• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권6호
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• pp.324-331
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• 2019

Objectives: This study investigated the types and antibiotic sensitivity of bacteria in odontogenic abscesses. Materials and Methods: Pus specimens from 1,772 patients were collected from affected areas during incision and drainage, and bacterial cultures and antibiotic sensitivity tests were performed. The number of antibiotic-resistant bacteria was analyzed relative to the total number of bacteria that were tested for antibiotic susceptibility. Results: Bacterial cultures from 1,772 patients showed a total of 2,489 bacterial species, 2,101 gram-positive and 388 gram-negative. For penicillin G susceptibility tests, 2 out of 31 Staphylococcus aureus strains tested showed sensitivity and 29 showed resistance. For ampicillin susceptibility tests, all 11 S. aureus strains tested showed resistance. In ampicillin susceptibility tests, 46 out of 50 Klebsiella pneumoniae subsp. pneumoniae strains tested showed resistance. Conclusion: When treating odontogenic maxillofacial abscesses, it is appropriate to use antibiotics other than penicillin G and ampicillin as the first-line treatment.

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.1-5
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• 2008

Silicide formation process and the formation sequence were investigated in this study. It was postulated that the formation of the second silicide phase involves glass formation between the first silicide phase and Si given that a thin metal film is deposited on a Si substrate. The concentration of glass was assumed to be located where the free energy of the liquid alloy with respect to the first nucleated compound and solid Si (${\Delta}$G') is most negative. It was also mentioned that the glass concentration is close to the composition of the second phase in order to achieve the maximum energy degradation. It was shown that the minimum ${\Delta}$G' concentration can be estimated by interpolating the portion of the liquidus where the liquid alloy is in equilibrium with the two solid constituents, namely the first compound phase and Si, thereby forming a hypothetical eutectic.

• KSBB Journal
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• 제13권4호
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• pp.444-448
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• 1998

Biosorption of Pb and Cu was evaluated for 23 species of marine algae collected from a Korean coast. Among a variety of species for biosorbent potential, Hypnea charoides showed the highest capacity for Pb. An adsorption equilibrium was reached in about 2 hr for Pb and 30 min for Cu. The uptake capacity was 192.8 mg Pb/g biomass and 256 mg Cu/g biomass, respectively. The adsorption parameters for Pb and Cu were determined according to Langmuir model. With an increase in pH value, more negative sites are becoming avaliable for adsorption of pH and Cu, thus the removal of Pb and Cu increases at alkaline conditions. The selectivity of mixture solution shows the uptake order of Pb>Cu>Cr>Cd. When Ca concentration increases in Pb solution, Pb was selectively adsorbed.

• 한국환경보건학회지
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• 제23권4호
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• pp.50-56
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• 1997

Applied for Drug Delivery System, polymer drug was prepared with chitosan and phthalylsulfathiazole. In spite of various application of chitin derivatives, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. In this study, Chitosan were prepared from chitin which were deacetylated under various condition. The synthetic procedures of polymer drug were performed by acid chloride methods. The antibiotic activities of polymer drug exhibited growth-inhibitory activity against Staphylococcus aureus, Staphylococcus epidermidis, E. coli, Salmonella typhimurium, Klebsiella pneumoniae at the concentration of 471-514 $\mu$g/ml in general. Comparatively, Polymer drug exhibited broad antibacterial activity on MICs 897-1280 $\mu$g/ml against Gram-positive and Gram-negative bacteria including Staphylococcus aureus, Staphylococcus epidermidis and E. coli.

• 한국산림과학회지
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• 제96권2호
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• pp.145-150
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• 2007

This study was conducted to elucidate the mid-growth of Norway spruce at the age of 27 and select the superior provenances in Korea. Growth performance of twenty-four provenances from Germany and Rumania were investigated in four plantations. Significant differences were found in growth (height, DBH, volume) with plantations. Maximum growth were detected on plantation Chuncheon which located in most northern area, and minimum growth were detected on plantation Wanju located in most southern area. The rank of height in provenances has fluctuated, but superior/inferior groups have been almost fixed. 840-23, 840-10, 840-19 in Germany, G1-64-57, G1-64-54 in Rumania proved excellent provenances. Height in early stage positively correlated with that in late stage. The growth was positively correlated with latitude and altitude of plantations, but negatively correlated with temperature.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.572-575
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• 2005

A microlens connected to microfluidic channel is fabricated. The microlens is sealed with an elastomeric membrane which deforms by pressure of fluid driven by a syringe pump resulting in the shape change of the microlens. The optical properties of the microlens could be controlled by changing the microlens shape. The microlens system were made of an elastomer, PDMS, using molding from a photoplastic master patterned by UV photolithography. The test results show the optical property of the lens could be made into convex and concave type by applying the fluidic pressure positive and negative.

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.220-225
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• 1993

The influence of temperature and pressure on the free energy of the ion hydration has been considered. The ion radii measured by conductometric method and the saturated dielectric constant cited from other works were used to calculate the free energy in the hydration shell. The Born equation was modified in order to fit in our model. In our model, the environment of ion consists of three regions. The innermost one is the hydration shell in which water is immobilized and electrostricted, the middle one is the one which contains less ordered waters than the bulk medium, and the outermost one is the bulk water which is under the influence of the electric field of ion. Our results for the free energy of ion hydration were compared with those of other attempts. Especially, ${\Delta}$G$_{hyd}$ of $Li^+$ ion is considerably too negative in this study at given temperature, comparing with those of other attempts. But ${\Delta}$G$_{hyd}$ of other ions coincides with each other.

