• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.197-197
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• 2016

Commercially pure titanium (CP Ti) and Ti-6Al-4V alloys have been widely used for biomedical applications. However, the use of the Ti-6Al-4V alloy in biomaterial is then a subject of controversy because aluminum ions and vanadium oxide have potential detrimental influence on the human body due to vanadium and aluminum. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Manganese(Mn) plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. Radio frequency(RF) magnetron sputtering in the various PVD methods has high deposition rates, high-purity films, extremely high adhesion of films, and excellent uniform layers for depositing a wide range of materials, including metals, alloys and ceramics like a hydroxyapatite. The aim of this study is to research the Mn coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. Mn coatings was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Mn coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.

• 한국재료학회지
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• 제24권12호
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• pp.671-676
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• 2014

It is known that bones get damaged by accidents and aging. Since the discovery of Bioglass, various kinds of ceramics have been also found to bond to living bone; some of these ceramics are already being clinically used as bone-repairing materials. In the present study, antibacterial calcium silicate gel ($Ag-30CaO{\cdot}70SiO_2$ gel) was prepared by sol-gel method in order to control the microstructure, which is related to the dissolution rate and induction period of apatite formation in body environment. In addition, biological $Ag-30CaO{\cdot}70SiO_2$ is tested. This was done to impart antimicrobial activity to the $30CaO{\cdot}70SiO_2$. Ag ion was added during sol-gel synthesis to replace the $H_2O$ added during the making of the $30CaO{\cdot}70SiO_2$ gel, which has silver solutions of various concentration. After the sol-gel process, 1N-$HNO_3$ solution was used to wash the gel when synthesizing the gel, in order to maintain the porous structure and remove PEG, water soluble polymers. Then, the apatite forming ability of the sol-gel derived CaO-$SiO_2$ gels was investigated using simulated body fluid (SBF), which had almost the same ion concentration as that of human blood plasma. The gels were analyzed by FT-IR spectroscopy, SEM observation, XRD, and fluorescent microscopy. The apatite was successfully created even after washing the gel; apatite is present in an amorphous state, and was found to affect the concentration of the Ag ion in cells in MC3T3 live & dead assay results. From these results, it is suggested that a good material that can be used to repair defects of nature bone is $Ag-30CaO{\cdot}70SiO_2$ gel.

• 대한한의학회지
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• 제31권4호
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• pp.9-19
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• 2010

Objective: To compare the contents and transfer rate of hazardous substances in crude, washing solution, crude after washing, decoction and remnant after boiling. Methods: The heavy metal contents of each step were measured by inductively coupled plasma mass spectrometer (ICP-MS) and mercury analyzer (SP-3DS). In order to analyze pesticides in each sample 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. Contents (mg/kg) of heavy metals were not detected in decoctions of any tested herbal medicine prescriptions. 2. Transfer rates (%) of heavy metals from crude to remnant were as follows: Yijin-tang (As: 46.9, Cd: 50.0 and Pb: 100.0), Oryung-san (As: 80.0, Cd: 100.0 and Pb: 73.8), Hwangryunhaedok-tang (As: 88.9, Cd: 71.4 and Pb: 92.7), Bangpungtongseong-san (As: 100.0, Cd: 17.3 and Pb: 56.1), Oyaksungi-san (As: 47.4, Cd: 175.0 and Pb: 142.4). 3. Contents (mg/kg) of residual pesticides were not detected in any samples. 4. Transfer rate (%) of sulfur dioxide ($SO_2$) from crude to remnant in all samples were as follows: Yijin-tang (25.0), Oryung-san (166.7), Hwangryunhaedok-tang (50.0), Bangpungtongseong-san (181.8), Oyaksungi-san (50.0). Conclusion: Our results showed that the boiled herbal medicine prescriptions which we take are safe from the hazardous substances.

