Sol-Gel방법에 의해서 성장시킨PbTiO₃박막의 결정화와 물리적 성질

구영진,강민진,정원태,김태현,김상수 昌原大學校 基礎科學硏究所 2000 基礎科學硏究所論文集 Vol.12 No.-

Ferroelectric PbTiO3 thin films coated on SiO2/Si(100) and ITO glass substrates were prepared by sol-gel processing of metal alkoxide solutions and solvents. The use of sol-gel method for preparing various functional films makes it possible for the homogeneous distribution of elements at the molecular level, precise composition control, lower temperature synthesis, large surface coating and high optical quality. First of all, the XRD investigation shows that perovskite phase of polycrystalline PbTiO3 was formed by four times coating of the concentrated solution and by the heat treatment over 500, 600℃(O2 gas and air) and over 10, 20, 30 min. Surfaces of thin films were crack-free and uniform and the average grain size investigated by SEM was 0.25∼1.00 ㎛. Dielectric constant of PbTiO3/ITO glass thin film were 380 ∼ 5.25 in the region of 1 kHz∼ 10 MHz at room temperature(30℃), respectively. From the hysteresis loop of PbTiO3/ITO glass thin film, a remnant polarization of 0.382 μC/cm2 and a coercive filed of 23.85 kV/cm were obtained. At the frequency(5 kHz), C-V measurements of films in MFIS and MFM configurations showed well-behaved C-V characteristics and an injection type hysteresis. The capacitance of flat band(CFB) was 60 pF. The band gap energies of the thin films depend on the assumption of direct or indirect transition. Using one layer structure model, we calculated refractive index, extinction coefficient, absorption coefficient and band gap energy of thin film in the wavelength range of 300 to 800 nm. The band gap energy, refractive index and extinction coefficient at λ = 6325 Å of the PbTiO3 thin film were 3.7 eV, 1.96 and 0.1 respectively.

농아에서의 측두골 전산화 단층촬영 소견과 다른검사 요인과의 연관성

조태환,이상흔,권대구,엄규상,성창섭,김용선,한기원 경북대학교 병원 1998 경북대학교병원의학연구소논문집 Vol.2 No.1

Temporal bone high resolution computed tomogram(TBHRCT)is a essential diagnostic tool in considering for cochlear implantation in patients with profound sensorineural hearing loss. This study was designed for an effort to provide and efficacy of TBHRCT in determination of inner ear malformations for the patients who have profound sensorineural hearing loss and to examine the relationships between TBHRCT findings and other preoperative evalutions for cochlear implantation in that patients. Authors examined 68 deaf patients to provide fundamental data for cochlear implantation. Inner ear abnormalities were founded in 13(19%) patients, among which 10(14.7%) patients had Mondini'dysplasia in which 5 patients were hypoplastic type and 5 patients were hydrops type. Other inner ear abnormalities were as follows : lateral semicircular canal hypoplasia ; internal auditory canal abnormality ; cochlear aqueduct widening ; vestibular aqueduct widening. No relationships were found between TBHRCT findings and other test results. : promontory test, K-WISC cognitive test etc.(Korean J Otolaryngol 39 : 8, 1996)

화농성 슬관절염이 동반된 수막구균성 수막염 1예

김태연,유진홍,박성환,김연식,임상현,신완식,강문원,정창훈,최문구,강지민 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.2

저자들은 최근 화농성 슬관절염과 병발한 수막구균성 수막염 1예를 체험하였고, 이는 국내에서 아직 보고되지 않은 드문 예로 사료되어 문헌고찰과 함께 보고하는 바이다. We recently experienced a case of meningococcal meningitis associated with pyogenic arthritis in a 37-year old male patient. Pyogenic arthritis developed in right knee joint during treatment for meningococcal meningitis. He was treated successfully by appropriate antibiotics and arthroscopic irrigation. To our knowledge, such a rare case has not ever been reported in Korea, Hence we report this case with a review of related literatures.

코일과 클립을 선택적으로 적용해서 성공적으로 치료했던 다발성뇌동맥류 1례 : A case report

이덕구,김범태,황선철,임수빈,이세영,신원한 순천향의학연구소;Soonchunhyang Medical Research Institute 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

The author report a case of multiple cerebral aneurysm successfully treated with an appropricate selection of surgical clipping and coil embolization. A 64 years old female patient was admitted with stuporous consciousness. Initial 3D CT angiography showed diffuse subrarachnoid hemorrhage on the basal cisterns, saccular aneurysms on the terminal basilar artery and right middle cerebral artery(MCA). Converntional angiography confirmed the ruptured aneurysm was basilar one. Coil embolization was perfromed on the basilar aneurysm with 6 Guglielmi detachable coils(GDC) on the 3 days after ictus. Sugical clipping was done on the unruptured right MCA aneurysm on 10 days after ictus without any morbidity. Each treatment modalities can be appropriate indicated for the coiling or clipping aneurysms.

