• Journal of Radiation Protection and Research
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• 제38권4호
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• pp.166-171
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• 2013

While high-dose ionizing radiation results in long term cellular cytotoxicity, chronic low-dose (<0.2 Gy) of X- or ${\gamma}$-ray irradiation can be beneficial to living organisms by inducing radiation hormesis, stimulating immune function, and adaptive responses. During chronic low-dose-rate radiation (LDR) exposure, whole body of mice is exposed to radiation, however, it remains unclear if LDR causes changes in gene expression of the whole brain. Therefore, we aim to investigate expressed genes (EGs) and signaling pathways specifically regulated by LDR-irradiation ($^{137}Cs$, a cumulative dose of 1.7 Gy for total 100 days) in the whole brain. Using microarray analysis of whole brain RNA extracts harvested from ICR and AKR/J mice after LDR-irradiation, we discovered that two mice strains displayed distinct gene regulation patterns upon LDR-irradiation. In ICR mice, genes involved in ion transport, transition metal ion transport, and developmental cell growth were turned on while, in AKR/J mice, genes involved in sensory perception, cognition, olfactory transduction, G-protein coupled receptor pathways, inflammatory response, proteolysis, and base excision repair were found to be affected by LDR. We validated LDR-sensitive EGs by qPCR and confirmed specific upregulation of S100a7a, Olfr624, and Gm4868 genes in AKR/J mice whole brain. Therefore, our data provide the first report of genetic changes regulated by LDR in the mouse whole brain, which may affect several aspects of brain function.

• 대한화장품학회지
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• 제25권2호
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• pp.59-75
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• 1999

Skin is continuously exposed to external stimuli including ultraviolet radiation, which is a major cause of skin photoaging. According to recent discoveries, UVA with a lower energy but deep-penetrating properties, compared to UVB, is likely to play a major part in causing skin photoaging. The clinical and histochemical changes of photoaging are well characterized, but the biochemical mechanisms are poorly understood partly due to the lack of suitable experimental systems. In this work, three-dimensional, reconstituted skin culture models were prepared. After certain period of maturation, the equivalent models were shown to be similar in structure and biochemical characteristics to normal skin. Mature dermal and skin equivalent models were exposed to sub-lethal doses of UVA, and the effects of UVA relevant to dermal photoaging were monitored, including the production of elastin, collagen, collagenase(MMP-1), and tissue inhibitor of metalloproteinases-1 (TIMP-1). Interestingly, dermal and skin equivalents reacted differently to acute and chronic exposure to UVA. Elastin production was increased as soon as one week after commencing UVA irradiation by chronic exposure, although a single exposure failed to do so. This early response could be an important advantage of equivalent models in studying elastosis in photoaged skin. Collagenase activity was increased by acute UVA irradiation, but returned to control levels after repeated exposure. On the other hand, collagen biosynthesis, which was increased by a single exposure, decreased slightly during 5 weeks of prolonged UVA exposure. Collagenase has been thought to be responsible for collagen degeneration in dermal photoaging. However, according to the results obtained in this study, elevated collagenase activity is not likely to be responsible for the degeneration of collagen in dermal photoagig, while reduced production of collagen may be the main reason. It can be concluded that reconstituted skin culture models can serve as useful experimental tools for the study of skin photoaging. These culture models are relatively simple to construct, easy to handle, and are reproducible Moreover the changes of dermal photoaging can be observed within 1-4 weeks of exposure to ultraviolet light compared to 4 months to 2 years for human or animal studies. These models will be useful for biochemical and mechanistic studies in a large number of fields including dermatology, toxicology, and pharmacology.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2225-2229
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• 2014