• Journal of Pharmaceutical Investigation
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• 제29권1호
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• pp.29-36
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• 1999

Aceclofenac is an non-steroidal antiinflammatory drug which has been used in the treatment of rheumatoidal rthritis and osteo-arthritis. In order to decrease the gastric ulcerogenic effects and contol the plasma level of aceclofenac, we have developed the transdermal delivery system of aceclofenac plaster, which were formulated employing matrix polymers of acrylates and penetration-enhancers such as $Lauroglycol^{\circledR}$, $Transcutol^{\circledR}$, oleic acid and linoleic acid. Using Franz diffusion cells mounted with a rat skin, transdermal penetration characteristics of the formulations were evaluated by the HPLC assay of aceclofenac and diclofenac, an active metabolite, in the receptor compartment of pH 7.2 phosphate buffered solution. Skin penetration was increased when the content of aceclofenac increased, showing the flux $(J,\;{\mu}g/cm^2/hr)$ of 0.37 and 2.50 for 2% and 6.75% of the content, respectively. The flux$(J,\;{\mu}g/cm^2/hr)$ from plasters made of $Durotak^{\circledR}$ 87-2074, $Durotak^{\circledR}$ 87-2510 and $Durotak^{\circledR}$ 87-2097 were 2.50, 2.77 and 4.39, respectively. $Durotak^{\circledR}$ 87-2074 showed the lowest penetration due to the carboxylic acid group in the polymer, which might form a strong hydrogen bonding with a secondary amine of aceclofenac. Although both $Durotak^{\circledR}$ 87-2510 and $Durotak^{\circledR}$ 87-2097 are amine-resistant adhesives, $Durotak^{\circledR}$ 872510 showed lower penetration than $Durotak^{\circledR}$ 87-2097 because of the hydroxyl group in $Durotak^{\circledR}$ 87-2510, which might form a weak hydrogen bonding with aceclofenac. These results reveal that the functional group in acrylic polymers would greatly affect the release of aceclofenac from the matrix, which is the rate-limiting step in the penetration of aceclofenac through rat skins. The penetration of aceclofenac from plasters using different penetration-enhancers increased in the following order: Transcutol < linoleic acid < oleic acid. And the flux from the plasters containing oleic acid as a penetrationenhancer was 2.22 times greater than that of creams, which suggest that a newly deveolped aceclofenac plaster could be used in the treatment of rheumatoidal arthritis and osteo-arthritis as an advanced transdermal delivery system.

• Journal of Pharmaceutical Investigation
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• 제35권3호
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• pp.193-199
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• 2005

Gabapentin is an antiepileptic drug that is structurally similar to ${\gamma}-aminobutyric$ acid (GABA), but does not interact with the GABA receptor. It does not bind significantly to plasma proteins, and is excreted to unchanged form in the urine. The purpose of the present study was to evaluate the bioequivalence of two gabapentin capsules, $Neurontin^{TM}$ capsule 300 mg (Pfizer Pharm. Co., Ltd.) and Kuhnil $Gabapentin^{TM}$ capsule 300 mg (Kuhnil Pharm. Co., Ltd), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of gabapentin from the two gabapentin formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, $22.46{\pm}1.86$ years in age and $67.64{\pm}7.24$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single capsule containing 300 mg as gabapentin was orally administered, blood samples were taken at predetermined time intervals and the concentrations of gabapentin in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Neurontin^{TM}$ capsule 300 mg, were -2.03, -0.43 and 4.29% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 $(e.g.,\;log\;0.89{\sim}log\;1.09\;and\;log\;0.91{\sim}log\;1.09$ for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kuhnil $Gabapentin^{TM}$ capsule 300 mg was bioequivalent to $Neurontin^{TM}$ capsule 300 mg.

• Journal of Animal Science and Technology
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• 제44권4호
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• pp.483-490
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• 2002

