• 상하수도학회지
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• 제19권1호
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• pp.16-24
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• 2005

Mathematical model was developed to verify a sequential particle removal taking place in a granular media gravity filter. Consequential multi-layer filtration cycle model was applied to verify the fraction of filter effluent particles that are filter influent particles that were never removed as well as the fraction of filter effluent particles that were detached after deposition were performed through laboratory experiments. Three sizes of marker particles were injected ahead of the filter column as a pulse in the presence of four sizes of polystyrene particles that were used as a primary source of particles in the raw suspension to investigate particle attachment alone in contrast to net removal from attachment and detachment. Microscopic counting of filter effluent particles was assumed to reflect attachment. Experimental results indicated that particle detachment is significant beginning from the early phase of filtration. For each size of fluorescent microspheres at one filter depth, fluorescent microsphere removal increased with filter runtime to a maximum due to ripening. The detached fraction of effluent particles increased with particle size and filter depth. The presence of detached particles and the increasing fraction of detached particles in deeper bed were confirmed.

• Journal of Periodontal and Implant Science
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• 제45권5호
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• pp.184-189
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• 2015

Purpose: The purpose of the present study was to evaluate the effect of root planing on the reduction of probing pocket depth and the gain of clinical attachment depending on the pattern of bone resorption (vertical versus horizontal bone loss) in the interproximal aspect of premolar teeth that showed an initial probing pocket depth of 4-6 mm. Methods: In this study, we analyzed 68 teeth (15 from the maxilla and 53 from the mandible) from 32 patients with chronic periodontitis (17 men and 15 women; mean age, 53.6 years). The probing pocket depth and clinical attachment level at all six sites around each tooth were recorded before treatment to establish a baseline value, and then three months and six months after root planing. Results: The reduction in interdental pocket depth was 1.1 mm in teeth that experienced horizontal bone loss and 0.7 mm in teeth that experienced vertical bone loss. Interdental attachment was increased by 1.0 mm in teeth with horizontal bone loss and by 0.7 mm in teeth with vertical bone loss. The reduction of probing pocket depth and the gain of clinical attachment occurred regardless of defect patterns three and six months after root planing. Conclusions: The reduction of pocket depth and gain in the clinical attachment level were significantly larger in horizontally patterned interproximal bone defects than in vertical bone defects.

• 구강회복응용과학지
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• 제29권2호
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• pp.127-140
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• 2013

Locator 어태치먼트는 임플란트 유지형 피개의치에 널리 사용하는 어태치먼트로 단일 임플란트에 연결하여 사용하는 개별유지장치이다. Locator 어태치먼트는 수직적으로 적은 공간을 필요로 하며, 유지력과 경사에 따른 나일론 선택이 가능한 특징을 가진다. 이 문헌고찰에서는 Locator 어태치먼트를 사용했을 때 초기유지력, 기능력을 재현한 상태의 유지력 변화에 관해 고찰하였다. 또한 회전자유도와 응력분포에 대해 연구한 문헌을 살펴보았으며 Locator에 관한 보철적 합병증과 유지관리를 연구한 다양한 문헌을 정리함으로써 Locator 어태치먼트의 한계와 장점에 관해 살펴볼 것이다.

• 한국산학기술학회논문지
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• 제20권1호
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• pp.354-361
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• 2019

