3Y-TZP (3 mol% yttria-stabilized tetragonal zirconia polycrystals) ceramics have excellent mechanical properties including high fracture toughness, good abrasion resistance as well as chemical and biological stability. As a result, they are widely used in mechanical and medical components such as bearings, grinding balls, and hip implants. In addition, they provide excellent light transmittance, biocompatibility, and can match tooth color when used as a dental implant. Recently, given the materials’ resemblance to human teeth, these ceramics have emerged as an alternative to titanium implants. Since the introduction of CAD/CAM in the manufacture of ceramic implants, they’ve been increasingly used for prosthetic restoration where aesthetics and strength are required. In this study, to improve the surface roughness of zirconia implants, we modified the 3YTZP surface with a biocomposite of hydroxyapatite and forsterite using room temperature spray coating methods, and investigated the mixed effect of the two powders on the evolution of surface microstructure, i.e., coating thickness and roughness, and biological interaction during the in vitro test in SBF solution. We compared improvement in bioactivity by observing dissolution and re-precipitation on the specimen surface. From the results of in vitro testing in SBF solution, we confirmed improvement in the bioactivity of the 3Y-TZP substrate after surface modification with a biocomposite of hydroxyapatite and forsterite. Surface dissolution of the coating layer and the precipitation of new hydroxyapatite particles was observed on the modified surface, indicating the improvement in bioactivity of the zirconia substrate.
This study was performed to investigate the antioxidative effect of Ligusticum chuanxiong Hort extracts (LCE) against the hyperlipidemia of high-fat diet-fed obese rats. The rats were divided into the three groups (normal group, control group and sample group) to perform the experimental research. 1.5 ml/kg of LCE was intraperitoneally administered into the sample group for 21 days. The equal dose of 0.9% saline was intraperitoneally administered into the normal group and the control group. On day 22, they were anesthetized with ether and dissected. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) were examined in serum of rats. Superoxide dismutase (SOD) was measured in mitochondrial fraction. Malondialdehyde (MDA), catalase (CAT), and glutamate peroxidase (GPx) were determined in liver homogenate. High-fat diet markedly increased the levels of AST, ALT and MDA, significantly decreasing those of SOD, CAT and GPx. But Ligusticum chuanxiong Hort-pretreatment decreased the levels of AST, ALT, and MDA. increasing those of SOD, CAT and GPx. These results demonstrated the antioxidative effects, suggesting that LCE could be the candidate for the functional material.
Ti scaffolds with a three-dimensional porous structure were successfully fabricated using powder metallurgy and modified rapid prototyping (RP) process. The fabricated Ti scaffolds showed a highly porous structure with interconnected pores. The porosity and pore size of the scaffolds were in the range of 66~72% and 300~400 μm, respectively. The sintering of the fabricated scaffolds under the vacuum caused the Ti particles to bond to each other. The strength of the scaffolds depended on the layering patterns. The compressive strength of the scaffolds ranged from 15 MPa to 52 MPa according to the scaffolds' architecture. The alkali treatment of the fabricated scaffolds in an aqueous NaOH solution was shown to be effective in improving the bioactivity. The surface of the alkali-treated Ti scaffolds had a nano-sized fibre-like structure. The modified surface showed a good apatite forming ability. The apatite was formed on the surface of the alkali treated Ti scaffolds within 1 day. The thickness of the apatite increased when the soaking time in a simulated body fluid (SBF) solution increased. It is expected that the surface modification of Ti scaffolds by alkali treatment could be effective in forming apatites in vivo and can subsequently enhance bone formation.
Sophorolipids were biosynthesized using a strain of yeast, Torulopsis bombicola ATCC22214. It has been reported that this yeast gives the highest yields for the production of biosurfactant sophorolipids. Hence, this yeast was used in this study. One of the objectives of this study is to increase the yield of the sophorolipid synthesis. To meet this end, basic culture medium was formulated on the basis of literature research to-date. When this medium was used, the increase in yield from 15% to 150% was observed compared to using the media in the literature. To examine how the interfacial characteristics of sophorolipids change with substrate, glucose (the first carbon source) was maintained in the media and after being cultured for three days, the second carbon sources such as alkanes, vegetable oils, alcohols or organic acids were added. The whole broth was extracted twice with ethyl acetate and the extract was analyzed by thin layer chromatograhy(TLC). After qualitative analyses by TLC, surface tensions of sophorolipids were measured by the Wilhelmy plate method and critical micelle concentration(CMC) was determined using these surface tension data. Also, interfacial tensions were measured by the spinning drop method and emulsions of the three-component water/decane/sophorolipid system were tested. Sophorolipids were effective and efficient in terms of surface tension reduction and CMC, but they were ineffective as emulsifiers because emulsions were separated within 30 minutes.
