• Advances in materials Research
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• 제13권4호
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• pp.321-334
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• 2024

The paper is a study on the biothermoelastic analysis in viscoelastic biological tissues in the presence of thermal relaxation times. Using Laplace transforms and related methodologies, we explore how living tissue responds to an exponentially decaying pulse of heat flux at the boundary. The Laplace transformations are reversed using the numerical method. The Tzuo technique was used to measure the reversal. Temperature, displacement, and stress distributions are affected by single-phase and delay relaxation coefficients as well as volume rheological factors, are provided with numerical findings and graphically depicted. In addition, we carry out a parametric analysis to provide assistance in choosing the design variables that are the most successful, which finally results in an improvement in the accuracy of hyperthermia treatments.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 하계학술연구발표회 및 한.일 공동심포지엄
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• pp.236-237
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• 2003

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2005년도 추계학술대회 초록집
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• pp.109-109
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• 2005

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2016년도 자성 및 자성재료 국제학술대회
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• pp.124-124
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• 2016

• Toxicological Research
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• 제11권1호
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• pp.161-168
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• 1995

It has been found that various stress challenges induce the myocardial antioxidant enzymes and produce an acquisition of the cellular resistance to the ischemic injury in animal hearts. Most of the stresses, however, seem to be guite dangerous to an animal's life. In the present study, therefore, we tried to search for safely applicable stress modalities which could lead to the induction of antioxidant enzymes and the production of myocardial tolerance to the ischemia-reperfusion injury. Male Sprague-Dawley rats (200-250 g) were exposed to various non-fatal stress conditions, i.e., hyperthermia (environmental temperature of $42^{\circ}C$ for 30 min, non-anesthetized animal), iramobilization (60 min), treadmill exercise (20 m/min, 30min), swimming (30 min), and hyperbaric oxyflenation (3 atm, 60 min), once a day for 5 days. The activities of myocardial antioxidant enzymes and the ischemia-reperfusion injury of isolated hearts were evaluated at 24 hr after the last application of the stresses. The activities of antioxidant enzymes, superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase (G6PD), were assayed in the freshly excised ventricular tissues. The ischemia-reperfusion injury was produced by 20 min-global ischemia followed by 30 min-reperfusion using a Langendorff perfusion system. In swimming and hyperbaric oxygenation groups, the activities of SOD and G6PD increased significantly and in the hyperthermia group, the catalase activity was elevated by 63% compared to the control. The percentile recoveries of cardiac function at 30 min of the post-ischemic reperfusion were 55.4%, 73.4%, and 74.2% in swimming, the hyperbaric oxygenation and the hyperthermia groups, respectively. The values were significantly higher than that of the control (38.6%). In additions, left ventricular end-diastolic pressure and lactate dehydrogenase release were significantly reduced in the stress groups. The results suggest that the antioxidant enzymes in the heart could be induced by the apparently safe in vivo-stresses and this may be involved in the myocardial protection from the ischemia-reperfusion injury.

• Radiation Oncology Journal
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• 제2권1호
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• pp.11-20
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• 1984

The renewed interest in the use of hyperthermia in cancer therapy is bases on radiobiological and clinical evidence indicated that there may be a significant therapeutic advantage with the use of heat alone or combined with radiation or chemotherapy, There are many methods for generating heat for localized tumor as like radiofrequency, microwave, electromagnetic induction and ultrasound. But it is very difficult to be even thermal dose distribution and stable output of power and then the detection of temperature in tumor is difficult to be precise with thermocouples and semiconductor sensors. We designed the microwave heating generator, dipole antenna applicators and autometic temperature controlled thermocouples for localized hyperthermia on skin and in cavities. 1. The microwave generator with 120 W, 2,450MHz magnetron could be heating up to $40^{\circ}C\~50^{\circ}C\;for\;1\~2$ hours in living tissues. 2. The thermal dose distribution in tissue with microwave was described $42^{\circ}C\~44^{\circ}C$ with in 3 cm depth and $2\~6cm$ diameter area. 3. Skin surface heating applicator with spiral 3 times wave length antenna radiated high Power of microwave. 4, Intracavitary heating applicator with dipole antenna with autometic control temperature sensor kept up continuously constant temperature in tissue. 5. For constant thermal distribution, applied two steps power with 10W microwave after $17\~20W$ during first 10 minutes. 6. The cooling rate by blood flew in living tissue was rised as $10\%$ then meats.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3241-3245
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• 2015

