• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.77-77
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• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• 대한한의학방제학회지
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• 제17권2호
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• pp.53-63
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• 2009

Objective : To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after a decoction. Methods : The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 4 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide ($SO_2$) were performed by Monier-Williams distillation method. Results: 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Jaeumganghwa-tang (before decoction - Pb; 1.190, Cd; 0.184, As; 0.099 and Hg; 0.028, after decoction - Pb; .033, Cd; 0.003, As; 0.005 and Hg; 0.001), Yukmijiwhang-tang (before decoction - Pb; 0.484, Cd; 0.133, As; 0.053 and Hg; 0.009, after decoction - Pb; 0.065, Cd; 0.008, As; 0.007 and Hg; not detected), Bojungikgi-tang (before decoction - Pb; 0.863, Cd; 0.197, As; below 0.016 and Hg; 0.011, after decoction - Pb; 0.071, Cd; 0.009, As; 0.004 and Hg; 0.001) and Ssangwha-tang (before decoction - Pb; 1.511, Cd; 0.212, As; 0.094 and Hg; 0.016, after decoction - Pb; 0.029, Cd; 0.006, As; 0.005 and Hg; 0.0004). 2. Contents (mg/kg) of sulfur dioxide ($SO_2$) before a decoction in Jaeumganghwa-tang, Yukmijiwhang-tang and Ssangwha-tang exhibited 22.7, 107.3 and 5.5, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. 3. Contents (mg/kg) of residual pesticides before/after a decoction in all samples were not detected. Conclusion : These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• Journal of Periodontal and Implant Science
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• 제32권3호
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• pp.489-500
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• 2002

The purpose of this study was to evaluate newly fabricated tricalcium phosphate(TCP)/chitosan microgranuls as bone substitutes. TCP/chitosan microgranules were fabricated by dropping TCP-chitosan suspension into the NaOH/ethanol solution. The size of microgranules could be controllable via airflow rate. PDGF-BB was loaded into the fabricated granules via freeze-drying methods(300 ng/20 mg). To evaluate cell proliferation, cultured osteoblasts cell lines(MC3T3-El) was dropped on the BioOss(R), chitosan microgranules, TCP/chitosan microgranules and cultured for 1, 7 , 14, and 28 days. Scanning electron microscopic observation was done after 7 days of culture and light microscopic examination was done after 28 days of culture. PDGF-BB release from the microgranules was tested. Rabbit calvarial defects(8 mm in diameter) were formed and chitosan, TCP/chitosan, PDGF-TCP/chitosan microgranules, and BioGran(R) were grafted to test the ability of new bone formation. At SEM view, the size of prepared microgranules was 250-1000 um and TCP powders were observed at the surface of TCP/chitosan microgranules. TCP powders gave roughness to the granules and this might help the attachment of osteoblasts. The pores formed between microgranules might be able to allow new bone ingrowth and vascularization. There were no significant differences in cell number among BioOss(R) and two microgranules at 28 day. Light and scanning electron microscopic examination showed that seeded osteoblastic cells were well attached to TCP/chitosan microgranules and proliferated in a multi-layer. PDGF-BB released from TCP/chitosan microgranules was at therapeutic concentration for at least 1 week. In rabbit calvarial defect models, PDGF-TCP/chitosan microgranules grafted sites showed thicker bone trabeculae pattern and faster bone maturation than others. These results suggested that the TCP/chitosan microgranules showed the potential as bone substitutes.

• Molecules and Cells
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• 제23권2호
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• pp.145-153
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• 2007

Elucidation of the roles of circadian associated factors requires a better understanding of the molecular mechanisms of circadian rhythms, control of flowering time through photoperiodic pathways, and photosensory signal transduction. In Arabidopsis, the APRR1 quintet, APRRs 1, 3, 5, 7, and 9, are known as central oscillator genes. Other plants may share the molecular mechanism underlying the circadian rhythm. To identify and characterize these circadian response genes in Brassica crops whose genome was triplicated after divergence from Arabidopsis, we identified B. rapa BAC clones containing these genes by BLAST analysis of B. rapa BAC end sequences against the five corresponding Arabidopsis regions. Subsequent fingerprinting, Southern hybridization, and PCR allowed identification of five BAC clones, one for each of the five circadian-related genes. By draft shotgun sequencing of the BAC clones, we identified the complete gene sequences and cloned the five expressed B. rapa circadian-associated gene members, BrPRRs 1, 3, 5, 7, and 9. Phylogenetic analysis revealed that each BrPRR was orthologous to the corresponding APRR at the sequence level. Northern hybridization revealed that the five genes were transcribed at distinct points in the 24 hour period, and Southern hybridization revealed that they are present in 2, 1, 2, 2, and 1 copies, respectively in the B. rapa genome, which was triplicated and then diploidized during the last 15 million years.

