http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Calcium phosphate 결정 성장 최적화를 위한 Ti 표면의 BaTiO_3 박막 형성에 관한 연구
조진우,양홍서,박영준,황규석,송종은,이용렬 전남대학교 치과대학 2001 구강과학 Vol.13 No.2
This study was purposed to establish an optimized manufacturing process for a negatively charged ferroelectric thin flim on titanium substrate in order to develop a new implant system having the mechanical strength and bone forming ability. Ferroelectric materials show an alignment of positive and negative charges by poling treatment. Based on this property, this study was performed with the assumption that the Ca^2+ ions would be easily attracted on negatively charged surface and the attracted cation might behave as nuclei for bone-like crystal grownth in biological solutions. In order to have an osteoinducibility by the ferroelectric thin film coating, continuous and flawless crystalline thin film should be formed with ferroelectricity, and finally should be adequately poling treated. In this study, BaTiO_3 (BTO) was selected as a ferroelectric material. Before thin film coating process, most favorable poling condition was investiged with the evaluation of the difference in calcium phosphate (Ca-P) formation in simulated body fluid (SBF). Moreover, the parameters to form an optimum thin film were studied. Dense bulk BTO disks were fabricate using cold isostatic pressing(CIP) and sintered in air at 1300℃ for 2 hours. Sintered BTO disk was polished, and he crystallinity, microstructure, and ferroelectric characteristics were evaluated using an X-ray diffraction analysis (XRD), a field emission scanning electron microscope (FE-SEM), and an Impedance analyzer. To find the optimum poling condition for the calcium phosphate crystal formation, sintered bulk BTO specimens were treated with either of following poling conditions; 1) room temperature poling treatment [ polarizing field (Ep) = 25kV/cm, at 25℃ for 2 hours], 2) under Tc medium-temperaturepoling treatment (Ep=20kV/cm, from 85˚C to 25˚C for 2 hour), and 3) above Tc high-temperature poling were immesed in simulated body fluid (SBF) for 30 days, and the formation of calcium phosphate (Ca-P) layer n the surface was evaluated. The crystallinity, microstructure, and ferroelectric characteristic of BTO thin film were evaluated withthe variation of final heat treatment. It was performed after establishing the starting substance-solvent mixing ratio, coating times, and pre-heating temperature optimal to form continuous and flawless BTO thin film adequate for having ferroelectricity. Perparation of BTO thin film was made by dipping-pyrolysis technique using metal naphthenates as starting substances. BTO thin films was spin-coated on Ti substrate by dipping-pyrolysis technique using sol obtained by mixing Ba-naphthenate and Ti-naphthenate as starting substances. Pre-firing temperature of BTO thin film was performed at 450℃ because organic-solvent ws completely volatilized without any crystal growth, and the final heat treatment was performed at 600, 700 or 800℃, respectively. The results are as follows; 1. BTO disk sintered at 1300℃ for 2 hours showed average grain size of about 1㎛ and the relative dielectric constant at 1㎑ was abut 3000∼3500. 2. After immersing the sintered bulk BTO poled at respective conditions in SBF for 30 days, Ca-P layers were present on the negatively charged surfaces. In contrary, positively charged Bto surface did not show any noticeable charge of the surface microstructure after SBF immersion. 3. In he case of poling condition 1 and 2 treated with below Tc, Ca/P ratio showed a relatively low value of 1,.2∼1.5. While, in the case of poling condition 3 treated with above Tc, Ca/P ratio was 1.5∼1.67, which is similar to that of biological apatite. This phenomenon demonstrates that poling the BTO above the temperature of Tc is preferable for the Ca-P formation. 4. For thin film BTO coastin, the starting substance was prepared by an equimolar mixing of the Ba and Ti-naphthenate. Dilution of the starting substance with toluene was most appropriate at sol : toluene ratio of 5.2:4.8 Too thin sol produced porosity in film, and too thick sol resulted cracks in the film. By repeating the coating and pre-firing procedure 15 times, homogeneous film of 0.5㎛ thickness could be fabricated, and perfomed well during the poling treatment without breakdown. 5. The heat-treatmen of the BTO thin film at 700℃ produced a homogeneous crystalline structure without heterogeneous TiO2 formation. The BTO thin film heat-treated at 600℃ showed non-crystallinity and no ferroelectricity. Treatment at 800℃ produced heterogeneous TiO2 phase in the film, which is unfavorabe for having ferroelectricity by the distortion of the perovskite structure. The relative dielectic constant at 1 ㎑ was 152 and 112 by heat-treatment at 700 and 800℃, respectively. In summary, these results demonstrated that poling the ferroelectric B_aT_iO_3 surface negatively is effective for the formation of Ca-P layer in simulated body fluids. Poling condition at a temperature cooling from above Tc down to room temperature is most effective. By optimizing the method of BTO thin film coating on metal substrate for the formation of Ca-P layer, the data of this study might be applied for the manufacture of new bioactive implant system.
