초등학생에서 인두배양과 항-OF 항체 보유율

정현주,김선주,김윤정,맹국영,정현주,김선주,김윤정,맹국영 대한임상병리학회 1998 대한임상병리학회지 Vol.18 No.3

Effect of Mechanical Alloying on the Microstructural Evolution of Al60Cr30Si10 Alloys Processed by Spark Plasma Sintering

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

In this study, Al, Cr and Si fine powders were alloyed by planetary ball milling to investigate their microstructural evolution,following their mechanical alloying behavior. The formation of Al(Cr) supersaturated solid solution by the Cr grainsembedded in Al-matrix, which contributed substitutional structure is discussed in relation to their structural evolution inaccordance with the distortion of a crystal lattice. The compacts of Al–Cr–Si alloys were prepared by rapid sintering withina short time by dense consolidation above the density of 99.9% as the formation of intermetallics, except in the case of thedistribution of single-phases induced by the Al-melting. The formation behavior of intermetallics was dominated by dependenceon the structures of the milled-powder and subsequent sintering temperature. To estimate the consolidated behaviorsof compacts, various approaches derived from TEM and XRD analysis were taken to obtain microstructural evidences ofthe inter-diffusion, following the presence of thermally stable intermetallics.

Rapid Consolidation of WC‑ZrSiO4 Hard Materials by Spark Plasma Sintering: Microstructure, Densification, and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9

Densely consolidated WC-based hard materials with 5–20 vol% ZrSiO4was fabricated by spark plasma sintering at 1400 ℃ ata constant heating rate of 70 ℃/min−1. To achieve mechanical alloying of WC-ZrSiO4, planetary ball milling was carried outfor 12 h, during which the brittle-brittle components (WC-ZrSiO4) became fragmented and their particles became refined. Itwas observed that certain, specific, non-isothermal sintering kinetics, such as apparent activation energy, sintering exponents,and densification strain, affected the densification behavior. The evolution of phase structure from powder to compact wasfound to be related the lattice distortion and micro-strain in the basal planes of WC. By examining the mechanical propertiesof the samples, it was that the added zircon content leads to enhanced fracture toughness (12.9 MPa m1/2) owing to thepresence of WC-ZrSiO4 in the cemented carbide. In fact, the microcrack propagation of the fracture passed through zirconfrom a transgranular to a ductile component (fcc) where the crack tips could be absorbed.

Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processedby the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ballmilling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states suchas a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine thestructural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated withthe Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures;the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coatingprocess is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). TheTiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understandingthe evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hardcoating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that correspondsto an increase in the silicon nitride contents.

상부소환관협착에 대한 Savary-Gilliard Dilatation의 치료효과와 안전성에 관한 관찰

정현용,육은주,임의혁,김병호,성자원,이기천,허승식,이헌영,김영건 충남대학교 의과대학 지역사회의학연구소 1992 충남의대잡지 Vol.19 No.2

For the patient with stenosis of upper digestive tract caused by either benign or malignant process, esophageal dilatation is an important therapeutic modality. We reviewed retrospectively 39 cases treated by Savary-Gilliard dilatation for upper digestive tract stenosis, and results were follows : (1) Dysphagia was improved in 95% of the patients. (2) Eight patients(20%) sufferd perforation, five of them were managed with conservative medical measures, others were managed operatively. (3) In the cases with benign stenosis dysphagia was not noticed for 8.8 months, but with malignant stenosis dysphagia was reappeared after 2.8 months despite concomitant chemoradiotherapy. In conclusion, Savary-Gilliard dilatation was an effective measure for symptome due to upper digestive tract stenosis, but more careful attention for perforation should be necessitated. Also another therapeutic modality for treatment of malignant stenosis was inevitable.

성견 치은에서 90% Phenol을 이용한 멜라닌 색소의 제거에 관한 연구

정태술,김영준,이영규,정현주 전남대학교 치의학연구소 2001 구강과학 Vol.13 No.4

In this present study, the healing process and the recurrence of pigmentation were evaluated clinically and histologically in accordance with the extent and the range of pigmentation after phenol was applied to remove melanin pigmentation in gingiva. Six mongrel dogs were used. The melanin pigmentation in canine gingiva were classified into slight, moderate, and severe according to the extent of pigmentation and divided into local and diffuse types according to the range. Following general and local anesthesia, 90% phenol was applied to the pigmented gingiva of the subjects with small cotton balls until the surface was etched to be whitish and was neutralized with small cotton balls soaked by 95% alcohol. The contralateral pigmented gingiva to the one treated with phenol, was treated by surgical deepithelialization. At1, 3, and 8 weeks, the treated gingiva was examined clinically and evaluated histologically following H-E stain, and HMB 45 stain for melanocyte after biopsy. In the phenol treated sites, epithelium and connective tissue healed normally and there was no pigmentation at 1 week. At 3 weeks of healing, melanin repigmentation was observed in the severe local type and moderate to severe diffuse type. In the surgically deepithelialized sites, healing was delayed, compared to phenol treated sites and the infiltration of the inflammatory cells and congestion in connective tissue was shown at 1 week. At 3 weeks, healing was completed and there was a partial melanin repigmentation. At 8 weeks of healing, the extent and the range of repigmentation were increased in both group according to the extent or range priot to depigmentation procedure. These results suggest that the removal of melanin pigmentation with 90% phenol application result in normal healing process of gingiva. However, in the severe local type and moderate to severe diffuse type, sites treated with phenol showed repigmentation at 3 week, which was earlier than surgical deepithelialized sites. Therefore it is required to select appropriate method according to initial condition of pigmentation.