• 디자인학연구
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• 제16권1호
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• pp.25-34
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• 2003

세계화시대에서 각 나라들은 자국의 고유한 이미지를 상징화시켜 다양한 디자인 개발을 하고 있다. 이는 타문화와의 차별화를 이용하여 부가가치 창출은 물론 국가 정체성과 이미지 제고 측면에서도 매우 중요하고 지속적인 발전이 이루어져야 한다. 우리나라를 대표하는 이미지는 무엇일까\ulcorner 태극기, 무궁화, 애국가, 김치, 한복, .등 많지만 본 연구에서는 한국의 태극기를 연상시킬 수 있고 시각적으로 강한 색상과 미적 요소를 지닌 태극무늬를 선택하였다. 태극무늬는 화합과 번영을 의미하여 예로부터 실생활의 소품이나 건축물 등에 많이 사용되어 왔다. 본 연구에서는 다양한 국제행사를 맞아 문화상품의 개발이 요구되는 시점에서 태극무늬를 현재 남북으로 분단되어 있는 우리의 현실에 적용하여 음양오행설에서의 음ㆍ양이 상극이지만, 상생과 서로 균형을 잘 이루어 상화로 이루어지듯이 남ㆍ북이 서로 대치국면이 아닌 서로 공생하고 화합하는 의미로서 태극무늬를 통일의 의미에 시각적으로 표현하여 엽서를 통해 통일을 앞당기고 세계에 우리의 바람을 알리고자 하는데 그 의의가 있다.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1351-1357
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• 2009

KH-red ginseng/chlorella (KH-RG/C) is the mixed material of the Korean red ginseng powder (Panax ginseng, 75%) and extract of Chlorella vulgaris (25%). To evaluate the effects of KH-RG/C on endurance capacity and immune regulation, the forced swimming test (FST) was conducted. The immobility time in the FST was significantly decreased in KH-RG/C treated group compared with the DW-treated group at the 3 and 10 days, respectively. In the analysis of the blood biochemical parameters, KH-RG/C treatment significantly increased the glucose level. However, the lactic dehydrogenase level decreased. Although KH-RG/C increased aspartate aminotransferase, it was not different significantly. And KH-RG/C had no affects in the alanine aminotransferase, and blood urea nitrogen levels. In splenocytes and macrophages, KH-RG/C also did not affect the interleukin (IL)-2, IL-4, and IL-12 production. These results suggest that KH-RG/C may influence to immune regulation through increasing the physical endurance capacity without effect in activation of immune cells.

• 한국재료학회지
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• 제20권10호
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• pp.518-523
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• 2010

In this study, partially stabilized zirconia was synthesized using a chemical $Y_2O_3$ stabilizer and hydrothermal method. First, $YCl_3-6H_2O$ and $ZrCl_2O-8H_2O$ was dissolved in distilled water. Y-TZP (a $Y_2O_3$-doped toughened zirconia polycrystalline precursor) was also prepared by conventional co-precipitates in the presence of an excess amount of $NH_4OH$ solution under a fixed pH of 12. The Y-TZP precursors were filtered and repeatedly washed with distilled water to remove $Cl^-$ ions. $ZrO_2$-Xmol%$Y_2O_3$ powder was synthesized by a hydrothermal method using Teflon Vessels at $180^{\circ}C$ for 6 h of optimized condition. The powder added with the Xmol%- $Y_2O_3$ (X = 0,1,3,5 mol%) stabilizer of the $ZrO_2$ was synthesized. The crystal phase, particle size, and morphologies were analyzed. Rectangular specimens of $33mm{\times}8mm{\times}3$ mm for three-point bend tests were used in the mechanical properties evaluation. A teragonal phase was observed in the samples, which contains more than 3 mol% $Y_2O_3$. The $3Y-ZrO_2$ agglomerated particle size was measured at $7.01{\mu}m$. The agglomerated particle was clearly observed in the sample of 5 mol % $Y_2O_3-ZrO_2$, and and the agglomerated particle size was measured at 16.4 um. However, a 20 nm particle was specifically observed by FE-SEM in the sample of 3 mol% $Y_2O_3-ZrO_2$. The highest bending fracture strength was measured as 321.3 MPa in sample of 3 mol% $Y_2O_3-ZrO_2$.

