• International Journal of Oral Biology
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• v.39 no.2
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• pp.65-73
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• 2014

Chios Gum Mastic (CGM) is a natural resin extracted from the leaves of Pistacia lentiscus, a plant endemic to the Greek island of Chios. It has been used by traditional healers, and it has antibacterial, antifungal properties, and therapeutic benefits for the skin. The CGM reduces the formation of dental plaque and bacterial growth in oral saliva, and recent studies have demonstrated the role of antioxidant activity of CGM. Although CGM has been widely investigated, its protective effect against oxidative-damage to keratinocytes, as well as the relationship between CGM and autophagy, has not been investigated. The aim of this study was to assess the protective effect of CGM against $H_2O_2$-induced oxidative stress and to evaluate the autophagic features induced by CGM in human keratinocytes. The pretreatment with CGM significantly reduced apoptosis in $H_2O_2$-exposed HaCaT cells. It promoted the degradation of caspase-3, caspase-8, and caspase-9; and it induced the formation of the processed PARP. The treatment with CGM caused an increase in vesicle formation compared to control group. The level of p62 was reduced and the conversion of LC3-I to LC3-II was increased in CGM treated HaCaT cells. Also, the treatment with CGM increased cleavage of ATG5-ATG12 complex. In summary, CGM helps the cells to survive under stressful conditions by preventing apoptosis and enhancing autophagy. Besides, the present investigation provides evidence to support the antioxidant potential of CGM in vitro and opens up a new horizon for future experiments.

• Journal of Korean Medical classics
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• v.21 no.1
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• pp.93-110
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• 2008

We got some conclusion about the function of five tastes from individual peculiarity, from "Sanghanjapbyeongnon(傷寒雜病論)" by Sungmoogi, like below. 1. Five tastes[五味] have their general function, but herbs of one tastes, each has special function, we can define it as individual peculiarity 2. For example, sour taste generally make it convergent, astringent. The sourness of Paeoniae Radix Alba[芍藥] can convergent resin, and be help nutrition, but same of Phaseoli Semen[赤小豆] can make him vomit. 3. Bitterness generally make it down, dry, and solid. Scutellariae Radix[黃芩], Coptidis Rhizoma[黃連] can bring down fever of heart and spleen, but Rhei Radix Et Rhizoma[大黃] eliminates solid illness. 4. Sweetness make it strong, harmonic, relax. Sweetness of Glycyrrhizae Radix[甘草] flows into spleen, make it relax the part of beneath heart. Puerariae Radix[葛根] can make scatter the cold on skin. 5. General nature of hot taste is diffusion, sheen, rampancy. Cinnam omi Ramulus[桂技] eliminates the Pung(風) in Wigi(衛氣). same Zingiberis Rhi zoma[乾薑] make inner cold scattered, and warm stomach. 6. Salty make Gi(氣) down, and slacken solidity, salty Natrii Sulfas[芒硝]removes heat of body. But Alismatis Rhizoma[澤瀉] removes needless water. 7. To know peculiarity of each herb, not only one taste but other combined tastes, and areas medical, agricultural, biologic, etc.

• Composites Research
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• v.35 no.2
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• pp.106-114
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• 2022

Carbon fiber-reinforced plastic, well known high specific strength and high specific stiffness, have been widely used in the aircraft industry. Mostly the CFRP structure is fabricated by lamination of carbon fiber or carbon prepreg, which has major disadvantage called delamination. Delamination is usually produced due to absence of the through-thickness direction fiber. In this study, three-dimensional carbon preform woven in three directions is used for fabrication of aircraft wing unit structure, a part of repeated structure in aircraft wing. The unit structure include skin, stringer and rib were prepared by resin transfer molding method. After, the 3D structure was compared with laminate structure through compression test. The results show that 3D structure is not only effective to prevent delamination but improved the mechanical strength. Therefore, the 3d preform structure is expected to be used in various fields requiring delamination prevention, especially in the aircraft industry.

• Composites Research
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• v.19 no.2
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• pp.13-19
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• 2006

In this paper, parametric study was carried out to design sandwich structures for EDM machines controlling stacking sequence, stacking thickness of composites and rib configuration. Sandwich structures which are dealt with in this paper are composed of fibre reinforced composite for skin material and foam or resin concrete for core materials. The sandwich column has cruciform rib to enhance bending stiffness of the structure and the bed has several vertical ribs to resist the normal forces and vibration. The design parameters such as rib thickness and stacking sequence were controlled to enhance the system robustness. Finite element analysis was also carried out to verify the variation of static and dynamic stiffness of the structures according to the variation of the parameters. Vibration tests were performed to verify the natural frequencies and damping ratios of the manufactured composite structures. The appropriate shape and configuration conditions for micro-EDM machine structures are proposed.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.27-32
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• 2017

