• Journal of electromagnetic engineering and science
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• v.7 no.2
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• pp.53-58
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• 2007

A general method to formulate the tissue-equivalent liquids for SAR measurement is proposed to make sucrose-free brain tissue applicable at 835 MHz as an example We suggest the tissue composition can be determined by measuring the dielectric constants and conductivities with the DI water and salt addition variation to the pre-manufactured auxiliary liquid of DGBE and TritonX-100 The manufactured liquid satisfies the specified electrical parameters of international standard at 835 MHz.

• Journal of Radiation Protection and Research
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• v.18 no.1
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• pp.1-7
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• 1993

In its recent recommendation No. 60(1990), ICRP has newly introduced several terminology which had not existed in its prior recommendation No. 26(1977). Of these, a newly defined quantity 'Equivalent Dose' replacing the 'Dose Equivalent' of the ICRU concept has been recommended to be adopted in the radiation protection programme. However, since the committee still uses the 'Dose Equivalent' and 'Equivalent Dose' in its several publications, it is likely to provoke unnecessary confusions and misuses in applying these two quantities. In this paper were described the definition and difference between these two quantities to help in understanding of these two quantitites among the person involved in the radiation protection activities.

• KSBB Journal
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• v.29 no.1
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• pp.42-49
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• 2014

The aim of this study was to develop a composite human skin equivalent for wound healing. Collagen type1 and acellular dermal matrix powder were utilized as the scaffold with dermal fibroblasts and keratinocytes for the development of a composite human skin equivalent. Fibroblast maintained the volume of composite skin equivalent and also induced keratinocytes to attach and proliferate on the surface of composite skin equivalent. The composite human skin equivalent had a structure and curvature similar to those of real skin. Balb-C nu/nu mice were used for the evaluation of full-thickness wound healing effect of the composite human skin equivalent. Graft of composite skin equivalent on full-thickness wound promoted re-epithelialization and granulation tissue formation at 9 days. Given the average wound-healing time (14 days), the wound in the developed composite skin equivalent healed quickly. The overall results indicated that this three-dimensional composite human skin equivalent can be used to effectively enhance wound healing.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.381-391
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• 1993

As the first stage of development of an artificial skin, fibroblasts were cultured in the collagen matrices to make a living dermal equivalent. Mouse embryonic fibroblasts were incorporated into a collagen matrices on plastic dishes containing concentrated DMEM culture media supplemented with sodium bicarbonate, hepes, antibiotics and fetal bovine serum. As the growth stimulation components, glycosaminoglycans were added: hyaluronic acid, chondroitin sulfate, heparin, chitosan were incorporated into the media at a concentration of either 1% or 5% w/w/ to collagen in order to investigate the effect on development of dermal equivalent. After the few days of incubation, gel matrics were contracted and firm dermal equivalent were formed. And the keratinocytes were cultured on top of dermal equivalent and make a three dimensional artificial skin tissue.

• Journal of Astronomy and Space Sciences
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• v.32 no.2
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• pp.145-149
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• 2015

A newly designed Tissue Equivalent Proportional Counter (TEPC) has been developed for the CubeSat mission, SIGMA (Scientific cubesat with Instruments for Global Magnetic field and rAdiation) to investigate space radiation. In order to test the performance of the TEPC, we have performed heavy ion beam experiments with the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. In space, human cells can be exposed to complex radiation sources, such as X-ray, Gamma ray, energetic electrons, protons, neutrons and heavy charged particles in a huge range of energies. These generate much a larger range of Linear Energy Transfer (LET) than on the ground and cause unexpected effects on human cells. In order to measure a large range of LET, from 0.3 to $1,000keV/{\mu}m$, we developed a compact TEPC which measures ionized particles produced by collisions between radiation sources and tissue equivalent materials in the detector. By measuring LET spectra, we can easily derive the equivalent dose from the complicated space radiation field. In this HIMAC experiment, we successfully obtained the linearity response for the TEPC with Fe 500 MeV/u and C 290 MeV/u beams and demonstrated the performance of the active radiation detector.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.427-433
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• 2018

Because of the expectation of the non-invasive treatment effect, Various studies on the treatment of varicose veins using focused ultrasound are reported. In this study, the bio-tissue phantom and tissue equivalent phantom that can be applied to estimation of ultrasonic varicose veins treatment effect. Each phantom was evaluated for its usefulness by evaluating the acoustic characteristics and the shrinkage rate according to the ultrasonic irradiation. A multi-layer structure phantom with three layers of skin, fat, and muscle was constructed considering the structure of the tissue where the varicose veins occurred. The materials constituting each layer were made to have characteristics similar to human body. In addition, the multi-layered phantoms with blood vessel mimic tube, with bovine blood vessel, and with animal tissue were fabricated. The degree of shrinkage of blood vessel mimic material and vascular tissue according to ultrasonic irradiation was evaluated using B-mode image. As the results of this study, it was thought that the proposed phantom could be used effectively in the evaluation of ultrasonic varicose veins treatment. In addition, it is thought that these phantoms could be applied to the development of varicose vein treatment device using the focused ultrasound and the verification of the therapeutic effect.