결명자차, 녹차 및 밤차가 인체의 생체기능활성화에 미치는 영향을 알아보기 위하여 국소뇌혈류량 및 혈압, in vitro상에서의 면역세포의 활성화, 그리고 암세포가 이식된 동물에서의 면역세포 활성화와 암세포의 증식억제 효과를 관찰한 결과 다음과 같은 결론을 얻었다. 1. 단당류는 현미녹차와 결명자차에는 glucose, galactose등이 들어 있으나 밤차에는 glucose, galactose, mannose가 들어 있다. 2. 아미노산은 현미녹차, 밤차, 결명자차 순으로 들어 있다. 3. 카페인은 현미녹차에는 들어 있으나 밤차와 결명자차에는 들어 있지 않았다. 4. 결명자 차는 국소뇌혈류량을 증가시킨 반면 밤차는 감소시켰다. 5. 녹차는 혈압을 증가시켰다. 6. 밤차는 in vitro상에서 흉선세포와 비장세포의 증식을 유의성있게 증가시켰다. 7. 결명자차와 녹차는 in vitro상에서 흉선세포의 증식을 감소시켰다. 8. 결명자차와 녹차는 L1210세포가 이식된 동물의 흉선세포 증식을 감소시켰다. 9. 밤차는 L1210세포가 이식된 동물의 비장세포 증식을 촉진시켰다. 10. 밤차와 결명자차는 L1210세포가 이식된 동물의 암세포 증식을 억제하였다.
Surfactants are the surface-active molecules that display amphiphilicity, Because of this surface activity and amphiphilicity, surfactants have been used in wide industrial applications such as foods, detergents, cosmetics, medicine, polymers, paints, flotation, textiles. These days, their applications extend to high-technology industries such as microelectronics, magnetic recording material, advanced batteries, novel separations, etc. As new applications of surfactants are found and the demand of the surfactants increases, surfactant industry has been more pressed to face a formidable challenge, which is to develop surfactants that are envirionmentally friendly. In this regard biosurfactants may be alternatives to chemical surfactants, since biosurfactants are biologically compatible, more biodegradable, less toxic, and highly specific. Because of these excellent advantages over those of chemical surfactants, much efforts have been made in biosurfactant research. This article reviews biosurfactants in several aspects, that is, their definition, structures, properties, applications, and prospects.
Background : Angelica gigas is a biennial or short lived perennial plant found in China, Japan, and Korea. The root of Angelica gigas has been used in oriental traditional medicine and is marketed as a functional food product in Europe and North America. Cham-Dang-Gui (Korean Angelica, the dried root of Angelica gigas Nakai (AGN)) has been principally cultivated in Korea and used as a Korean medicinal herb. It contains several chemicals, such as pyranocoumarins, essential oils, and polyacetylenes. Methods and Results : Fresh Angelica gigas Nakai was purchased from Pyeongchang (Korea). Standard samples of D, DA were obtained from Korea Promotion Institute for Traditional Medicine Industry (Gyeongsan, Korea). Soluplus was purchased from BASF (Ludwigshafen, Germany). AGN was dried in the oven at 55°C for 24 h and cooled at room temperature. The AGN sample was then stored at 4°C until milling. Oral solid formulations based on Angelica gigas Nakai and Soluplus were prepared by the hot melt extrusion (HME) method. AGN was pulverized into coarse and ultrafine particles, and their particle size and morphology were investigated. Ultrafine AGN particles were used in the HME process with high shear to produce AGN-based formulations. In simulated gastrointestinal fluids (pH 1.2 and pH 6.8) and water, significantly higher amounts of the major active components of AGN, decursin (D) and decursinol angelate (DA), were extracted from the HME-processed AGN/Soluplus group than the AGN EtOH extract group (p < 0.05). Based on an in vivo pharmacokinetic study in rats, the relative oral bioavailability of decursinol (DOH), a hepatic metabolite of D and DA, in administered mice was 8.75-fold higher than in AGN EtOH ext-treated group. Conclusion : Soluplus-included solid formulation prepared by HME can be a promising carrier for oral delivery of phytochemicals. These findings suggest that HME-processed AGN/Soluplus formulation could be a promising therapeutic candidate for oral bioavailability.
