• Journal of the Korean Medical Association
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• v.61 no.11
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• pp.644-648
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• 2018

The incidence of skin cancer has continuously increased in Korea, probably due to sun exposure and increases in the aging population. Ultraviolet light, a well-known risk factor for skin cancer, can cause DNA damage, mutation, and immune suppression, followed by abnormal proliferation. To prevent photocarcinogenesis, the appropriate use of sunscreen should be emphasized. Using broad-spectrum sunscreens with sun protection factor values of 15 or higher and frequent reapplication are recommended. Controversy exists about whether vitamin D synthesis is inhibited by the use of sunscreen. However, considering that skin cancer most commonly develops on the head and neck area, applying it to the face and neck is reasonable in terms of balancing the risk-benefit ratio.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.296-302
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• 2002

In recent years, the safety of sunscreens have been challenged based on the reports of its adverse effects on users; dermatitis, allergic contact dermatitis, photoallergic contact dermatitis. In the toxicological aspect, the need to investigate the safety of sunscreens is steadily increasing. However, there were few studies on the correlation between sun protection factor (SPF) and the safety of sunscreens. The objective of this study was to assess whether there was a correlation between SPF and the skin irritation index of sunscreens. Octyl methoxycinnamate (OMC) was selected, which was the most frequently used (about 92% in korea and about 90% in the world) in sunscreens. In vitro SPF test was performed using the standard samples recommended by KFDA guideline. We examined primary and cumulative skin irritation and eye irritation of OMC standard sample as well as homosalate. As in vitro SPF was increased, skin irritation index was increased in primary skin irritation test ($r^2$=0.986) and cumulative skin irritation test ($r^2$=0.939). In addition, OMC was non-irritating and non-sensitizing. In this results, there was a good correlation between SPF index and skin irritation index.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.561-568
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• 2014

Background: The skin is the largest body organ that regulates excretion of metabolic waste products, temperature, and plays an important role in body protection against environmental physical and chemical, as well as biological factors. These include agents that may act as oxidants or catalysts of reactions producing reactive oxygen species (ROS), reactive nitrogen species (RNS), and other oxidants in skin cells. An increased amount of the oxidants, exceeding the antioxidant defense system capacity is called oxidative stress, leading to chronic inflammation, which, in turn, can cause collagen fragmentation and disorganization of collagen fibers and skin cell functions, and thus contribute to skin diseases including cancer. Moreover, research suggests that oxidative stress participates in all stages of carcinogenesis. We report here a summary of the present state of knowledge on the role of oxidative stress in pathogenesis of dermatologic diseases, defensive systems against ROS/RNS, and discuss how physical activity may modulate skin diseases through effects on oxidative stress. The data show duality of physical activity actions: regular moderate activity protects against ROS/RNS damage, and endurance exercise with a lack of training mediates oxidative stress. These findings indicate that the redox balance should be considered in the development of new antioxidant strategies linked to the prevention and therapy of skin diseases.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.246-252
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• 2002

In recent years, the safety of sunscreens has been challenged based on the reports of their adverse effect on users; dermatitis, allergic contact dermatitis and photo allergic contact dermatitis. The unscientific idea that higher SPF sunsreen is good for health mealeads many users to tend to prefer higher SPF sunscreen. In the toxicological aspect, the need to investigate the safety of sunscreens is steadily increasing. However, there were few studies on the correlation between sun protection factor (SPF) and the safety of sunscreens. The objective of this study was to assess whether there was a correlation between SPF and the safety of sunscreens. We measured in vitro SPF index using homosalate as a standard and examined the toxicity tests such as primary skin irritation tests, ocular irritation test and skin sensitization test. Homosalate (HS), octyl methoxycinnamate (OMC), octyl salicylate (OS), octocrylene (OC) as UVB organic filter and benzophenone-3 (BP3), butyl methoxy dibenzoil methane (BMDM) as UVA organic filter, and titanium dioxide (TD), zinc oxide (ZO) as inorganic filters were used. The skin irritation indexes in rabbits treated with HS, OMC, OS, BP3, and BMDM were significantly increased as SPF indices were increased. Neither ocular irritation in rabbits nor skin sensitization in guinea pigs were increased. It suggests that there might be a good correlation between SPF and the skin irritation indices of organic UV filters and skin irritation might be one of most sensitive index to assess the safety of sunscreens.