Cao-MgO-SiO₂-P₂O -CaF₂계 생체활성 결정화 유리의 기계적 성질에 미치는 ZrO₂및 Al₂O₃의 분산 강화 효과

박찬운,강건구,원대희,이민호,배태성 대한치과기재학회 1998 대한치과재료학회지 Vol.25 No.2

Bioactive glass-ceramics can form tight chemical bonds with bone, however, their poor mechanical properties may limit their clinical applications. Alumina ceramics show good biocompatibility and high strength but can't form chemical bonds with bone. Hydroxyapatite ceramics and bioglass form chemical bonds with bone but their strength and fracture are relatively low. Glass ceramics containing apatite and wollastonite crystals can form tight chemical bonds with bone and show relatively high strength and fracture toughness. Bioactive glass-ceramics toughened by alumina and tetragonal zirconia polycrystals show relatively high mechanical strength. Both bioactive and high strength ceramics will be widely applicable to many clinical applications. In this study, bioactive glass-ceramics toughened by alumina and zirconia polycrystals were fabricated, and crystallization behavior, biaxial flexure strength, fracture toughness, and bioactivity were measured. The results obtained were summarized as follows; 1. The major crystaline phase in the matrix glass were observed to be apatite, wollastonite, and β-TCP. 2. Biaxial flexure strength and fracture toughness values were more improved by the dispersion toughening of alumina and zirconia, and the improvement of mechanical strength was more higher in the dispersion toughening of zirconia than that of alumina. 3. The bioactivity, which was evaluted from apatite formation in the simulated body fluid, was higher in the dispersion toughening of Zr-O₂than that of Al₂O₃.

A. 高校 科學 (生物·地球科學) 및 數學科 探究學習의 評價模型 定立과 評價紙 開發

李相協,權炳奎,林在圭,孫文求,吳岱燮,楊洪準,梁承榮,姜用熙,林成圭,金正遠,金吉民,兪正在 경북대학교 과학교육연구소 1982 科學敎育硏究誌 Vol.6 No.-

Currently the evaluation of high school science and mathematics learning has been too much knowledge-centered without concerning the inquiring ability or scientific attitude. This study, therefore, was made for the purpose of establishing of evaluation model for high school science (biology and earth science) and mathematics learning and its evaluation items. In this paper, the research was done about three fields, biology, earth science and mathematics. 1. For the biology, the evaluation methods of inquiry learning were studied with the foreign references, and proper evaluation items were suggested. 2. For the earth science, after analizing 5 kinds of earth science textbook of current using in high school, essential 19 items were selected. 5 of them were tested in test group and control group, then, the results were analized. 3. For the mathematice, the teaching elements of「Set」and「Flow chart」in mathematics (Ⅰ) were selected and structured. Detailed teaching objects were established and evaluation items were introduced.

전자토모그래피의 정량적 분석에서 대물렌즈 조리개의 영향

김진규,이상희,권희석,정종만,정원구,이수정,주형태,김윤중 韓國電子顯微鏡學會 2008 Applied microscopy Vol.38 No.4

Electron tomography의 정량적 분석을 위해서 대물렌즈 조리개가 투과빔의 강도에 미치는 영향을 평가하였다. Electron tomography에 도입되는 Beer’s law의 올바른 적용을 위해서는 투과빔은 시료의 기울기에 따른 mass thickness의 변화에 의한 효과만을 반영해야 한다. 그러므로 빔 경로상의 대물렌즈 조리개, 홀더 등에 의한 다른 효과는 제거되어야 한다. 본 연구에서는 대물렌즈 조리개의 cut-off 효과를 120 kV TEM과 Quantifoil holey 카본 시료를 이용하여 상세히 평가하였다. 대물렌즈 조리개를 사용하지 않은 경우와 비교할 때, 30 μm 크기의 대물렌즈 조리개를 통과한 투과전자빔의 강도는 약 16.7%의 감소가 일어난다. 또한 55˚이상의 고경사각 기울기에서는 대물렌즈 조리개의 cut-off 효과에 의해 14.2%의 강도 감소가 추가적으로 발생함을 알 수 있었다. Electron tomography에서 정량적 분석을 위해서는 이러한 대물렌즈 조리개의 영향을 고려해야만 한다. 또한 Beer’s law의 올바른 적용을 위해서는 일련의 기울기에 따른 2차원적 영상은 가능하면 대물렌즈 조리개를 사용하지 않은 상태에서 획득하는 것이 바람직하다. We have evaluated the effects of experimental factors on transmitted electron beam intensities for quantitative analysis in electron tomography. For the correct application of Beer’s law in electron tomography, the transmitted beam intensity should reflect the net effect of mass properties on beam path. So, the any other effects of the objective aperture and the specimen holder on beam path should be removed. The cut-off effects of objective aperture were examined using Quantifoil holey carbon film and a transmission electron microscope operated at 120 kV. The transmitted beam intensities with 30 μm objective aperture dropped about 16.7% compared to electron beam intensities without the objective aperture. Also, the additional losses of about 14.2% at high tilt angles were occurred by cut-off effects of the objective apertures. For the precise quantitative analysis in electron tomography, the effect of the objective aperture on transmitted electron beam intensities should be considered. It is desirable that 2-D tilt series images are obtained without the objective aperture for correct application of Bee’s law.

