• Tunnel and Underground Space
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• v.31 no.1
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• pp.52-65
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• 2021

In this study, authors analyzed the vapor cloud explosion induced by propane leak at the PEMIX Terminal, which is the propane storage facility outside of Mexico City. TNT equivalence mass for the leaked 4750 kg propane was estimated to be 9398 kg. Blast parameters such as peak overpressure, positive phase duration, and impact at 40-400 (m) away from the center of the explosion were calculated by applying TNT Equivalency Method and Multi-Energy Method. The probability of damage due to lung damage, eardrum rupture, head impact, and whole-body displacement impact by applying the probit function obtained using blast parameters was evaluated. The peak overpressure obtained using Multi-Energy Method was found to be greater than the peak overpressure obtained by applying the TNT Equivalency Method at all distances considered, but it was evaluated that there was no significant difference from the points above 200 m. The peak overpressure obtained by Multi-Energy Method was computed to assess the extent of damage to the structure, and it was shown that structures within 100 m of the explosion center would collapse completely, and that the glasses of the structures 400 m away would be almost broken. The probability of death due to lung damage was shown to vary depending on a human body's position located in the propagating direction of shock wave, and if there is a reflecting surface in the immediate surroundings of a human body, the probability of death was estimated to be the greatest. The impact of shock wave on lung damage, eardrum rupture, head impact, and whole-body displacement impact was evaluated and found to affect whole-body impact < lung damage < eardrum rupture

• The Korea Journal of Herbology
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• v.26 no.2
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• pp.31-37
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• 2011

Objectives : This study was focused to investigate the toxicity of Saussurea lappa (SL) extracts in HL-60 cells and human lymphocytes. We also examined the differentiation effect of SL against leukemia cells. Methods : For examining the toxicity of SL, cytokinesis-block micronucleus (CBMN) assay and single cell gel eletrophoresis (SCGE) assay were used in present study. The cell differentiation effect of SL was evaluated by nitroblue tetrazolium (NBT) reduction assay. Results : The inhibition of cell growth in HL-60 cells was observed in a dose-dependant manner after SL treatment for 24 h. According to SCGE assay, HL-60 cells treated with SL increased DNA damage at $10{\mu}g/m{\ell}$, while DNA damage was induced by 0.1, 1, $10{\mu}g/m{\ell}$ concentration of SL in human lymphocytes. Our results indicated that SL have no genotoxic effect in HL-60 cells and human lymphocytes. Additionally, the differentiation effect was induced in $1{\mu}g/m{\ell}$ SL-treated HL-60 cells. Conclusions : From above results it is suggested that SL could be beneficial for the preparation of the useful agent for treating leukemia.

• Structural Monitoring and Maintenance
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• v.11 no.2
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• pp.87-100
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• 2024

Traffic-induced vibrations (TIVs) possess the potential to induce structural damage in both historical and critical edifices. Recent investigations have underscored the adverse impact of TIVs within buildings, manifesting as a deleterious influence on the quality of life and operational efficiency of occupants. Consequently, these studies have dichotomized TIVs into two primary limit categories: the threshold for vibrations capable of causing structural damage and the limit values associated with human comfort. In this current research endeavor, an exhaustive analysis of peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and the frequency spectrum of ground motions originating from diverse traffic sources has been conducted. Furthermore, the detrimental repercussions of these vibrations on structures, gauged through the assessment of the peak particle velocity (PPV) parameter, have been systematically evaluated. The findings of this study elucidate that TIVs within the examined structures do not attain magnitudes conducive to structural compromise; however, the levels surpassing human comfort limits are evident, attributable to specific sources and distances. Moreover, this investigation sheds light on the absence of comprehensive criteria and guidelines pertaining to the assessment of TIVs in structures within the Turkish Building Seismic Design Code 2018. It seeks to raise awareness among building constructors about the critical importance of addressing this issue, emphasizing the imperative for guidelines in mitigating the impact of TIVs on both structural integrity and human well-being.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.301-307
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• 2014

Fucodiphlorethol G (6'-[2,4-dihydroxy-6-(2,4,6-trihydroxyphenoxy)phenoxy]biphenyl-2,2',4,4',6-pentol) is a compound purified from Ecklonia cava, a brown alga that is widely distributed offshore of Jeju Island. This study investigated the protective effects of fucodiphlorethol G against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) irradiation. Fucodiphlorethol G attenuated the generation of 2, 2-diphenyl-1-picrylhydrazyl radicals and intracellular reactive oxygen species in response to UVB irradiation. Fucodiphlorethol G suppressed the inhibition of human keratinocyte growth by UVB irradiation. Additionally, the wavelength of light absorbed by fucodiphlorethol G was close to the UVB spectrum. Fucodiphlorethol G reduced UVB radiation-induced 8-isoprostane generation and DNA fragmentation in human keratinocytes. Moreover, fucodiphlorethol G reduced UVB radiation-induced loss of mitochondrial membrane potential, generation of apoptotic cells, and active caspase-9 expression. Taken together, fucodiphlorethol G protected human keratinocytes against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging reactive oxygen species.

• Biomolecules & Therapeutics
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• v.23 no.4
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• pp.357-366
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• 2015

Isorhamnetin (3-methylquercetin) is a flavonoid derived from the fruits of certain medicinal plants. This study investigated the photoprotective properties of isorhamnetin against cell damage and apoptosis resulting from excessive ultraviolet (UV) B exposure in human HaCaT keratinocytes. Isorhamnetin eliminated UVB-induced intracellular reactive oxygen species (ROS) and attenuated the oxidative modification of DNA, lipids, and proteins in response to UVB radiation. Moreover, isorhamnetin repressed UVB-facilitated programmed cell death in the keratinocytes, as evidenced by a reduction in apoptotic body formation, and nuclear fragmentation. Additionally, isorhamnetin suppressed the ability of UVB light to trigger mitochondrial dysfunction. Taken together, these results indicate that isorhamnetin has the potential to protect human keratinocytes against UVB-induced cell damage and death.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.1
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• pp.1-7
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• 2015

Cornus walteri Wanger has been used in folk medicine in Korea. Ultraviolet (UV) irradiation has been known as a major cause of photo damage in skin. In the present study, research on how to cure damaged cells by UVB was conducted using an extract of Cornus walteri Wanger leaves (CWE), which was treated with an enzyme. CWE was applied to human dermal fibroblasts (HDFs) affected by UVB. UVB-irradiated HS68 cells showed increased caspase-3 activity, phosphorylation of p53, ${\gamma}H2AX$, cyclobutane pyrimidine dimers (CPDs) formation, and DNA fragmentation compared with non-irradiated cells. However, all these effects were inhibited by treatment with CWE for 12 h after UVB irradiation. Furthermore, CWE has proved not to cause primary skin irritation through the human patch test. Collectively, these results suggest that CWE could be a new potential candidate as photoprotective agent against UVB-induced cellular damage in HDFs.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.1
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• pp.20-29
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• 2019

Soy isoflavones have been reported to possess many physiological activities such as antioxidant activity and inhibition of cancer cell proliferation. This study investigated the photoprotective effects of soybean extract in human fibroblast cell line and hairless mice model. Human fibroblast was treated with soybean extract before and after ultraviolet B (UVB; 290-302 nm) irradiation. In the soybean extract treated group, the cells showed better resistance to ultraviolet (UV) than control group. The amount of type I collagen recovered from the soybean treated group was higher than the vehicle group exposed to UV-induced damage. Moreover, increased expression of metalloproteinases-1 as a result of UV irradiation was suppressed by the soybean extract. Female mice were orally administered soybean extract and irradiated with UVB light for 8 weeks. The effects of the soybean extract on the skin appearance, collagen deposition and epidermal thickness in the UV-damaged mouse skin were analyzed using histopathological methods. In soybean extract treated group, the skin had a better morphology than that of the control group. Furthermore, the amount of type I collagen was increased and overexpression of MMP-1 was reduced in the soybean extract group compared to vehicle group. Additionally, up-regulation of pro-inflammatory cytokines induced by UV irradiation was suppressed by dietary soybean extract treatment. It appears that soybean extract had a photoprotective effect, including anti-aging and anti-inflammatory effect, from UV-induced damage in not only human fibroblast, but also hairless mice. We confirmed that these effects were possibly due to promotion of collagen synthesis and inhibition of MMP-1 expression.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2961-2966
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• 2012

