• 제목/요약/키워드: radiation category

검색결과 56건 처리시간 0.028초

암 환자 삶의 질에 대한 근거이론적 접근 (Quality of Life in Cancer Patients;Grounded Theory)

  • 이은현;송영숙;전미선;오가실;이원희;이영희
    • 종양간호연구
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    • 제4권1호
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    • pp.71-81
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    • 2004
  • The purpose of the study was to understand and explore the quality of life in cancer patients in the context of a Korean culture and society. Grounded theory method guided the data collection and analysis. A total of 10 cancer patients was selected by a theoretical sampling. The data were collected by an open question. All interviews were audio taped and transcribed verbatim. Constant comparison analysis was employed to analyze the data. As the results, eighty-five concepts and twelve categories were emerged, and "keeping well-being status" identified as a core category. Quality of life related categories derived from this study will academically contribute to the understanding and expansion of theoretical bases for quality of life of Korean cancer patients and to the contexts for the development of measurement of quality of life. Furthermore, they will function as the foundation of a intervention development for quality of life.

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자외선 차단 제품의 SPF 측정과 안전성 (SPF Evaluation and Safety of Sunscreen Products)

  • 김종일;이병곤;고재숙
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 1992년도 자외선 차단 화장품의 SPF에 관한 심포지움(대한화장품학회)
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    • pp.5-26
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    • 1992
  • Many methods of in vitro SPF evaluation have been developed in order to measure SPF of sunscreen products. In this study, we compared two spectrophotometric in vitro measurements using the skin cast made of Luviset CAP- $X^{R}$ resin and Transpor $e^{R}$ tape as substrate with two in vivo measurements using guinea pig and human. And we also observed the radiation reaching on the earth's surface in Seoul for one year and the change of the primary skin irritancy along the change of SPF value. According to the our research, the first, in vivo measurement using guinea pig had the close agreement with SPF measurement using human and showed the tendancy that guinea pig SPF was lower than human SPF. The second, there was the good relationship between in vitro SPF by using Transpor $e^{R}$ tape and in vivo SPF, and it is possible to predict human SPF from Protection Index(PI) by using tape. The third, it is thought that SPE 20 is reasonable value because of UV intensity in Seoul and the primary skin irritancy of higher SPF than 25. So we propose that it is important to distinguish the sunscreen product having higher than approximate 25 from the category of general cosmetics including lower SPF sunscreen product.oduct.

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Simulation and design of individual neutron dosimeter and optimization of energy response using an array of semiconductor sensors

  • Noushinmehr, R.;Moussavi zarandi, A.;Hassanzadeh, M.;Payervand, F.
    • Nuclear Engineering and Technology
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    • 제51권1호
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    • pp.293-302
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    • 2019
  • Many researches have been done to develop and improve the performance of personal (individual) dosimeter response to cover a wide of neutron energy range (from thermal to fast). Depending on the individual category of the dosimeter, the semiconductor sensor has been used to simplify and lightweight. In this plan, it's very important to have a fairly accurate counting of doses rate in different energies. With a general design and single-sensor simulations, all optimal thicknesses have been extracted. The performance of the simulation scheme has been compared with the commercial and laboratory samples in the world. Due to the deviation of all dosimeters with a flat energy response, in this paper, has been used an idea of one semi-conductor sensor to have the flat energy-response in the entire neutron energy range. Finally, by analyzing of the sensors data as arrays for the first time, we have reached a nearly flat and acceptable energy-response. Also a comparison has been made between Lucite-PMMA ($H_5C_5O_2$) and polyethylene-PE ($CH_2$) as a radiator and $B_4C$ has been studied as absorbent. Moreover, in this paper, the effect of gamma dose in the dosimeter has been investigated and shown around the standard has not been exceeded.

