• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.693-701
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• 2002

When the lowest dose level compared with zero-dose control has significant difference in effect, it is referred as minimum effective dose (MED). In this paper, we discuss several nonparametric methods for finding MED using updated rank at each sequential test step in small sample size and suggest new nonparametric procedures based on placement. Monte Carlo Simulation is adapted to compare power and Familywise Error Rate(FWE) of the new procedures with those of discussed nonparametric tests for finding MED.

• 한방재활의학과학회지
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• 제28권2호
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• pp.61-72
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• 2018

Objectives The purpose of this experiment is to evaluate 4 weeks DRF (Dose Rate Finding) and single oral dose toxicity of ChondroT in rats. Methods In 4-week DRF, male and female Sprague-Dawely rats were treated with ChondroT at oral dose of 0, 500, 1000, and 2000 mg/kg. clinical signs, body weight, food consumption, necropsy findings, organ weight, hematological and blood-chemical parameters, and histological findings were monitored for 4 weeks. Also, after single oral administration of ChondroT, mortality, clinical signs, body weight, and necropsy findings were minitored for 2 weeks. Results In 4-week DRF and single dose oral toxicity study of ChondroT in sprague-Dawley rats, ChondroT did not exhibit any toxicity under the study conditions employed. Conclusions The results suggested a no-observed adverse effects level (NOAEL) was over 2,000 mg/kg/day in SD rats after oral administration, this study could be used as basic study of the repeated dose 13-week oral toxicity study of ChondroT.

• Communications for Statistical Applications and Methods
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• 제19권1호
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• pp.33-45
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• 2012

신약 개발 연구 또는 임상시험에서 개발된 약이 0용량 대조군과 비교해 효과 차이가 있는 가장 작은 용량을 최소 효과 용량(MED)이라 한다. 본 논문에서는 다중 그룹 상황에서 동시적(simultaneous)으로 각 각 그룹의 최소 효과 용량을 확인하기 위하여 위치(placement)에 기초한 비모수적 방법을 제시하였다. 또한 Monte Carlo 모의실험을 통하여 기존에 제시된 검정법과 본 논문에서 제안한 검정법의 검정력(power)과 FWE(Family-wise Error Rate)를비교하였다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.162-165
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• 2003

Uptake efficiencies of PCB 153 in fathead minnow through food chain of sediment-midge-fish were evaluated. Contaminated fish food, the midge Chironomus plumosus was prepared by exposing to sediments with PCB 153. We could harvest the midges with body PCB 153 levels of ∼ 1.0 mg/g and ∼ 10.0 mg/g, respectively, in 2 wk of exposure. PCB 153 level in fish fed with midge of 10.0 mg/g PCB 153 (high-dose group) reached its highest at 11.2 mg/g after 30 d of exposure. However, PCB level in fish fed with midge of 1.0 mg/g PCB 153 (low-dose group) kept increasing following first order rate kinetics until the end of exposure (38 d). When the fish food was changed to the uncontaminated ones, the fish body PCB levels were stabilized in ∼ 3 wk. The uptake efficiency in high-dose fish group was 37%, whereas low-dose group was 55%. Uptake efficiencies in fathead minnows were notably lower than that of pike (∼ 70%). This finding suggests that the uptake efficiency of this PCB congener may depend on the amount of the PCB in diet.

• 한국발생생물학회지:발생과생식
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• 제22권1호
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• pp.85-94
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• 2018

Endocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing $133{\mu}g/L$ and $1,330{\mu}g/L$ DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of $1,330{\mu}g/L$ DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at $1,330{\mu}g/L$ DEHP water. The number of epididymal sperm was significantly increased by drinking of $1,330{\mu}g/L$ DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at $1,330{\mu}g/L$ DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

• Advances in environmental research
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• 제3권3호
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• pp.231-251
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• 2014