( Jong Ryeol Eun ) 대한간학회 2015 춘·추계 학술대회 (KASL) Vol.2015 No.2
Background: SK Hep-1 cells (SK cells) derived from a patient with liver adenocarcinoma have been considered a human hepatoma cell line with mesenchymal origin characteristics, however, SK cells do not express liver genes and exhibit liver function, thus, we hypothesized whether mesenchymal cells might contribute to human liver primary cancers. Here, we characterized SK cells and its tumourigenicity. Methods and Principal Findings: We found that classical mesenchymal stem cell (MSC) markers were presented on SK cells, but endothelial marker CD31, hematopoietic markers CD34 and CD45 were negative. SK cells are capable of differentiate into adipocytes and osteoblasts as adipose-derived MSC (Ad-MSC) and bone marrow-derived MSC (BM-MSC) do. Importantly, a single SK cell exhibited a substantial tumourigenicity and metastatic capacity in immunodefficient mice. Metastasis not only occurred in circulating organs such as lung, liver, and kidneys, but also in muscle, outer abdomen, and skin. SK cells presented greater in vitro invasive capacity than those of Ad-MSC and BM-MSC. The xenograft cells from subcutaneous and metastatic tumors exhibited a similar tumourigenicity and metastatic capacity, and showed the same relatively homogenous population with MSC characteristics when compared to parental SK cells. SK cells could unlimitedly expand in vitro without losing MSC characteristics, its tumuorigenicity and metastatic capacity, indicating that SK cells are oncogenic MSC with enhanced self-renewal capacity. We believe that this is the first report that human MSC appear to be transformed into cancer stem cells (CSC), and that their derivatives also function as CSCs. Conclusion: Our findings demonstrate that SK cells represent a transformation mechanism of normal MSC into an enhanced self-renewal CSC with metastasis capacity, SK cells and their xenografts represent a same relative homogeneity of CSC with substantial metastatic capacity. Thus, it represents a novel mechanism of tumor initiation, development and metastasis by CSCs of non-epithelial and endothelia origin.
( Jong Ryeol Eun ),( Hyun Jung Chung ),( Hyo-seok Lee ),( Jung Hoon Lee ),( Jin Ho Jeong ),( Jae Hyung Park ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1
Aims: Hepatic arterial infusion chemotherapy (HAIC) is often used for the treatment of inoperable advanced hepatocellular carcinomas. Methods: We reviewed 12 HCC cases treated with HAIC from Sep 2015 to Aug 2016 retrospectively. The patients received HAIC (5-FU 750mg/m2 D1-4 and cisplatin 25mg/m2 D1-4 every 4-5 weeks). All the patients were Child-Pugh class A and ECOG 0-1 performance status. Results: Eight patients (66.7%) received HAIC as first-line therapy, and the other 4 patients received HAIC as second-line therapy because of sorafenib-refractory (n=2) or transarterial chemoembolization (TACE)-refractory state (n=2). The objective tumor response rate of HAIC was 50.0% (6/12) including 2 cases of complete response (16.7%). Stable disease was in 2 (16.7%). Four (33.3%) were progressive disease (n=2), stopped treatment after day 1 chemo therapy due to poor general condition (n=1), or died from bone marrow suppression after 1st cycle of chemotherapy (n=1). Conclusions: The tumor response of HAIC was favorable. HAIC can be considered as rescue therapy for TACE or sorafenib-refractory advanced HCCs as well as 1st line therapy.
