utilized to evaluate cytotoxicity, antioxidant and immune activities. The callus extracted via ultrasonification extraction showed relatively low cytotoxicity on normal human cell lines, HEK293 and HEL299, showing 13.17% and 21.78%, respectively. The callus extract has 59.82% which was similar to 61.70% for water extracts. It was also found that callus extract yielded higher nitric oxide secretion form macrophage than other extracts. The growths of both human stomach adenocarcinoma (AGS) cell and human lung carcinoma (A549) were inhibited up to 70% by adding 1.0 mg/mL of the callus extracts with ultrasonification extraction. This inhibition ratio (70%) was almost close to that of water extract. Human hepatoma carcinoma (HEP3B) cell growth was most significantly inhibited up to 75% by adding 1.0 mg/mL of callus extracts, and its selectivity was highest compared to other extracts. It indicates that the callus extracts could selectively inhibit growth of digestive system-related cancer cells. It can be also concluded from the results of this study that the callus extracts associated with ultrasonification extraction process have the potential for anticancer activity.

Developments of Water Treatment System by Biological Fluidized Bed for Water Reuse Aquaculture (생물학적 유동층을 이용한 어류양식 순환수의 처리씨스템 개발)

  • LEE Ki-Wan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.26 no.4
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    • pp.380-391
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    • 1993
  • The experimental study was made to propose the treatment method of wastewater in the high-density fish culture system. The BOD to COD ratios of effluents were almost same to 0.65 in the eel-farm, but were various in the farm rearing together with tilapia etc. A BOD rate curve of the eel-farm effluent could be described mathematically by the equation, $BODu=14.1(1-10^{-0.222t})+30.9(1-10^{-0.035(t-8)})$. Nitrification in Biological Fluidized Bed(BFB) system to treat the fish-farm wastewater could be reduce ammonium level up to $65{\sim}79\%$ when ammonium loading rates were between 0.014 and 0.075g $NH_4/g$ BVS-day. Nitrification efficiency was decreased by organic matters in the wastewater when ammonium loading was low(0.014 g $NH_4/g$ BVS-day). T-N removal ratios were decreased to increase loading in denitrification process, because of low C/N ratio. Based on much higher biological mass concentrations, BFB system takes many advantages of a practical viewpoint, such as stability of treatment efficiency and reduction of necessary site area for the facility, as compared with conventional treatment systems.

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Surgical Treatment of Pulmonary Atresia with Intact Ventricular Septum -Effect of the size of tricuspid valve annulus on the surgical outcome- (영아기에 발견된 심실중격이 온전한 폐동맥 폐쇄증의 외과적 수술요법 술전 삼첨판륜 크기 가 수술 결과에 미치는 영향)

  • 이정렬;윤태진
    • Journal of Chest Surgery
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    • v.29 no.10
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    • pp.1081-1089
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    • 1996
  • Pulmonary atresia with intact ventricular septum has continued to have a high surgical mortality and morbidity. This mAy attribute to the non-uniformity of the anomaly. We reviewed a total of 34 infants with pulmonary atresla and intact ventricular septum managed in this hospital between 1987 and 1995. Mean age and body weight were 57.2 (range, 3-208) days and 4.1 (range, B.3∼6.8) kg. The preoperative Z-value of the diameter of the tricuspid valve was less than -2 in 85.2% of patients and less than -4 in 33. 3% . It is well correlated w th right ventricular cavity size (n=27. r10.68, p< 0.05). Coronary artery-right ventricular fistulas were identified in 3 patients, and right ventricular dependency was suspected in 1 Over All hospital mortality was 23.5%(8/34), although it decreased to 16.6%(4124) in 1990s. Subsequent procedures were performed in 6 patients between 3 days and 58 months after Initial palliation : one bidirectional cavopulmonary shunt and 1 Fontan operation after systemic-pulmonary shunt, 3 transannular patch + atrial septal defect closure and 1 additional systemic-pulmonary shunt after polmonary valvectomy or valvotomy. Changes of Z-values of the diameter of tricuspid valve have been followed up in 11 patients between 1 and 66 months postoperatively. Z-values were increased In 5 out of 8 transannular right ventriculAr outflow tract enlargement group and in 1 out of 3 pulmonary valvectomy or valvotomy group. Our data suggest that tailoring a treatment to right ventricular cavity size and coronary anom lies may improve the surgical outcome. A Z-value of the tricuspid valve diameter could be used.

