• The Journal of Korean Society for Radiation Therapy
• /
• v.7 no.1
• /
• pp.103-110
• /
• 1995

Dynamic wedge system has been introduced to modify the beam profile and to make homogeneous isodose curves in the mass of irregular shape. Before the clinical use of dynamic wedge, several factors such as wedge transmission factor, dose profile, percent depth dose, and wedge angle have to be measured quantitatively. Film dosimetry is used to evaluate these factors in this study. A comparison of the result of the dynamic wedge to physical wedge system is made. A positive result for the application of the dynamic wedge to clinic is derived even though there is a limitation in accuracy of the dosimetry system used. To measure all factors quantitatively, more accurate dosimetry systems are required.

• Analytical Science and Technology
• /
• v.26 no.3
• /
• pp.199-204
• /
• 2013

In this study, the reproducibility of blood alcohol concentration (BAC) - time profile for the same individuals were investigated. Five Korean males were made to drink 55.5 g of ethyl alcohol (neglecting body weight) in the form of undiluted Soju (22% v/v), Korean popular liquor, within 30 min and each drinking sessions were performed for five times. Two kind of side dishes, a sliced raw fish and a sweet and sour pork, were served alternately along with alcohol. The peak BAC reaching time, the maximum BAC and the reduction rate of BAC of an individual varied greatly even though the dose and drinking time interval were not changed. Also, the food taken along with alcohol varies the shape of BAC - time profile. From the repetitive drinking sessions we can know that the BAC - time profile of an individual is not a reproducible one even though the dose, kind of liquer, drinking time and food were maintained constantly. It means that any assumption of blood alcohol concentration of an individual at a previous time stage based on the alcohol dose can not be justified because of large fluctuation of BAC-time profile of an individual.

• The Journal of Korean Society for Radiation Therapy
• /
• v.7 no.1
• /
• pp.15-31
• /
• 1995

The radiosurgery treatment is one time, non surgical approach to the treatment of patients with intracranial disorders whose conditions would be difficult or dangerous to treat with conventional sugical procedures. The LINAC based radiosurgery is based on the combination of multiple isocentric arc irradiation with small fields centered in the stereotactic target. The absorption of the beam in a tissue equivalent medium, such as water, as well as the uniformity, or profile, of the beam must be precisely documented. The beam characteristics and dosimetric measurememts of the 6MV X-ray beam from a ML-6M linear accelerator are examined. The percent depth dose (PDD) and beam profile (including flatness, symmetry and penumbra) is calibrated with the radiosurgery cone in water phantom. The cone is made of lead which size is from $10{\times}10mm{\phi}$ to $30{\times}30mm{\phi}$ All of these dosimetric measurements sufficiently characterized the beam to permit safe clinical use.

• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.413-416
• /
• 2008

Effects of extracts obtained from the flowers of Elsholtzia splendens on the serum lipid profile and hepatotoxicity in mice were investigated. Female ICR mice were given E. splendens ethanolic extract (ESEs) orally at a dose of 10 or 50 mg/kg BW for 50 days. Significant dose-dependent decreases in triglyceride and low-density lipoprotein (LDL)-cholesterol of serum were observed. In addition, ESEs prolonged the lag-time of LDL oxidation in vitro. In the serum of ICE mice given ESEs orally at 10 and 50 mg/kg BW, the serum levels of aspartate aminotransferase (AST) and lactic dehydrogenase (LDH) increased significantly, while total protein, albumin, creatinine, alanine aminotransferase (ALT), and total bilirubin did not change. Therefore, ESEs may be beneficial to human health, although it has some hepatotoxicity.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.129-133
• /
• 2007

Focused Ion Beam(FIB) systems is a useful tool for the fabrication of micro-nano scale structures. In this study, the effects of FIB etching on the Au microstructure are systematically investigated. As the fabrication parameters, ion dose, dwell time and beam overlap ratio are studied. First, the increases of Ga ion dose makes the milling yield higher and the sidewall of milling profile steeper. Dwell time is found to have little effects on the milling profile due to the relatively large milling area of $1\times1{\mu}m^2$ used in this study. However, beam overlap significantly affects not only milling rate but also milling profile. As the beam overlap ratio changes from positive to negative, the development of regular cross-stripe patterns at the bottom with low milling rate is observed.

• Journal of Radiation Protection and Research
• /
• v.36 no.3
• /
• pp.168-173
• /
• 2011

This study investigated characteristics of dose distribution at junction field of X-ray and electron beams according to the method for fabricating the insert block on the electron cone. Insert block were fabricated to the divergency cutout block and the straight cutout block. For the 6 MV X-ray and 10 MeV nominal energy of electron beam, we was adjacent to the light field of X-ray and electron beam at a surface of matrix chamber and measured to beam profile of abutted field in the 0, 1, 2, 3 cm measurement depth. As a result, characteristics of dose distribution at junction field, straight block was existent that over dose area exceed the give dose more than 5% and under dose area with a rapid change in dose distribution. However, divergency block had remarkably decreased the over dose area caused by the lateral scattering effects of decrease, and being existed uniformity dose distribution in the junction field. Therefore, divergency block were the benefits of radiation dose delivery, in order to applied the clinical, measurement of electron beams according to the fabrication method of the block should be considered carefully.

