Solubility of TiO2 in NaF‑CaF2‑BaF2 Melts

Jeong‑Hyun Yoo,Sung‑Wook Cho 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

The solubility of TiO2in NaF-CaF2-BaF2 ternary eutectic melts was investigated at the temperature range of 1025–1150 °C. The least-squares equation was obtained from the relationship between the reciprocal temperature and the natural logarithm ofthe titanium concentration in the melts saturated with TiO2. The corresponding partial molar enthalpy of dissolution of TiO2was found to be 188 kJ/mol. The titanium saturation concentration was 3.73 wt% at 1100 °C. From the titanium concentrationchange with the added amount of TiO2at different holding time after a final stirring, it was found that not only completedissolution of TiO2but also enough sedimentation of excessive TiO2should be guaranteed to obtain more reliable solubilitydata. The holding time of 10 h was found to be enough for the excessive TiO2particles to settle down in our experimentalconditions. It is noteworthy that in case of adding TiO2in excess of its solubility, the Ba1.12(Ti8O16) phase was observed atthe lower and bottom of the solidified salt ingots.

麻黃의 사람 비점막 섬유아세포 monocyte chemotactic protein 중 MCP - 1 , MCP - 2 , 및 MCP - 3 분비에 대한 효과

김현미,이향숙,김정선,조정제,유영천,안현종,최훈,임강현 대한본초학회 2002 大韓本草學會誌 Vol.17 No.1

Recent reports have proposed that Ephedrae Herba may modulate the immune response on allergy or asthma. Human nasal mucosal fibroblasts are a rich source cytokines, inflammatory mediators, and chemokines. Chemokines are important for the recruitment of leukocytes to sites of infection, which is essential in host defense. Objectives : The objective of this study was to investigate the effect of Ephedrae Herba on the release of the chemokines such as monocyte chemotactic protein(MCP)-1, MCP-2, and MCP-3 in human nasal mucosal fibroblasts after stimulation with cytokines like tumor necrosis factor -α(TNF-α), interferon-γ(IFN-γ), and interleukin -1β(IL-1β).

갓김치 ether 추출물의 발효 과정상의 생리 기능성 변화

유은정,임현수,최명락,송상호 여수대학교 1999 論文集 Vol.14 No.2

일반 김치의 경우 17±1℃에서 2일 사이에 pH가 4.0에 이르는 것에 비해 갓김치의 경우 18℃에서 저장한 경우에 14일 경에 pH가 4.0(Fig.1)에 이르러 일반 김치 보다 저장성이 3~5배 높은 것으로 나타났으며 총균수에서도 비슷한 양상을 나타내었다. 또한 간암세포에 대한 항암성에서 IC30의 농도가 발효기간별 시료 모두 1000㎍이상으로 나타났으며 발효 0일째 시료가 1000㎍에서 50%의 간암세포 사멸성을 나타내서 가장 항암효과가 우수한 것으로 나타났고, 간정상세포에 대해서는 1000㎍ 이상에서도 28% 이하의 사멸성을 나타내서 정상세포에 대해 큰 영향을 미치지 않는 것으로 나타났다. 또한 항산화 효과에 있어서는 초기(0~2일) 발효시 수소공여능이 53%로 나타나서 다른 식품 추출물의 항산화 효과에 비해서는 비교적 높은 효과를 나타내었다. 그러나 발효 14일에는 15%로 감소되어서, ethyl ether에 의해 추출되어 항산화 효과를 나타내었던 물질들이 발효가 진행됨에 따라 감소된 것으로 사료되었다. The anticancer and antioxidative effects of Mustard Leaf Kimch ether extracts according to various fermentation period were investigated. pH of the Mustard Leaf Kimchi was reached at 4.0 on 14th day, so the period reaching well-fermentating state was up to 3~5 times longer than that of ordinary Kimchi. The anticancer effect on HepG2 by the addition of fermented Mustard Leaf Kimchi ether extracts was higher than that on CCL-13. IC30 of Mustard Leaf Kimchi in HepG2 was showed more than 1000㎍.Especially, 50% of death ratio was showed in HepG2 cells by the addition of ether extracts(0 day). the other side. 28% of death ratio was shown in CCL-13 up to 1000㎍ of ether extracts. As well as the Mustard Leaf Kimchi ether extracts(0-2 days) showed higher antioxidative effect than of others. The hydrogen donor activity was 53% at initial fermentation period, but it was decreased at 14% on 14th day. So, ether soluble antioxidative materials in Mustard Leaf Kimchi was decreased during fermentation.

