• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.224-225
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• 2007

This paper is to be linked the discharge theory with parameter t the coefficient of restitution used in physics. The collisions is of particular importance in high voltage engineering, nuclear, and high-energy physics. Here the bodies collided may be atoms, nuclei or various elementary particles, such as electrons, protons, and so on.

• Toxicological Research
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• 제7권2호
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• pp.129-139
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• 1991

Preventive effect of red ginseng saponin on experimentally-induced hyperkeratosis was investigated by ultrastructural observation, skin weight and epidermal lipid analysis. Hexadecane increased skin weight per unit area and epidermal lipids, free fatty acids, cholesterol and triglyceride in guinea pig skin. Topical application of ginseng saponin reduced these hyperkeratotic responses regradless of the concentration and the purity of ginseng saponin. Ultrastructurally, lipids and empty space-containing multiple horny cells were piled and nuclear remnants, desmosome, desmosomal bodies, tight junction were shown in the stratum corneum of hexadecane-treated skin.

• 비파괴검사학회지
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• 제4권1호
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• pp.23-29
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• 1984

This paper describes the evolution of quality assurance in Korea from it's total reliance on foreign contractors to the present status of conducting all QA functions independently. A brief status of the Republic of Korea Regulatory Bodies, licensing precess, codes and standards, and the quality organization of the Korea Electric Power Corporation are also included.

• Biomolecules & Therapeutics
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• 제22권2호
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• pp.136-142
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• 2014

We investigated the protective effects of chlorogenic acid (CGA), a polyphenol compound, on oxidative damage induced by UVB exposure on human HaCaT cells. In a cell-free system, CGA scavenged 1,1-diphenyl-2-picrylhydrazyl radicals, superoxide anions, hydroxyl radicals, and intracellular reactive oxygen species (ROS) generated by hydrogen peroxide and ultraviolet B (UVB). Furthermore, CGA absorbed electromagnetic radiation in the UVB range (280-320 nm). UVB exposure resulted in damage to cellular DNA, as demonstrated in a comet assay; pre-treatment of cells with CGA prior to UVB irradiation prevented DNA damage and increased cell viability. Furthermore, CGA pre-treatment prevented or ameliorated apoptosis-related changes in UVB-exposed cells, including the formation of apoptotic bodies, disruption of mitochondrial membrane potential, and alterations in the levels of the apoptosis-related proteins Bcl-2, Bax, and caspase-3. Our findings suggest that CGA protects cells from oxidative stress induced by UVB radiation.

• Asian Pacific Journal of Cancer Prevention
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• 제15권19호
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• pp.8019-8026
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• 2014

The promyelocytic leukemia (PML) gene is a gene known to be a tumor suppressor, although recent data suggest that it has a dual function in tumorigenesis. It was initially discovered in acute promyelocytic leukemia (APL) in which a t(15; 17) chromosomal translocation fused it to the retinoic acid receptor alpha ($RAR{\alpha}$). It has been shown to be involved in various types of cancer. It has at least 6 nuclear isoforms and a cytoplasmic type with different characteristics. Its multiple functions in growth inhibition, apoptosis induction, replicative senescence, inhibition of oncogenic transformation, and suppression of migration and angiogenesis have made it a therapeutic target for cancer therapy. However, its dual role in the process of tumorigenesis has made this field challenging. In this review, we discuss PML structure, functions and expression in tumors.

• Nuclear Engineering and Technology
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• 제46권4호
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• pp.461-466
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• 2014

Security of radioactive sources has been an issue since the earliest days of safety regulation of such materials. Since the events of September 11 2001, some governments and regulatory bodies have been much more focussed on these issues and have introduced extensive and enhanced security arrangements. International organisations like the IAEA and WINS have worked hard to help States in this regard. However, only a minority of States have implemented statutory security systems for radioactive source security. Why have so many States still to take action? What can be done to encourage and support these changes? This paper will offer some possible explanations for the lack of action in so many States and some potential answers to these questions.