• The Journal of Korean Academic Society of Nursing Education
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• v.25 no.2
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• pp.206-215
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• 2019

Purpose: This study was conducted to examine the effects of an intervention program for human tissue donation with nurses, modified from the Korea Foundation for Human Tissue Donation, to promote human tissue donation via nurses' knowledge and attitudes toward human tissue donation, and self-efficacy for teaching tissue donation. Methods: A non-equivalent control group quasi-experimental design was adopted, and data were collected from 82 nurses (41 of each group: experimental and comparison) working at a general hospital in Inchon, South Korea. Results: In a multivariate analysis (MANOVA), the integrative effect on outcome variables from the intervention program was statistically significant (p<.001). Accordingly, an ANOVA was performed to determine which individual outcome variable showed a significant effect with intervention, and it was found that the effects of intervention on all the outcome variables (knowledge and attitude, and self-efficacy for teaching human tissue donation) were significant (p<.001). Conclusion: The results of the study showed that the intervention had positive effects on knowledge and attitudes toward tissue donation, and self-efficacy for teaching tissue donation among nurses. These outcome variables derived from the intervention might be essential for eliciting positive behavior toward human tissue donation.

• Publications of The Korean Astronomical Society
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• v.27 no.3
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• pp.81-86
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• 2012

The International Space Station (ISS) orbits the Earth within the inner radiation belt, where high-energy protons are produced by collisions of cosmic rays to the upper atmosphere. About 6 astronauts stay in the ISS for a long period, and it should be important to monitor and assess the radiation environment in the ISS. The tissue equivalent proportional counter (TEPC) is an instrument to measure the impact of radiation on the human tissue. KASI is developing a TEPC as a candidate payload of the ISS. Before the detailed design of the TEPC, we performed simulations to test whether our conceptual design of the TEPC will work propertly in the ISS and to predict its performance. The simulations estimated that the TEPC will measure the dose equivalent of about 1:1 mSv during a day in the ISS, which is consistent with previous measurements.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.308-318
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• 2022

The purpose of this study is to evaluate the biomechanical properties of fractured adjacent soft tissue during closed reduction after forearm fracture using the finite element method. To accomplish this, a finite element (FE) model of the forearm including soft tissue was constructed, and the material properties reported in previous studies were implemented. Based on this, nine finite element models with different fracture types and fracture positions, which are the main parameters, were subjected to finite element analysis under the same load and boundary conditions. The load condition simulated the traction of increasing the fracture site spacing from 0.4 mm to 1.6 mm at intervals of 0.4 mm at the distal end of the radioulnar bone. Through the finite element analysis, the fracture type, fracture location, and displacement were compared and analyzed for the fracture site spacing of the fractured portion and the maximum equivalent stress of the soft tissues adjacent to the fracture(interosseous membrane, muscle, fat, and skin). The results of this study are as follows. The effect of the major parameters on the fracture site spacing of the fractured part is negligible. Also, from the displacement of 1.2 mm, the maximum equivalent stress of the interosseous membrane and muscle adjacent to the fractured bone exceeds the ultimate tensile strength of the material. In addition, it was confirmed that the maximum equivalent stresses of soft tissues(fat, skin) were different in size but similar in trend. As a result, this study was able to numerically confirm the damage to the adjacent soft tissue due to the fracture site spacing during closed reduction of forearm fracture.

• Journal of Radiation Protection and Research
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• v.10 no.2
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• pp.89-95
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• 1985

An alternative estimator for dose equivalent was derived. The original LET distribution concept was transformed into a charged particle fluence spectrum concept along with the definition of an average quality factor named slowing-down averaged quality factor by adopting the continuous slowing down approximation. With the alternative estimator, the dose equivalent delivered into a receptor located in a given radiation field can be directly and conveniently estimated in a Monte Carlo procedure. The slowing-down averaged quality factors for the energy range below 10 MeV were evaluated and tabulated for the charged particles which may be generated from the interactions of neutron with the nuclei composing soft tissue.