• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.3835-3838
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• 2016

Background: Breast cancer is one of the most frequent cancer types within female populations. Silibinin is a chemotherapeutic agent ative against cancer. Niosomes are biodegradable, biocompatible, safe and effective carriers for drug delivery. Objective:To prepare nanoniosomal silibinin and evaluate its cytotoxicity inthe T-47D breast cancer cell line. Materials and Methods: Niosomes were prepared by reverse phase evaporation of a mixture of span 20, silibinin, PEG-2000 and cholesterol in chloroform and methanol solvent (1:2 v/v). The solvent phase was evaporated using a rotary evaporator and the remaining gel phase was hydrated in phosphate buffer saline. Mean size, size distribution and zeta potential of niosomes were measured with a Zetasizer instrument and then nanoparticles underwent scanning electron microscopy. The drug releasing pattern was evaluated by dialysis and the cytotoxicity of nanoniosomes in T-47D cells was assessed by MTT assay. Results: Particle size, size variation and zeta potential of the niosomal nanoparticles were measured as $178.4{\pm}5.4nm$, $0.38{\pm}0.09$ and $-15.3{\pm}1.3mV$, respectively. The amount of encapsulated drug and the level of drug loading were determined $98.6{\pm}2.7%$ and $22.3{\pm}1.8%$, respectively; released drug was estimated about $18.6{\pm}2.5%$ after 37 hours. The cytotoxic effects of nanoniosome were significantly increased when compared with the free drug. Conclusions: This study finding suggests that silibinin nanoniosomes could serve as a new drug formulation for breast cancer therapy.

• Journal of Electrochemical Science and Technology
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• 제6권4호
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• pp.121-130
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• 2015

The micro emulsion method has been successfully used for preparing perovskite LaCoO₃ with uniform, fine-shaped nanoparticles showing high activity as electro catalysts in oxygen reduction reactions (ORRs). They are, therefore, promising candidates for the air-cathode in metal-air rechargeable batteries. Since the activity of a catalyst is highly dependent on its specific surface area, nanoparticles of the perovskite catalyst are desirable for catalyzing both oxygen reduction and evolution reactions. Herein, LaCoO₃ powder was also prepared by sol-gel method for comparison, with a broad particle distribution and high agglomeration. The electro catalytic properties of LaCoO₃ and LaCoO₃-carbon Super P mixture layers toward the ORR were studied comparatively using the rotating disk electrode technique in 0.1 M KOH electrolyte to elucidate the effect of carbon Super P. Koutecky-Levich theory was applied to acquire the overall electron transfer number (n) during the ORR, calculated to be ~3.74 for the LaCoO₃-Super P mixture, quite close to the theoretical value (4.0), and ~2.7 for carbon-free LaCoO₃. A synergistic effect toward the ORR is observed when carbon is present in the LaCoO₃ layer. Carbon is assumed to be more than an additive, enhancing the electronic conductivity of the oxide catalyst. It is suggested that ORRs, catalyzed by the LaCoO₃-Super P mixture, are dominated by a 2+2-electron transfer pathway to form the final, hydroxyl ion product.

• 한국세라믹학회지
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• 제34권2호
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• pp.188-194
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• 1997

TMCS(Trimethylchlorosilane)로 표면개질한 습윤겔을 에탄올에 재분산시켜 코팅용 재분산 실리카 졸을 제조하였고 제조된 졸을 실리콘 기판에 스핀 코팅한 후 상압 하에서 건조(8$0^{\circ}C$) 및 열처리(>25$0^{\circ}C$)하여 열처리온도에 따른 박막의 물성 변화를 관찰하였다. 습윤겔의 재분산시 안정한 재분산 실리카 졸의 제조를 위한 최적 재분산 조건을 습윤겔:에탄올=1g110$m\ell$로 하였고, 이렇게 제조된 재분산 실리카 졸의 농도와 점도는 각각 0.11 M, 2.0-2.2cP였으며 평균 졸 입자크기는 약 30nm정도였다. 1500rpm, 10회 스핀 코팅한 후 8$0^{\circ}C$에서 2시간 건조, 45$0^{\circ}C$에서 2시간 열처리에 의하여 굴절율이 약 1.14, 두께가 400nm정도인 균열이 없는 박막을 얻을 수 있었다.