The present study examines the phosphate adsorption potential and behavior of mixture of Ground Burnt Patties (GBP), a solid waste generated from cooking fuel used in earthen stoves and Red Soil (RS), a natural substance in fixed bed column mode operation. The characterization of adsorbent was done by Proton Induced X-ray Emission (PIXE), and Proton Induced ${\gamma}$-ray Emission (PIGE) methods. The FTIR spectroscopy of spent adsorbent reveals the presence of absorbance peak at $1127cm^{-1}$ which appears due to P = O stretching, thus confirming phosphate adsorption. The effects of bed height (10, 15 and 20 cm), flow rate (2.5, 5 and 7.5 mL/min) and initial phosphate concentration (5 and 15 mg/L) on breakthrough curves were explored. Both the breakthrough and exhaustion time increased with increase in bed depth, decrease in flow rate and influent concentration. Thomas model, Yoon-Nelson model and Modified Dose Response model were used to fit the column adsorption data using nonlinear regression analysis while Bed Depth Service Time model followed linear regression analysis under different experimental condition to evaluate model parameters that are useful in scale up of the process. The values of correlation coefficient ($R^2$) and the Sum of Square Error (SSE) revealed the Modified Dose Response model as the best fitted model to the experimental data. The adsorbent mixture responded effectively to the desorption and reusability experiment. The results of this finding advocated that mixture of GBP and RS can be used as a low cost, highly efficient adsorbent for phosphate removal from aqueous solution.

• 대한수의학회지
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• 제43권1호
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• pp.57-66
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• 2003

Single and 28-day repeated dose toxicity studies of botulimnn toxin type A were carried out in ICR mice and Sprague-Dawley rats, respectively. In the single dose toxicity study, botulinwn toxin was injected intraperitoneally to male and female mice at a single dose of 40, 59, 89 133 and 200 ng/10 ml saline/kg. All animals died from 59 ng/kg group. Some clinical signs, such as decrease in locomotor activity, dyspnea, prone position and ptosis, were observed in most of both sexes from 59 ng/kg group, but no signs were seen in all animals at 40 ng/kg group. The results showed that the median lethal dose of botulinum toxin might be in the range of 40-59 ng/kg in both sexes. In the repeated dose toxicity study, the test material was administered intradermally for 28 days at doses of 0 (vehicle-treated control), 1.25, 2.5, 5.0 and $10.0ng/head/50{\mu}{\ell}$ saline in male and female rats. No test material-related changes were noted in survivals, clinical signs, food and water consumptions and gross finding in any group. Botulinum toxin treatment significantly decreased the body weight gain rate in male of 5.0 ng/head group and over and in female of 10.0 ng/head group compared to vehicle-treated control. One or more relative organ weights (i.e., spleen, thymus, liver and kidney) were increased significantly from 5.0 ng/head group compared to vehicle-treated control in both sexes. Serum biochemistry revealed increases in aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase, total protein and albumin in male, and increases in AST and ALT and decreases in $K^+$ and $Cl^-$ in female without dose-pendent manners. In the histopathological study, physical stimulation by needle caused slight inflammations of dennis. In addition, botulinum toxin treatment induced denervation of nerve cell and disuse of muscle, resulting in atrophy of skeletal muscle in both sexes from 2.5 ng/head group. When the antibodies to toxin were determined in all animals, a significant increase in serum antibodies was observed from 5.0 ng/head group. The results showed that the NOAEL of botulinum toxin might be 1.25 ng/head for 28-day repeated dose toxicity in rats.

• 한국작물학회지
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• 제10권
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• pp.45-50
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• 1971

방사선조사시 열처리의 효과를 알기 위하여 수도종자에 방사선조사시 열전후처리를 행하였던바$M_1$ 세대의 생물학적인 반응 및 $M_2$ 세대의 변이율에 대해 몇가지 결과를 얻었다. 1. 방사선선량 20kR에서 열전처리는 방사선단독조사에 비해 생물학적인 장해를 적게하고 변이율을 증가시켰다. 2. 방사선단독조사 및 조사전열처리에 비해 heat shocking으로서 열후처리하는 것은 변이율을 증가시켰다. 3. 열전처리에 의해 $M_1$ 세대의 장해가 적고 변이율이증가되는 가장 효과적인 열처리온도 및 시간은 6$0^{\circ}C$에서 30분간이었다. 4. 열처리는 방사선단독조사에 비해 mutation spectrum을 달리했다.