• 대한핵의학회지
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• 제23권2호
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• pp.209-214
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• 1989

Yasculogenic impotence is produced by abnormalities of vascular blood supply or drainage, and is the most common cause of various organic impotences. An increasing awareness of vascular causes of impotence has resulted from development of various diagnostic tests, but precise measurement of penile blood flow is difficult. Radionuclide penogram has been introduced recently to diagnose vasculogenic impotence. Forty-one impotent patients and 12 normal men were studied with radionuclide erection penogram using Tc-99m pertechnetate and an intracavernous injection of papaverine. We defined arteriogenic impotence as arterial index less than 0.66, and venogenic impotence as venous index greater than 0.09. By this criteria, the false positive ratio in normal men was 17%, and the false negative ratio in radically cystectomized patients was 0%. Side effects were small purpura of the penile shaft and dull pain during injection of papaverine. The radionuclide erection penogram was noninvasive and gave a dynamic evaluation of the arterial supply, venous drainage, and blood flow in the corporeal bodies. This method should be considered as a valuable adjunct to evaluate patients with vasculogenic impotence.

• KSBB Journal
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• 제15권3호
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• pp.307-312
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• 2000

버섯에서 추출되는 생리활성물질얀 ${\beta}$-glucan은 탁월한 항암 효과를 갖는 물질이다. 특히 Agaricus blazei에 $\beta$-glucan이 많이 포함되어 있는 것으로 보고되어져 있다. 본 연구의 목적은 마이 크로웨이브를 사용하여 아가리쿠스버섯으로부터 ${\beta}$-glucan을 추 출하는 공정의 추출효율을 극대화하는 것으로, 다양한 추출시간 과 마이크로웨이브 출력을 이용하여 최적 운전조건을 결정하였 다. 최적 마이크로웨이브의 최적 출력은 200, 500, 650 watt의 경우에서 실험하여 결정하였다. 추출물질의 구조와 농도 분석은 nuclear magnetic resonance spectroscopy와 infrared spectroscopy 를 이용하여 수행하였다 본 실험 결과로 마이크로웨이브를 이 용한 추출의 다당류 수율이 전통적 인 열수추출방법보다 향상됨을 확인하였고, 소량의 용매와 짧은 추출 시간으로 향상된 수율을 얻을 수 있음을 알 수 있었다.

• 대한핵의학회지
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• 제38권5호
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• pp.331-337
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• 2004

Cardiac neurotransmission imaging allows in vivo assessment of presynaptic reuptake, neurotransmitter storage and postsynaptic receptors. Among the various neurotransmitter, I-123 MIBG is most available and relatively well-established. Metaiodobenzylguanidine (MIBG) is an analogue of the false neurotransmitter guanethidine. It is taken up to adrenergic neurons by uptake-1 mechanism as same as norepinephrine. As tagged with I-123, it can be used to image sympathetic function in various organs including heart with planar or SPECT techniques. I-123 MIBG imaging has a unique advantage to evaluate myocardial neuronal activity in which the heart has no significant structural abnormality or even no functional derangement measured with other conventional examination. In patients with cardiomyopathy and heart failure, this imaging has most sensitive technique to predict prognosis and treatment response of betablocker or ACE inhibitor. In diabetic patients, it allow very early detection of autonomic neuropathy. In patients with dangerous arrhythmia such as ventricular tachycardia or fibrillation, MIBG imaging may be only an abnormal result among various exams. In patients with ischemic heart disease, sympathetic derangement may be used as the method of risk stratification. In heart transplanted patients, sympathetic reinnervation is well evaluated. Adriamycin-induced cardiotoxicity is detected earlier than ventricular dysfunction with sympathetic dysfunction. Neurodegenerative disorder such as Parkinson's disease or dementia with Lewy bodies has also cardiac sympathetic dysfunction. Noninvasive assessment of cardiac sympathetic nerve activity with I-123 MIBG imaging nay be improve understanding of the pathophysiology of cardiac disease and make a contribution to predict survival and therapy efficacy.

• 대한세포병리학회지
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• 제11권1호
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• pp.47-52
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• 2000

Diffuse sclerosing papillary carcinoma(DSPC), a variant of papillary carcinoma of the thyroid, is characterized by diffuse involvement of one or both thyroid lobes, and histologic features such as prominent sclerosis, intense lymphocytic infiltrate, numerous psammoma bodies, and squamous metaplasia together with the characteristic cytoarchitectural pattern of classical papillary carcinoma. We experienced a case of fine needle aspiration cytologic(FNAC) findings of DSPC, which was confirmed by histologic examination of the thyroidectomy specimens. The patient was 26 years old female who presented with diffuse firm enlargement of the thyroid gland with enlargement of many cervical lymph nodes. FNAC smears showed numerous psammoma bodies, many lymphocytes, metaplastic squamous cells, absence of stringy colloid, and epithelial cells showing classical features of papillary carcinoma, such as nuclear grooves, intranuclear unclusions, and ground glass chromatin pattern.