• 대한수의학회지
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• 제39권6호
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• pp.1081-1090
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• 1999

To establish the protocol of a standardized exercise test for evaluating exercise intolerance and degree of fitness in Thoroughbred racehorses, we examined serum lactate concentrations related to exercise intensities using the high speed treadmill. Twelve clinically healthy Thoroughbred racehorses with or without previous training or racing history were assigned to two gorups, fit and unfit group, respectively. The protocol used for the standardized exercise test was consisted of two stages : stage of warm-up and that of acceleration. During the warm-up, the horses exercised 5 min at 1.8m/s and 3 min 3.4m/s without inclination. At the acceleration stage, exercise test was performed at 10% slope and the speed was increased from the initial 5m/s to the maximal speed which each tested horse could keep up with. The speed was increased with incremental steps of 1 m/s every minute. During the last 15 sec of each step, blood samples were collected for serum lactate determination. $V_{max}$(maximal treadmill speed which tested horses could keep up with) of the fit group ($10.93{\pm}0.33m/s$, mean${\pm}$SE, n = 6) was higher than that of the unfit group ($9.52{\pm}0.23m/s$, mean${\pm}$SE, n = 6). Serum lactate concentrations increased exponentially according to exercise intensities. $V_{La4}$(speed producing a serum lactate concentration of 4mmol/l) of the fit group, $6.45{\pm}0.26m/s$, was higher than that of the unfit group, $5.45{\pm}0.23m/s$. $La_{peak}$(peak plasma lactate concentration during the exercise test) was lower in the fit group ($20.34{\pm}1.62mmol/l$ at 1 min after maximal intensity exercise) than in the unfit group ($24.78{\pm}1.09mmol/l$ at 2 min after maximal exercise step). $t_{50%}$(time required for the recovery of lactate concentration to be one-half of $La_{peak}$ after maximal exercise) of the unfit group and the fit group were 40.0 and 18.0 min, respectively. Therefore, the protocol of the incremental standardized exercise test utilized in this study seems to be reliable for the assessment of fitness and exercise intolerance for the Thoroughbred racehorses.

• 한국식품영양학회지
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• 제28권4호
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• pp.571-578
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• 2015

수확과정에서 버려지고 있는 고구마 잎을 이용한 기능성 식품소재로서 활용가능성을 검토하고자, 밀가루 중량 대비 고구마 잎 분말을 2, 3, 5, 7%의 비율로 첨가하여 식빵을 제조하고, 반죽 및 제빵 특성, 생리활성 및 기능성분 등을 조사하였다. 반죽의 수분흡수량은 7% 첨가 시 가장 높았고, 반죽시 간은 유의적인 차이를 보이지 않았으며, 반죽의 저항도는 2~3% 첨가할 때가 가장 안정적이었다. 식빵의 수분 함량은 첨가량이 증가하여도 큰 차이를 보이지 않았고, 식빵의 내부색은 첨가량이 증가할수록 L값과 a값은 감소하였으나, b값은 증가하였다. 식빵의 부피와 비용적 및 굽기 손실률은 첨가량이 증가할수록 감소하였으나, 항산화 활성과 총 폴리페놀, 루테인 및 베타카로틴 함량은 증가하였다. 관능평가의 결과, 고구마 잎 분말의 2~3% 첨가 시 맛과 색깔, 조직감, 입안에서의 씹힘성과 종합적인 기호도에서 가장 우수한 값을 얻었다. 이상의 결과에서 고구마 잎 분말의 2~3% 첨가 시, 제빵 적성과 기능성, 상품성이 우수한 식빵을 제조할 수 있었다.

• Tuberculosis and Respiratory Diseases
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• 제64권5호
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• pp.383-386
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• 2008

CA19-9의 상승은 췌장 및 담도계 악성 종양을 시사하는 소견이다. 하지만, 최근에 양성 소화기계 질환 뿐 아니라 특발성 간질성 폐렴, 교원성 폐 질환, 미만성 범세기관지염, 기관지확장증 등 다양한 양성 폐 질환에서도 혈중 CA19-9 수치가 증가되어 있다고 보고된다. 저자들은 최근 지속적으로 혈중 CA19-9 수치는 증가되어 있지만, 내시경적 역류성 담도 췌장 조영술, 복부 전산화 단층 촬영, PET-CT에서 악성 종양이 발견되지 않은 기관지확장증 1예를 경험 하였다. 3년 10개월의 추적 관찰 기간 중에도 췌장암과 같은 악성 종양은 발견되지 않아서, 혈중 CA19-9 수치의 상승은 기관지확장증에 의한 것으로 추정 되었다. 혈중 CA19-9 수치의 상승은 환자의 임상 양상과 연관하여 조심스럽게 판단하여야 될 것으로 생각된다.