Objectives: Oncological hyperthermia is a treatment to selectively kill cancer cells by directly applying heat to cancer cells or indirectly demage cancer cells. One of the most side effects of treatment is burn that can appear on the skin. In areas with irregularities such as the umbilicus, the patient feels a sense of hot and treatment may be discontinued. Therefore, in order to eliminate the irregularities of these areas, compensators are manufactured and measured to decrease in temperature. Materials and Methods: The temperature of the four sites (umbilicus, near the umbilicus, 5 cm below the umbilicus, back) was measured five times around the umbilicus in patients who were treated at oncological hyperthermia treatment device(EHY-2000, Oncotherm Kft, Hungary). The temperature sensor (TM-100, Oncotherm Kft, Hungary) was attached to four sites and the changes were observed at 5, 15, 25, 35, and 50 minutes after treatment. Compensators of three materials were used(Vaseline, Bolus, Dental resin). The data measured five times were compared for each compensator. Results: The temperature change when the compensator was not used increase from 34.65 degrees to 42.9 degrees on average. The near umbilicus was changed from 32.20 degrees to 37.00 degrees, and the 5 cm below the umbilicus was changed from 31.90 to 34.41 degrees. When the compensator material was inserted into the umbilicus, the temperature change was measured as 5.42 degrees for bolus, 6.55 degrees for vaseline, and 6.83 degrees for resin. Conclusion: Using the compensator in the region where the irregularities such as the umbilicus, the heat sensation could be reduced. the use of a resin that can be customized not only lowers the temperature but also significantly reduces the feeling of the patient. It will be possible to reduce the heat sensation in the treatment and to treat it in a more comfortable condition.

• Journal of Technologic Dentistry
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• v.22 no.1
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• pp.89-112
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• 2000

Although dental laboratory technicians are prone to be exposed to various work-related health hazardous materials such as dusts, chemicals, etc., the prevalence and nature of work-related health problems of them have not been a matter of great concern in the field of occupational health service in Korea. The purpose of the present investigation was to describe a collected profile of subjective health symptoms and their attributable factors in Korean dental laboratory technicians. A questionnaire listing five groups of health symptoms and five health symptom-related factors was mailed to randomly selected 1,900 dental laboratory technicians. Among them, 1,344 dental laboratory technicians filled out the questionnaires and returnde them. Five groups of health symptoms included musculoskeletal symptom, dermal symptoms, respiratory symptoms, eys symptoms, and ear symptoms. Five health symptom-related factors were occupational environment-related health risk factors, work history, health related habits and status, use of personal protective equipment and general characteristics. Detailed parameters of health risk factors were work posture, vibration, and chemical or physical hazards such as dust, fume, vapor, solvent, light, and noise for occupational environment-related factors; work place, area, number of employees, work hours, career, work part, and work load for work history; Broca's index, hours of sleep, eating, smoking, alcohol, exercise, health examination, and self assessed health status for health habits and status; face masks, goggles, and so on for use of personal protective equipment, and; age, sex, marital status, and education for general characteristics. Before the start of main survey, a pilot survey was carried out for validity and reliability tests of the questionnaire. All the data obtained were coded and analyzed with PC/SAS 6.12 program. The prevalence of health symptoms was the highest in musculoskelton (87.3%), and followde by eyes (78.9%), respiratory organs (64.3%), ears (57.8%), and skin (52.2%) in descending order. Statistically significant risk factors by multiple logistic regression analyses were sex, health examination, self assessed health status, and hand/finger posture in musculoskeletal symptoms; sex, self assessed health status, career, acid gas, and hand contact with resin mixture in deraml symptoms; Broka's smoking, exercise, self assessed health status, and face mask in respiratory symptoms; sex, hours of sleep, self assessed health status, work hours, work load, plaster dust, inadequate lighting, and goggle in eys symptoms, and eating, smoking, self assessed health status, and work load in ear symptoms. With the above considerations in mind, prevalence of subjective symptoms among Korean dental laboratory technicians was relatively high, and they were attributable to most of the occupational environment-related factors, work history, use of personal protective equipment, health habits and status, and general characteristics. Particularly, it is suggested that health promotion programs for promoting self- assessed health status and smoking cessation, preventive measures for protection of the female technicians’health, and reducing work load be necessary, since those factors were associated with more than one subjective symptom.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.159-166
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• 2020

