• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3026-3034
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• 2021

Multi-target X-ray tube is a new type X-ray source, and can be applied in many fields such as sensitive X-ray fluorescence analysis and medical imaging. In this work, we report an electric field modulation multi-target X-ray tube, which contains four targets (Cr, Ni, Au, Mo) coated on a Beryllium (Be) window. A four-valve electric field deflector was developed to deflect the electron beam to bombard the corresponding targets. Particle dynamics analysis software was employed to simulate the particle tracking of electron beam. The results show that the 30 keV electron beam could get a 6.7 mm displacement on the target plane by 10⁵ V/m electric field. The focus areas are about 2 mm × 5 mm and 4 mm × 2.5 mm after deflection in two directions. Thermal behavior calculated by ANSYS shows that the designed target assembly could withstand a 10 W continuous power. The optimum target thicknesses and emission spectra were obtained by Geant4 when the thickness of Be window was 300 mm and the electron beam incident angle was 0.141 rad. The results indicate that this multi-target X-ray tube could provide different X-ray sources effectively.

• 대한약침학회지
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• 제22권1호
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• pp.35-40
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• 2019

Objective: Adriamycin (ADR) is an important anti-cancer drug which can cause renal toxicity. Given the known anti-inflammatory and antioxidant effects of Plantago major (P. major), the aim of this study was to determine the effects of hydroalcoholic extract of P. major on ADR- induced nephropathy in rats. Methods: Fifty male Wistar albino rats were randomly divided into 5 groups including: control, ADR (5 mg/kg), ADR + P. major (600 and 1200 mg/kg) and P. major (1200 mg/kg). The animals were treated with P. major extract for 5 consecutive weeks and ADR was intravenously injected on the 7th day of the study. Urine and serum samples were collected on days 0, 14, 21, 28, and 35 for the measurement of serum cholesterol and albumin levels and urine protein excretion rate. At the end of the study, the left kidneys were removed for apoptosis assessment. Results: Administration of ADR significantly decreased serum albumin level and increased serum cholesterol and urine protein excretion rate as well as, apoptotic cell numbers compared to the control group (P < 0.001) while had no effect on glomerular filtration rate (P > 0.05). Treatment with P. major, in both 600 and 1200 mg/kg doses, increased serum albumin level and decreased serum cholesterol concentration, urine protein excretion rate and as well as the number of apoptotic cell compared to the ADR group (P < 0.001). Conclusion: Our results showed that the P. major extract effectively protects against ADR- induced nephropathy by reducing kidney apoptosis and improving renal functioning in rats.

• 대한약침학회지
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• 제21권4호
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• pp.249-257
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• 2018

Objectives: The hepatotoxicity induced by Acetaminophen (AAP) mostly mediated by effect on oxidative stress parameters. The Zataria multiflora (Z.M) is an herbal medicine with well-known antioxidant effect. The aim of this study is investigation of preventive effects of Z.M and Carvacrol (CAR) on AAP-induced hepatotoxicity in rats. Methods: Rats were randomly divided into four groups including: 1) Control, 2) Acetaminophen (AAP), 3) and 4) CAR. The saline, Z.M (200 mg/kg) and CAR (20 mg/kg) were administrated orally for 6 days, after that AAP (600 mg/kg) was administrated in the $7^{th}$ day. Blood sampling was performed on the first and last days. Also, the liver tissue was removed for evaluation of Malondyaldehide (MDA), Thiol content, Superoxide dismutase (SOD) and Catalase (CAT). Total Protein (tPro), Glutamic Oxaloacetic Transaminase (GOT), Glutamic Pyruvic Transaminase (GPT) and Alkaline Phosphatase (ALP) in liver tissue were evaluated. The changes (${\Delta}$) of enzymes activities were presented. Results: The ${\Delta}GOT$, ${\Delta}GPT$ and ${\Delta}ALP$ in CAR group significantly decreased compared to AAP group (P < 0.01 to P < 0.001) and ${\Delta}GPT$ in Z.M group was significantly reduced in comparison with AAP group (P < 0.05). Also, MDA, Thiol, SOD and CAT levels in treated groups were attenuated compared to AAP group (P < 0.05 to P < 0.001). Conclusion: Z.M and CAR have a powerful hepatoprotective effect. CAR is more effective than Z.M. Based on the results. Z.M and CAR could be potent supplementary agents against hepatotoxicity of AAP in patients.

• Journal of Preventive Medicine and Public Health
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• 제54권1호
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• pp.73-80
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• 2021

Objectives: Household overcrowding (HC) can contribute to both physical and mental disorders among the members of overcrowded households. This study aimed to measure the status of HC and its main determinants across the provinces of Iran. Methods: Data from 39 864 households from the 2016 Iranian Household Income and Expenditures Survey were used in this study. The Equivalized Crowding Index (ECI) and HC index were applied to measure the overcrowding of households. Regression models were estimated to show the relationships between different variables and the ECI. Results: The overall, urban, and rural prevalence of HC was 8.2%, 6.3%, and 10.1%, respectively. The highest prevalence of HC was found in Sistan and Baluchestan Province (28.7%), while the lowest was found in Guilan Province (1.8%). The number of men in the household, rural residency, the average age of household members, yearly income, and the household wealth index were identified as the main determinants of the ECI and HC. Conclusions: The study demonstrated that the ECI and HC were higher in regions near the borders of Iran than in other regions. Therefore, health promotion and empowerment strategies are required to avoid the negative consequences of HC, and screening programs are needed to identify at-risk families.

• 한국환경보건학회지
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• 제47권4호
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• pp.330-338
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• 2021

Background: This study was conducted to provide background information for the proper management of radon contamination in apartments using mechanical ventilation facilities in residential environments. Objectives: To this end, this study compared and evaluated changes in radon concentrations based on different operating intensities of mechanical ventilation with or without natural ventilation. Methods: For the continuous measurement of radon concentrations, an RAD7 instrument was installed in four apartments equipped with a ventilation system. The measurements were done for comparison of ventilation types and different ventilation intensities ("high", "middle", "low"). Results: The results confirmed that both mechanical and natural ventilation sufficiently reduced the radon concentration in the apartments. In particular, mechanical ventilation at "high" intensity was the most effective. Natural ventilation combined with mechanical ventilation and then natural ventilation alone were the second and the third most effective, respectively. Conclusions: When using ventilation to reduce indoor radon concentrations, it is most effective to operate mechanical ventilation ("high") or natural ventilation and mechanical ventilation at the same time. In cases where mechanical ventilation is available alone, it is recommended to operate it at a minimum of "middle" intensity.

• 한국산업정보학회논문지
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• 제15권4호
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• pp.7-15
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• 2010

본 연구는 SC-FDMA(Single Carrier-Frequency Division Multiple Access) 접속기술을 사용하는 LTE(Long Term Evolution) 상향링크의 성능을 최대화하기 위한 무선자원관리(radio resource management) 기법을 제안한다. 셀간의 상호작용을 고려해야하는 다중셀(multi-cell) 시스템을 대상으로 하여 단일셀 대상의 기존 SC-FDMA관련 연구와는 차별화된다. 본 연구는 무선자원관리를 무선자원 계획단계(planning phase)와 운용단계(operation phase)로 구분하여 정의한다. 계획단계는 마스터 eBN(evolved-NodeB)가 소속된 eNB에 연속적인 무선자원(RB; radio bearer)를 배정하기 위한 것이고 운용단계는 eNB가 마스터 eBN로부터 배정받은 RB를 단말기에 할당하기 위한 것이다. 두 단계에 대하여 각각 최적화 문제를 모형화하고 각 모형에 대한 탐색적 해법을 제시한다. 제시하는 해법은 인접해중에서 목적함수 개선치가 가장 높은 방향으로 이동하는 일반적인 형태를 띄고 있다. 다수의 실험결과를 통하여 두 알고리즘의 성능과 특징을 분석하였다. 본 연구는 다중셀 SC-FDMA 시스템을 대상으로 효율적인 무선자원 관리 기법을 개발하기 위한 연구에 선구자적인 역할을 할 것으로 기대된다.

• 한국비블리아학회지
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• 제17권2호
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• pp.137-155
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• 2006

행정박물은 증거적 가치, 역사적 가치, 행정적 가치를 지닌 기록물의 한 종류이다. 그러나 이러한 행정박물에 대한 연구가 미비 되어 있고 소홀히 관리되어 오고 있다. 따라서 본 논문에서는 박물자료의 체계적인 관리를 위해 행정박물의 기술요소(안)을 제시함을 목적으로 하였다. 행정박물의 기술요소안의 제시를 위해서 기록물 기술규칙이 마련되어 있는 국가의 기술규칙인 RAD와 기록물 표준 기술규칙인 ISAD(G)와 도서관계에서 사용되어 오던 기술규칙인 AACR2와 KCR4의 비교, 분석을 하였으며 이를 토대로 행정박물에 대한 기록물 기술규칙을 제시해 보았다. 행정박물에 대한 기술요소 제시(안)은 식별영역, 배경영역, 내용과 구조영역, 열람과 이용조건 영역, 연관자료 영역, 주기영역, 기술통제영역으로 구분하여 제시하고 박물관에서 사용하는 분류체계의 내용요소를 참고하여 그에 따른 하위 요소별 내용요소들을 제시하였다.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1538-1543
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• 2024

The importance of determining the radon exhalation rate from water surface is emphasized by the increased use of radon and its daughter products as tracers in large-scale circulation studies of the atmosphere. There were many methods to measure radon exhalation from water surface. With the development of radon exhalation rate measurement methods and instruments on the surface of the soil, the rock and building materials, so the radon exhalation rate from water surface can be more accurately measured by applying these improved methods and instruments. In this paper, a cuboid accumulation chamber surrounded by foam boards and a RAD7 were used to measure the radon exhalation rate on the water surface at three different positions by Yixin lake. Each measurement was performed 2 h. The radon exhalation rate from the water surface was about 6 × 10^-3 Bq m^-2s^-1. The thoron exhalation rate from the water surface also can be estimated, it is about 0.16 Bq m^-2s^-1. These results hint that the radon transmission from the lake bottom soil to water and then into the atmosphere.

• 대한방사선기술학회지:방사선기술과학
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• 제38권3호
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• pp.205-211
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• 2015

복부 전후 방향 검사 시 automatic exposure control (AEC) mode에서 조사시간을 제한하지 않고 검사를 하는 방법 (non-time limit, NTL) 과 조사시간을 제한하고 검사하는 방법 (time limit, TL)에 대해서 영상 품질 평가인 신호 대 잡음비 (signal to noise ratio, SNR), 대조도 대 잡음비 (contrast to ratio, CNR)를 측정하여 TL 방법과 NTL방법을 비교 평가하고자 하였다. 실험 기기는 XGEO GC 80 (Samsung, Korea), Unfors ThinX RAD (Unfors, Sweden), Rando Phantom (alderson research laboratories, USA)과 $5.5{\times}9{\times}0.1cm^3$ 크기의 차폐재를 사용하였으며, AEC mode에서 전리함 (ionization chamber)를 상단 2 개만 작동하도록 설정하고 관전압은 80 kVp로 설정하였다. TL 방법의 경우에는 조사시간을 51 msec로 제한하였으며, 전리함에 차폐재를 부착하지 않은 상태와 부착한 상태에서 NTL AEC mode와 TL AEC mode의 영상을 획득하였다. 또한 'Image J"를 이용하여 영상 평가방법인 SNR과 CNR로 평가하였다. 결론적으로 차폐재를 부착했을 때 NTL AEC mode가 다른 실험 방법보다 선량이 최대 130.7% 최소 80%까지 증가한 결과 값을 보였으며, TL AEC mode는 NTL AEC mode보다 mAs와 피폭선량에서 각 각 43.8%, 44.4% 감소한 값을 보였다. 통계적으로는 SNR과 CNR은 유의한 차이를 보이지 않았다($p{\geq}0.05$). 그러므로, 본 연구에서는 BMI 지수가 높은 환자나 수술 후 인체 내에 금속물질이 있는 환자를 검사할 경우에는 TL AEC mode가 유효한 검사법이라고 사료된다.

• Journal of Chest Surgery
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• 제29권4호
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• pp.386-392
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• 1996

전북의대 흉부외과학교실에는 1984년 1월부터 1993년 6월까지 치험한 20세이상의 성인 심방중격 결손 60예를 대상으로 수술전후 결과를 분석하였다. 평균연령은40.2$\pm$ 12.5세였고남녀비는 1:2.3이었다 60예의 선천성 심방중격결손증에서 1차형 심 방중격이 2예, 2차형 심방중격이 58예이었고 수술은 1차공형은 모두 심막절편으로 폐쇄하였으며, 2 차공형은 78 %에서 단순봉합을 22 %에서는 심막절편으로 결손을 폐쇄하였다. 가장 흔한 증상은 운 동시 호흡곤란이었고 술전 NYHA 기능본류는 class 110예, class II 31예, class III 19예이 었고 class IV는 없었다. 술전 심전도 소견은 동정동 환자가 81%,동성 부정맥,동성서맥과 심방세동등의 부정맥이 19%, 우측편위가 30%, 우심실비대 32%에서 있었고, 전도장애의 소견중에 서는 불완전우각차단이 22% 로 가장 많았다. 술후 변화된 심전도 소견으로는 2예에서 심 방세동이, 1예에서 동성 빈맥 이 발생되 었 으나 모두 자연소실되거나 약물투여로 맥박조절이 가능하였으며 4예에서 우심실비대의 소실을, 2예 에서 우심방확장 소실이 관찰되 었다. 혈역학적 검사성적상 평균 Qp/qs는 술전, 술후 각각 3.75$\pm$1.21와 1.17 $\pm$ 0.11, 평균 Rp/Rs는 0.11 $\pm$ 0.09와 0.09 $\pm$ 0.12, 평균 수축기 폐동맥 압은 36.18 $\pm$ 14.05rnmHg와 24 $\pm$ 3.6이었다. 혈역학적 검사 성적을40세 이상과 40세 이하의 군으로 나눠 비교한 결과 40세 이상의 군에서 유의하게 수축기폐동 맥압이 높았으며 또 동정동 군자 부정맥 군의 비교에 있어서는 부정맥 군에서 평균연령과 평균수축 기 폐동맥 압이 높았다. 수술합병증은 부정맥 3예, 각각 1예의 기흥,혈흉,간염,탈모증이 있었으며 수술 사망예는 없었다. 평균 4년 7개월의 추적관찰기간중 45%에서 술후 중상의 호전을 보였다.