• Journal of Radiation Protection and Research
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• v.20 no.3
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• pp.181-186
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• 1995

UV irradiation causes a variety of biologic effects on the skin. These effects can be devided to acute reactuons and chronic reacxtions by duration of UV irradiation. Acute reactions are erythema reaction, pigment reactions and changes in epidermal thickness. Among them erythema reaction is most common and conspicuous acute effects of the skin. Upon exposure to sun or artificial UV soures, a faint redness response of skin may begin. Larger exposure causes sunburn reaction which is exaggerated erythema reactionassociated with pain, swelling, vesicle and dulla. Extent and time course of erythema reaction depend upon several factors including wavelength and dose of UVR, skin conditions likeas skin type, site, color, temperature, humidity and environmental factors. Evaluation of erythema erythema induced by UV irradiation is difficult to quantify. Degree of redness of skin are usually estimated by subjective visual evaluation. The lowest exposure dose required to protuce erythema is called minimal erythema dose (mod). Repeated exposures of UVR result in photaging skin. In this condition we can see wrinkling, skin atrophy, dilated blood vessels and keratoses. In sensitive persons photocarcinogenesis is can Be developed on exposed area of skin. Recently skin canser is increasing now in our country. An effective public education and photopreventive method must be developed.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1495-1504
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• 2017

In a previous study, a set of polygon-mesh (PM)-based skin models including a $50-{\mu}m-thick$ radiosensitive target layer were constructed and used to calculate skin dose coefficients (DCs) for idealized external beams of electrons. The results showed that the calculated skin DCs were significantly different from the International Commission on Radiological Protection (ICRP) Publication 116 skin DCs calculated using voxel-type ICRP reference phantoms that do not include the thin target layer. The difference was as large as 7,700 times for electron energies less than 1 MeV, which raises a significant issue that should be addressed subsequently. In the present study, therefore, as an extension of the initial, previous study, skin DCs for three other particles (photons, protons, and helium ions) were calculated by using the PM-based skin models and the calculated values were compared with the ICRP-116 skin DCs. The analysis of our results showed that for the photon exposures, the calculated values were generally in good agreement with the ICRP-116 values. For the charged particles, by contrast, there was a significant difference between the PM-model-calculated skin DCs and the ICRP-116 values. Specifically, the ICRP-116 skin DCs were smaller than those calculated by the PM models-which is to say that they were under-estimated-by up to ~16 times for both protons and helium ions. These differences in skin dose also significantly affected the calculation of the effective dose (E) values, which is reasonable, considering that the skin dose is the major factor determining effective dose calculation for charged particles. The results of the current study generally show that the ICRP-116 DCs for skin dose and effective dose are not reliable for charged particles.

• Korean Journal of Medicinal Crop Science
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• v.18 no.2
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• pp.79-85
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• 2010

Enhancement effect of ultrasonification process on UV-protection and skin-whitening activities using Centella asiatica L. Urban extract was investigated. Cytotoxicity of the extracts measured on human skin fibroblast cells, CCD-986sk, and then, ultrasonification associated extracts showed 5~9% lower cytotoxicity then normal crude extracts on 1.0 mg/$m{\ell}$ of highest sample concentration. The associated extrats showed highest inhibition activity of hyaluronidase on 1.0 mg/$m{\ell}$ of concentration as 54.2%. Also, the associated extract reduced expression of MMP-1 on UV-irradiated CCD-986sk cells down to 100.2% from 136.1%, and revealed high inhibitory potency on tyrosinase as 74.6% by adding 1.0 mg/$m{\ell}$ of concentration. Ultrasonification associated extract showed strong inhibition effect of melanin production on Clone M-3 cells as 84.2% by adding 1.0 mg/$m{\ell}$ of concentration. From the preliminary observations, we considered that the extracts from C. asiatica could be potent natural materials for skin-whitening and anti-aging agent, and could enhance the activities by ultrasonification process.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.237-244
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• 2005

Sunscreens have been in use for about 70years and 'tanning without burning' was propagated as their major advantage. The objective changed from 'getting a tanned skin' to 'getting skin protection' since UV have been proposed to a major risk of skin cancer and the risk of developing skin cancer related also to non-burning UVA. The new expectation from consumers has triggered the development of new UV absorbers and led to the approval of 7 new, organic UV absorbers in Europe over the last few years. The significant progress due to these new UV absorbers will be discussed in this report. These UV absorbers provide an efficient absorption of UV radiation (UVB and/or UVA) and easily incorporate in any kind of formulation. These are also safe, i.e. devoid of adverse effects. These new filters give the formulators new possibilities to cover the whole UV range iron 290 to 400 nm, and also to use less filter due to the boosting effect of the new UVA and broadband fitters.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.64-69
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• 2012

Head injury is one of the most common cause of deaths in car-to-pedestrian collisions. To reduce the severity of such injuries, many international safety committees have performed headform impact test for pedestrian protection. In this paper, an adult headform impactor model is developed based on the finite element (FE) method and validated through the numerical simulation. The skin material of headform impactor is known as polyvinyl chloride skin (PVC) and its material was assumed as viscoelastic. The viscoelastic parameters of headform skin are identified by a series of trial and error methods. The new developed FE adult headform impactor is verified by the drop test and FE JARI adult headform impactor provided by Madymo program.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.609-614
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• 2009

The purpose of this paper is to design the metal object detection system for drive inside protection. To do this, we propose the algorithm for designing the color filter that can detect the metal object using fuzzy theory and the algorithm for detecting area of the driver's face using fuzzy skin color filter. Also, by using the proposed algorithm, we propose the algorithm for detecting the metallic object candidate regions. And, the metallic object color filter is then applied to find the candidate regions. Finally, we show the effectiveness and feasibility of the proposed method through some experiments.