Purpose: To examine the effectiveness of mitomycin-C and chemo-hyperthermia in combination for patients with high-risk non-muscle-invasive bladder cancer. Materials and Methods: Between November 2011-September 2013, 43 patients with high-risk non-muscle-invasive bladder cancer undergoing adjuvant chemo-hyperthermia in two centers were evaluated retrospectively. Treatment consisted of 6 weekly sessions, followed by 6 sessions. Recurrence and progression rate, recurrence-free interval and side effects were examined. Analyzed factors included age, gender, smoking status, AB0 blood group, body mass index, T stage and grade, concominant CIS assets. The associations between predictors and recurrence were assessed using multivariate Cox proportional hazard analyses. Results: A total of 40 patients completed induction therapy. Thirteen (32.5%) were diagnosed with tumor recurrence. Median follow-up was 30 months (range 9-39). Median recurrence-free survival was 23 months (range 6-36). The Kaplan-Meier-estimated recurrence-free rates for the entire group at 12 and 24 months were 82% and 61%. There was no statistically significant difference between patient subgroups. Cox hazard analyses showed that an A blood type (OR=6.23, p=0.031) was an independent predictor of recurrence-free. Adverse effects were seen in 53% of patients and these were frequently grades 1 and 2. Conclusions: Intravesical therapy with combination of mitomycin-C and chemohyperthermia seems to be appropriate in high-risk patients with non-muscle-invasive bladder cancer who cannot tolerate or have contraindications for standard BCG therapy.

• 한국재료학회지
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• 제13권9호
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• pp.613-618
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• 2003

The magnetic heating effect of $SiO_2$coated $ \Upsilon-Fe_2$$O_3$nanocomposite particle due to magnetic relaxational loss of superparamagnetic regime was investigated by measuring the generated heat from nanocomposite particles in alternative applied magnetic fields. The commercial $ \Upsilon-Fe_2$$O_3$nanoparticles were coated by SiO$_2$in water solution with TEOS and the synthesized nanocomposite powders and its magnetic properties were characterized and compared with the raw$ \Upsilon-Fe_2$$O_3$nanoparticles. The 10∼30 nm sized $ \Upsilon-Fe_2$$O_3$. nanoparticles were coated by 5 nm thickness of amorphous $SiO_2$film. The nanocomposite particle has very low Mr and Hc value showing superparamagnetic behavior The magnetic heating effect of nanocomposite particle on surface coating phase of $SiO_2$was discussed in terms of superparamagnetic behaviors of each particles, and their potential for hyperthermia application was evaluated.

• 폴리머
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• 제30권6호
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• pp.572-575
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• 2006

사회적 관심이 되고 있는 전력선과 휴대폰의 전자파 영향에 의한 인체 유해성 문제에 대한 상대적 개념으로 암 치료에 있어서 보조요법의 일환으로 제시될 수 있는 전자파를 이용한 온열치료법 개발을 위한 기초연구로서 고분자계의 젤리팬텀을 제작하였다. 폴리에틸렌을 비롯한 다양한 구성비를 가지는 팬텀 재료의 조합을 통해 CDMA와 PCS 대역에 적용되는 인체 두뇌의 젤리팬텀을 제작한 후 전기적 특성을 분석하였다. 본 연구는 향후 제조된 젤리팬텀을 비롯한 각종 장기의 모의인체에 대한 전기적 특성 값을 분석한 다음, 자성유체를 젤리팬텀에 주입시킨 후 실제 온도상승을 온도감지 적외선 카메라로 촬영하여 확인, 젤리팬텀의 전자기적 특성 분석을 통한 암 치료에 있어서의 새로운 방법론을 제시할 수 있을 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제36권6호
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• pp.241-250
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• 2015

Noninvasive temperature monitoring is feasible with Magnetic Resonance Imaging (MRI) based on temperature sensitive MR parameters such as $T_1$ and $T_2$ relaxation times, Proton Resonance Frequency shift (PRFs), diffusion, exchange process, magnetization transfer contrast, chemical exchange saturation transfer, etc. While the temperature monitoring is very useful to guide the thermal treatment such as RF hyperthermia or thermal ablation, the optimization of the MR thermometry method is essential because the range of temperature measurement depends on the choice of the measurement methods. Useful temperature range depends on the purpose of treatment methods, for example, $42^{\circ}C$ to $45^{\circ}C$ for RF hyperthermia and over $50^{\circ}C$ for thermal ablation. In this paper, MR thermometry methods using $T_1$ and $T_2$ relaxation times and PRFs-based MR thermometry are tried on a 3.0 T MRI system and their results are reported and compared. In addition, the scanning protocol and temperature calculation algorithms from $T_1$ and $T_2$ relaxation times and PRFs are optimized for the different temperature ranges for the purpose of RF hyperthermia and/or thermal ablation.