• Journal of Pharmacopuncture
• /
• v.19 no.3
• /
• pp.253-258
• /
• 2016

Objectives: The goals of this research were to evaluate acute (single-dose) and sub-acute (repeated-dose) toxicity profiles of methanolic extract of Pistacia integerrima J. L. Stewart ex Brandis (PI) for Wistar rats and to assess the safety profile of PI by observing physiological changes, mortality, changes in body weight, the histopathology of body organs, the hematology and the biochemistry of the animals. Methods: The toxicity profile of PI was evaluated using Wistar rats of both sexes. Animals were divided into four groups: Group 1; control group (normal saline), Group 2; PI-1 (250 mg/kg), Group 3; PI-2 (500 mg/kg), Group 4; PL-3 (1,000 mg/kg). An acute-toxicity study in which animals received a single dose of PI extract (2,000 mg/kg) and were then observed for 14 days for changes in skin, fur, eye color, mucous membrane secretions and excretions, gait, posture, and tonic or clonic movements was performed according to guideline 425 of the Organization of Economic and Corporation Development (OECD). In the repeated-dose toxicity study (OECD - 407) animals received a daily dose of PI extract for 28 days (4 weeks). The parameters observed in this study include body weight, hematology and biochemistry of the animals. Results: In the acute toxicity study, no mortalities or changes in behavior were noted in the animals. The repeated-dose toxicity study was also devoid of any toxicity in the animals during the 28 days of testing with PI extract. The extract did not alter- the body weight, hematology or biochemistry of the animals. The methanolic extract of PI was to be found safe to the no-observed-adverse-effect-level (NOAEL) for the single-dose and repeated-dose toxicity tests in rats. Conclusion: The methanolic extract of PI was devoid of toxicity; hence, it can be used for various ayurvedic preparations and treatments of diseases.

• Nuclear Engineering and Technology
• /
• v.55 no.8
• /
• pp.2734-2741
• /
• 2023

Brachytherapy is a special case of radiotherapy. It should be arranged according to some principles in medical radiation applications and radiation physics. The primary principle is to use as low as reasonably achievable dose in all ionizing radiation applications for diagnostic and therapeutic treatments. Dosimetric distributions are dependent on radioactive source properties and radiation-matter interactions in an absorber medium such as phantom or tissue. In this consideration, the geometrical structure and material of the seed capsule, which surrounds a radioactive material, are directly responsible for isodose profiles and dosimetric functions. In this study, the radiometric properties of capsule material were investigated on dose distribution in a water phantom by changing its nuclear properties using the EGSnrc Monte Carlo (MC) simulation code. Effective atomic numbers of hypothetic mixtures were calculated by using different elements with several fractions for capsule material. Model 6711 brachytherapy seed was modeled by EGSnrc/Dosrcnrc Code and dosimetric functions were calculated. As a result, dosimetric parameters of hypothetic sources have been acquired in large-scale atomic number. Dosimetric deviations between the data of hypothetic seeds and the original one were analyzed. Unit dose (Gy/Particle) distributions belonging to different types of material in seed capsule have remarkably differed from the original capsule's data. Capsule type is major variable to manage the expected dose profile and isodose distribution around a seed. This study shows us systematically varied scale of material type (cross section or effective atomic number dependent) offers selective material usage in production of seed capsules for the expected isodose profile of a specific source.

• Nuclear Engineering and Technology
• /
• v.49 no.4
• /
• pp.801-809
• /
• 2017

The purpose of this study is to assess the additional neutron effective dose during passive scattering proton therapy. Monte Carlo code (Monte Carlo N-Particle 6) simulation was conducted based on a precise modeling of the National Cancer Center's proton therapy facility. A three-dimensional neutron effective dose profile of the interior of the treatment room was acquired via a computer simulation of the 217.8-MeV proton beam. Measurements were taken with a $^3He$ neutron detector to support the simulation results, which were lower than the simulation results by 16% on average. The secondary photon dose was about 0.8% of the neutron dose. The dominant neutron source was deduced based on flux calculation. The secondary neutron effective dose per proton absorbed dose ranged from $4.942{\pm}0.031mSv/Gy$ at the end of the field to $0.324{\pm}0.006mSv/Gy$ at 150 cm in axial distance.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.132-132
• /
• 2018

The aim of this study was to enhance the Tartary buckwheat growth and phenolic profile by the application of $SiO_2$ on potsin the glasshouse. The liquid of $SiO_2$ were applied at three times after three weeks of sowing at ten days interval. The doses of the $SiO_2$ was low (2.5 ml/5 L water), high (10 ml in 5 L water) and control experiment was done without $SiO_2$. In this study, it is clearly shown that high dose of $SiO_2$ increased the buckwheat plant growth including, plant height, leaf length and width, stem diameter, fresh weight and number of seed per plant compared to control treatment. In the same way, the total phenolic compound (1421 mg/100 g), total flavonoid (35.1 mg/100g), rutin (3,130 mg/100g) and DPPH (82%) in plant were also increased high dose of $SiO_2$ compared to control (1,175 mg/100g, 31.9mg/100g, 860 mg/100g, 59%, respectively). Moreover, higher phenolic compound (1,421 mg/100g) and DPPH (82%) was observed in plant compared to seed (196 mg/100mg, 72 %, respectively). In the contrary, total flavonoid (36.2 mg/100g) and rutin (1,400 mg/100g) was higher in buckwheat seed compared to plant (35.1 mg/100g, 3,130 mg/100g, respectively). Finally, it is concluded that higher dose of $SiO_2$ enhance buckwheat growth and phenolic profile. Further investigation is needed to evaluate the optimum dose of $SiO_2$ according to soil conditions in the field.