Improvement of Skin Photoaging by Polysaccharide Extract Derived from Tremella fuciformis (White Jelly Mushroom)

  • Choi, Jae-Hwan;Kim, Bora
    • Natural Product Sciences
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    • 제27권4호
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    • pp.300-306
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    • 2021
  • Chronic ultraviolet (UV) radiation causes photoaging, which represents skin damage, disrupts skin barrier function, and promotes wrinkle formation. We investigated that the polysaccharide extract of an edible basidiomycetous white jelly mushroom, Tremella fuciformis, (TF-Glucan®) exhibited statistically photoprotective activity by inhibiting matrix metalloproteases (MMPs) and increasing collagen synthesis, and an anti-inflammatory activity by inhibiting nitric oxide and pro-inflammatory cytokines at the concentrations of less than 1000 ㎍/ml, which is not cytotoxic (p < 0.05). Additionally, TF-Glucan® increased the expression of involucrin and filaggrin to prevent the disruption of UVB-induced barrier function (p < 0.05). TF-Glucan® was assessed as a safe material by the human primary skin irritation (1, 3, 5%), human repeated insult patch test (no sensitization at 5%), 3T3 NRU phototoxicity assay (no phototoxicity, PIF < 2, MPE < 0.1), eye irritation test test by BCOP (no category, IVIS ≤ 3) and local lymph node assay (negative at 10, 25, 50%) for identifying potential skin sensitizing. These results suggest that TF-Glucan® may be useful as an anti-photoaging ingredient for developing cosmeceuticals.

Planning and decommissioning of a disused Theratron- 780 teletherapy machine and the dose assessment methodology for normal and radiological emergency conditions

  • Mohamed M.Elsayed Breky ;Muhammad S. Mansy;A.A. El-Sadek ;Yousif M. Mousa ;Yasser T. Mohamed
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.238-247
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    • 2023
  • The present work represents a technical guideline for decommissioning a disused teletherapy machine model Theratron-780 and contains category one 60Co radioactive source. The first section predicts the dose rate from the source in case of normal and radiological emergency situations via FLUKA-MC simulation code. Moreover, the dose assessment for the occupational during the whole process is calculated and compared to the measured values. A suggested cordoned area for safety and security in a radiological emergency is simulated. The second section lists the whole process's technical procedures, including (preview, dismantle, securing, transport and storage) of the disused teletherapy machine. Results show that the maximum obtained accumulated dose for occupational were found to be 24.5 ± 4.9 μSv in the dismantle and securing process in addition to 3.5 ± 1.8 μSv during loading on the transport vehicle and unloading at the storage facility. It was found that the measured accumulated dose for workers is in good agreement with the estimated one by uncertainty not exceeding 5% in normal operating conditions.

Weight status in survivors of childhood acute lymphocytic leukemia in South Korea: a retrospective descriptive study

  • Yeongseon Kim;Kyung-Sook Bang
    • Child Health Nursing Research
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    • 제29권4호
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    • pp.280-289
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    • 2023
  • Purpose: This study investigated weight status in survivors of childhood acute lymphocytic leukemia (ALL) and identified related factors. Methods: A retrospective review of the electronic medical records of survivors of childhood ALL (n=230) was conducted. We analyzed the survivors' characteristics, including sex, age, weight status at diagnosis, central nervous system involvement, risk classification, length of treatment, radiation therapy, and hematopoietic stem cell transplantation. Analysis of variance and the chi-squared test were applied to investigate influencing factors. Results: The weight status distribution was as follows: 23 individuals (10.0%) were classified as underweight, 151 individuals (65.7%) were healthy weight, and 56 individuals (24.3%) were overweight/obese. Age at diagnosis (F=10.03, p<.001), weight status at diagnosis (x2=43.41, p<.001), and risk classification (F=10.98, p=0.027) showed significant differences among the weight status groups. Survivors who were older at diagnosis and those in the very high-risk category had a higher likelihood of experiencing underweight status during their survivorship, while survivors who were overweight/obese at diagnosis were more likely to remain overweight/obese at the time of survival. Conclusion: Considering the potential health implications related to an unhealthy weight status in survivors of ALL, it is imperative to undertake early identification and implement interventions for at-risk individuals.