• 한국의류학회지
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• 제47권2호
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• pp.256-276
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• 2023

In South Korea, it has become popular for adolescent girls to wear makeup. From social perspectives on their makeup use, however, it remains controversial among parents, teachers, and even the girls. This study examined the status of adolescent girls' makeup usage, identified factors that influence their makeup use, and laid the groundwork for establishing a social consensus on makeup use among adolescent girls in South Korean society. Data from South Korean adolescent girls were collected and analyzed using MANOVA for repeated measures, confirmatory factor analysis, and structural equation modeling. Adolescent girls were found to wear less makeup at school than outside of school. Additionally, their makeup use was influenced by both positive (e.g., fashion leaders and social support from friends) and negative factors (e.g., low self-esteem). The findings of this study suggest that instead of strict bans against the use of makeup by girls, educational programs are needed to help adolescent girls grow up with healthy perspectives.

• 한국작물학회지
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• 제56권4호
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• pp.394-399
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• 2011

땅콩의 새로운 수요개발을 위해 국내 육성품종 37종에 대한 땅콩 싹나물 비교시험을 통하여 싹나물에 적합한 우량품종을 선발하고 생육형질 상호간의 관계를 조사여 싹나물 연구를 위한 기초 자료자료로 활용하고자 수행한 결과는 다음과 같다. 본 시험에 이용한 각 품종의 100립중은 조광 56 g에서 호광 142 g까지 넓게 분포하였다. 전체품종의 하배축길이는 팔광 4.3 cm에서 대신 5.8 cm 분포하고 평균 5.1 cm였으며 하배축의 직경은 평균 6.9 mm 미광 5.0 mm에서 대청 8.0mm까지 걸쳐 분포하였다. 뿌리길이는 대청 11.1 cm에서 미광 20.6 mm에 분포하였으며 평균 14.6 cm이였다. 상배축의 길이는 평균 1.8 cm로서 대풍 0.8 cm에서 미광 4.6 cm에 걸쳐 분포하였다. 미광은 하배축이 가늘고 짧으며, 상배축과 뿌리가 가장 길었고 기능성 성분 resveratrol 함량($88.2\;{\mu}g/g$)도 높았다. 중소립종 조광은 하배축의 길이(5.0 cm)가 짧은 편이나 하배축 직경(7.8 mm)은 통통하고 싹나물의 크기가 균일하며 수율은 820%로 가장 높았으며 특히 깨끗한 외관 품질을 가져 땅콩 싹나물로 적합한 특성을 가졌다. 땅콩 싹나물 형질 상호간의 상관관계에서 땅콩 종자의 100립중은 싹나물의 resveratrol함량, 성묘율, 수율과는 부(-)의 상관관계를 나타냈고, 묘중, 곡묘 하배축 개열성과는 정(+)의 상관관계를 나타내었다. 또한 싹나물 뿌리 길이는 상배축의 길이, resveratrol 함량, 수율과는 정의 관계를 나타내고 하배축 직경과 개열성과는 부의 관계를 나타냈다.

• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.200-206
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• 2014

PURPOSE. This in vitro study investigated the fracture resistance of endodontically treated premolars restored using silorane-or methacrylate-based composite along with or without fiber or nano-ionomer base. MATERIALS AND METHODS. Ninety-six intact maxillary premolars were randomly divided into eight groups (n = 12). G1 (negative control) was the intact teeth. In Groups 2-8, root canal treatment with mesio-occlusodistal preparation was performed. G2 (positive control) was kept unrestored. The other groups were restored using composite resin as follows: G3, methacrylate-based composite (Z250); G4, methacrylate composite (Z250) with polyethylene fiber; G5 and G6, silorane-based composite (Filtek P90) without and with the fiber, respectively; G7 and G8, methacrylate-and silorane-based composite with nano-ionomer base, respectively. After aging period and thermocycling for 1000 cycles, fracture strength was tested and fracture patterns were inspected. The results were analyzed using ANOVA and Tukey HSD tests (${\alpha}$=0.05). RESULTS. Mean fracture resistance for the eight groups (in Newton) were G1: $1200{\pm}169^a$, G2: $360{\pm}93^b$, G3: $632{\pm}196^c$, G4: $692{\pm}195^c$, G5: $917{\pm}159^d$, G6: $1013{\pm}125^{ad}$, G7: $959{\pm}148^d$, G8: $947{\pm}105^d$ (different superscript letters revealed significant difference among groups). Most of the fractures in all the groups were restorable, except Group 3. CONCLUSION. Silorane-based composite revealed significantly higher strength of the restored premolars compared to that of methacrylate one. Fiber insertion demonstrated no additional effect on the strength of both composite restorations; however, it increased the prevalence of restorable fracture of methacrylate-based composite restored teeth. Using nano-ionomer base under methacrylate-based composite had a positive effect on fracture resistance and pattern. Only fiber-reinforced silorane composite restoration resulted in a strength similar to that of the intact teeth.