• Title/Summary/Keyword: repeated dose

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Development of Radiation Detector with Intensifying Screen (증감지를 이용한 방사선검출기 개발)

  • Jeong-Min Seo
    • Journal of the Korean Society of Radiology
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    • v.17 no.6
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    • pp.859-863
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    • 2023
  • In this study, simple and portable radiation detection system using X-ray intensifying screen, optical sensor and micro-controller unit for education was proposed. The system was simply composed of detection unit consisting of an optical sensor and intensifying screen, micro-controller unit, and was designed to be suitable for portable. Radiation was measured using developed detection system and absorbed dose dosimeter with changing tube voltage from 50 to 100 kVp. The tube current and SDD were fixed on 100 mAs and 100 cm, and dose were measured repeated ten times at each tube voltage. The response and linearity of the detection system were confirmed using the measured values. It was confirmed that the comparison measurement results of the detection system and absorbed dose dosimeter showed a high correlation(r : 0.998, p<.001). In this results, the feasibility of the detection system with intensifying screen and micro-controller unit based was confirmed, and we considered that the developed detection system could be applied to portable, compact, low cost system for education.

Development of a Thermoplastic Oral Compensator for Improving Dose Uniformity in Radiation Therapy for Head and Neck Cancer (두경부암 방사선치료 시 선량 균일도 향상을 위한 Thermoplastic 구강 보상체의 개발)

  • Choi, Joon-Yong;Won, Young-Jin;Park, Ji-Yeon;Kim, Jong-Won;Moon, Bong-Ki;Yoon, Hyong-Geun;Moon, Soo-Ho;Jeon, Jong-Byeong;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.23 no.4
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    • pp.269-278
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    • 2012
  • Aquaplast Thermoplastic (AT) is a tissue-equivalent oral compensator that has been developed to improve dose uniformity at the common boundary and around the treated area during radiotherapy in patients with head and neck cancer. In order to assess the usefulness of AT, the degree of improvement in dose distribution and physical properties were compared to those of oral compensators made using paraffin, alginate, and putty, which are materials conventionally used in dental imprinting. To assess the physical properties, strength evaluations (compression and drop evaluations) and natural deformation evaluations (volume change over time) were performed; a Gafchromic EBT2 film and a glass dosimeter inserted into a developed phantom for dose verification were used to measure the common boundary dose and the beam profile to assess the dose delivery. When the natural deformation of the oral compensators was assessed over a two-month period, alginate exhibited a maximum of 80% change in volume from moisture evaporation, while the remaining tissue-equivalent properties, including those of AT, showed a change in volume that was less than 3%. In a free-fall test at a height of 1.5 m (repeated 5 times as a strength evaluation), paraffin was easily damaged by the impact, but AT exhibited no damage from the fall. In compressive strength testing, AT was not destroyed even at 8 times the force needed for paraffin. In dose verification using a glass dosimeter, the results showed that in a single test, the tissue-equivalent (about 80 Hounsfield Units [HU]) AT delivered about 4.9% lower surface dose in terms of delivery of an output coefficient (monitor unit), which was 4% lower than putty and exhibited a value of about 1,000 HU or higher during a dose delivery of the same formulation. In addition, when the incident direction of the beam was used as a reference, the uniformity of the dose, as assessed from the beam profile at the boundary after passing through the oral compensators, was 11.41, 3.98, and 4.30 for air, AT, and putty, respectively. The AT oral compensator had a higher strength and lower probability of material transformation than the oral compensators conventionally used as a tissue-equivalent material, and a uniform dose distribution was successfully formed at the boundary and surrounding area including the mouth. It was also possible to deliver a uniformly formulated dose and reduce the skin dose delivery.

A Case of Visceral Autonomic Neuropathy Complicated by Guillain-Barre Syndrome Accompanied with Cyclic Vomiting Syndrome-like Disorder in a Child

  • Hong, Suk Jin;Choe, Byung-Ho
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.18 no.2
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    • pp.128-133
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    • 2015
  • We present a case of an 8-year-old boy with visceral autonomic neuropathy complicated by Guillain-Barre syndrome. In this pediatric patient, gastroparesis was the major symptom among the autonomic symptoms. Due to the gastroparesis, there was no progress with the oral diet, and nutrition was therefore supplied through a nasojejunal tube and gastrojejunal tube via Percutaneous endoscopic gastrostomy (PEG). After tube feeding for 9 months, the patient's gastrointestinal symptoms improved and his oral ingestion increased. The pediatric patient was maintained well without gastrointestinal symptoms for 3 months after removal of the PEG, had repeated vomiting episodes which lead to the suspicion of cyclic vomiting syndrome. Then he started treatment with low-dose amitriptyline, which resulted in improvement. Currently, the patient has been maintained well for 6 months without recurrence, and his present growth status is normal.