생체수는 링거액, 인공관절액, 세포 배양 등 다양한 분야에서 연구되어 왔다. 이는 생체수가 체온을 조절하는데 결정적인 역할을 하고, 생체 내 다양한 대사 과정에서 용매로 사용되며, 삼투압이나 능동적 섭취를 통한 혈액 또는 림프액을 통해 세포에서 세포로 전달되는 미네랄, 에너지원, 호르몬, 시그널과 약물의 전달 물질로 이용되기 때문이다. 세포외 지질과 자연보습성분(natural moisturizing factor, NMF)을 함유하는 각질층은 외부의 수분을 끌어들여 내부 수화에 이용하며, 이러한 과정들은 피부 장벽 기능과의 연관성이 높다. 본 연구에서는 피부 장벽 기능을 강화하는 아미노산, 펩타이드, 단당류를 포함한 생체모사수(Cell Bio Fluid SyncTM)를 인체 피부에 처리하여 세포활성을 관찰하고, 생체 모사수를 함유한 제품을 피부에 도포하여 인체 피부 개선 효과를 연구 하였다. 피부 세포 활성을 보기 위해 각질세포인 HaCaT 세포를 이용하였고, 에너지 고갈 상태로 만들기 위해 3시간 동안 PBS에 전 처리한 후 이후 세포 배양액인 DMEM 및 등장액인 PBS, 생체 모사수 (Cell Bio Fluid SyncTM)에 각각 3시간 처리하였다. 이후 MTT assay와 이미지 분석을 수행하였다. 인체의 피부 개선 효능을 위한 임상 연구에 21명의 여성이 참여하였다. 생체 모사수를 함유한 제품을 1주일간 안면에 도포하였고, 수분량, 피부결, 밝기 그리고 피부 균일도를 측정하였다. 모든 측정은 피험자가 세안 후 항온항습 조건(22 ± 2 ℃, 50 ± 5%)에서 20분 간 대기하고 수행하였다. 모든 데이터는 SPSS ver. 21을 이용하여 분석하였다. 그 결과, 생체 모사수(Cell Bio Fluid SyncTM)가 세포 활성을 높이고 인체의 피부에서 수분, 거칠기, 밝기, 균일도, 투명도 등의 개선 효과가 있음을 확인할 수 있었다.
본 연구에서는 지유 에탄올추출물의 항산화 효과를 조사하였다. Pyrogallol의 억제율을 100%로 기준하였을 때, DPPH 라디칼을 50% 억제시키는데 필요한 지유 추출물의 농도는 0.33 mg/mL으로 α-tocopherol의 IC50(0.40 mg/mL)과 유사하게 나타났다. 지유 추출물의 총항산화능은 α-tocopherol에 비해 높게 나타났다. 지유 추출물의 superoxide 소거활성은 catechin에 비해 높게 나타났다. 지유 추출물의 peroxyl 라디칼 소거활성은 ascorbic acid에 비해 높게 나타났다. 지유 추출물의 구리이온 환원력은 α-tocopherol에 비해 높게 나타났다. 지유 추출물은 hydroxyl 라디칼 및 peroxyl 라디칼로 유발된 supercoiled DNA strand의 절단을 억제시켰다. 지유 추출물 0.5 및 5 mg/mL의 총페놀 함량은 각각 0.50 및 3.33 mM gallic acid와 동등한 수준이었다. 또한, HepG2 세포주를 이용한 세포배양에서 지유 추출물 0.01, 0.1 및 0.5 mg/mL 농도의 첨가는 0.2 mM t-BHP로 유도된 세포독성을 각각 33.8, 79.1 및 96.9% 감소시켰다. 따라서, 본 연구 결과들은 지유 추출물의 강력한 항산화 효과와 세포독성 억제효과를 나타내며, 이러한 효능은 적어도 자유라디칼의 산화억제와 높은 총페놀 함량에 기인하는 것으로 사료된다.
The biosorption of dye, Rhodamine B(Rh-B), onto waste activated sludge was investigated. The biosorption capacity and contact time were shown as a simulation of dye adsorption equilibrium and kinetics models.
We observed that biosorption of Rh-B occurred rapidly less than 4hr. These experimental data could be better fitted by a pseudo-second-order rate equation than a pseudo-first-order rate equation. The equilibrium dependence between biosorption capacity and initial concentration of Rh-B was estimated and it was found that the equilibrium data of biosorption were fitted by four kinds of model such as Langmuir, Freundlich, Redlich- Peterson, and Koble-Corrigan model. The average percentage errors, ε(%), observed between experimental and predicted values by above each model were 21.19%, 9.97%, 10.10% and 11.76%, respectively, indicating that Freundlich and Redlich-Peterson model could be fitted more accrately than other models.