• Structural Engineering and Mechanics
• /
• 제43권6호
• /
• pp.725-737
• /
• 2012

The temperature on steel structures is larger than the ambient air temperature under solar radiation and the temperature distribution on the affected structure is non-uniform and complicated. The steel tube, as a main structural member, has been investigated through experiment and numerical analysis. In this study, the temperature distribution on a properly designed steel tube under solar radiation is measured. A finite element transient thermal analysis method is presented and verified by the experimental results and a series of parametric studies are carried out to investigate the influence of various geometric properties and orientation on the temperature distribution. Furthermore, a simplified approach is proposed to predict the temperature distribution of steel tube. Based on both the experimental and the numerical results, it is concluded that the solar radiation has a significant effect on the temperature distribution of steel tubes. Under the solar radiation, the temperature of steel tubes is about $20.6^{\circ}C$ higher than the ambient air temperature. The temperature distribution of steel tubes is sensitive to the steel solar radiation absorption, steel tube diameter and orientation, but insensitive to the solar radiation reflectance and thickness of steel tube.

• Journal of the Korean Society of Food Science and Nutrition
• /
• 제30권1호
• /
• pp.193-195
• /
• 2001

A radiation-resistant bacterium was isolated from gamma irradiated dried laver (Porphyra tenera) and its microbiological characteristics were examined. As a result of resistance test to gamma irradiation, the isolate was survived $10^{3}$ CFU/mL even at 30 kGy and significant shoulder line zone was shown until 20 kGy. The $D_{10}$ value was 11.27 kGy. The isolate was gram-positive, non-motile coccus and catalase-positive. n culture, the red-pigmented smooth colony was observed. The biochemical test in API (analytical profile index) system showed that the isolate fermented glucose and fructose as the carbon source. Therefore, a radiation-resistant bacterium isolated from laver was potentially identified as Micrococcus roseus sp.

• Genomics & Informatics
• /
• 제8권1호
• /
• pp.34-40
• /
• 2010

Radiofrequency (RF) radiation might induce the transcription of a certain set of genes as other physical stresses like ionizing radiation and UV. To observe transcriptional changes upon RF radiation, we exposed WI-38, human lung fibroblast cell to 1763 MHz of mobile phone RF radiation at 60 W/kg of specific absorption rate (SAR) for 24h with or without heat control. There were no significant changes in cell numbers and morphology after exposure to RF radiation. Using quantitative RT-PCR, we checked the expression of three heat shock protein (HSP) (HSPA1A, HSPA6 and HSP105) and seven stress-related genes (TNFRSF11B, FGF2, TGFB2, ITGA2, BRIP1, EXO1, and MCM10) in RF only and RF/HS groups of RF-exposed cells. The expressions of three heat shock proteins and seven stress-related genes were selectively changed only in RF/HS groups. Based on the expression of ten genes, we could classify thermal and non-thermal effect of RF-exposure, which genes can be used as biomarkers for RF radiation exposure.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권10호
• /
• pp.4879-4881
• /
• 2012

Epidermal growth factor receptor (EGFR) overexpression is associated with resistance to chemotherapy and radiotherapy. The EGFR modulates DNA repair after radiation-induced damage through an association with the catalytic subunit of DNA protein kinase. DNA double-strand breaks (DSBs) are the most lethal type of DNA damage induced by ionizing radiation, and non-homologous end joining is the predominant pathway for repair of radiation-induced DSBs. Some cell signaling pathways that respond to normal growth factors are abnormally activated in human cancer. These pathways also invoke the cell survival mechanisms that lead to resistance to radiation. The molecular connection between the EGFR and its control over DNA repair capacity appears to be mediated by one or more signaling pathways downstream of this receptor. The purpose of this mini-review was not only to highlight the relation of the EGFR signal as a regulatory mechanism to DNA repair and radiation resistance, but also to provide clues to improving existing radiation resistance through novel therapies based on the above-mentioned mechanism.

• Journal of radiological science and technology
• /
• 제41권6호
• /
• pp.581-586
• /
• 2018

This study was conducted to analyze factors Influencing Protective Behavior against Radiation Exposure using questionnaires for 231 radiological technologists working in Computed Tomography(CT) examination room with high radiation dose in diagnostic radiology field. Statistical analysis of the collected data revealed that the reasons for partially shielding the examination part in the CT scan were the lack of protective equipment, securing of radiation justification, being annoying and maybe not being harm to adults in order. It was also revealed that the variables influencing the protective behavior were protective behavior against radiation harm, self-efficacy, protective environment, organization culture, protective knowledge and protective instrument in order. The higher the radiological protective environment(${\beta}=0.245$) and the lower the radiological protective knowledge(${\beta}=-0.034$), the more influential the protective behavior against radiation harm was. In this study, it was shown that non examination parts were not shielded in the CT scan. Therefore, it is necessary to improve the level of protective environment, to cultivate knowledge to improve the protective behavior against radiation harm and to have an intervention strategy for concrete action.

• Nuclear Engineering and Technology
• /
• 제55권1호
• /
• pp.270-277
• /
• 2023

Exposure to ionizing radiation induces free radicals in human nails. These free radicals generate a radiation-induced signal (RIS) in electron paramagnetic resonance (EPR) spectroscopy. Compared with the RIS of tooth enamel samples, that in human nails is more affected by moisture and heat, but has the advantages of being sensitive to radiation and easy to collect. The fingernail as a biological sample is applicable in retrospective dosimetry in cases of localized hand exposure accidents. In this study, the dosimetric characteristics of fingernails were analyzed in fingernail clippings collected from Korean donors. The dose response, fading of radiation-induced and mechanically induced signals, treatment method for evaluation of background signal, minimum detectable dose, and minimum detectable mass were investigated to propose a fingernail-EPR dosimetry protocol. In addition, to validate the practicality of the protocol, blind and field experiments were performed in the laboratory and a non-destructive testing facility. The relative biases in the dose assessment result of the blind and field experiments were 8.43% and 21.68% on average between the reference and reconstructed doses. The results of this study suggest that fingernail-EPR dosimetry can be a useful method for the application of retrospective dosimetry in cases of radiological accidents.

• Radiation Oncology Journal
• /
• 제33권2호
• /
• pp.149-154
• /
• 2015

Purpose: We performed exome sequencing in a breast cancer family without BRCA mutations. Materials and Methods: A family that three sisters have a history of breast cancer was selected for analysis. There were no family members with breast cancer in the previous generation. Genetic testing for BRCA mutation was negative, even by the multiplex ligation-dependent probe amplification method. Two sisters with breast cancer were selected as affected members, while the mother of the sisters was a non-affected member. Whole exome sequencing was performed on the HiSeq 2000 platform with paired-end reads of 101 bp in the three members. Results: We identified 19,436, 19,468, and 19,345 single-nucleotide polymorphisms (SNPs) in the coding regions. Among them, 8,759, 8,789, and 8,772 were non-synonymous SNPs, respectively. After filtering out 12,843 synonymous variations and 12,105 known variations with indels found in the dbSNP135 or 1000 Genomes Project database, we selected 73 variations in the samples from the affected sisters that did not occur in the sample from the unaffected mother. Using the Sorting Intolerant From Tolerant (SIFT), PolyPhen-2, and MutationTaster algorithms to predict amino acid substitutions, the XCR1, DLL1, TH, ACCS, SPPL3, CCNF, and SRL genes were risky among all three algorithms, while definite candidate genes could not be conclusively determined. Conclusion: Using exome sequencing, we found 7 variants for a breast cancer family without BRCA mutations. Genetic evidence of disease association should be confirmed by future studies.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권20호
• /
• pp.8591-8594
• /
• 2014

Background: Lung cancer is the most common cancer in males worldwide. The principal mode of treatment in the early stage of non-small cell lung cancer (NSCLC) is surgery. However, five-year survival is only about 15% for all stages. The aim is to investigate the effect of daily low dose cisplatin concurrently with radiation therapy in advanced NSCLC patients with poor performance status. Materials and Methods: Ten patients diagnosed as inoperable Stage IIIB NSCLC with comorbid disease were assessed retrospectively in Bezmialem Vakif University, Faculty of Medicine, Department of Radiation Oncology, between 2011 to 2013. ECOG performance status was between 3 and 4. Cisplatin was administered at $6mg/m^2$ daily, for 5 days a week concurrently with radiotherapy using 160-200 cGy daily fractions, 54 Gy being the lowest and 63 Gy being the highest dose. Results: Complete response at the primary tumour site was obtained in 20% patients. Grade I esophagitis was seen 70 percent of patients, and the grade II haematological toxicity rate was 20 %. Median survival time was 7 months. Conclusions: Median survival time was reasonable, despite the patients ECOG performance status of 3-4, which is similar to groups even without comorbid disorders in comparison to other published papers in the literature. Acceptable toxicity, high response rates and quality of life of patients are the other favourable features.

• Tuberculosis and Respiratory Diseases
• /
• 제49권4호
• /
• pp.466-473
• /
• 2000

Background : Patients with locally advanced non-small cell lung cancer are often treated with radiation alone or in combination with chemotherapy. Both modalities have a potentially damaging effect on pulmonary function. In order to examine changes in the cardiopulmonary exercise function of patients with locally advanced non-small cell lung cancer before and after conventional radiotherapy, we conducted a prospective study involving patients with such cancer, that had received radiation therapy. Method : Resting pulmonary function test, thoracic radiographic finding and cardiopulmonary exercise test(CPET) were assessed prior to and 4 weeks following radiation therapy in 11 male patients with locally advanced non-small cell lung cancer. Patient with endobronchial mass were excluded. Results : The forces vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$ and maximal voluntary ventilation (MVV) did not decreased between before and 4 weeks after radiation but the diffusing capacity (DLCO) had decreased by 11% 4 weeks after radiation, which was not statistically significant. No changes in maximal oxygen consumption ($VO_2$max), carbon dioxide production ($VCO_2$), exercise time and work load were attributed to radiation therapy. Follow up cardiopulmonary exercise testing revealed unchanged cardiovascular function, ventilatory function and gas exchange. No difference in cardiopulmonary exercise test performance was observed between pre- and post-radiation. Conclusion : Cardiopulmonary exercise function did not decrease within the short-term after the radiation of patients with locally advanced non-small cell lung cancer.

• Radiation Oncology Journal
• /
• 제32권1호
• /
• pp.43-47
• /
• 2014

Purpose: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intra-class correlation coefficient (ICC). Results: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.