• 대한의생명과학회지
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• 제10권4호
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• pp.515-521
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• 2004

To measure regional cerebral blood volume (rCBV) with perfusion MR imaging of cerebral fat embolism by neutral fat and free fatty acids in cats. Triolein (group 1, n=15), oleic acid (group 2, n=9) and linoleic acid (group 3, n=11) were infused into unilateral internal carotid artery using microcatheter through the transfemoral approach. PVA particle was used as a non-fat embolic material in a control group (group 4, n=9). Perfusion-weighted MR image was obtained at 30 minutes and 2 hours postembolization, based on T2-and diffusion-weighted images. The data of lesion and contralateral normal area were transferred to personal computer, time-to-signal intensity curve was drawn and trans for used to △R2/sup */ curve in regular order. The process in the personal computer was done by using the author's developmental image processing program and interactive data language (IDL) softwares. Statistical significance was approved by paired t-test and ANOVA. rCBV of the lesion was decreased comparing to the normal area in all groups. The ratios of rCBV were as follows (group No, at 30 minutes, at 2 hours); group 1,32％, 51％; group 2, 30％, 44％; group 3, 39％, 61％; group 4, 21％, 36％. rCBVs of 2 hours was significantly increased compared to those of 30 minutes in all groups (P<0.005). rCBV was decreased at 30 minutes in cerebral fat embolism and recovered a little, but significantly at 2 hours. Perfusion-weighted images was useful method in offering hemodynamic information in cerebral fat embolism.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.17-18
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• 2007

Solid oxide fuel cells are clean, pollution-free technology for the electrochemical generation of electricity at high efficiency. Specially, the polarization resistance between electrolyte and electrode of SOFC unit cell is of importance, because it is desirable to develop SOFC operating at intermediate temperature below $800^{\circ}C$. The LSCF cathode prepared using modified oxalate method was investigated with different electrolyte. A precursor was prepared with oxalic acid, ethanol and $NH_4OH$ solution. The LSCF precursor was prepared at $80^{\circ}C$, and pH control was 2, 6, 8, 9 and 10. The precursor powder was calcined at $800^{\circ}C$, $1000^{\circ}C$ and $1200^{\circ}C$ for 4hrs. The crystal of LSCF powders show single phase at pH 2, 6, 8 and 9, and the average particle size was about $3{\mu}m$. The LSCF cathode with heat treatment at $1200^{\circ}C$ showed a plot of electric conductivity versus temperature. Unit cell prepared from the LSCF cathode, buffer layer between cathode and electrolyte and the LSGM, YSZ, ScSZ and CeSZ electrolyte. Also interface reaction between LSCF, buffer layer and electrolyte were measured by EPMA and the polarization resistance for unit cell with cycle measure using a Solatron 1260 analyzer.

• 한국세라믹학회지
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• 제13권1호
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• pp.35-44
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• 1976

The effect of quartz which exists in clays, especially in kaolin used for the production of chamotte sagger, on the strength of refractory was examined. In this study, a mixture of chamotte 50%, kaolin 25%, plastic clay 25% in ternary component system was selected as a batch composition. To this mixture 1%, 3% and 5% of feldspar and sericite were added respectively. The plastic clay used here was separated under 170 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. In order to change the particle size and the content of quartz, the kaolin was separated under 60, 115, 170 and 325 mesh by wet process, substituted quartz for coarse parts of it. Chamotte was classified into three grades, coarse (5-10mesh): medium (10-20mesh): fine(20-115mesh) and the ratio was 1:1:1. Samples were formed in 0.8xIx10cm size with 12.5% water at 160kg/$\textrm{cm}^2$ pressure, and fired at 130$0^{\circ}C$ for 1 hr. The fired samples were ivnestigated by means of x-ray diffraction analysis and microscopic observation, and the physical properties of them were also examined, such as firing shrinkage, apparent specific gravity and bulk specific gravity, apparent porosity, water absorption and modulus of rupture. The obtained results are as follows: 1. When screened kaolin with low content of quartz was added to fixed chamotte-plastic clay system, the sample lowered modulus of rupture and increased apparent porosity as the size of kaolin became finer. 2. When kaolin under 325 mesh with 7.2-15.81% quartz between 60-325 mesh was added to fixed chamotte-plastic clay system, the sample had higher apparent porosity and lower modulus of ruputure as the size and the amount of quartz became larger. 3. The addition of feldspar and sericite to chamotte-plastic clay system improved apparent porosity and modulus of rupture. The effect of feldspar was better when quartz content was low, although that of sericite was better than quartz content was high.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.238-243
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• 2014