The effect of 5-aminoimidazole-4-carboxamide- ribonucleoside was mediated by p38 mitogen activated protein kinase signaling pathway in FRO thyroid cancer cells

( Won Gu Kim ),( Hyun Jeung Choi ),( Tae Yong Kim ),( Young Kee Shong ),( Won Bae Kim ) 대한내과학회 2014 The Korean Journal of Internal Medicine Vol.29 No.4

Background/Aims: 5′-Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that monitors intracellular AMP/adenosine triphosphate (ATP) ratios and is a key regulator of the proliferation and survival of diverse malignant cell types. In the present study, we investigated the effect of activating AMPK by 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR) in thyroid cancer cells. Methods: We used FRO thyroid cancer cells harboring the BRAFV600E mutation to examine the effect of AICAR on cell proliferation and cell survival. We also evaluated the involvement of mitogen-activated protein kinase (MAPK) pathways in this effect. Results: We found that AICAR treatment promoted AMPK activation and suppressed cell proliferation and survival by inducing p21 accumulation and activating caspase-3. AICAR significantly induced activation of p38 MAPK, and pretreatment with SB203580, a specific inhibitor of the p38 MAPK pathway, partially but significantly rescued cell survival. Furthermore, small interfering RNA targeting AMPK-α1 abolished AICAR-induced activation of p38 MAPK, p21 accumulation, and activation of caspase-3. Conclusions: Our findings demonstrate that AMPK activation using AICAR inhibited cell proliferation and survival by activating p38 MAPK and proapoptotic molecules in FRO thyroid cancer cells. These results suggest that the AMPK and p38 MAPK signaling pathways may be useful therapeutic targets to treat thyroid cancer.

ORIGINALARTICLE : Follicular and Hurthle cell carcinoma of the thyroid in iodine-sufficient area: retrospective analysis of Korean multicenter data

( Won Gu Kim ),( Tae Yong Kim ),( Tae Hyuk Kim ),( Hye Won Jang ),( Young Suk Jo ),( Young Joo Park ),( Sun Wook Kim ),( Won Bae Kim ),( Min Ho Shong ),( Do Joon Park ),( Jae Hoon Chung ),( Young Kee 대한내과학회 2014 The Korean Journal of Internal Medicine Vol.29 No.3

Background/Aims: Follicular thyroid carcinoma (FTC) and Hurthle cell carcinoma(HCC) of the thyroid are relatively uncommon thyroid malignancies in iodine-sufficient areas. In this study we evaluated the clinical behavior, prognosticfactors and treatment outcomes of FTC and HCC in Korea. Methods: This multicenter study included 483 patients with FTC and 80 patientswith HCC who underwent an initial surgery between 1995 and 2006 in one of thefour tertiary referral hospitals in Korea. We evaluated clinicopathological factorsassociated with distant metastases and recurrence during a median of 6 years offollow-up. Results: HCC patients were significantly older (49 years vs. 43 years; p < 0.001) andhad more lymphovascular invasions (22% vs. 14%; p = 0.03) compared with FTCpatients. Distant metastases were confirmed in 40 patients (8%) in the FTC groupand in two patients (3%) in the HCC group (p = 0.07). Distant metastases weresignificantly associated with older age, widely invasive cancer and extrathyroidalinvasion. Only 14 patients (3%) had recurrent disease and there was no significantdifference between FTC and HCC groups (p = 0.38). Recurrence was associatedwith larger tumor size and cervical lymph node metastasis. Conclusions: HCC patients were older and had more lymphovascular invasionsthan FTC patients. However, FTC and HCC patients had similar initial clinicopathologicalfeatures. Older age, wide invasiveness and extrathyroidal invasionwere independent risk factors for predicting distant metastases in FTC and HCCpatients.

Extracts from the Red Algae Gracilaria vermiculophylla have Antioxidant Effects in Human Bone Marrow Mesenchymal Stem Cells

Sin-Gu Jeong,Jae-Joon Lee,Ho-Tae Kim,Min-Ji Ahn,Hee-Kyoung Son,Jun Sik Lee,Won Keun Oh,Tae Oh Cho,Goang-Won Cho 조선대학교 기초과학연구원 2018 조선자연과학논문집 Vol.11 No.2