Extremely low frequency electro magnetic fields (EMFs) have been classified as possibly carcinogenic to humans by the International Agency for Research on Cancer. An increased number of chromosomal alterations in peripheral lymphocytes are correlated with elevated incidence of cancer. The aim of the present study was to assess occupationally induced chromosomal damage in EMF workers exposed to low levels of radiation. We used conventional metaphase chromosome aberration (CA) analysis and the micronucleus (MN) assay as biological indicators of non ionizing radiation exposure. In the present study totally 70 subjects were selected including 50 exposed and 20 controls. Informed written consent was obtained from all participants and the study was performed in accordance with the Declaration of Helsinki and the approval of the local ethical committee. A higher degree of CA and MN was observed in exposed subjects compared to controls, the frequency of CA being significantly enhanced with long years of exposure (P<0.05). Moreover increase in CA and MN with age was noted in both exposed subjects and controls, but was significantly greater in the former. The results of this study demonstrated that a significant induction of cytogenetic damage in peripheral lymphocytes of workers occupationally exposed to EMFs in electric transformer and distribution stations. In conclusion, our findings suggest that EMFs possess genotoxic capability, as measured by CA and MN assays; CA analysis appeared more sensitive than other cytogenetic end-points. It can be concluded that chronic occupational exposure to EMFs may lead to an increased risk of genetic damage among electrical workers.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.395-408
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• 2013

Environmental condition can induce changes in early life-history traits in order to maximise the ecological fitness. Here I investigated how temperature change and variation in human aquatic activity/behaviour affect early life-history consequences in fish using a dynamic-state-dependent model. In this study, I developed a general fish's life-history model including three life-history states depend-ing on foraging activity, such as body mass, mass of reproductive tissue (i.e., gonadal development) and accumulated stress (i.e., cellular or physiological damage). I assumed the level of foraging activity maximises reproductive success-ultimately, fitness. The model predicts that growth rate, development of reproductive tissues and damage accumulation are greater in higher temperature whereas higher human aquatic activity rapidly reduced the growth rate and development of reproductive tissue and increased damage accumulation. While higher foraging activity in higher temperature is less affected by human aquatic activity, the foraging activity in lower temperature rapidly declined with human aquatic activity. Moreover, lower survival rate in higher temperature or human aquatic activity was independent on mortality rate due to human aquatic activity or mortality rate when foraging activity, respectively. However, the survival rate in lower temperature or human aquatic activity was dependent on these mortality rates. My findings suggest that including of early life-history traits in relation to climate-change and human aquatic activity on the analysis may improve conservation plan and health assessment in aquatic ecosystem.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.54-54
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• 2023

Nypa fruticans Wurmb (N. fruticans) is a plant that belongs to Araceae and N. fruticans is mainly found in tropical mangrove systems. The parts (leaves, stems, and roots) of N. fruticans are traditionally used for asthma, sore throat, and liver disease. N. fruticans contains flavonoids and polyphenols, which are substances that have inhibitory effects on cancer and oxidant. In previous studies, some pharmaceutical effects of N. fruticans on melanogenesis and inflammation have been reported. The present study is conducted to investigate the effect of the ethyl acetate fraction of N. fruticans (ENF) on oxidative DNA damage and UVB-induced DNA damage. DNA damage response (DDR) pathway is important in research on cancer, apoptosis, and so on. DDR pathways are considered a crucial factor affecting the alleviation of cellular damage. ENF could reduce oxidative DNA damage derived from reactive oxygen species by the Fenton reaction. Also, ENF reduced the intensity of intracellular ROS in the live cell image by DCFDA assay. UVB is known to cause skin and cellular damage, then finally contribute to causing the formation of tumors. As for the strategies of reducing DNA damage by UVB, inhibition of p53, H2AX, and Chk2 can be important indexes to protect the human body from DNA damage. As a result of confirming the protective effect of ENF for UVB damage, MMPs significantly decreased, and the expression of apoptosis-related factors tended to decrease. In conclusion, ENF can provide protective effects against double-stranded DNA break (DSB) caused by oxidative DNA damage and UVB-induced DNA damage. These results are considered to be closely related to the protective effect against radicals based on catechin, epicatechin, and isoquercitrin contained in ENF. Based on these results, it is thought that additional mechanism studies for inhibiting cell damage are needed.