• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.108-114
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• 2008

Objectives : To estimate the normal range of blood and urine cadmium levels using data from occupationally non-exposed office workers to cadmium in selected Korean women. Methods : A total of 437 women from healthy office workers were analyzed. To analyze blood and urine cadmium levels, blood and urine samples of study subjects were collected carefully and analyzed. Using a structured questionnaire, characteristics of the study subjects were investigated by well trained interviewers. Results : Mean blood cadmium concentration (CdB) was $0.46\;{\mu}g/{\ell}$ (GM; 0.16), whereas mean urine cadmium concentration (CdU) was $0.94\;{\mu}g/g$ creatinine (GM; 0.37). A significant increase of cadmium levels in blood and urine was observed by the rise of age (p=0.007; p=0.002, respectively). In the analysis of smoking state, blood and urine cadmium levels were higher in current smokers than in nonsmokers. In the multiple regression analysis, the rise of age and currently smoking were observed as a significant factor associated with cadmium level. Conclusion : These findings suggest that mean cadmium level in blood and urine indicated a relatively low level, although the rise of age and currently smoking were observed as a significant factor related to cadmium level. It can be used for the basic data to prevent harmful effects of cadmium exposure among female workers occupationally exposed to cadmium.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2063-2068
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• 2013

Ship and offshore structures, those are to be used under the seawater conditions are prone to corrosion. In this research, the effect of rust existence on the fatigue strength at structural member of ship and offshore structure was investigated. For this purpose, fatigue tests for the rust removed specimen were conducted. In addition, the comparison of fatigue strength between rust removed specimen and rusted specimen was conducted. With these test results, fatigue strength share effect was investigated. Finally, at this research, it was found that there is fatigue strength share effect on the rust. In comparison of fatigue strength reduction factor, fatigue strength of the rust removed specimen is 18.1% lower than that of the rusted specimen. From the above, it was known that as far as there are not any harmful ingredients in it, rust on the steel plate is beneficial in an aspect of fatigue strength.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1184-1194
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• 2020

Melanin is a major factor that darkens skin color as one of the defense systems to prevent the harmful effects of UV light. However, darkened skin from the localized or systemic accumulation of melanin is viewed in many cultures as an esthetic problem. Consequentially, searching for anti-melanogenic agents from natural sources is very popular worldwide. Previous screening of fermented rice products, obtained from various rice cultivars fermented with different sources of loog-pang (Thai traditional fermentation starter), revealed that the highest ability to reduce the melanin content in B16F10 melanoma cells was from unpolished black rice fermented with a defined starter mixture of microbes isolated from loog-pang E11. The aim of this study was to investigate the mechanism of the fermented unpolished black rice (FUBR) on the inhibition of melanogenesis in B16F10 melanoma cells. The strongest reduction of cellular melanin content was found in the FUBR sap (FUBRS). The melanin reduction activity was consistent with the significant decrease in the intracellular tyrosinase activity. The FUBRS showed no cytotoxic effect to B16F10 melanoma or Hs68 human fibroblast cell lines. It also significantly reduced the transcript and protein expression levels of tyrosinase, tyrosinase-related protein 1 (TYRP-1), TYRP-2, and microphthalmia-associated transcription factor. Furthermore, it induced a significantly increased level of phosphorylated ERK, p38 and Akt signaling pathways, which likely contributed to the negative regulation of melanogenesis. From these results, a model for the mechanism of FUBRS on melanogenesis inhibition was proposed. Moreover, these results strongly suggested that FUBRS possesses anti-melanogenesis activity with high potential for cosmeceutical application as a skin depigmenting agent.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.19-27
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• 2010