본 논문에서는 카제인 가수분해물의 in vivo 상에서 혈압강하 효과를 알아보고, 혈압강하 기능을 갖는 기능성 펩타이드로서의 활용 가능성을 검토하기 위하여 안전성 검사를 실시하였다. 카제인 가수분해물의 소화관 단백질 분해효소 (펩신, 트립신, 카이모트립신) 내성 시험 결과 카제인 가수분해물은 소화관 효소 처리에 의하여 ACE 저해효과에 차이가 없었으며, 자연발증고혈압쥐를 이용한 혈압강하 실험에서 500 mg/kg을 경구 투여한 결과 12.9% (－28.88 mmHg, P<0.05) 저하하였고, 이들 가수분해물을 30% 난황으로 유화할 경우 15.9% (－30.76 mmHg, P<0.01)의 혈압이 감소하여 난황으로 유화에 의해 다소 혈압강화 효과가 증가하였다. 장기 투여에 의한 혈압강하 효과에서 35일 부터 수축기혈압 감소효과가 나타났으며 12.46% (P<0.05) 감소하였다. 가수분해물의 장기투여에 의한 자연발증고혈압쥐의 체중변화는 대조구와 비교하여 차이가 없었다. 혈압강하 효과를 가지는 카제인 가수분해물의 안전성을 조사한 결과 간장장애 지표로서 사용되는 GOT, GPT 활성에 차이가 없었다. 간장 비대 등의 장기 비대 현상도 없었고 조직병리학적 검사에서도 차이가 없었다. ACE 저해활성을 가지는 카제인 가수분해물은 혈압강하제와 비교하였을 때 비교적 낮은 활성을 나타내지만 항상 섭취하는 식품 중에 존재한다는 점에서 그 유용성이 기대되며, 고혈압 예방을 위한 기능성 식품이나 의약품으로서 개발하기 위해서 앞으로 ACE 저해 펩타이드에 대한 체계적인 안전성 검사가 이루어져야 할 것으로 생각된다.

• 한국결정성장학회지
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• 제23권1호
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• pp.51-57
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• 2013

본 연구에서는 Heusler $Fe_2VAl$ 열전화합물을 제조하기 위하여 순금속 $Fe_{50}V_{25}Al_{25}$ 혼합분말을 기계적 합금화 처리하였다. $Fe_2VAl$ 열전화합물을 얻기 위하여 최적 볼밀조건 및 열처리 조건을 X선 회절분석과 시차주사 열량분석을 이용하여 조사하였다. $Fe_{50}V_{25}Al_{25}$ 혼합분말을 60시간까지 볼밀 처리한 경우 bcc 구조의 ${\alpha}$-(Fe,V,Al) 고용체가 얻어졌다. 단상의 Heusler $Fe_2VAl$ 화합물은 $Fe_{50}V_{25}Al_{25}$ 혼합분말을 60시간 동안 MA 처리 후 $700^{\circ}C$까지 열처리함으로써 얻을 수 있었다. MA 분말시료의 치밀화를 위하여 인가압력 60 MPa 및 소결온도 $900{\sim}1000^{\circ}C$에서 흑연다이를 사용하여 SPS 소결을 실시하였다. $1000^{\circ}C$에서 SPS 소결 후 얻어진 벌크체의 Vickers 경도는 870으로 매우 높은 값을 보였다. 또한 SPS 법으로 얻어진 벌크체의 밀도측정 결과, 모든 시료에서 상대밀도 90 % 이상의 금속광택을 나타내는 치밀한 소결체임을 알 수 있었다.

• 한국환경보건학회지
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• 제43권3호
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• pp.194-201
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• 2017

Objectives: Zinc oxide nanoparticles (ZnO NPs) are widely used in various commercial products, but they are exposed to the environment and can induce toxicity. In this study, we investigated the environmental fate and bioaccumulation of ZnO NPs in a microcosm. Methods: The microcosm was composed of water, soil (Lufa Soil 2.2) and organisms (Oryzias latipes, Neocaridina denticulata, Semisulcospira libertina). Point five and 5 mg/L of ZnO NPs were exposed in the microcosm for 14 days. Total Zn concentrations were measured using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and intracellular NPs were observed using Transmission Electron Microscopy (TEM). Results: In the initial stages of exposure, the Zn concentrations in water increased in all exposure groups and then decreased, while the Zn concentration in soil increased after three hours for the 5 mg/L solution. Zn concentrations also showed increasing trends in N. denticulata and S. libertina at 0.5 and 5 mg/L, and in O. latipes at 5 mg/L. Accumulation of NPs was found in the livers of O. latipes and hepatopancreas of N. denticulata and S. libertina. Conclusions: In the early stages of exposure, ZnO NPs remained in the water, and then were transported to the soil and test species. Unlike other species, total Zn concentrations in N. denticulata and S. libertina increased for both 0.5 mg/L and 5 mg/L. Therefore, ZnO NPs were more easily accumulated in zoobenthos than in fish.

