• 대한화장품학회지
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• 제49권4호
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• pp.349-354
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• 2023

자외선 차단제는 자외선을 차단 및 산란시켜 자외선으로부터 보호하는 제품으로 이제 화장품을 넘어서 생활필수품으로 자리 잡고 있다. 자외선 차단제 바르기는 일반적이면서도 손쉬운 자외선에 의한 피부 손상 예방법이다. 이러한 중요성에 따라 자외선 차단제 평가시험은 1978 년 Fod and Drug Administration (FDA)에서 규정을 마련한 이후, 현재는 International Organization For Standardization (ISO)에서 표준화된 방법까지 발전되었다. 더불어 물이나 땀 등 신체활동에 의한 자외선 차단제 손실을 평가하기 위해 국내 식약처와 ISO에서 내수성 자외선 차단지수 평가시험을 제정하고 있다. 그러나 지금까지의 내수성 자외선 차단지수 평가시험은 주로 일반 물을 사용한 시험 방법에 국한되어 있으며, 해변에서의 레저, 스포츠 및 여가활동에 의한 해수의 영향을 고려한 시험 방법은 아직 정립되지 않았다. 본 연구는 기존의 내수성 자외선 차단지수 평가시험 방법 가이드라인을 기반으로 일반 물, 인공 해수(소금물) 및 자연 해수(바닷물)에서의 내수성 자외선 차단지수를 비교하여 해양 레저, 스포츠 및 여가활동 등과 같은 실제 상황에서의 자외선 차단지수를 평가할 수 있는 방법에 대하여 조사하였다. 이러한 결과를 통해 일반 물과 인공 해수 및 자연 해수에서의 내수성 자외선 차단지수 평가시험의 차이를 비교하여 자연 해수를 이용한 내수성 자외선 차단지수 평가시험 방법을 제시할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1567-1573
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• 2020

Ultraviolet (UV) is one of the major factors harmful to skin health. Irradiation with ultraviolet accelerates the decline of skin function, causing the skin to have deep wrinkles, dryness, decreased procollagen production, and degradation of collagen. Novel materials are needed to prevent the aging of the skin by blocking the effects of UV. Safflower seed oil (Charthamus tinctorius L., SSO) contains significantly high levels of unsaturated fatty acids and phytochemicals. SSO has been traditionally used in China, Japan, and Korea to improve skin and hair. Our objective in this study was to determine the effect of SSO and its active compound acacetin on UVB-induced skin photoaging in HaCaT cells and human dermal fibroblasts (HDF). SSO inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) at both protein and mRNA levels in HaCaT cells and HDF. MMP-1 is known to play important roles in collagen degradation and wrinkle formation. Acacetin, a type of flavonoid, is present in SSO. Similar to SSO, acacetin also inhibited UVB-induced MMP-1 protein and mRNA levels in HaCaT cells and HDF. MMP-1 mRNA is primarily regulated by the mitogen-activated kinase (MAPK) signaling pathway. Acacetin regulated the phosphorylation of JNK1/2 and c-jun, but did not inhibit the phosphorylation of ERK1/2, p38 and AKT. Taken together, these results indicate that SSO and its active compound acacetin can prevent UVB-induced MMP-1 expression, which leads to skin photoaging, and may therefore have therapeutic potential as an anti-wrinkle agent to improve skin health.

• 대한화장품학회지
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• 제43권4호
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• pp.321-327
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• 2017

본 연구는 기존의 인공적으로 합성된 유기 자외선 차단제를 대체하는 안정적인 식물유래 천연 자외선 차단제(BHC-S)를 개발하기 위하여 수행하였다. 땅콩싹추출물, 병출추출물 및 곰피추출물로 구성된 천연 자외선 차단제(BHC-S)는 합성 자외선 차단제인 Parsol MCX-XR (OMC)와 동등 수준의 자외선 차단 효과를 가질뿐만 아니라, 피부에 대한 안전성을 가지며, 주름개선 등 다기능성 효과를 가지는 것으로 확인되었다. 이로써, 자외선 차단 및 항노화을 위한 천연 화장품 원료로서의 이용이 가능할 것으로 판단된다.