Background: Carcinoma of the tongue is the most common intra-oral malignancy in Western countries. Incidence and mortality rates have increased in recent years, and survival has not improved. This study aimed to determine etiologic factors for tongue cancer with age-sex matched case-control data. Materials and Methods: 47 patients with carcinoma of the tongue referred to our oral medicine clinic between years 2005-2006 were analyzed and compared with control group data. The medical records, including family history of cancer, dental trauma, and history of abuse of alcohol and tobacco products was recorded for all subjects. Chi square comparison tests and linear regression analysis were performed using the SPSS program for statistics. Results: Patient and randomly selected control groups each consisted of 30 male and 17 female subjects with mean ages 53.2 (${\pm}12.6$) and 52.6 (${\pm}11.5$) years respectively. Smoking and alcohol abuse proportions were significantly higher in the patient group (p=0.0001, p<0.0001 respectively). Chronic mechanical trauma was observed in 44.7% of the patients and 17.0% of the control group (p=0.004). Similarly, family history of cancer of any type (for the first degree relatives) was found to be more common in the patient group (p=0.009). On regression analysis, alcohol abuse, family history of cancer, smoking, chronic mechanical traumas appeared as significant etiologic factors (p=0.0001). Conclusions: We believe that field cancerization may become evident in oral and oropharyngeal mucosa with multiple steps of molecular changes starting from the first sign of dysplasia with chronic exposure to etiological factors. Chronic trauma cases need particular attention to search for very early signs of cancer.

• Clinical Endoscopy
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• 제55권1호
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• pp.22-32
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• 2022

Radiotherapy (RT) is a treatment modality that uses high-energy rays or radioactive agents to generate ionizing radiation against rapidly dividing cells. The main objective of using radiation in cancer therapy is to impair or halt the division of the tumor cells. Over the past few decades, advancements in technology, the introduction of newer methods of RT, and a better understanding of the pathophysiology of cancers have enabled physicians to deliver doses of radiation that match the exact dimensions of the tumor for greater efficacy, with minimal exposure of the surrounding tissues. However, RT has numerous complications, the most common being radiation proctitis (RP). It is characterized by damage to the rectal epithelium by secondary ionizing radiation. Based on the onset of signs and symptoms, post-radiotherapy RP can be classified as acute or chronic, each with varying levels of severity and complication rates. The treatment options available for RP are limited, with most of the data on treatment available from case reports or small studies. Here, we describe the types of RT used in modern-day medicine and radiation-mediated tissue injury. We have primarily focused on the classification, epidemiology, pathogenesis, clinical features, treatment strategies, complications, and prognosis of RP.

• 대한의생명과학회지
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• 제26권4호
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• pp.249-255
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• 2020

Radiation therapy is one of the primary options for the treatment of malignant tumors. Even though it is an effective anti-cancer treatment, it can cause serious complications owing to radiation-induced damage to the normal tissue around the tumor. It was recently reported that normal stem cell response to the genotoxic stress of ionizing radiation can boost the therapeutic effectiveness of radiation by repairing damaged cells. Therefore, we focused on annexin A-1 (ANXA1), one of the genes induced by low-dose irradiation, and assessed whether it can protect adipose-derived stem cells (ADSCs) against oxidative stress-induced damage caused by low-dose irradiation and improve effectively cell survival. After confirming ANXA1 expression in ADSCs transfected with an ANXA1 expression vector, exposure to hydrogen peroxide (H2O2) was used to mimic cellular damage induced by a chronic oxidative environment to assess cell survival under oxidative conditions. ANXA1-transfected ADSCs demonstrated that increased viability compared with un-transfected cells and exhibited enhanced anti-oxidative properties. Taken together, these results suggest that ANXA1 could be used as a potential therapeutic target to improve the survival of stem cells after low-dose radiation treatment.

• Geomechanics and Engineering
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• 제32권6호
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• pp.627-637
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• 2023

Volleyball is an international sport with many fans. This sport has made significant progress in schools and clubs. Volleyball is suitable for all age groups and can be used in different environments. It has many social and physical benefits. During the game provides special physical training for the players and is considered one of the most exciting games. Another type of volleyball is beach volleyball, a beach sport and one of the Olympic sports held on the sand with the same rules as volleyball. This sport is usually played in coastal areas, especially with wide sandy beaches. Because this sport is played in open spaces, the players stay in this space for a long time and are exposed to dangerous ultraviolet radiation. It is a wavelength of light in the range of electromagnetic waves with a wavelength between 10 and 400 nm. This wavelength is shorter than visible light and more protracted than X-ray. Ultraviolet (UV) rays are naturally present in sunlight and include about 10% of all waves emitted from the sun's surface. Prolonged exposure to ultraviolet light causes acute and chronic damage to the skin and vision and even destroys the entire immune system. Different covers of the earth's surface reflect different amounts of UV rays. For example, snow cover, sand, and seawater surface reflect this radiation. Therefore, the health of volleyball players is in danger due to this harmful radiation. This work aims to introduce a type of clothing made of nanoparticles that can repel ultraviolet rays and protect beach volleyball players whose health is at risk from this radiation.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.459-461
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• 2022