Alendronate가 백서에서 두개골 결손의 재생에 미치는 영향

정찬두,김정근,정현주 전남대학교 치의학연구소 2001 구강과학 Vol.13 No.4

Previous studies have demonstrated an increase in bone mass and density with the use of bisphosphonate in osteoporosis. This agent acts as an inhibitor of osteoclastic activity, and results in increase of net osteoblastic activity. Currently, it has been reported that bisphosphonate has direct effect on osteoblast. This study was designed to evaluate the effect of alendronate on bone regeneration in defect of rat calvaria. The animals used for these experiments were 48 male rats, over 6-8 weeks old. They were divided into three groups according to the dose of alendronate(MK-217®, Merck, USA) administered. After the calvarial defects were surgically created, the rats received a peritoneal alendronate (0.25mg/kg) in group I, a peritoneal alendronate (1.25mg/kg) in group Ⅱ, and a peritoneal normal saline injection in the control group. Three and six weeks later, blood was sampled and evaluated for alkaline phosphatase activity. the animals were sacrificed for histological observation and histometric analysis of the level of bone formation. The alkaline phosphatase activity was similar in three groups at 3 weeks of experiment. The activity at 6 weeks increased more than twice, compared to 3 weeks, and was slightly higher in group Ⅰ than the other two groups. In histological observation, all the groups at 3 weeks, osteoblast rimming and new bone formation were observed along the defect margin. At 6 weeks, the defect was almost closed with new and more mature bone, but new bone is thinner than original bone in the central portion of defect. In histometric analysis, group Ⅰ and Ⅱ at 3 weeks showed significantly greater new bone formation than the control, and all the groups at 6 weeks showed similar amount of bone formation. These result suggest that alendronate administration in the dose of 0.25mg/kg and 1.25mg/kg promote osseous regeneration.

백서 대뇌피질절편에서 산소 및 포도당 결핍에 의한 [³H]Acetylcholine의 유리에 관한 연구

이정주,김기원,서만욱,김영현,김기원 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

방사선 치료를 받는 암 환자들의 사회적 지지와 삶의 질과의 관계

정주희,류소연,윤혜은,남택근,오윤경,안현옥,박계남,이영선 朝鮮大學校 附設 醫學硏究所 2002 The Medical Journal of Chosun University Vol.27 No.2

Objective : This study was performed to investigate the relationship between social support and quality of life among cancer patients receiving radiation therapy. Matehals and Methods : The data were collected from 98 patients, who were receiving radiation therapy at two university hospitals located in GwangUJu, used by structured questionnaire. For statistical analyses of the association between quality of life and various characteristics, data were analyzed using t-test, ANOVA, Pearson 's correlation, and multiple regression analysis. Results: 1. There were 56(57.1%) males and 42(42.9%) females. Age ranged from 21 to 82 years. The primary sites of cancer were gastrointestinal tract (24.5%), lung (23.5%), breast (21.4%), and head and neck (11.2%) in order. 2. The mean scores of social, family, and medical support were 4.30 0.58, 4.49 0.78, 4.11 0.65, respectively. The score of quality of life was 5.83 1.63 (range: 1.95 ~ 9.05). 3. An analysis of the association between several factors of patients and quality of life showed that the statistically significant factors were age, the presence of distant metastasis, family support, medical support and social support. 4. As a result of the multiple regression analysis, only social support was significant (β=0.932, P=0.02) with quality of life, but age and presence of distant metastasis were not significant. Conclusion : This suggests that quality of life in cancer patients could be improved by strengthening the social support which consists of family and medical support. Further study would be necessary to evaluate separately several aspects of quality of life among cancer patients.

2단계 醱酵에 의한 人蔘食醋와 市販食醋의 品質比較

鄭宰顯,趙載敏,崔元碩,曺柱鉉 충주대 2003 産業科學論文集 Vol.11 No.-

본 연구는 인삼의 약리성분과 식초의 기능성을 갖는 인삼식초를 제조하기 위하여 시판 식초와 2단계 발효를 거친 인삼식초와의 품질 을 비교 평가하여 다음과 같은 결과를 얻었다. 가. 인삼식초의 산도는 시판식초보다 약간 낮았으며, pH는 3.7정도로 시판식초보다 약간 높았다. 나. 인삼식초 중에는 fructose, maltose, sucrose, glucose등의 유리당이 존재하였으며 시판중인 식초에는 fructose의 양이 많이 함유되어 있었으며 기타 maltose, sucrose 등도 일부 존재하였다. 다. 인삼식초에는 acetic acid, tartaric acid, propionic acid, lactic acid, malic acid, succinic acid 등의 유기산이 함유되어 있었고 일반 시판식초에는 oxalic acid, citric acid, malic acid, acetic acid등을 함유하고 있었다. We producted the ginseng vinegar through two stages fermentation(alcohol fermentation and acetic acid fermentation). At the first stage, ginseng wine contained 17% alcohol was producted at the 11th day. And through the second stage, acetic acid fermentation ginseng vinegar of which total acidity is 5.8% were produced. In comparison with commercial vinegars for physicochemical quality, acidity of ginseng vinegar was lower than those of commercial vinegars and ph was higher than those of commercial vinegars. The major free sugar compositions in ginseng vinegar were fructose, maltose, sucrose and glucose and in commercial vinegar were fructose, sucrose and maltose. The major organic acid compositions were acetic acid, tartaric acid, propionic acid, lactic acid, malic acid and succinic acid and in commercial vinegar were oxalic acid, citric acid, malic acid and acetic acid.