PRECLINICAL TOXICITY STUDY OF A NEW PHOSPHODIESTERASE-5 INHIBITOR (II) FOUR-WEEK SUBACUTE TOXICITY STUDY IN RATS

  • Hyeon Cho;Kim, Dong-Hwan;Kang, Kyung-Koo;Ahn, Byoung-Ok;Kim, Won-Bae
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.05a
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    • pp.128-128
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    • 2001
  • Toxic effects of a new phosphodiesterse-5 inhibitor, DA-8159, were investigated in Sprague-Dawley rats by repeated oral administration. Four groups of 10 male and 10 female rats were treated with DA-8159 at a dose of 0, 40, 80, or 320 mg/kg/day for 4 weeks.(omitted)

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Type I Error Rates and Power for Omnibus Tests of Repeated Measures Measn in the Split-Plot Design : F test, $\widetilde{\xi}$F test, and CIGA test

  • Kim, Hyunchul
    • Communications for Statistical Applications and Methods
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    • v.4 no.1
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    • pp.139-149
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    • 1997
  • For split plot designs exact univariate F tests of the within-subjects main effect are based on the assumption of multisample sphericity. Type I error rates and power are reported for the F test and two tests designed for use when multisample sphericity is violated: the $\widetilde{\xi}$-adjusted test and the Corrected Improved General Approximation(CIGA) test.The results indicate that even though the F test and the $\widetilde{\xi}$-adjusted test have better power than the CIGA test in some conditions, the F test and the $\widetilde{\xi}$-adjusted test do not control Type I error rates when the design is unbalanced and the F test dose not have a good control of Type I error rates when sphericity assumption is severely violated.

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Effects of Carbonated Water Intake on Constipation in Elderly Patients Following a Cerebrovascular Accident (노인 뇌졸중환자의 변비완화를 위한 탄산수 음용의 효과)

  • Mun, Jae-Hee;Jun, Seong-Sook
    • Journal of Korean Academy of Nursing
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    • v.41 no.2
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    • pp.269-275
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    • 2011
  • Purpose: This study was done to identify effects of carbonated water intake on constipation in elders who have experienced a cerebrovascular accident (CVA) and are bed-ridden. Methods: Forty elderly patients with CVA were randomly assigned to one of two groups in a double-blind study. Patients in the experimental group drank carbonated water and those in the control group drank tap water for two weeks. Six patients dropped out during the study period. Data were analyzed by repeated measured ANCOVA and the covariance was the dose of laxatives used for the two weeks. Results: Frequency of defecation increased significantly and symptoms of constipation decreased significantly for patients in the experimental group. Conclusion: The study results suggest that the intake of carbonated water is an effective method for the intervention of constipation in elderly patients with CVA.

Acyl-CoA: Cholesterol Acyltransferase Inhibitors from llex macropoda

  • Im Kyung-Ran;Jeong Tae-Sook;Kwon Byoung-Mog;Baek Nam-In;Kim Sung-Hoon;Kim Dae-Keun
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.191-194
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    • 2006
  • Twigs from llex macropoda were extracted with MeOH, and the concentrated extracts were partitioned with $CH_2Cl_2$, EtOAc, n-BuOH, and $H_2O$. Repeated column chromatography of the $CH_2Cl_2$ fraction ultimately resulted in the isolation of two compounds, via activity-guided fractionation, using ACAT inhibitory activity measurements. According to the physico-chemical data, the chemical structures of these isolated compounds were identified as lupeol (1) and betulin (2). Compounds 1 and 2 were shown to inhibit the activity of hACAT-1 and hACAT-2 in a dose-dependent manner, and compounds 1 and 2 inhibited hACAT-1 with $IC_{50}$ values of 48 and $83{\mu}M$, respectively.

Subacute toxicities and toxicokinetics of CJ-10882, a type IV phosphodiesterase inhibitor, after 4-week repeated oral administration in dogs

  • Junghee Han;Cha, Shin-Woo;Im, Doo-Hyun;Chung, Moon-Koo
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.05a
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    • pp.43-44
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    • 2003
  • The subacute toxicity and toxicokinetics of a type IV phosphodiesterase inhibitor, CJ-10882, were evaluated after single (on the 1st day) and 4-week (on the 27th day) oral administration of the drug, in doses of 0 (to serve as a control), 2, 10 and 50 mg/kg/d, to male and female dogs (n = 3 for male and female dogs for each dose). During the test period, clinical signs, mortality, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weight and histopathology were examined.(omitted)

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13 Weeks Repeated-Dose Toxicity Studies 1,3-dichloro-2-propanol in Rats

  • Oh, Jae-Ho;Shin, Dong-Hwan;Kim, Sheen-Hee;Hwang, Myung-Sil;Lim, Chul-Joo;Yum, Young-Na;Yang, Ki-Hwa;Cho, Dae-Hyun
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.05a
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    • pp.54-54
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    • 2003
  • 1,3-Dichloro-2-propanol(1,3-DCP), together with 3-monochloro-propane -1,2-diol(3-MCPD), is a well-known contaminant of acid-hydrolysed vegetable protein. 1,3-DCP has also been found to occur in a range of other foods and ingredients, most notable in soy sauce. The objective of the study was to determine the toxicity of the 1,3-DCP in the rat following oral administration for 13 weeks. (omitted)

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