• 대한소아치과학회지
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• 제34권4호
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• pp.613-622
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• 2007

본 연구의 목적은 법랑질 시편에 수종의 불소 제재를 도포한 후 우식 예방 효과를 광밀도 및 미세경도 측정을 통해 평가하는 것이다. 소의 절치를 이용하여 80개의 법랑질 시편을 제작하고 각 군당 20개씩, 네 군으로 나누었다. I군은 대조군으로서 아무런 처치도 하지 않았고 II군은 acidulated phosphate fluoride(APF) gel(60 seconds $taste^{(R)}$, PASCAL, USA)을 4분간 적용한 후 수세하였다. III군은 Fluor $Protector^{(R)}$(Ivoclar Vivadent, Liechtenstein)를, IV군은 $CavityShield^{TM}$(Omnii Pharmaceuticals, USA)를 1분간 도포하고 증류수에 보관한 뒤 24시간 후 부드러운 모를 가진 칫솔을 이용하여 칫솔질하였다. 각 시편을 인공우식용액에 48시간동안 침잠시켜 인공우식병소를 유발한 후 광밀도를 컴퓨터 영상분석 프로그램으로 분석하고 표면미세경도를 측정하여 다음의 결과를 얻었다. 1. 광밀도는 APF gel을 도포한 II군에 비해 불소 바니쉬를 도포한 III, IV군이 높았으나(p<0.05) III군과 IV군 사이의 유의한 차이는 없었다. 2. 표면미세경도는 IV군, III군, II군, I군의 순으로 높았다(p<0.05). 3. $CavityShield^{TM}$를 도포한 IV군과 Fluor $Protector^{(R)}$를 도포한 III군은 광밀도에서는 유의한 차이가 없었으나 표면 미세경도는 IV군이 III군보다 유의하게 높았다. 이상의 결과를 종합해 볼 때 불소 바니쉬가 APF gel에 비해 법랑질 탈회 억제 효과가 우수한 것으로 나타났다. 임상적용의 용이성과 안전성을 고려할 때 불소 바니쉬의 사용이 영유아나 장애인에게 유용할 것으로 사료된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.4-4
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• 2008

The progress in flat panel displays over the last two decades has been astonishing. In just 20 years, the LCD-TV grew up from a 2-inch curiosity, to an industry that will sell about 120 million flat panel TV's this year, with viewing area up to 4000 times larger. That success is based on continuous innovation, especially in manufacturing processes. For the next decade to bring another doubling of the business, progress will need to continue in four major areas: Human factors, ecological impact, visual quality, and of course continued drive towards affordability. This talk will detail the technology advances that can allow this industry to meet those challenges. Human factors. Today, we adapt our lifestyle to our technology. People organize their offices, and their homes, around displays. We pass around mobile phones to share images, rather than experiencing them as a group. Billions of newspapers continue to be sold daily. Advances in flexible displays can lead to large portable displays. "New era projection" includes the handheld Pico Projectors that are already on the market, and will ultimately appear integrated in mobile phones the same way cameras do today. "Eco" impact. Today TV's are one of the top energy consumers in a U.S. home, and the fastest growing. Watching a large flat panel TV can cost twice as much as running a large refrigerator. With today's concern about energy consumption, regulations are starting to emerge worldwide to limit TV electrical use. Fortunately, good solutions exist in using light management films to eliminate bulbs, saving power without increasing cost. Going forward, LED backlights will drive another step downward. OLED displays might be the ultimate solution. Visual quality. The color of an LCD-TV is still often considered inferior to a far less expensive CRT. And almost all displays suffer from representing a three-dimensional world on a two dimensional surface. The technology to improve color is available today, and will likely move from premium sets into the mainstream as costs come down. 3D is now arriving in movie theaters worldwide, and that will drive up the demand for similar realistic images in home theaters. And the technology is emerging today for 3D representation to move beyond specialized applications into everyday use, on screens large and small. Affordability. The world takes cost-down miracles for granted in consumer electronics. Each of these other advances will be balanced with a drive for affordability, especially as the market grows in emerging countries. The other three challenges must be met without increasing cost. Putting this all together, the next few years will emphasize "eco friendly" designs, and enhanced images such as 3D. By 2013 we will start to see serious penetration by emissive technologies (OLED, high efficiency plasma, or other), with the "ultimate display" likely not in the market for a decade. Lots of opportunities for innovation remain ahead of us.