AMSR-E NASA Team2 알고리즘에서 빙하빙의 마이크로파 복사특성 (Microwave Radiation Characteristics of Glacial Ice in the AMSR-E NASA Team2 Algorithm)

  • 한향선;이훈열
    • 대한원격탐사학회지
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    • 제27권5호
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    • pp.543-553
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    • 2011
  • Aqua에 탑재된 AMSR-E는 NASA Team2 해빙 알고리즘을 사용하여 해밍 면적비를 계산하고 있으며, 이는 남극의 해빙 지역에서 매우 정확하다는 것이 증명되었다. 그러나 AMSR-E의 관측 영역 내에 빙산 및 빙붕과 같은 빙하빙이 많이 포함될 경우 해빙과는 다른 빙하빙의 복사특성 때문에 NASA Team2알고리즘으로부터 계산되는 얼음의 면적비는 그 정확성이 유지되지 않는다. 본 논문에서는 남극의 George V 해안이 촬영된 두 장의 ENVISAT ASAR 영상으로부터 해빙과 빙하빙의 면적비를 추출하였고, 이를 NASA Team2 해빙 면적비와 비교하였다. NASA Team2 알고리즘은 빙하빙에 대해 실제보다 작은 면적비를 계산하였다. 빙하빙에 대한 NASA Team2 알고리즘의 면적비 계산 오류를 해석하기 위해 PR(polarization ratio), GR(spectral gradient ratio), $PR_R$(rotated PR), 그리고 ${\Delta}GR$ 영역에서 빙하빙의 마이크로파 복사특성을 분석하였다. 빙하빙은 PR, GR, $PR_R$, ${\Delta}GR$ 영역에서 ice type A, B, C와 같은 남극의 해빙 및 open water와 구분되는 고유한 범위를 형성하였으며, 이는 빙하빙이 얼음의 새로운 종류로 AMSR-ENASA Team2 해빙 알고리즘에 추가될 수 있음을 의미한다.

구강암 환자의 종양 선량 측정을 위한 In-vivo Diode Dosimetry의 유용성 평가 (Evaluation of Usefulness on In-vivo Diode Dosimetry for Measuring the Tumor Dose of Oral Cancer Patient)