본 논문에서는 실내 환경에서 검출되는 방사능을 측정하기 위한 계측 시스템을 제시한다. 일반 가정, 작업장, 연구소 등 다양한 공간에서 발생되는 방사능을 측정하고 이에 대한 예방을 위함이다. 다중 방사능 센서를 이용해서 여러 공간을 동시에 측정한다. 측정된 방사능 데이터는 지그비를 통해서 실시간으로 PC로 전달하여 모니터링하는 시스템이다. 소량의 방사능이라고 하더라고 만성 피폭으로부터의 예방을 위해 연구소 또는 작업장 같은 방사능 노출이 예상되는 곳은 필수적으로 설치되어야 한다고 생각된다.

• Journal of Photoscience
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• 제9권2호
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• pp.162-165
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• 2002

Rice is widely cultivated in various regions throughout Asia. Over a five-year period, we investigated the effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars in the field. The findings of that study indicated that supplemental UVB radiation has inhibitory effects on the growth and grain development. Furthermore, we investigated the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, and found that rice cultivars vary widely in UVB sensitivity. The aim of our study is improving UVB resistance in plants by bioengineering or breeding programs. In order to make it, there is need to find the molecular origin of the sensitivity to UVB. Cyclobutane pyrimidine dimer (CPD) is major UV-induced DNA lesions. Plants possess two mechanisms to cope with such DNA damage. The first is the accumulation of UV-absorbing compounds. Our previous data showed that the steady-state CPD levels in leaves of rice grown under chronic radiation in any culture were not so greatly influenced by the increased UV-absorbing compounds content, although there was a significant positive correlation between the CPD levels induced by challenge UVB exposure and the UV-absorbing compounds content. The other is the repair of DNA damage. Photorepair is the major pathway in plants for repairing CPD. We found that the sensitivity to UVB could seriously correlate with the low ability in CPD photorepair in rice plants. These results suggest that photo lyase might be an excellent candidate for restoration by way of selective breeding or engineering in rice.

• The Korean Journal of Pain
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• 제26권2호
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• pp.111-124
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• 2013

Ultrasound has emerged to become a commonly used modality in the performance of chronic pain interventions. It allows direct visualization of tissue structure while allowing real time guidance of needle placement and medication administration. Ultrasound is a relatively affordable imaging tool and does not subject the practitioner or patient to radiation exposure. This review focuses on the anatomy and sonoanatomy of peripheral non-axial structures commonly involved in chronic pain conditions including the stellate ganglion, suprascapular, ilioinguinal, iliohypogastric, genitofemoral and lateral femoral cutaneous nerves. Additionally, the review discusses ultrasound guided intervention techniques applicable to these structures.

• Nuclear Engineering and Technology
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• 제42권1호
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• pp.109-114
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• 2010

Bioassay data analysis software (BiDAS-2007) has been developed by KAERI, which adds several new functions to its previous version. New functions of the BiDAS-2007 computer code enable the user not only to do a simultaneous analysis by using two or more types of bioassay for the best internal dose evaluation, but also to do a continual internal dose evaluation from a change of the internal exposure conditions such as an intake type (acute, chronic), an intake pathway (inhalation, ingestion), an absorption type (Type F, M, S), and a particle size (AMAD, activity median aerodynamic diameter), and also to estimate the intakes in various conditions of an internal exposure at a time. The values calculated by the BiDAS-2007 code are consistent and in good agreement with those values by IMIE-2004 code by Berkovski and IMBA code by Birchall. The BiDAS-2007 computer code is very useful and user-friendly to estimate the radionuclide intakes and committed effective doses of a radiation worker.