본 연구는 성인애착, 자아분화 및 간호대학생의 임상수행능력 간의 상관관계를 파악하고 성인애착과 자아분화 정도가 간호대학생의 임상수행능력에 영향을 미치는 지를 파악하고자 시행되었다. 자료수집은 대전과 충청남도 4년제 대학교 간호학과 재학생 중 임상실습을 경험한 3학년과 4학년을 대상으로 설문조사하였다. 총 200명을 설문조사하였고 최종 169부의 설문지가 분석에 사용되었다. 수집된 자료는 SPSS Statistics 22 Windows program를 이용하여 서술적 통계, Pearson's correlation coefficient, 단계별 다중회귀분석으로 분석하였다. 본 연구결과 성인애착의 하위영역인 애착회피는 자아분화(r=-.240, p=.002), 임상수행능력(r=-.237, p=.002)과 유의한 상관관계가 있었다. 임상수행능력은 애착회피(r=-.237, p=.002)와 자아분화(r=.248, p=.001)와 유의한 상관관계를 나타내었다. 회귀분석을 시행한 결과 간호대학생의 임상수행능력에 미치는 요인은 자아분화(${\beta}=.203$, p=.008), 애착회피(${\beta}=-.188$, p=.0015) 순으로 유의한 영향을 미치는 것으로 나타났으며 모형의 설명력은 8.4%(F=8.707, p<.001)로 나타났다. 따라서 간호대학생들의 임상수행능력을 높이기 위해서는 간호대학생들의 성인애착과 자아분화수준을 파악하여 낮은 자아분화 수준을 높이고 간호대학생들의 성인애착의 하위영역인 애착회피 정도를 낮추는 교육 및 상담프로그램 개발과 적용이 필요하다고 볼 수 있다.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.145-157
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• 2000

Cytotoxic substances in dental calculus and root cementum of periodontally diseased teeth inhibit new attachment and regeneration. The purpose of scaling and root planing is to remove pathologic structures harboring these cytotoxic substances in order to create a biologically acceptable root surface. However, these procedures inevitably leave a non-biocompatible smear layer. Conventionally, the smear layer has been removed with low pH etching agents such as citric acid, phosphoric acid and tetracycline hydrochloride(TC). Lately, a supersaturated neutral pH etching solution of ethylene diamine tetraacetic acid(EDTA) has been found to be as effective as low pH etchants with respect to smear removal and to be superior in exposing root surfaceassociated collagen. The aim of the present study was to determine the effect of root surface treatment using EDTA on the initial attachment of human gingival fibroblasts. 27 human teeth, extracted due to severe periodontitis, were cut into dentin slices after root planing. The specimens were divided into TC group(treated with $50㎎/m{\ell}$ tetracycline-HCl, pH 1.52), EDTA group(treated with 17% EDTA, pH 7.4), and non-treated control group. After sterilization, 5th subcultured human gingival fibroblasts were seeded in each culture well containing a prepared root slice and incubated for 15 min., 60 min., and 4 hours in 5% $CO_2$ incubator at $37^{\circ}C$. At each incubation time, the number of attached fibroblasts were counted on the microphotographs taken at a magnification of x100. The difference of the number of attached cells between groups was statistically analyzed by the ANOVA followed by Duncan test in SPSS/PC＋programs. The results were as follows : 1. After incubation for 15 min, the attached cells were significantly more in EDTA group and TC group than non-treated control group(p<0.05), but there was no significance in the difference between EDTA group and TC group(p>0.1). 2. After incubation for 60 min and 4 hours, there was no significant difference in the number of attached cells between all groups(p>0.1). 3. In both EDTA group and TC group, there was no significant difference in the number of attached cells between different incubation(p>0.1). But in control group, the number of attached cells was significantly increased after incubation for 60 min, compared with incubation for 15 min(p<0.05). The above results suggest that root surface treatment using EDTA could enhance the initial attachment of gingival fibroblasts to root surface as effective as tetracycline-HCl.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.81-88
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• 2015

We investigated factors affecting primary cultures of Pacific abalone Haliotis discus hannai ovary-dissociated cells to identify general aspects of their early-phase culture. Ninety-seven cell populations derived from 30 individuals were cultured in different media with varying compositions of medium supplements, and initial attachment, subculture, and survival for ${\geq}10$ weeks were assessed according to medium composition and individual. We also examined the time required for subculture and the rate of cell death according to both culturing period and passage number within 10 weeks. A lack of fetal bovine serum (FBS) and hemolymph significantly inhibited the growth of cultured cells, while we detected no significant effect of medium composition on initial cell attachment. Through data reallocation, with the omission of data from cell populations cultured in FBS-free and hemolymph-free media, we showed that growth inhibition was also affected by individual differences among the abalones used. During the culture, we observed four different types of cell morphology. Moreover, considerable time was required for subculture-18.4 and 19.5 days for first and second subcultures, respectively-and cell death did not occur within 30 days or for passage 0. Our results will provide valuable information for developing universal cell culturing guidelines in abalone species and suggest the feasibility of culturing abalone ovary-dissociated cells.