  • 나경수;이제희;박흥득
    • 대한방사선치료학회지
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    • 제17권2호
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    • pp.133-140
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    • 2005
  • 목 적 : 3차원치료계획 (3D plan)과 대향2문조사(POP plan)의 선량 계획시 치료표적 (Planning Target Volume, PTV)와 정상조직(Organ at Risk, OAR)에 실제 흡수되는 선량을 반도체검출기를 이용하여 실시간선량측정(Real- time dosimetry)을 시행함으로써 치료계획의 타당성을 확인하고자 한다. 대상 및 방법 : 실제 치료할 환자의 구강안을 채워줄 Aquaplaste를 Simulation과정에서 제작하며 측정하고자 하는 부위에 Aquaplaste를 성형하여 반도체 검출기가 자리할 공간을 확보한다. 치료시 반도체검출기를 측정부위에 위치시키고 치료가 진행중 각 Port에 해당하는 Electrometer의 지시치를 얻는다. 얻은 지시치에 선량변환계수(Diode Calibration Factor, DCF)를 이용하여 실제 선량으로 환원하여 Exp. Dose와 실제 Dose를 비교하며 오차를 구한다. 실험의 수를 증가시켜 보다 정확한 결과를 얻기 위하여 Alderson Rando phantom(Huestis, USA)을 이용하여 같은 실험을 반복한다. 결 과 : 대향2문조사를 한 A환자의 경우 Exp. value와 측정선량의 비(exp.D/eff.D)가 197.5/199로 -1.2%, 3차원치료계획을 한 B환자는 exp.D/eff.D가 199.9/198.7로 +0.6%, C환자의 경우 exp.D/eff.D가 196/200으로 -1.5%가 차이 남을 알 수 있었다. 또 Target dose 외에 방어하고자 하는 부위의 측정도 병행한 C환자의 결과치는 96/200으로 47%의 선량이 측정되어 방어의 목적을 달성했음을 알 수 있었다. Phantom을 이용한 측정에서는 A환자와 같이 (a) point(target), (b) point(protect)로 나뉘어 측정하여 다음의 결과치를 얻었다. Phantom 1 (a): 190.6/198.4=-3.9%, (b): 119.6/124.2=-3.7%, Phantom 2 (a): 185.4/191.3=-3%, (b): 109.6/113.8=-3.7%의 결과치를 얻어 목적한 선량에 ${\pm}5%$이내로 만족함을 알 수 있었다. 결 론 : 반도체검출기를 이용한 치료전 선량 측정의 유용성을 알아본 이번 실험은 Target dose 뿐만 아니라 방어하고자 하는 영역 또한 알아봄으로써 치료의 타당성을 확인하는데 매우 유용했고 단순선량계산에 의한 확인되지 않는 Target dose를 확인하는 데에도 큰 이점이 있다고 생각된다. 치료 전 L-gram과 같이 이런 측정은 매우 효과적으로 치료방법의 타당성과 이후의 치료계획에도 많은 이득을 가져다 줄 것이라고 생각된다.

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확장된 slip-weakening 모델의 응력 강하량과 에너지 수지 특성 및 스케일링 관계 (Characteristics of Stress Drop and Energy Budget from Extended Slip-Weakening Model and Scaling Relationships)

  • 최항;윤병익
    • 한국지진공학회논문집
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    • 제24권6호
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    • pp.253-266
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    • 2020
  • The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment Mo, S-wave velocity Vs, corner-frequency fc, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, MW 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, Gc. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to fc given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga's dimensionless number was equivalent to the breakdown stress drop, as well as Brune's effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to Mo = 1017~1018 Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent Vr-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate Gc with respect to breakdown distance Dc from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop, ${\tilde{e}}$ and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.

개인선량계 성능의 국내 상호비교 (Domestic Intercomparison Study for the Performance of Personnel Dosimeters)

  • 김장렬;장시영;김봉환
    • Journal of Radiation Protection and Research
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    • 제21권3호
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    • pp.147-153
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    • 1996
  • 한국원자력연구소에서는 국내 개인선량계 판독기관들의 선량판독평가기술의 정밀 정확도 향상을 위한 국내 상호비교시험을 실시하였다. 본 시험에 참가한 기관은 모두 7개 기관으로 총 9종의 선량계(TLD 6종, 필름배지 3종)가 참가하였다. 사용된 방사선장은 Cs-137 감마, Sr/Y-90 베타 및 ISO의 wide series X-선장중 4종등 6개의 방사선장 이었으며, 참가기관당 30개의 선량계를 제출하여 각 시험조사당 4개씩 PMMA팬톰위에서 같은 선량이 조사되었다. 조사선량의 범위는 하한 ${\sim}10mSv$ 이하였다. 참가기관은 판독선량을 ICRU가 정한 개인선량당량 Hp(10) 및 Hp(0.07)로 평가하였다. 시험 결과 Cs-137 및 Sr/Y-90의 경우 1개 기관을 제외한 모든 기관의 판독선량과 부여선량의 비가 ${\pm}25%$ 이내에서 잘 일치하고 있었으나 X-선장의 경우, 모든 판독기관의 선량평가 알고리즘이 ANSI N13.11의 X-선장에 기초하여 개발되었기 때문에 판독선량과 부여선량의 편중이 ${\pm}35%$를 초과하는 경우들이 발견되었다.

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