은종렬 ( Jong Ryeol Eun ) 영남대학교 의과대학 2015 Yeungnam University Journal of Medicine Vol.32 No.1
Over several decades, a hierarchical cancer stem cell (CSC) model has been established in development of solid cancers, including hepatocellular carcinoma(HCC). In terms of this concept, HCCs originate from liver CSCs. Clinically HCCs show a wide range of manifestations from slow growth to very aggressive metastasis. One of the reasons may be that liver CSCs originate from different cells. This review describes the basic concept of CSCs and the cellular origin of liver CSCs.
Eun-Jin Lee,Sung-Gi Kim,Sang-Ryeol Yoo,Sang-Suk Oh,In-Gyun Hwang,Gi-Sung Kwon,Jong-Hyun Park 한국식품과학회 2007 Food Science and Biotechnology Vol.16 No.6
The powdered cereal sunsik is a partially thermal-processed product that required safety evaluations for food-borne pathogens. Thirty-six sunsik products from Korean markets were collected and analyzed for contamination by total viable cell counts, coliforms, Escherichia coli, and the spore-forming Clostridium perfringens and Bacillus cereus. Enterobacter sakazakii, as a newly emerging pathogen, was also analyzed. Approximately 28% of sunsik were contaminated at 5 log CFU/g for total viable counts. Coliforms and E. coli were detected in 33 and 4% of the samples, respectively. The spore-forming B. cereus was found in 42% of the samples at a maximal level of 3 log CFU/g on average. About 6% the samples were contaminated with Cl. perfringens at an average level of 15 CFU/g. Forty-five % of sunsik contained E. sakazakii, at levels from 0.007 to over 1.1 cell/g by MPN method. In addition, one sunsik product for infants and children showed over 3 log CFU/g for both B. cereus and E. sakazaki. Therefore, concern should be placed on controlling for microbial hazards such as B. cereus and E. sakazakii in sunsik, particularly for the products fed to infants under 6 months of age.
다클론성 감마글로불린병증을 동반한 C-ANCA 양성 급속진행성 사구체신염 1예
백은경,노선희,박진경,조정연,권성신,심은진,권경주,노영욱,이경종,윤정윤,김인선,김소이,류동열,성순희,홍기숙 이화여자대학교 의과학연구소 2008 EMJ (Ewha medical journal) Vol.31 No.1
저자들은 육안적 혈뇨, 체중 감소를 주소로 입원하여 특별한 원인을 찾을 수 없는 심한 빈혈과 고감마글로불린병증을 보이고 신조직 검사에서 C-ANCA 양성 급속 진행성 사구체신염으로 진단된 예를 경험하였기에 보고 하는 바이다. Rapidly progressive glomerulonephritis(RPGN) is one of the most calamitous renal disease which is clinically characterized by sudden and relentless deterioration in renal function within weeks to months and associated with the pathologic finding of extensive extracapillary proliferation. Pauci-immune RPGN is mostly associated with anti neutrophil cytoplasmic antibody (ANCA) positive systemic vasculitis, but renal-limited RPGN may be found in part. We experienced a case of ANCA positive RPGN associated with polyclonal gammopathy without systemic symptoms. A 64-year-old woman was admitted with gross hematuria and azotemia. Laboratory findings revealed polyclonal gammopathy and severe anemia without definite cause, and she was diagnosed as C-ANCA positive crescentic glomerulonephritis without systemic vasculitis. She was treated with steroid pulse therapy and her renal function and anemia were progressively improved. We report herein a rare case of C-ANCA positive crescentic glomerulonephritis associated with polyclonal gammopathy and severe anemia with the review of literature.