The aim of this study is to compare the sensitivity of both two NCI-H292 and A549 cell types to acute inflammatory responses induced by cigarette smoke. For this, we treated two kinds of smoke fractions derived from 2R4F reference cigarettes: total particulate matter(TPM) collected onto a Cambridge filter pad and gas/vapor phase(GVP) prepared by bubbling through in buffer solution. When we measured cellular cytotoxicity by neutral red uptake assay after treatment for 24 hours, TPM and GVP induced cytotoxic effect in a dose-dependent manner in the range of 10-$100{\mu}g$/mL and 60-$300 {\mu}g$/mL., respectively, in both cell types without any cellular difference. Additionally, when we examined acute inflammatory responses by analyzing cytokines secreted into culture media including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), interleukin-8(IL-8), and transforming growth factor-$\alpha$(TGF-$\alpha$) as well as matrix metalloproteinase-1(MMP-1), the treatment with smoke fractions increased those marker proteins in a dose-dependent manner in NCI-H292. Meanwhile, in A549 cells only MMP-1 was observed to be increased in a dose-dependent fashion. Collectively, our data indicate that NCI-H292 cell type is more sensitive to cigarette smoke-induced inflammatory response than A549 cells. This suggests that NCI-H292 could be useful as an in vitro evaluation tool to assess harmful effects of cigarette smoke.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.4
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• pp.624-629
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• 2010

Nardostachys jatamansi water extract (NJ) has long been used for the treatment of inflammation-and immune-mediated disorders in the oriental countries. However, its site of action and pharmacological mechanism are not fully investigated. In this study, the authors tried to explore the cytoprotective and anti-inflammatory actions of NJ. First of all, NJ has no harmful effects on viability of neuronal cell line HT22 cells in the dose range of 300 mg/ml. On the contrary, it shows cytoprotective effects on the cells treated with reactive oxygen species H2O2. Probably the cytoprotective effects of NJ might be caused by its ability to induce well known cytoprotective gene hem oxygenase-1 (HO-1). Furthermore, NJ shows inhibitory effects on the expression of inducible nitric oxide synthase (iNOS) and NO production which are known to destroy the integrity of both cells and tissues. It also inhibits potent proinflammatory cytokine tumor necrosis factor-alpha (TNF-a) production. The blocking effects of NJ on cytopathic and proinflammatory actions of LPS might be caused by the induction of cytoprotective and anti-inflammatory genes HO-1 in macrophages cell line RAW 264.7 cells. The results in this study suggest NJ could be used for the amelioration of inflammation which is underlying mechanism responsible for most chronic diseases.

• Nuclear Engineering and Technology
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• v.32 no.1
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• pp.1-9
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• 2000

Delayed hydride cracking (DHC) velocity and threshold stress intensity factor for DHC ($K_{IH}$) tests in the radial direction on M11 pressure tube material in Wolsong unit 1 were carried out following the Atomic Energy Canada Limited (AECL) standard test procedure in order to identify the effect of undercooling on DHCV and to acquire the $K_{IH}$ data. The results showed that $K_{IH}$ 's were 8.8$\pm$0.8 MPa√m in the back offcut and 11.4$\pm$0.7 MPa√m in the front offcut. The fact that $K_{IH}$ in the front offcut is about 20% higher than that in the back offcut is attributed to the microstructural difference between the materials of the front and back ends. $K_{IH}$ 's in M11 pressure tube appeared to be higher than the values from the tubes made of double melted ingot reported earlier. This can be interpreted by the fact that very small amounts of Chlorine (Cl) and Phosphorus (P) are contained in the ingot and that the content of the harmful elements in the M11 pressure tube is equivalent to that made of a quadruple melting process. DHC velocities at 25$0^{\circ}C$ in the front offcut in the radial direction are measured to be 5~8$\times$10$^{-8}$ m/s. The results show that the prior thermal history change the DHC velocity significantly. This effect was confirmed by the experiment of undercooling prior to the DHC tests.DHC tests.

• The Journal of Korean Medicine
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• v.36 no.2
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• pp.21-35
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• 2015

Objectives: The purpose of this study was to examine the efficacy of Picrorrhizae Rhizoma (PR) aqueous extracts on the formalin-induced paw chronic inflammation in mice. Methods: PR extracts (500, 250 and 125mg/kg) or distilled water (DW) were orally administered once a day for 10 days to formalin-injected chronic inflammatory mice. The paw thicknesses and volumes were measured daily and the paw wet-weight and histological profiles were conducted at termination with paw tumor necrosis factor (TNF)-${\alpha}$ contents measurement. The anti-inflammatory effects of PR extracts were compared with dexamethasone. Results: In DW treated control group, the paw thickness, paw wet-weights and paw TNF-${\alpha}$ contents were markedly increased. Severe chronic inflammation signs such as severe fibrosis, the formation of necrotic debris, and infiltration of inflammatory cells were detected in histopathological observations. However, these formalin-induced changes were dramatically decreased by treatment of dexamethasone and all three different dosages of PR extracts. The anti-inflammatory effects of PR at highest dose were slighter than that of dexamethasone, but it did not show any harmful effects on the body weight contrary to dexamethasone. Conclusion: These results suggest that PR extracts have safe and favorable effects on formalin-induced chronic inflammation.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.477-487
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• 2017

This study is for empirical analyzing the ethical contents in using social media, such as what kind of ethical responsibility do the teenage users have, how do they recognize the ethical concept in producing or sharing the information and how these ethical factors affect their behavior of social media uses. After survey with the structured questionnaire, statistical analyses with available 227 cases are processed. As a result, there are 4 ethical factors in using social media which as included 'privacy', 'copyright', 'fullness', 'accuracy', 'truth-telling', 'fairness', 'relief of harmful effect', 'credibility', 'objectivity', 'impartiality', included 'moderation', 'respect', 'autonomy', 'control', 'care of mischief', included 'interactivity', 'multiplicity', 'anonymity', 'divergence', 'social community', included 'transparency', 'openness'. All these ethical factors are positive correlated to the level of social media users' opinion expression, opinion support, information leading, information searching. Especially, is the most effective factor to social media users' behavior.

• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.119-126
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• 2011

Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging, and contributes to harmful effects in cultured cells and animal tissues. mtDNA biogenesis genes (NRF-1, TFAM) are essential for the maintenance of mtDNA, as well as the transcription and replication of mitochondrial genomes. Considering that oxidative stress is known to affect mitochondrial biogenesis, we hypothesized that ionizing radiation (IR)-induced reactive oxygen species (ROS) causes mtDNA deletion by modulating the mitochondrial biogenesis, thereby leading to cellular senescence. Therefore, we examined the effects of IR on ROS levels, cellular senescence, mitochondrial biogenesis, and mtDNA deletion in IMR-90 human lung fibroblast cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated at 4 or 8 Gy. Old cells at PD55, and H2O2-treated young cells at PD 39, were compared as a positive control. The IR increased the intracellular ROS level, senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity, and mtDNA common deletion (4977 bp), and it decreased the mRNA expression of NRF-1 and TFAM in IMR-90 cells. Similar results were also observed in old cells (PD 55) and $H_2O_2$-treated young cells. To confirm that a increase in ROS level is essential for mtDNA deletion and changes of mitochondrial biogenesis in irradiated cells, the effects of N-acetylcysteine (NAC) were examined. In irradiated and $H_2O_2$-treated cells, 5 mM NAC significantly attenuated the increases of ROS, mtDNA deletion, and SA-${\beta}$-gal activity, and recovered from decreased expressions of NRF-1 and TFAM mRNA. These results suggest that ROS is a key cause of IR-induced mtDNA deletion, and the suppression of the mitochondrial biogenesis gene may mediate this process.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.3
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• pp.201-208
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• 2022

Neuroinflammation is defined as a neurological inflammation within the brain and the spinal cord. In neuroinflammation, microglia are the tissue-resident macrophages of the central nervous system, which act as the first line of defense against harmful pathogens. Dexmedetomidine (Dex) has an anti-inflammatory effect in many neurological conditions. Additionally, the microRNA-30a-5p (miR-30a-5p) mimic has been proven to be effective in macrophages in inflammatory conditions. This study aimed to investigate the synergistic anti-inflammatory effects of both miR-30a-5p and Dex in lipopolysaccharide (LPS)-induced BV2 cells. This study showed that miR-30a-5p and Dex decreased nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) translocation in LPS-induced BV2 cells. MiR-30a-5p and Dex alleviated tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), LPS-induced phosphorylation c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinase (ERK) and p38. Also, the expression of the NOD-like receptor pyrin domain containing 3 inflammasome (NLRP3), cleaved caspase-1, and ASC was inhibited. Furthermore, LPS-stimulated nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) expression were attenuated by Dex and miR-30a-5p. Our results indicate that a combination of Dex and miR-30a-5p, attenuates NF-κB activation, the mitogen-activated protein kinase (MAPK) signaling pathway, and inflammatory mediators involved in LPS-induced inflammation and inhibits the activation of the NLRP3 inflammasome in LPS-activated BV2 cells.