합성된 스테인레스 스틸에 대한 NATM(New Austria Tunnel Method) 수지의 기계적 특성은 SEM, FT-IR, 인장특성, 그리고 [NCO]/[OH]의 mole %, 입도분석에 의해 측정하였다. 친환경적인 NATM에 관한 관심이 고조됨에 따라 스테인레스 등의 금속에 코팅하는 무용제 도료를 합성하였다. 폴리올, IPDI, 충진제, 실리콘 계면활성제, 촉매 등이 함유된 기존 NATM수지보다 폴리올, MDI, 충진제, 실리콘 계면활성제, 촉매, 가교제가 함유되어 합성된 NATM 수지의 도료가 내구력과 강도가 양호하였다. 견고한 NATM 수지의 기계적 특성은 가교와 [NCO]/[OH]의 mole%가 증가함에 따라 강도가 증가하였다. 결론적으로 NATM의 가교된 미세조직는 스테인레스 스틸 같은 금속물질 코팅에 좋은 물질이다.

• 한국재료학회지
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• 제28권1호
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• pp.6-11
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• 2018

There are various manufacturing processes for pure $SiO_2$ that is used as abrasives, chemicals, filters, and glasses, and in metallurgy and optical industries. In the optical fiber industry, to produce $SiO_2$ preform, $SiCl_4$ is utilized as a raw material. However, the combustion reaction of $SiCl_4$ has caused critical environmental issues, such as ozone deficiency by chlorine compounds, the greenhouse effect by carbon dioxide and corrosive gas such as hydrochloric acid. Thus, finding an alternative source that does not have those environmental issues is important for the future. Octamethylcyclotetrasiloxane (OMCTS or D4) as a chlorine free source is recently promising candidate for the $SiO_2$ preform formation. In this study, we first conducted a vaporizer design to vaporize the OMCTS. The vaporizer for the OMCTS vaporization was produced on the basis of the results of the vaporizer design. The size of the primary particle of the $SiO_2$ formed by OMCTS was less than 100 nm. X-ray diffraction patterns of the $SiO_2$ indicated an amorphous phase. Fourier-transform infrared spectroscopy analysis revealed the Si-O-Si bond without the -OH group.

• 멤브레인
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• 제24권1호
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• pp.20-30
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• 2014

C/N 비가 낮은 농촌마을 하수의 고도처리를 위하여 $0.4{\mu}m$의 세공크기를 갖고 있는 평막이 침지된 연속회분식 반응기를 사용하였다. 분말활성탄의 투입, 폭기량 및 유입 유기물 농도가 처리효율과 여과 성능에 미치는 영향을 조사하였다. 54일 이내의 조업 초기에서는 C/N 비가 증가할수록 COD, T-N 및 T-P의 제거율과 MLSS 농도는 증가하였다. 조업 89일 후의 COD, T-N 및 T-P의 제거율은 각각 97.1%, 75.0% 및 48.3%이었다. 막여과에 의해 처리수에서 SS는 검출되지 않았으며, T-P의 제거율이 낮게 나온 이유는 과잉의 슬러지를 배출하지 않았기 때문이다. 분말활성탄을 투여한 경우 조업이 진행됨에 따라 분말활성탄의 혼합강도와 충돌빈도가 증가하여 슬러지의 입자크기가 감소하였으며, 이로 인해 분말활성탄을 투여하지 않은 경우에 비해 TMP 상승이 크게 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권8호
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• pp.1165-1169
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• 2002

Palm kernel cake (PKC), a by-product of oil palm seeds after extraction of their oil. The aim of this study was to investigate the effects of different levels of PKC on growth performance and blood lipids in rats. A total of 64 Sprague-Dawley (8 weeks of age) male rats were assigned individually to four treatments with different levels of PKC in the diet: 0, 15, 20 and 25%. No differences (p<0.05) were found in daily feed intake (6-8 g/day), body weight, growth rate and epididymal fat weight for all the dietary groups. Plasma protein and very low density lipoprotein (VLDL) triacylglycerol (TG) were higher (p<0.05) for 20% PKC fed rats than the control rats. Conversely, the plasma cholesterol and TG and VLDL-phospholipid (PL) concentrations of the control rats were higher (p<0.05) than those of PKC fed rats. The VLDL-protein, total cholesterol, free cholesterol (FC) and cholesteryl ester (CE) were not significantly different (p>0.05) among the treatment groups. Rats fed PKC had greater (p<0.05) ratios of total surface to core lipid components [(FC+PL)/(CE+TG)] than control rats. The results reflect dissimilarities of VLDL particle size between PKC treatment and control rats, where the plasma of the PKC treated rats contained more lipid rich VLDL. In conclusion, there was no adverse effect on growth performance when inclusion of PKC up to 25%. However, fibre content may affect the plasma lipid concentrations.