• Title/Summary/Keyword: Radiation Effect

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Inhibitory Effects of a Combination of Grapefruit and Rosemary Extracts for Alleviating UV-Induced Skin Ageing

  • Choi, Hee-Jeong;Alam, Badrul;Zhao, Peijun;Cha, Yeong-Ho;Kim, Tae-Ho;Lee, Sang-Han
    • Korean Journal of Plant Resources
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    • v.32 no.3
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    • pp.207-219
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    • 2019
  • Ultraviolet (UV) radiation is associated with the development of extrinsic skin aging. We performed in vivo assays in order to investigate the protective effect of a combination of grapefruit and rosemary extracts (cG&Re) on UVB-induced skin aging. The results indicated that cG&Re displayed elastase inhibitory activity in a dose-dependent manner. Topical application of cG&Re mitigated photo-aging related lesions such as skin erythema and thickening in photo-aged BALB/c mice dorsal skin, by preventing UVB-induced collagen degradation. Immunohistochemical analyses revealed that cG&Re stimulated SIRT-1 expression, and suppressed MMP-1 and $IL-1{\beta}$ expression. It was observed that expression of MMP-1 and -13 mRNA was downregulated in the cG&Re-treated group. Furthermore, cG&Re treatment drastically suppressed protein expression of MMP-1 and regulated the phosphorylation of p-38 kinase. As expected, oral administration of cG&Re resulted in the same SIRT-1, MMP-1, and $IL-1{\beta}$ expression patterns observed upon topical application of cG&Re in the UV-induced mice model. Overall, the current results demonstrated that cG&Re attenuated both the downregulation of MMP-1 expression and up-regulation of SIRT-1 expression, as well as decreased phosphorylation of MAPK in UVB-induced skin ageing mice model, suggesting that cG&Re might be used as an internal food ingredient for beauty-purposes as well as a functional food material.

A Study on Minimum Separation Distance for Aboveground High-pressure Natural Gas Pipelines (지상 고압 천연가스 배관의 최소 이격거리 기준에 관한 연구)

  • Lee, Jin-Han;Jo, Young-Do
    • Korean Chemical Engineering Research
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    • v.57 no.2
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    • pp.225-231
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    • 2019
  • In Korea, the minimum separation distance between aboveground high-pressure natural gas pipeline and buildings is regulated by Korea gas safety (KGS) code. In this paper, The technical backgrounds for the revision of the KGS code related to the minimum separation distance was presented. A consequence-based approach was adopted to determine the minimum separation distance by a reasonable accident scenario, which was a jet fire caused by the rupture of one inch branch line attached the gas pipeline. Where, the higher thermal radiation flux threshold was selected for workers in industrial area than for people in non-industrial area, because the workers in industrial area were able to escape in a shorter time than the people in public. As result of consequence analysis for the accident scenario, we suggested the KGS code revision that the minimum separation distances between high-pressure natural gas pipeline installed above ground and buildings should be 30 meter in non-industrial area and 15 meter in industrial area. The revised code was accepted by the committee of the KGS code and now in effect.

Postoperative Cure for Metastatic Gastrointestinal Stromal Tumor (전이성 위장관 기질종양의 수술 후 완치)

  • Park, Eun Hyea;Kim, Jin Il;Cheung, Dae Yong;Park, Soo-Heon
    • The Korean journal of helicobacter and upper gastrointestinal research
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    • v.18 no.4
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    • pp.264-270
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    • 2018
  • Gastrointestinal stromal tumor (GIST) is a mesenchymal tumor derived from Cajal cells originating from the myotonic plexus. The expression of tyrosine kinase (KIT) membrane receptors that are active on KIT is inhibited by the KIT inhibitor imatinib mesylate. GISTs are resistant to conventional chemotherapy, and radiation therapy is not significantly beneficial for GISTs. With the development of imatinib mesylate, approximately 81.6% of patients with advanced and metastatic GIST exhibit an effect above the stabilization response, thereby increasing the survival time. However, imatinib mesylate alone is unlikely to cure metastatic GISTs. Even with a partial or stable response, imatinib mesylate may be used for a longer time period. However, resection of grossly visible lesions should be considered for patients with a stable response during surgical treatment. In this study, we present a case of GIST with liver metastasis after imatinib mesylate treatment, which was followed up without recurrence after partial resection.

Evaluation of the Dose According to the Movement of Breath During Field-in-Field Technique Treatment of Breast Cancer Patients (유방암 환자의 Field-in-Field Technique 치료 시 호흡의 움직임에 따른 선량 평가)

  • Kwon, Kyung-Tae
    • Journal of radiological science and technology
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    • v.41 no.6
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    • pp.561-566
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    • 2018
  • Field-in-Field Technique is applied to the radiation therapy of breast cancer patients, and it is possible to compensate the difference in breast thickness and deliver uniform dose in the breast. However, there are several fields in the treatment field that result in a more complex dose delivery than a single field dose delivery. If the patient's respiration is irregular during the delivery of the dose by several fields and the change of respiration occurs, the dose distribution in the breast changes. Therefore, based on the computed tomography images of breast cancer patients, a human model was created by using a 3D printer (Builder Extreme 1000) to describe the volume in the same manner. A computerized tomography (CT) of the human body model was performed and a treatment plan of 260 cGy / fx was established using a 6-MV field-in-field technique using a computerized treatment planning system (Eclipse 13.6, Varian, USA). The distribution of the dose in the breast according to the change of the respiration was measured using a moving phantom at 0.1 cm, 0.3 cm, 0.5 cm amplitude, using a MOSOXIDE Silicon Field Effect Transistor (MOSFET, Best Medical, Canada) Were measured and compared. The distribution of dose in the breast according to the change of respiration showed similar value within ${\pm}2%$ in the movement up to 0.3 cm compared to the treatment plan. In this experiment, we found that the dose distribution in the breast due to the change of respiration when the change of respiration was increased was not much different from the treatment plan.

Assessment of Effective Dose for General Radiography of Adults Based on Diagnostic Reference Level(DRL) by Using PCXMC Program (진단참고준위(DRL)를 기준으로 PCXMC 프로그램을 이용한 성인의 일반촬영 부위별 유효선량 평가)

  • Jeong, Hee-Cheol;Lee, SamYol
    • Journal of the Korean Society of Radiology
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    • v.12 no.7
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    • pp.807-812
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    • 2018
  • In this study, we investigated the conditions used in setting the recommendation level of general radiography diagnostic reference and tried to evaluate the effective dose and biological evaluation using PCXMC v2.0 program. As a result based on the effective dose of male in ICRP 60, the highest Pelvis AP was 0.794 mSv. The lowest Chest PA was 0.050 mSv. In the case of ICRP 103, the highest T-Spine AP was 0.906 mSv The lowest Chest PA was 0.052 mSv. For 40 years old male and female adults, effective doses of general radiography were evaluated and even if the medical exposures are not subject to the limit of dose, efforts should be made to reduce the medical exposures of the people by keeping the dose below the recommended amount in order to minimize the probable effect of radiation hazard.

Workplace Diesel Exhausts and Gasoline Exposure and Risk of Colorectal Cancer in Four Nordic Countries

  • Talibov, Madar;Sormunen, Jorma;Weiderpass, Elisabete;Kjaerheim, Kristina;Martinsen, Jan-Ivar;Sparen, Per;Tryggvadottir, Laufey;Hansen, Johnni;Pukkala, Eero
    • Safety and Health at Work
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    • v.10 no.2
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    • pp.141-150
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    • 2019
  • Background: Evidence on associations between occupational diesel exhaust and gasoline exposure and colorectal cancer is limited. We aimed to assess the effect of workplace exposure to diesel exhaust and gasoline on the risk of colorectal cancer. Methods: This case-control study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway, and Sweden. Cases and controls were identified from the Nordic Occupational Cancer Study cohort and matched for country, birth year, and sex. Diesel exhaust and gasoline exposure values were assigned by country-specific job-exposure matrices. Odds ratios and 95% confidence intervals were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work and occupational exposure to benzene, formaldehyde, ionizing radiation, chlorinated hydrocarbons, chromium, and wood dust. Results: Diesel exhaust exposure was associated with a small increase in the risk of rectal cancer (odds ratio - 1.05, 95% confidence interval 1.02-1.08). Gasoline exposure was not associated with colorectal cancer risk. Conclusion: This study showed a small risk increase for rectal cancer after workplace diesel exhaust exposure. However, this finding could be due to chance, given the limitations of the study.

Agastache rugosa Kuntze Attenuates UVB-Induced Photoaging in Hairless Mice through the Regulation of MAPK/AP-1 and TGF-β/Smad Pathways

  • Yun, Mann-Seok;Kim, Changhee;Hwang, Jae-Kwan
    • Journal of Microbiology and Biotechnology
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    • v.29 no.9
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    • pp.1349-1360
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    • 2019
  • Chronic exposure to ultraviolet (UV) radiation, regarded as a major cause of extrinsic aging or photoaging characterized by wrinkle formation and skin dehydration, exerts adverse effects on skin by causing the overproduction of reactive oxygen species. Agastache rugosa Kuntze, known as Korean mint, possesses a wide spectrum of biological properties including anti-oxidation, anti-inflammation, and anti-atherosclerosis. Previous studies have reported that A. rugosa protected human keratinocytes against UVB irradiation by restoring the anti-oxidant defense system. However, the anti-photoaging effect of A. rugosa extract (ARE) in animal models has not yet been evaluated. ARE was orally administered to hairless mice at doses of 100 or 250 mg/kg/day along with UVB exposure for 12 weeks. ARE histologically improved UVB-induced wrinkle formation, epidermal thickening, erythema, and hyperpigmentation. In addition, ARE recovered skin moisture by improving skin hydration and transepidermal water loss (TEWL). Along with this, ARE increased hyaluronic acid levels by upregulating HA synthase genes. ARE markedly increased the density of collagen and the amounts of hydroxypoline via two pathways. First, ARE significantly downregulated the mRNA expression of matrix metalloproteinases responsible for collagen degradation by inactivating the mitogen-activated protein kinase/activator protein 1 pathway. Second, ARE stimulated the transforming growth factor beta/Smad signaling, consequently raising the mRNA levels of collagen-related genes. In addition, ARE not only increased the mRNA expression of anti-oxidant enzymes but also decreased inflammatory cytokines by blocking the protein expression of nuclear factor kappa B. Collectively, our findings suggest that A. rugosa may be a potential preventive and therapeutic agent for photoaging.

Cesium removal in water using magnetic materials ; A review (자성체 물질을 이용한 수중의 세슘제거 동향)

  • Yeo, Wooseok;Cho, Byungrae;Kim, Jong Kyu
    • Journal of the Korean Society of Industry Convergence
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    • v.21 no.6
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    • pp.395-408
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    • 2018
  • Even after the Fukushima nuclear accident in 2011, the rate of production of electric energy using nuclear energy is increasing, but there is a great danger such as the radioactive waste produced when using nuclear power, the catastrophic accident of nuclear power plant, and connection with nuclear weapons. In particular, Cs present in the ionic form of alkaline elements has a long half-life (30.17 years) because it is readily absorbed by the organism and emits intense gamma rays, thus presenting a serious radiation hazard. Therefore, it must be completely removed before it can be released into the natural ecosystem, because it can adversely affect not only humans but also natural ecosystems. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. In addition, researches have been doing to synthesize magnetic materials with adsorbents such as HCF and PB, and it shows a great effect in the removal rate of Cs present in wastewater or the maximum Cs adsorption amount. In particular, when a magnetic material was applied, excellent results were obtained in which only Cs was selectively removed from other cations. However, new problems such as applicability in the sea where Cs is directly released, applicability in various pH ranges, and failure to preserve the magnetizing force possessed by the magnetic body have been found. However, researches using ferromagnetic field with stronger magnetic properties than those of magnetic bodies is considered to be insufficient. Therefore, it is considered that if the researches combining the ferromagnetic field with the magnetization ability and functional adsorbents more actively, the radioactive material Cs which adversely affects the natural ecosystem can be effectively removed.

Effects of Catechin-rich Green Tea Extract on the MMP-1 Activity of HaCaT Keratinocyte Cells and on UVB-induced Skin Damage in Hairless Mice (각질형성세포에서 MMP-1 활성 및 자외선 유도 무모쥐 피부손상에 대한 카테킨 고함유 녹차추출물의 영향)

  • Yang, Won Kyung;Park, Yang Chun;Kim, Bok Kyu;Choi, Jeong June;Ryu, Geon Seek;Kim, Seung Hyung
    • Korean Journal of Medicinal Crop Science
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    • v.27 no.2
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    • pp.143-150
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    • 2019
  • Background: Skin is an organ that protects the human body from various environmental stimuli that can induce immune system activation. Skin aging can be largely divided into two categories: physiological aging, which is caused by the a decreased physiological function of the skin and structural changes with aging, and photoaging, which is caused by the chemical stress induced by external stimuli such as ultraviolet (UV) radiation. Methods and Results: The objective of this study was to investigate the anti-wrinkle and UV protective effect of catechin-rich green tea extract (CGTE) in activated keratinocyte (HaCaT cells) and UV-induced skin damage in hairless mice. The results showed that CGTE inhibits the tumor necrosis factor-alpha interferon-gamma ($TNF-{\alpha}+IFN-{\gamma}$)-induced expression of matrix metalloproteinase (MMP)-1 in HaCaT cells. In addition, the CGTE treatment significantly reduced wrinkle formation, epidermal thickness, collagen deposition, and transepidermal water loss in dorsal skin irradiated with UVB. However, the ${\beta}$-glucosidase activity was significantly increased. The CGTE treatment inhibits mRNA expression and enzyme activity of MMP-2 and MMP-9 in the dorsal skin irradiated with UVB. Conclusions: It is expected that CGTE can be effectively used as a functional food and cosmetic ingredient to improve skin moisture retention and reduce wrinkle formation.

A Study on the Shielding of Orbit by 3D Printed Filament in Brain CT (Brain CT검사 시 3D프린터 필라멘트에 따른 수정체 차폐 연구)

  • Choi, Woo Jeon;Kim, Dong Hyun
    • Journal of the Korean Society of Radiology
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    • v.15 no.2
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    • pp.101-108
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    • 2021
  • The CT can accurately present the anatomical structure of an organ in the human body, and the resolution of the image is excellent. On Brain CT examination, the radiation sensitivity of the orbit is high and it is subject to many exposure effects. To reduce exposure dose of lens, this study compares change of exposure dose and shielding rate about non-shielding and shielding in a way of using two shielding materials, bismuth and tungsten. In this study, we used bismuth and tungsten filament as shielding materials made by 3D printing to measure the exposure dose according to the materials thickness and each of slices. To compare each shielding rate, 1 mm to 5 mm of two materials was measured with the head phantom fixed and the Magicmax universal dosimeter placed on the eye when the shielding material is not placed, and the shielding material is placed on it. In the 1 mm thick filament, the bismuth filament showed 26.8% and the tungsten filament showed 43.1% shielding rate. Therefore, tungsten presents much greater shielding effect than bismuth.