Propolis is a sticky resinous substance that is formed by the combination of honeybee secretions and resin of plants, which serves to protect from bacteria and viruses. This study aims to evaluate the efficacy of propolis extract from Korea (KPE), China (CPE), and Brazil (BPE) through antioxidant, antibacterial, whitening, and anti-inflammatory tests, and to examine their potential as cosmetic materials. KPE, CPE, and BPE showed significant antioxidant activities on flavonoid/polyphenol content and free radical scavenging activity. The antibacterial effect of propolis on skin flora was determined by measuring the minimal inhibitory concentration (MIC). KPE showed better antibacterial efficacy than CPE and BPE in C. acnes (KPE, CPE, and BPE: (62.5, 250, and 500) ㎍/mL, respectively). Furthermore, KPE inhibited the melanin synthesis in human epidermal melanocytes and production of nitric oxide and PGE₂ induced by lipopolysaccharide (LPS) in mouse macrophages, which showed better than did CPE or BPE. Taken together, the propolis extracts can be applied to antioxidant, antibacterial, and anti-inflammatory ingredient for cosmetics, while KPE showed superior potential in antibacterial, anti-inflammatory, and whitening efficacies.

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.87-94
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• 2007

Pyrethroid insecticide have widely been used for agricultural sector and residential environments. To assess the exposure of insecticide which is absorbed through skin the analysis of urinary metabolite is essential. At present, the urinary 3-PBA was analyzed using liquid-phase extraction. But LPE have many limitations, such as long pre-treatment time and low recovery. So, this study was conducted to determine the optimum conditions for analysing 3-PBA in urine using solid phase extraction. Furthermore, this study intend to investigate the relation of concentrations of pyrethroid, deltamethrin in air and 3-PBA in urine. The optimum condition for hydrolysis was found to be done with hydrochloric acid for one hour. The recovery rates of 3-PBA were $84.6%{\pm}1.2%$, $54.8{\pm}0.9%$, $99.8{\pm}1.2%$ with XAD-2, XAD-7, XAD-16 using as the aborbents and acetone as eluents respectively. But acetonitrle and methanol gave low recovery rate and methyl cellosolve could not elute the compound. The amount of acetone for elution were 6mL, 9mL, 3mL for XAD-2, XAD-7, XAD-16 as absorbents respectively. The non-absorbed rates was $0.8{\pm}0.5%$, and $0.7{\pm}0.3%$ under XAD-16, mesh size 140-200, amount of resin 1.4g and the flow rate of eluent was 0.1mL/min. In the concentration process, we obtained 11 times higher concentration of material. The amounts of urinary 3-PBA were. The LODs of 3-PBA and deltamethrin were 0.004 mg/L, 0.038 mg/L, respectively. The further research of minute monitoring which include spray pattern, environmental condition is needed And more research about the relation between total pyrethroid exposure and urinary various metabolite are also necessary.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.69-75
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• 2002

A number of techniques may be employed to reduce the discomfort of syringe or needle for dental care. The use of topical anesthesia is one such method. Topical anesthetics are applied to alleviate pain during many clinical procedures, such as injection of local infiltration anesthetics, primary tooth extraction, X-ray taking of sensitive patients, reducing gag reflex prior to impression taking. In children, placement of a rubber dam clamp, however, may cause significant discomfort for purpose of pit and fissure sealant and preventive resin restoration(PRR). A topical anesthetic would be beneficial to aid in rubber dam placement for this purpose. It has been suggested that all intra-oral topical anesthetics are equally effective on reflected mucosa, however EMLA(an acronym for eutectic mixture of local anesthetics), which was developed in the 1980s and produces surface anesthesia of skin, has been shown to be more effective than conventional topical anesthetics when used on attached gingivae. This report is topical anesthesized 4 case by EMLA cream, who showed better effect in reducing the pain of infiltration anesthesia, extraction of deciduous teeth, rubber dam clamp placement and reducing the pain of preformed crown adaptation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.1
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• pp.67-72
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• 2020

In this study, we attempted to obtain an active ingredient that inhibits the production of matrix metalloproteinase-1 (MMP-1) that breaks down collagen in human skin fibroblasts. More than 50 plant extracts were screened, and Lonicera japonica was selected for this study. The stem of L. japonica was extracted with 70% ethanol and fractions with solvents in the order of hexane, ethyl acetate, and butanol. MMP-1 production were significantly inhibited at the concentration of 50 ㎍/mL of the ethyl acetate layer and 200 ㎍/mL of the butanol layer. To get a fraction containing all of these effective components, 80% ethanol fraction (LJ F80) was obtained through HP20 resin column chromatography. The reference substance, loganin and LJ F80 inhibited dose-dependently MMP-1 production. At the same concentration, LJ F80 showed a higher inhibitory effect than loganin. The stability of this fraction was analyzed with HPLC while kept storing at 4 ℃, room temperature, and 40 ℃, for 16 week. The stability was maintained as ± 10% of initial value with reference loganin. Therefore, it is thought that LJ F80 of L. japonica may be used to improve wrinkles.