• Archives of Plastic Surgery
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• 제36권6호
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• pp.784-787
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• 2009

Purpose: Reduction mammaplasty is one of the most commonly performed operations in plastic surgery. Although secondary surgery is occasionally required for minor aesthetic problems or for treatment of the complications of the primary surgery, there are no clear operative guidelines of management. We report here two cases of secondary reduction mammaplasty using differrent pedicle from the initial ones. Methods: One case of secondary reduction mammaplasty were performed using medial pedicle after central (19 years) pedicle reduction mammaplasty because of subsequent breast ptosis and asymmetry. The other case were performed using medial pedicle after superior (4 years) pedicle reduction mammaplasty with contralateral immediate breast reconstruction with TRAM flap because of subsequent breast ptosis and asymmetry. Care was taken to include sufficient width of pedicle and adequate soft tissue attachment beneath the nipple - areolar complex. Results: There was no significant complication such as nipple - areolar necrosis or fat necrosis. The results were well maintained throughout the follow - up period. Conclusion: Medial pedicle reduction mammaplasty can be safely performed after central or superior pedicle reduction mammaplasty when sufficient width of pedicle and adequate soft tissue attachment beneath the nipple - areolar complex are maintained.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.24-24
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• 2018

One of the challenges in tissue engineering is the design of optimal biomedical scaffolds, which can be governed by topographical surface characteristics, such as size, shape, and direction. Of these properties, we focus on the effects of nano - to micro - sized hierarchical surface. To fabricate the hierarchical surface structure on poly(${\varepsilon}$-caprolactone) (PCL) film, we employed a nano/micro-casting technique (NCT) and modified plasma process. The micro size topography of PCL film was controlled by sizes of the micro structures on lotus leaf. Also, the nano-size topography and hydrophilicity of PCL film were controlled by modified plasma process. After the plasma treatment, the hydrophobic property of the PCL film was significantly changed into hydrophilic property, and the nano-sized structure was well developed, as increasing the plasma exposure time and applied power. The surface properties of the modified PCL film were investigated in terms of initial cell morphology, attachment, and proliferation using osteoblast-like-cells (MG63). In particular, initial cell attachment, proliferation and osteogenic differentiation in the hierarchical structure were enhanced dramatically compared to those of the smooth surface.

• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.453-466
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• 2008

Purpose: The purpose of this research is to study about initial adhesion, proliferation and activation of osteoblast to titanium surface treated with machined, hydroxyapatite coating, resorbable blast material blasting and anodizing method. Material and Methods: After treating the titanium surface of each block with machined, impurities were removed and sterilized. The number of cells attached from cultured osteoblast of respective experimental groups were measured at 1, 4, 7, and 14day and alkaline phosphatase, calcium, and inorganic phosphate concentration of cultured solution was measured. Result: Anodizing group showed the highest rate of cell attachment and proliferation activity. RBM treated group showed the highest increasing on their alkaline phosphatase activity, on the calcium apposition, on inorganic phosphate apposition of 1 and 4 days in cultured osteoblast to compare with other groups. Conclusion: On the basis of these findings, we conclude that surface modification of titanium was profoundly effected on the attachment, proliferation and activation of osteoblast in initial stage osseointegration.

• Journal of Periodontal and Implant Science
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• 제41권2호
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• pp.67-72
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• 2011

Purpose: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. Methods: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with $\beta$-tricalcium phosphate (TCP), and pure $\beta$-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. Results: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. Conclusions: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment.