• Journal of Gastric Cancer
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• 제21권4호
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• pp.426-438
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• 2021

Purpose: While the incidence of Barrett's neoplasia has been increasing in Western countries, the disease remains rare in Asian countries. Therefore, very few studies have investigated the endoscopic treatment for Barrett's neoplasia in Korea. Endoscopic submucosal dissection (ESD) enables en bloc and complete resection of gastrointestinal neoplastic lesions. This study aimed to evaluate the therapeutic outcomes of ESD for Barrett's neoplasia in a single center in Korea and to examine the predictive factors for incomplete resection. Materials and Methods: We conducted a retrospective observational study of 18 patients who underwent ESD for superficial Barrett's neoplasia (dysplasia and early cancer) between January 2010 and December 2019 at Pusan National University Hospital. The therapeutic outcomes of ESD and procedure-related complications were analyzed. Results: En bloc resection, complete resection, and curative resection were performed in 94%, 72%, and 61% of patients, respectively. Histopathology (submucosal or deeper invasion of the tumor) was a significant predictive factor for incomplete resection (P=0.047). Procedure-related bleeding and stenosis were not observed, whereas perforation occurred in one case. During the median follow-up period of 12 months (range, 6-74 months), local recurrence occurred in 2 patients with incomplete resection, one patient underwent repeat ESD, and the other patient received concurrent chemoradiotherapy. The 3-year overall and disease-specific survival rates were 73% and 93%, respectively. Conclusions: ESD seems to be an effective and safe treatment for superficial Barrett's neoplasia in Korea. Nevertheless, the suitability of ESD for Barrett's cancer cases should be determined considering the high risk of deep submucosal invasion.

• The Journal of Advanced Prosthodontics
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• 제14권5호
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• pp.315-323
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• 2022

PURPOSE. The purpose of this study was to investigate the effect of barium silicate filler contents on mechanical properties of resin nanoceramics (RNCs) for additive manufacturing (AM). MATERIALS AND METHODS. Additively manufactured RNC specimens were divided into 4 groups depending on the content of ceramic fillers and polymers: 0% barium silicate and 100% polymer (B0/P10, control group); 50% barium silicate and 50% polymer (B5/P5); 60% barium silicate and 40% polymer (B6/P4); 67% barium silicate and 33% polymer (B6.7/P3.3). The compressive strength (n = 15) and fracture toughness (n = 12) of the specimens were measured, and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) analyses were performed. Independent sample Kruskal-Wallis tests were performed on the compressive strength and fracture toughness test results, and the significance of each group was analyzed at the 95% confidence interval through post-tests using the Bonferroni's method. RESULTS. B6/P4 and B6.7/P3.3 exhibited much higher yield strength than B0/P10 and B5/P5 (P < .05). Compared to the control group (B0/P10), the other three groups exhibited higher ultimate strength (P < .05). The fracture toughness of B6/P4 and B6.7/P3.3 were similar (P > .05). The content of barium silicate and fracture toughness showed a positive correlation coefficient (R = 0.582). SEM and EDS analyses revealed the presence of an oval-shaped ceramic aggregate in B6/P4 specimens, whereas the ceramic filler and polymer substrate were homogeneously mixed in B6.7/P3.3. CONCLUSION. Increasing the ceramic filler content improves the mechanical properties, but it can be accompanied by a decrease in the flowability and the homogeneity of the slurry.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1587-1592
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• 2023

Time-encoded imagers (TEI) are important class of instruments to search for potential radioactive sources to prevent illicit transportation and trafficking of nuclear materials and other radioactive sources. The energy of the radiation cannot be known in advance due to the type and shielding of source is unknown in practice. However, the response function of the time-encoded imagers is related to the energy of neutrons or gamma-rays. An improved image reconstruction method based on MLEM was proposed to correct for the energy induced response difference. In this method, the count vector versus time was first smoothed. Then, the preset response function was adaptively corrected according to the measured counts. Finally, the smoothed count vector and corrected response were used in MLEM to reconstruct the source distribution. A one-dimensional dual-particle time-encode imager was developed and used to verify the improved method through imaging an Am-Be neutron source. The improvement of this method was demonstrated by the image reconstruction results. For gamma-ray and neutron images, the angular resolution improved by 17.2% and 7.0%; the contrast-to-noise ratio improved by 58.7% and 14.9%; the signal-to-noise ratio improved by 36.3% and 11.7%, respectively.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2662-2669
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• 2023

For the precise measurements of special nuclear materials (SNM) including Pu and Am isotopes, we have used phoswich detector combination of two single crystal scintillators of Gd₃Ga₃Al₂O₁₂:Ce and CsI:Tl. High detection efficiency and sensitivity along with high figure of merit for the discrimination of these phoswich detectors ensures the detection and discrimination of thermal neutrons and gammas from spontaneous fission of Pu and other isotopes in presence of high gamma background. Using this detector, the low energy gammas, which is stopped completely in 1mm thick disc of GGAG, can be also discriminated from high energies gamma and shows linearity in wide range of sample quantities. By changing only the appropriate shielding, the similar setup was used for thermal neutron detection and shows a very good linearity over wide range. The quantity of a test sample was also calculated accurately by using the measured calibrated plot.

• Journal of Digestive Cancer Research
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• 제4권1호
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• pp.32-35
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• 2016

복막 가성점액종은 표준치료인 종양감축수술과 함께 복강 내 고온열 항암요법과의 병합치료로 생존율의 향상을 기대할 수 있다. 재발성 병변에 대해서는 추가적인 종양감축 수술이 권고되고 있지만, 치료시기에 따른 이환율과 사망률의 차이가 있어 조기발견이 중요하다. 수술 전 혈청 종양표지자 검사의 수치 이상 여부에 따른 재발과 생존율의 상관관계를 알아보고자 하는 연구들은 있지만, 추적관찰 중 수치 이상에 따른 재발여부에 관한 연구는 거의 없다. 저자들은 CSR과 HIPEC, 그리고 전신 항암화학요법을 시행받은 환자에서 CEA의 수치 상승이 질병의 재발과 상관관계가 있었음을 경험하였기에 보고하는 바이다.

• 환경영향평가
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• 제16권1호
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• pp.69-77
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• 2007

This study has been conducted to assess blackish-water phenomena in Dam reservoir. To searching for the reason, we survey physical changes in reservoir and analyze metal and organic content in particulate materials and water. The blackish-water phenomena in lake A are occurred with turbidity increases in turnover season irregularly. It was reported on 6 Jan. 2005 weakly and the water column mixed with 35~40m depth and water temperature shows $7^{\circ}C$. The turbidity of AD and AM site increased up to 20NTU. Especially, AN site shows 27NTU, such a result makes that Dam manager conclude it to blackish-water phenomena. The results of sequential extraction analysis show that over 80% of Al, Cr and Fe is existed in residual form in sediment. On the other hand, the most part of Mn shows exchangeable and carbonates form, which have a good possibility of release to water column. Mn contents in pore waters of the sediment samples are also found to be ~4 times higher than Fe contents. The metal contents in pore water of different dam sites are in order of AN (Fe: 9.98, Mn: 40.6) > AD(8.33, 37.5) > DD(1.91, 2.55). According to the results of extracted organic materials from sediment, humic substances is occupied with over 85% in total organic carbon including 23~45% of humic acid (HA) and 0.9~8.5% of fulvic acid (FA). However, HA content in pore water is not detectable while FA contents, acid-soluble humic fractions is higher than that of sediment(10~15%). which indicating that FA is a main humic components affecting water color. The color unit per DOC of FA in pore waters of different dam sites are found to be higher in lake A than lake D. From the results, it could be suggested that blackish-water phenomena of lake A are mainly arise from higher concentration of Mn and water soluble organic fractions (e.g., FA) released from sediments as well as the strength of turnover in Dam reservoir.

• 한국산학기술학회논문지
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• 제18권11호
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• pp.731-739
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• 2017

오늘날 3D 프린팅 기술은 다품종 소량 생산 및 맞춤형 생산, 생산 비용 및 시간 절감의 가능성이 가시화되고 있으며, 그 활용 범위가 제조업분야에서 건축분야로 확장되고 있다. 최근 국외를 중심으로 3D 프린팅 기술을 이용한 건축물, 건축 부재 및 부품을 제작한 사례가 등장하고 있으며, 국내에서도 건축 설계 및 시공 기술과 3D 프린팅 재료 및 장비 등 제반 기반 기술 개발이 이루어지고 있다. 건축분야의 3D 프린팅 기술은 도입 초기 단계로 시제품 제작 수준이나, 향후 상용화 단계로 발전하기 위해서는 현 업계의 실정을 고려한 현실적이고 체계적인 도입 전략이 필요하다. 이에 본 연구는 국내 건축분야 3D 프린팅 기술이 상용화 단계로 도입하기 위한 기반 연구로서, 3D 프린팅 기술의 도입에 대한 실무자 인식에 대한 현황을 파악하고자 설계, 시공, 자재 및 3D 프린팅 전문가를 대상으로 설문조사 및 면담을 실시하였다. 인식 현황 분석 결과, 실무에서는 3D 프린팅 건설 기술이 일반 건설시장의 대체 형태보다는 비정형 건축물, 특수한 디자인 형태의 소형 건축물, 인테리어 시장 중심으로 상용화될 것으로 전망하고 있었다. 상용화가 기대되는 3D 프린팅 건축 상품은 부재 및 부품 단위 수준으로 제한적이며, 경제성과 기능성보다는 심미성이 상품 경쟁력의 가장 큰 요인으로 인식하고 있었다. 향후 시설물 단위의 상품으로 상용화 가능성을 높이기 위해서는 재료와 장비의 성능, 안정성 확보와 함께 건축에 특화된 공법 및 정책과 제도가 요구되는 것으로 파악되었다.

• 한국지역사회생활과학회지
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• 제18권2호
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• pp.323-334
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• 2007

This study was made to analyze the condition and the needs of nutrition education considering the different stage of nutrition education recognized by the dietitian in industrial area. 165 female dietitian were surveyed by questionnaire and they were divided into 4 groups according to the different recognition stages of nutrition education: Pre-contemplation(PC) 4.8%, Contemplation(CO) 46.7%, Preparation(PR) 22.4%, Action & Maintenance phase(AM) 26.1%. For statistical analysis, SAS(Ver.8.1. for Window) was used to find out the distribution related with nutrition education and to calculate the scores of mean and standard deviation. General characteristics of the subjects are about 20 years old(71.5%), single(69.7%), careers over 5 years(40%) and university graduates(73.9%). The number of meals(p<0.05) and the employment status(p<0.05) were significantly different according to the recognized stage of nutrition education. The practice of nutrition education was different depending on the dietitian in the industry. Many of the factory dietitian were in pre-contemplation stage(87.5%), however, those in the office and service area were more in Action & Maintenance stage(27.9%). In the industrial area, just 26.1% of dietitian operated the nutrition education and most did not due to the work overload and insufficient support of staff(73.3%). The frequency for the most effective nutrition education was once a month(61.2%). The contents for desirable nutrition education were in the order of 'eating habits'(36.1%), 'relation with the daily life'(23.5%), 'food hygiene' (21.7%), 'nutrition knowledge'(9.7%), and 'disease prevention'(9%). In operating nutrition education, dietitian had concerns about 'insufficient support of staff', 'shortage of teaching materials' and 'lack of time'. And, the dietitian who were with lower recognition stage of nutrition education(P<0.05) concerned more about the insufficient educational contents. In conclusion, dietitian in the industry highly recognized the need of nutrition education, but it was so difficult to practice. For more programs and various materials should be developed, and the staff's perception, the view of dietitian and the meal service should be changed, too. For the health improvement of industrial workers, it would be necessary to proclaim the importance of nutrition education nationwide.

• 한국재료학회지
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• 제8권2호
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• pp.135-140
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• 1998

본 연구에서는 회전 원판 장치에 고분자-계면활성제의 혼합체를 첨가제로 사용하여 난류 유동장에서의 마찰저항 감소효과에 대해서 조사 연구하였다. 세가지의 분자량이 다른 PAA를 마찰저항 감소효과에 영향을 줄 수 있는 여러 인자들에 대헤서 살펴 보았다. 특히 이 연구에서는 이온성 고분자와 계면활성제의복합체가 마찰저항 감소현상에 어떠한 영향을 미치는 지에 대해서 연구하였다. 계면활성제와 고분자첨가제 사이의 형태학적 차이점에 특별한 관심을 가지고 실험을 하였으며 이온성 고분자의 pH에 대한 영향에 대해서도 조사하였다. 고분자와 계면활성제간의 복합체는 거대한 전해질과 같은 거동을 보이며 계면활성제가 고분자의 형태를 변화시켜 고분자의 크기를 확대시킨다. 따라서 이러한 복합체는 단일 고분자계와 비교해서 수력학적부피, 관성반경, 점도등의 값이 크게 나타나며 이렇게 팽창된 고분자는 난류 유동장에서의 마찰저항 감소효율을 증가시킨다.

• 디지털융복합연구
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• 제15권4호
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• pp.233-242
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• 2017

간호대학생의 카데바 모델을 이용한 인체 해부 관찰 경험을 확인하여 카데바 실습 프로그램 개발 및 해부학 교육과정 등의 기초자료를 제공하기 위함이다. 19명을 대상으로 2팀의 포커스그룹 인터뷰(Morgan, 1997)로 수집된 자료를, Colaizzi 분석방법을 선택하여 간호대학생의 카데바 모델을 이용한 인체 해부 관찰 경험의 의미와 그 본질을 파악하고자 하였다. 간호대 학생의 카데바 모델을 이용한 인체 해부 관찰 경험에 대한 분석 결과는 6개 범주와 13개의 주제묶음(theme clusters)으로 도출되었다. 본질적 구조로는 '카데바 실습에 대한 양가감정', '실제에 맞닥뜨림', '값진 것을 배움', '인간을 대하는 마음이 깊어짐', '간호인이 되어 감을 느낌', '온전히 내어줌에 대한 숙고.'등 6개의 범주로 도출되었다. 간호대학생은 카데바 실습을 통해 해부학에 대한 이해뿐만 아니라 인간의 이해, 생명 및 존중, 죽음, 직업윤리 등을 경험하고 또 고민하면서 간호인이 되어가는 것을 확인하였다. 본 연구의 결과는 향후 해부학교육에 대한 기초자료 뿐 만 아니라 해부학교육의 효과를 극대화하기 위한 교육방법에 도움이 되고, 인간의 이해 및 생명윤리, 간호윤리 등을 확립 할 수 있는 교육프로그램을 위해 기초자료로 활용될 것이다.