• 한국의학물리학회지:의학물리
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• 제5권2호
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• pp.57-68
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• 1994

선형가속기에 의한 뇌정위적 방사선수술에 적용되는 원형 소조사변의 선량분포를 측정하기 위해 측정기 선정 이유와 선축 결정, 자체 제작한 소형 물 팬톰에 의한 선량분포 측정시 고려해야 할 점에 대해 논의하고, 치료계획에 필요한 자료인 Clinac-18의 10MV X-선의 TMR, OAR, 조사면 계수와 같은 선량분포 측정결과를 보고하고자 한다. 뇌정위적 방사선수술에 권고되고 있는 조사면 크기가 3cm 이하의 작은 조사면에 대한 선량 분포를 측정하기 위해서는 크기나 감도에 있어서 적합한 p-형 실리콘(Si) 검출기가 선량에 대한 선형성과 선량율 독립성이 적합한지 측정에 의해 판단하였다. 크기와 형태가 같은 아크릴 통을 두 개 제작하여 호스로 연결하여 하나는 물 팬톰으로 이용하고 다른 하나는 높이를 조절하여 측정기의 깊이를 조절하였다. 측정할 위치에서 직각 방향의 측방선량분포를 측정하여 선축의 위치를 찾았다. SAD 100cm 위치에서 조사면 크기 10, 20, 30, 40mm 네 개 콘에 대하여 TMR을 측정하였으며, 일정한 선원-측정기간 거리(SCD)에서 최대선량점깊이(d$_{max}$) 및 6, 10, 15cm 깊이에서 OAR을 측정하여 비교하였다. 조사면 계수는 MU당 SAD, d$_{max}$에서 콘에 대한 선량으로 실리콘 검출기로 측정하였다. 실리콘 검출기는 선량에 대한 선형성이 거의 완벽하였으며 감도는 선량율이 증가함에 따라 감소하였다. 낮은 선량율 때문에 조사면 밖의 선량을 약간 과대평가할 수 있을지라도 100MU/min 이상의 선량율에 대해서는 일정하였다. 직각 방향의 측방선량분포 측정에 의하여 선축을 찾는 방식은 간편하였다. 1cm 두께의 아크릴 판을 보조 물통 아래에 삽입ㆍ제거하는 방식으로 측정기의 깊이 조절도 간편하면서 정확하였다. 측정에 의한 TMR, OAR, 조사면 계수는 충분히 정확하여 뇌정위적 방사선수술의 치료계획에 이용할 수 있었으며, OAR은 조사면 범위 내에서는 깊이에 거의 무관하였다. 실리콘 검출기는 소조사면 선량분포 측정에 적합하였으며 직각 방향의 측방선량분포의 측정으로 0.05mm까지 정확히 선축을 찾을 수 있었고, 보조 물통과 아크릴 판을 이용하여 측정기의 깊이를 조절하는 것이 용이하였다. TMR, OAR, 조사면계수의 측정치는 뇌정위적 방사선수술의 치료 계획에 이용할 수 있을 정도로 정확하였으며, OAR은 하나의 깊이에서 측정해도 충분할 것이라고 사료된다.

• Journal of Yeungnam Medical Science
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• 제36권2호
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• pp.115-123
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• 2019

Background: This study aimed to assess the in-field lymph node (LN) failure rate according to LN size and to investigate effect of LN size on the survival outcome of patients with locally advanced cervical carcinoma treated with concurrent chemoradiotherapy (CCRT). Methods: A total of 310 patients with locally advanced cervical carcinoma treated with CCRT were enrolled in retrospective study. LN status was evaluated by magnetic resonance imaging. All patients received conventional external beam irradiation and high-dose rate brachytherapy, and concurrent cisplatin-based chemotherapy. In-field LN failure rate according to LN size was analyzed. Results: The median follow-up period was 83 months (range, 3-201 months). In-field LN failure rate in patients with pelvic LN size more than 10 mm was significantly higher than that in patients with pelvic LN size less than 10 mm (p<0.001). A similar finding was observed in the infield para-aortic LN (PALN) failure rate (p=0.024). The pelvic and PALN size (${\geq}10mm$) was a significant prognostic factor of overall-survival (OS) and disease-free survival rate in univariate and multivariate analyses. The OS rate was significantly different between groups according to LN size (<10 mm vs. ${\geq}10mm$). Conclusion: A LN of less than 10 mm in size in an imaging study is controlled by CCRT. On the other hand, in LN of more than 10 mm in size, the in-field LN failure rate increase and the prognosis deteriorate. Therefore, a more aggressive treatment strategy is needed.