• 폴리머
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• 제32권4호
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• pp.366-371
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• 2008

The controlled/living cationic polymerization of $\alpha$-methylstyrene (${\alpha}MeSt$) and sequential block copolymerization of isobutylene (IB) with ${\alpha}MeSt$ were achieved using 2-chloro-2,4,4-trimethylpentane (TMPCl)/titanium tetrachloride ($TiCl_4$)/titanium isopropoxide ($Ti(OiPr)_4$)/2,6-ditert-butylpyridine (DtBP) initiating system in $CH_3Cl$/hexane(50/50 v/v) solvent mixture at $-80^{\circ}C$. The polymerization rate decreased with increasing $[Ti(OiPr)_4]/[TiCl_4]$ ratio in the homopolymerization of ${\alpha}MeSt$. The effects of $[Ti(OiPr)_4]/[TiCl_4]$ ratios and $PIB^+$ molecular weight on the polymerization rate and blocking efficiency were also investigated. Well-defined poly(isobutylene-b-$\alpha$-methylstyrene)s were demonstrated by $^1H$-NMR and triple detection SEC; refractive index (RI), multiangle laser light scattering (MALLS) and ultraviolet (UV) detectors. Blocking efficiencies for the poly(isobutylene-b-$\alpha$-methylstyrene)s of almost 100% were obtained when ${\alpha}MeSt$ was induced by PIB's of $M_n\;{\geq}\;41000$ at $[Ti(OiPr)_4]/[TiCl_4]=1$. Differential scanning calorimetry (DSC) of the block copolymers showed two glass transition temperatures, thereby demonstrating microphase separation.

• 한국표면공학회지
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• 제56권4호
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• pp.233-242
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• 2023

In recent years, energy-management studies in buildings have proven useful for energy savings. Typically, during heating and cooling, the energy from a given building is lost through its windows. Generally, to block the entry of ultraviolet (UV) and infrared (IR) rays, thin films of deposited metals or metal oxides are used, and the blocking of UV and IR rays by these thin films depends on the materials deposited on them. Therefore, by controlling the thicknesses and densities of the thin films, improving the transmittance of visible light and the blocking of heat rays such as UV and IR may be possible. Such improvements can be realized not only by changing the two-dimensional thin films but also by altering the zero-dimensional (0-D) nanostructures deposited on the films. In this study, 0-D nanoparticles were synthesized using a sol -gel procedure. The synthesized nanoparticles were deposited as deep coatings on polymer and glass substrates. Through spectral analysis in the UV-visible (vis) region, thin-film layers of deposited zinc oxide nanoparticles blocked >95 % of UV rays. For high transmittance in the visible-light region and low transmittance in the IR and UV regions, hybrid multiple layers of silica nanoparticles, zinc oxide particles, and fluorine-doped tin oxide nanoparticles were formed on glass and polymer substrates. Spectrophotometry in the UV-vis-near-IR regions revealed that the substrates prevented heat loss well. The glass and polymer substrates achieved transmittance values of 80 % in the visible-light region, 50 % to 60 % in the IR region, and 90 % in the UV region.

• Natural Product Sciences
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• 제18권1호
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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.

• 상하수도학회지
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• 제12권1호
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• pp.88-95
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• 1998

The Electron/Hole Pair is generated when the Activation Energy produces by Ultraviolet Ray illumination to the Semiconductor. And $OH^-$ ion produces by Water Photo-Cleavage reacts with Positive Hole. As a result, OH Radical acting as strong oxidant is generated and then Photocatalytic Oxidation Reaction occurs. The Photocatalytic Oxidation can oxidize the chlorophenol to Chloride and Carbon Dioxide easier, safer and shorter than conventional Water Treatment Process With the same degree of chlorination, the $Cl^-$ ion at para (C4) position is most easily replaced by the OH radical. And then, the blocking effect of $OH^-$ ion between the $Cl^-$ ions and $Cl^-$ ions at symmetrical location is easily replaced by the OH radical. For mono-, di-, tri-chlorophenols, there is no obvious difference in decomposition rate, decomposition efficiency and completeness of the decomposition reaction except for 2,3-dichloropheno, 2,4,5-, 2,3,4-trichlorophenol. The decomposition efficiency is higher than 75% and completeness of the decomposition reaction is higher than 70%. Therefore, continuous flow photocatalytic reactor is promising process to remove the chlorinated aromatic compounds which is more toxic than non-chlorinated aromatic compound.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.300.2-300.2
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• 2016