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

임플란트의 collar design이 변연골과 연조직에 미치는 영향

유현상,강선녀,정창모,윤미정,허중보,전영찬 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

연구 목적: 임플란트 경부가 잘 설계된 경우 양호한 연조직 반응을 통해 변연골을 보존하는데 도움이 된다. 본 실험에서는 연, 경조직 경계부에 가장 가까이 위치하는 임플란트의 collar design이 변연골 변화와 연조직 반응에 미치는 영향을 동물실험을 통해 알아보고자 하였다. 연구 재료 및 방법: 2마리의 건강한 Beagle dog에 임플란트 collar design만 다른 두 종류의 임플란트(Neobiotech Co. Seoul, Korea)를 식립하였다. Collar에 bevel 을 부여한 군(Bevel 군)과 "S"자 형태를 부여한 군(Bioseal 군)으로 나누어 마리 당 7개, 군당 7개, 총 14개의 임플란트를 무작위로 식립한 후 Healing abutment를 즉시 체결하였다. 디지털 표준구내 방사선사진을 이용해 4주 간격으로 총 12주간 근원심 변연골 변화를 관찰하였고, 12주에 희생하여 조직학적 분석을 통해 협설 변연골 흡수 및 임플란트 주변 연조직 반응을 평가하였다. Mann-Whitney test를 통해 동일한 방사선 사진 촬영 시점에서 근원심 변연골 변화량 및 조직계측치를 군 간 비교하였고, Kruskal-Wallis test를 통해 방사선 사진상 근원심 변연골 변화량이 시간에 따른 차이가 있는지 군 내 분석 한 후 Duncan test를 통해 사후 검증하였다(α=.05). 결과: 방사선학적 분석 결과 각 촬영 시점에서 두 군간 근원심 변연골 변화량의 차이를 보이지 않았다(P>.05). 군 내에서 시간에 따른 근원심 변연골의 흡수량을 분석한 결과 Bevel 군에서는 시간에 따른 차이를 보이지 않았으나 (P>.05), Bioseal 군에서는 시간에 따른 차이를 보였으며, 4주및8주와 비교했을 때 12주에서 변연골의 증가를 보였다(P<.05). 조직학적 분석 결과 협설측 변연골 흡수량에서 두 군간 차이를 보이지 않았으나 (P>.05), Bevel 군에 비해 Bioseal 군에서 더 견고한 결합조직부착을 관찰할 수 있었으며, 생물학적 폭경의 값은 두 집단 간 차이를 보이지 않은 반면에 (P>.05), 접합상피부착은 Bevel 군에서 유의하게 길었고, 결합조직부착은 Bioseal 군에서 더 길게 나타났다(P<.05). 결론: Bevel 군에 비해 Bioseal 군에서 결합조직부착은 길게 형성된 반면에 접합상피부착은 더 짧게 나타났으며, 생물학적 폭경과 초기 변연골 흡수에는 차이가 없음을 알 수 있었다. 연조직 반응의 차이가 실제 기능하중 하에서 변연골 변화에 미치는 영향에 대해서 향후 연구가 필요할 것으로 생각된다. PURPOSE. The purpose of this study was to investigate the effects of implant collar design on marginal bone change and soft tissue response by an animal test. MATERIALS AND METHODS. Two types of Implant (Neobiotech Co. Seoul, Korea) that only differs in collar design were planted on two healthy Beagle dogs. The implants were divided into two groups, the first group with a beveled collar (Bevel Group) and the second group with "S" shaped collar (Bioseal group). Standardized intraoral radiographs were used to investigate the mesio-distal change of the marginal bone. Histological analysis was done to evaluate the bucco-lingual marginal bone resorption and the soft tissue response adjacent to the implant. Mann-Whitney test was done to compare the mesio-distal marginal bone change at equivalent time for taking the radiographs and the tissue measurements between the groups. RESULTS. Radiographic and histological analysis showed that there was no difference in marginal bone change between the two groups (P>.05). Histological analysis showed Bioseal group had more rigid connective tissue attachment than the Bevel group. There was no difference in biological width (P>.05). Bevel group showed significantly longer junctional epithelium attachment and Bioseal group showed longer connective tissue attachment (P<.05). CONCLUSION. For three months there were no differences in marginal bone change between the Bevel group and the Bioseal group. As for the soft tissue adjacent to the implant, Bioseal group showed longer connective tissue attachment while showing shorter junctional epithelium attachment. There were no differences in biologic width.