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Grain-Size Trend Analysis for Identifying Net Sediment Transport Pathways: Potentials and Limitations (퇴적물 이동경로 식별을 위한 입도경향 분석법의 가능성과 한계)

  • Kim, Sung-Hwan;Rhew, Ho-Sahng;Yu, Keun-Bae
    • Journal of the Korean Geographical Society
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    • v.42 no.4
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    • pp.469-487
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    • 2007
  • Grain-Size Trend Analysis is the methodology to identify net sediment transport pathways, based on the assumption that the movement of sediment from the source to deposit leaves the identifiable spatial pattern of mean, sorting, and skewness of grain size. It can easily be implemented with low cost, so it has great potentials to contribute to geomorphological research, whereas it can also be used inadequately without recognition of its limitations. This research aims to compare three established methods of grain-size trend analysis to search for the adequate way of application, and also suggest the research tasks needed in improving this methodology 1D pathway method can corporate the field experience into analyzing the pathway, provide the useful information of depositional environments through X-distribution, and identify the long-term trend effectively. However, it has disadvantage of the dependence on subjective interpretation, and a relatively coarse temporal scale. Gao-Collins's 2D transport vector method has the objective procedure, has the capability to visualize the transport pattern in 2D format, and to identify the pattern at a finer temporal scale, whereas characteristic distance and semiquantitative filtering are controversial. Le Roux's alternative 2D transport vector method has two improvement of Gao-Collins's in that it expands the empirical rules, considers the gradient of each parameters as well as the order, and has the ability to identify the pattern at a finer temporal scale, while the basic concepts are arbitrary and complicated. The application of grain sire trend analysis requires the selection of adequate method and the design of proper sampling scheme, based on the field knowledge of researcher, the temporal scale of sediment transport pattern targeted, and information needed. Besides, the relationship between the depth of sample and representative temporal scale should be systematically investigated in improving this methodology.

The efficacy of denture cleansing agents: A scanning electron microscopic study (수종 의치세정제의 세척 효과에 관한 주사전자현미경적 비교 연구)

  • Yun, Bo-Hyeok;Yun, Mi-Jung;Hur, Jung-Bo;Jeon, Young-Chan;Jeong, Chang-Mo
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.1
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    • pp.57-64
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    • 2011
  • Purpose: The purpose of this study was to compare the cleansing performance of a distilled water, a diluted solution of sodium hypochlorite as a household bleaching cleanser and three alkaline peroxide cleansers in vivo plaque deposits by using scanning electron microscope. Materials and methods: Five individuals were selected from department of the prosthodontics in Pusan National University Hospital, and each of them was inserted with specimens for plaque accumulation in their temporary dentures for 48 hours. The specimens were removed and cleaned by each cleansing agents for 8 hours. Scanning electron micrographs were made from the specimens at a magnification of ${\times}2,000$. A panel of ten persons with a dental or paradental background, but not directly involved in the study, was selected to analyze the photomicrographs to determine which denture cleanser was more effective in removing plaque. Results: Diluted solution of sodium hypochlorite was the most effective at removing plaque following $Polident^{(R)}$, $Cleadent^{(R)}e$, $Bonyplus^{(R)}$ and distilled water in order. But there was no significant difference of cleansing efficacy between diluted solution of sodium hypochlorite and $Polident^{(R)}$, $Polident^{(R)}$ and $Cleadent^{(R)}e$, $Cleadent^{(R)}e$ and $Bonyplus^{(R)}$, respectively (P > .05). Alkaline peroxide cleansers by themselves cannot adequately remove accumulated plaque deposits, especially if the deposits are heavy. Corrosion could be seen on the surface of non-precious alloy specimens immersed in diluted solution of sodium hypochlorite. Conclusion: It is recommended to use of alkaline peroxide type cleansers with brushing whenever possible, since denture cleanliness is often poor due to the relative inefficiency of these cleansers.