Increasing of the demand for energy savings for buildings, thermal barrier films have more attracted. In particular, as heat loss through the windows have been pointed out to major problems in the construction and automobile industries, the research is consistently conducted for improving the thermal blocking performance for windows. The main theory of the technology is reflect the infrared rays to help the cut off the inflow of the solar energy in summer and outflow of the heat from indoors in winter to save the energy on cooling and heating. Furthermore, this is well known for prevent glare, reduces fading caused by harmful ultraviolet radiation and easy to apply on constructed buildings if it made as a film. In addition to these advantages, apply the transparent electrode to eliminate condensation by heating. Generally ITO is used as a transparent electrode, but is has a low stability in environmental factors. In this study, ITO and its alternative, ATO, is deposited by sputtering system and then the characteristic is evaluated each material based thermal barrier thin film. The optical property was measured on wide range of wavelength (200 nm 2500 nm) to know the transparency in visible wavelength and reflectivity in IR wavelength range. The electrical property was judged by sheet resistivity. Finally the changes of the temperature and current of the deposited film was observed while applying a DC power.

• 한국재료학회지
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• 제28권8호
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• pp.452-458
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• 2018

This research is conducted to create a functional hydrogel ophthalmic lens containing nanoparticles. Carbon nanoparticles and PEGMEMA are used as additives for the basic combination of HEMA, MA, and MMA, and the materials are copolymerized with EGDMA as the cross-linking agent and AIBN as the thermal initiator. The hydrogel lens is produced using a cast-mold method, and the materials are thermally polymerized at $100^{\circ}C$ for an hour. The polymerized lens sample is hydrated in a 0.9 % saline solution for 24 hours before the optical and physical characteristics of the lens are measured. The refractive index, water content, contact angle, light transmittance, and tensile strength are measured to evaluate the physical and optical characteristics of the hydrogel lens. The refractive index, water content, contact angle, UV-B light transmittance, UV-A light transmittance, visible light transmittance, tensile strength and breaking strength of the hydrogel lens polymer are 1.4019~1.4281, 43.05~51.18 %, $31.95{\sim}68.61^{\circ}$, 21.69~58.11 %, 35.59~84.26 %, 45.85~88.06 %, 0.1075~0.1649 kgf and 0.1520~0.2250 kgf, respectively. The results demonstrate an increase in refractive index, tensile strength and breaking strength and a decrease in contact angle and light transmittance. Furthermore, the visible light transmissibility is significantly increased at PEG 10 %. It is clear that this material can be used for high-performance ophthalmic lenses with wettability, ultraviolet ray blocking effect, and tensile strength.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.169-169
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• 2014

Interfacial electronic structure of bathocuproine and Al was investigated using in-situ photoemission spectroscopy and density functional theory (DFT) calculations. Bathocuproine is used for exciton blocking and electron transport material in organic photovoltaics and Al is typical cathode material. When thin thickness of Al was thermally evaporated on BCP, gap states were observed by ultraviolet photoemission spectroscopy. The closest gap state yielded below 0.3 eV from Fermi level. By x-ray photoemission spectroscopy, interaction of Al with nitrogen of BCP was observed. To understand the origin of gap states, DFT calculation was carried out and gap states was verified with successive calculation of interaction of Al and nitrogen of BCP. Furthermore, emergency of another state above Fermi level was observed. Remarkable reduction of electron injection barrier between Al and BCP, therefore, is possible.