사람 비만세포주에서 Clozapine과 Fluoxetine에 의한 케모카인 및 케모카인 수용체의 상이한 발현

유영민,김종우,조정제,임강현 대한생물치료정신의학회 2001 생물치료정신의학 Vol.7 No.2

Objectives : It has been suggested that the immune system has a role in the pathophsiology of neuropsychiatric diseases. There are some reports that clozapine and fluoxetine affect on cytokine networks. Recently, it has been known that chemokines have chemotactic effect, and modulate a number of biological responses including the process of inflammation and the maintenance of CNS homeostasis. In the present study, we investigated the effect of clozapine or fluoxetine on the expression of chemokines and their receptors. Methods : Human mast cells(HMC-1) was incubated with phorbol myristate acetate(PMA, 100ng/㎖) and calcium ionophore A23187(350ng/㎖) for 3 hours. Colzapine(10^-7M) or fluoxetine(10^-7M) were pretreated for 1 hour. RT-PCR was performed for the detection of expression of various chemokines and chemokine receptors. Results : after treatment of clozapine, the expression of MCP-1, MIP-1β, CCR3,CXCR2, CXCR3 and CXCR4 were lower than the PMA/Ca ionophore-treated group, while the expression of MIP-1α, RANTES and IL-8 were not changed. However, fluoxetine was not affected the changes of expression of various chemokines and chemokine receptors. Conclusion : This result indicates that clozapine may affect on the expression of chemokines and chemokine receptors. Therefore, this study could, in part, provide the important basic data on the explanation of side effects of clozapine, such as fever and pancreatitis.

아동의 창의성 신장을 위한 동화 활용 음악 학습 프로그램 개발

유현정,김경자 이화여자대학교 사범대학 교육과학연구소 2001 교육과학연구 Vol.32 No.2

본 연구는 초등 음악과 영역에서 아동의 창의성 신장을 위한 동화 활용 음악 학습 프로그램을 개발하고, 이를 학교 현장에서 적용할 수 있도록 하는 데 그 목적이 있다. 21세기의 세계화, 정보화, 다변화의 시대에 부응하는 초등학교 음악교육은 인간의 정서에 작용할 뿐 아니라, 아동의 창의성을 신장시킬 수 있는 음악적 경험을 제공해야 한다. 이에 친숙한 동화의 이야기 자료를 재구성하고, 그것을 음악으로 표현할 수 있는 프로그램을 개발하여 현장에서의 실제 활용에 도움을 주고자 하였다. Tyler의 교육과정 개발 모형에 기초하여 개발한 본 프로그램은 S초등학교 3학년을 대상으로 실시되었고, 프로그램을 개선하고 타당화하기 위해 창의성 검사, 음악적성 검사를 프로그램 실시 이전과 이후에 평가하였다. 프로그램의 실시 결과, 아동들의 창의성과 음악성은 통계적으로 유의미한 차이(p<.01)을 보이며 향상되었고, 아동들의 음악에 대한 전반적인 인식과 태도에 긍정적인 변화를 가져왔음이 입증되었다. 이는 본 연구에서 개발한 프로그램이 아동의 창의성을 신장시키고, 음악적 창의성의 기초가 되는 음악성과 음악적 흥미 및 정서를 풍부하게 하는데 효과적임을 보여주는 것이다. The purpose of this study was to develop a music education program which integrated the children's literature of fairy tales to enhance creativity in elementary school students. The 7th national music education curriculum emphasizes musical experiences to develop creativity in students and to enrich student's emotion. In doing so, a music education program which integrated fairy tales which most children are familiar to and interested in was developed. The program was developed following Tyler's model of curriculum development. It was implemented with 41 3rd grade students in S elementary School, Incheon for 7 weeks. The validation of the program was carried out using 'Creativity Test' & 'Musical Talent Test'. To measure students' interest and their classroom participation, teachers' participant observation and students' self-evaluation were made. And the results were compared with those of the control group. The results of the study are in the following: First, statistical differences(p<.01) between the experimental group and the control group were found in creativity and musical ability in students. It means the program developed in this study is good for the development of creativity and musical ability in students. Second, the results of teacher's participant observation and student's self-evaluation shows that students' emotion and attitudes toward music changed significantly in a positive way. These results that the music education program making use of fairy tales is effective to enhance creativity and musical ability in students and to enrich student's emotion.

