• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1744-1752
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• 2013

We investigated the protective effect of UVB inducing photodamage from mulberry extract (ME) and Lithospermum erythrorhizon extract (LE). The contents of total anthocyanin and shikonin as a color compound of ME and LE were 4.92 mg/g and 9.58 mg/g, respectively. The electron donating ability and superoxide radical scavenging activity of ME were 84.32% and 76.34%, respectively. The oxygen radical absorbance capacity of the ME ($545.37{\mu}moles$ TE/g) was higher than LE ($427.18{\mu}moles$ TE/g). MMP-1 production in the HS68 cells were exposed to UVB suppressed by treatment with $200{\mu}g/mL$ of ME (68.6%) and LE (32.7%). ME and LE were applied to a skin aging mouse model, which was induced by the irradiation of UVB to the backs of hairless mice. The value of skin erythema index, wrinkle depth and thickness, epidermis thickness, and collagenous fiber damage in the experiment groups (MEL: ME 3%, MEM: ME 5%, MEH: ME 7%, LEL: LE 3%, LEM: LE 5%, LEH: LE 7%) were remarkably reduced than in the control group (only UVB exposure group), while water capacity increased. The level of total wrinkles depth in the skin was decreased to be 30% of the control group by MEH and LEM. These results suggest that ME and LE are useful cosmetic materials for skin protection against UVB-inducing.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.51-57
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• 2003

Mitigation of fast neutron irradiation damage on reactor vessel and improvement of mechanical integrity are desired for the successful plant life-time extension. In this study, the performance of metallic hydride for this application is reviewed and compared. First, selected prospective metallic hydrides are evaluated by MCNP code and put into the attenuation test using Cf-252 neutron source. Since for the reactor application high moderation and reflection with no absorption are favored, Z factor is introduced for the evaluation. According to the Z value estimation $ZrD_2$ and $TiD_2$ are turned out to be the most favorable fast neutron shielding materials. More thorough evaluation by computer simulation and experimentally, will be followed.

• Journal of Conservation Science
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• v.32 no.3
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• pp.377-384
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• 2016

There are physical and chemical method for removement of a lacquered layer existing on the surface when gilding an iron Buddha, these caused environmental pollution by surface degradation and is very noxious for conservation scientist's health. Thus, on this study, we conducted a lacquered layer removement experiments using Nd:YAG Laser which is contactless and eco-friendly. Specimens were made by polishing $5{\times}5$ size of iron(99.9%) specimens surfaces evenly and by differing of number of coating of unrefined lacquer, so there were thickness differences of $10{\mu}m$, $20{\mu}m$, and $30{\mu}m$. The laser machine used in this study was Nd:YAG Laser, and we used two wavelength modes; 1064 nm(160~180 mJ) for infrared light region and 532 nm(50~350 mJ) for ultraviolet light region. The experiment done by investigating the transition of specimens' surfaces with laser wavelength, energy, and numbers of investigation. The remain amount of lacquered layer surfaces before/after laser irradiation was investigated by stereoscopic microscope, observation by SEM, Non-contact Surface Roughness Measurement Device, and FT-IR etc. As a result of each analysis, we could verify the thickness of $10{\mu}m$, $20{\mu}m$ of lacquered layer removed without surface degradation when using 1064 nm wavelength with $1.0J/cm^2$ density. We could find out that Nd:YAG Laser is effective for removing remained lacquered layers when gilding an iron Buddha. In the future, when not only the metal has made various studies also wood lacquered furniture or the like, it seems to be utilized to remove the lacquer without surface damage.

• Natural Product Sciences
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• v.18 no.1
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• pp.60-66
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• 2012

Human skin is the first line of defense for the protection of the internal organs of the body from different stimuli. Ultraviolet B (UVB) irradiation induces skin damage and inflammation through the secretion of various cytokines, which are immune regulators produced by cells. To prevent the initiation of skin inflammation, keratinocytes that have been irreversibly damaged by radiation must be removed through the apoptotic mechanism. Ixeris dentata (family: Asteraceae) is a perennial medicinal herb indigenous to Korea. It has been used in Korea, China, and Japan to treat in digestion, pneumonia, diabetes, hepatitis, and tumors. To gain insight into the anti-inflammatory effects of I. dentata, we examined its influence on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells), by observing cells that were stimulated with UVB in the presence or absence of I. dentata. In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and western blot analysis to measure the activation of mitogen-activated protein kinase (MAPKs). I. dentata inhibited UVBinduced production of the pro-inflammatory cytokine interleukin (IL)-6 in a dose-dependent manner. Further, I. dentata inhibited the UVB-induced expression of cyclooxygenase (COX)-2. Furthermore, I. dentata inhibited the phosphorylation of c-Jun NH2-terminal kinase and p38 MAPKs, suggesting that it inhibits the secretion of the pro-inflammatory cytokines IL-6 and IL-8, and COX-2 expression, by blocking MAPK phosphorylation. These results suggest that I. dentate can potentially protect against UVB-induced skin inflammation.

• Applied Microscopy
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• v.29 no.4
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• pp.471-477
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• 1999

Microstructural observations on the pyrochlore-type $Lu_2Ti_2O_7$ and the similar type of compounds, $In_2(Ti_{1.7}Zn_{0.3})O_{6.7}$ and $In_2(Ti_{1.7}Mg_{0.3})O_{6.7}$ which were made by the isothermal heat-treatment at 1623K for 18 days in Pt tube, were carried out using a top-entry HRTEM working at 200 kV. The modulated structures were found in both compounds, however, not in $Lu_2Ti_2O_7$. From the electron diffraction pattern analysis, the modulated superlattices are incommensurate and are 2.69 times of sublattices along (220) direction. The high resolution TEM images have shown that the superlattices consist of alternate superlattices which are composed of two or three sublattices, resulting in the average of 2.7 times of sublattices in accordance with the analysis of electron diffraction patterns. The crystal structures of both compounds are found to quite similar to those of pyrochlore, however the evidence that the cubic axes are slightly deviated from right angle. The modulated structure has gradually changed to the unmodulated structure induced by electron irradiation.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.458-463
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• 2011

Recent studies have revealed that collagen peptide (CP) plays a protective role in skin by improving the activity of antioxidants and acts as an inducer of skin regeneration by positive feedback. In this study, we focused on the beneficial effect of reinforcing the CP skin barrier. To evaluate the skin barrier, hairless mice were exposed to UVB irradiation and acetone-treatment, with or without oral administration of CP. The effects on skin appearance, trans-epidermal water loss, epidermal thickness, and cytokine content were measured using bioengineering and histochemical methods. In the CP treated group, the skin had better appearance and less damage than that of the control. Furthermore, in HaCaT cells, the amount of serinepalmytoyl transferase (SPT) mRNA increased by about 1.6-fold after treatment (CP, 100 mg/L), reflecting that CP can induce SPT expression and reinforce the recovery of skin barrier function. These results suggest that CP is not only an anti-wrinkling agent but also a potent candidate as an epidermal moisturizer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1055-1061
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• 2014

Innovative freezing technology is currently applied to preserve foodstuffs for long-term storage. Generally, the quality of frozen food is closely related to the types of freezing and thawing processes. In this study, we characterized the physicochemical properties of onions depending on freezing rate. When onions were frozen at $-40^{\circ}C$, freezing rates were 0.1, 0.5, and $0.7^{\circ}C/min$ depending on air-blast quick freezer mode. Onions were thawed by microwave irradiation at 400 W. Hardness of onion dramatically decreased after freezing and thawing compared with blanched onion. However, the fastest freezing rate did not affect hardness. Thawing loss of onion decreased with a faster freezing rate. For morphological observation, onion frozen at a faster rate showed a smaller ice-crystal size. Vitamin C content decreased upon blanching or freezing, but there was no significant difference according to freezing rate. Although free sugar content also decreased upon blanching and freezing, its highest content was at $0.7^{\circ}C/min$ freezing. Among organic acids, malic acid content was highest at $0.7^{\circ}C/min$ freezing. Based on this study, it could be suggested that a faster freezing rate is effective to improve frozen food quality in accordance with preventing tissue damage or minimizing destruction of nutrients.

• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.66-74
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• 2018

Background: Tumor response to anticancer therapies can much be influenced by microenvironmental factors. In this study, we determined the effect of these microenvironmental factors on DNA methylation using A549 human lung adenocarcinoma cell line. Materials and Methods: We subjected A549 cells to various conditions mimicking tumor microenvironment including hypoxia, acidosis (sodium lactate), oxidative stress ($H_2O_2$), bystander effect (supernatant from doxorubicin (Dox)-treated or irradiated cells), and immune cell infiltration (supernatant from THP-1 or Jurkat T cells). Genomic DNA was isolated from these cells and analyzed for DNA methylation. Clonogenic cell survival, gene expression, and metabolism were analyzed in cells treated with some of these conditions. Results and Discussion: We found that DNA methylation level was significantly decreased in A549 cells treated with conditioned media from Dox-treated cells or Jurkat T cells, or sodium lactate, indicating an active transcription. To determine whether the decreased DNA methylation affects radiation sensitivity, we exposed cells to these conditions followed by 6 Gy irradiation and found that cell survival was significantly increased by sodium lactate while it was decreased by conditioned media from Dox-treated cells. We further observed that cells treated with conditioned media from Dox-treated cells exhibited significant changes in expression of genes including BAX and FAS (involved in apoptosis), NADPH dehydrogenase (mitochondria), EGFR (cellular survival) and RAD51 (DNA damage repair) while sodium lactate increased cellular metabolism rather than changing the gene expression. Conclusion: Our results suggest that various tumor microenvironmental factors can differentially influence DNA methylation and hence radiosensitivity and gene expression in A549 cancer cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.245-251
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• 2005

Safety is one of the key issue in the regulation of cosmetics. Cosmetic Act deals with it in Korea. The guidance for the testing cosmetic ingredients and their safety evaluation are prepared by Korea Food and Drug Administration. Ultraviolet radiation could Induce skin damage, edema, erythema, photoaging, immune dysfunction and skin cancer. Ultraviolet radiation is classified as Group 2A(probably carcinogenic to humans) by International Agenry for Reaserch on Cancer(IARC). The in vitro methodologies for evaluating the toxic potential of ingredients reported in the literature have not yet been sufficiently validated for use in areas other than the study for mutagenicity/genotoxicity, for pre-screening for severe irritancy, for screening of phototoxicity and for evaluating the percutaneous absorption. The 3T3 neutral red uptake photoxicity test (3T3 NRU PT) was accepted as OECD toxicity guideline in 2002. The 3T3 NRU PT is an in vitro method based on a comparison of the cytotoxicitv of a chemical when tested in the presence and in the absence of exposure to a non-cytotoxic dose of UVA/visible light.

• Radiation Oncology Journal
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• v.4 no.2
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• pp.99-105
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• 1986

Optimal balance between control probability and risk of complication is emphasized even in present time, Although certain incidence of intestinal injury is accepted as an inevitable consequence after abdominopelvic irradiation, these complications still remain as problems. 60 mice were irradiated with 250 kVp orthovoltage x-ray machine and $200rad{\times}5/wk$ regimen. Histpathologic findings of colorectum and the relationship with occult blood test were analyzed and possible tolerable dose which would be safe from permanent complication was also estimated. Followings are the results: Mild mucosal and submucosal edema were observed in 1,000 rad irradiated group. Congestion of small vessels was prominent in 2,000 rad irradiated group and infiltration of inflammatory cells was observed in 3,000 rad irradiated group. Denuded mucosa was observed in 3,000 rad irradiated group. Occult blood test is not a proper indicator for rectal denuding or rectal ulcer, but our results suggest the possibility of using this as a relative scale of intestinal damage. Mitotic figures of crypt cells were observed even in 5,000 rad irradiated group, these suggest that the repair capacity of crypt cells are still functioning.