심부정맥혈전에서 조영증강 FISP 기법을 이용한 자기공명술의 유용성

유정현,최수승 梨花女子大學校 醫科大學 醫科學硏究所 1999 EMJ (Ewha medical journal) Vol.22 No.3

Objectives: To demonstrate a number of advantages of Gd-enhanced MR-venography with FISP techinuque in diagnosis of extremity deep vein thrombosis. Method and Materials: Gd-enhanced MR venography with FISP technique was performed in patients had deep venous thrombosis of lower limb. Findngs of MR venography was retrogradely analyzed. Results : Gd-enhanced MR-venography clearly demonstrates venous anatomy of the lower extremities in all cases. And, deep vein thrombosis was well detected with signal void filling defect. MR-venography also shows additional combined findings in deep vein thrombosis. Conclusion : Gd-enhanced MR venography well demonstrates the anatomy of lower extremities and is a useful method for detection of deep vein thrombosis.

요추추간판탈출증에 대한 현미경적 수술과 고식적 수술의 비교분석

유정현,김현철 關東大學校 醫科大學 醫科學硏究所 2004 關東醫大學術誌 Vol.8 No.1

This study was performed in an attempt to compare clinical results after microscopic and standard discectomy of lumbar disc herniation. From Jan. 1994 to Feb. 2002, 15I cases of lumbar disc herniation was operated by either method. Average age was 42.1years. There were 104cases in microscopic discetomy group and 47cases in standard discectomy group. Mean follow-up duration were 7yrs and 6ms. Clinical results by the criteria of Macnab and back pain functional scale, the change of lower back pain score and recovery rate were compared between microscopic and standard discectomy group retrospectively. Statistical analysis was made using paired two-tailed t-test. By criteria of Macnab and back pain fuctional improvement score. there was no significant difference between standard and microscopic surgery group(p>0.05) at 6 years follow-up. Mean operation time in microscopic surgery group was 54mins whereas in standard surgery group was 72mins. Ambulation was begun postoperative 3.7days in microscopic surgery group, 6.1days in standard surgery group. As for the hospital stay, 6.6days in microscopic group and 11.2days in standard surgery group. Microsopic discectomy is an effective method because it has same results in clinical aspect and has much advantages such as short operation time, short hospitalization, minimal incision.

국균세포벽을 모델로 한 새로운 고정화담체의 개발

유은정,김종덕,송상호,임현수,최명락,정규화 여수대학교 1997 論文集 Vol.11 No.2

The purpose of this investigation was to develop a new carrier using chitin and glucan as the model for Aspergillus oryzae cell wall. In case of the ratio of chitin and glucan(3/1), the activity of the immobilized protease had higher than that of model(chitin/glucan=1/3) and carriers were formed gel. In case of soluble chitin and glucan treated with calcium carbonate, there were a 1.8-fold increase in activity of immobilized protease compared with untreated chitin. The scanning electron microscope image showed that a pore size of this carrier had a homogenized pore size and a smooth surface.