• Fire Science and Engineering
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• v.32 no.6
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• pp.108-116
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• 2018

A melted bead microstructure can be divided into a deformed and undeformed layer. Measurement errors occur in the presence of a deformed layer, which should be removed through grinding/polishing whilst preserving the original structure. This paper proposes a grinding/polishing process to analyze the microstructure of copper melted beads. For the removal of the deformed layer, the correlation between the abrasive type/size, the polishing time and polishing rate was analyzed and the thickness of the deformed layer was less than $1{\mu}m$. The results suggest a new grinding/polishing procedure: silicon carbide abrasive $15{\mu}m$ (SiC P1200) 2 min, and $10{\mu}m$ (SiC P2400) 1 min; and diamond abrasive $6{\mu}m$ 8 min, $3{\mu}m$ 6 min, $1{\mu}m$ 10 min, and $0.25{\mu}m$ 8 min. In addition, a method of increasing the sharpness of the microstructure by chemical polishing with $0.04{\mu}m$ colloidal silica for 3 min at the final stage is also proposed. The overall grinding/polishing time is 38 min, which is shorter than that of the conventional procedure.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.95-101
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• 2011

Present study aimed to investigate morphological change and gene expression in the gill of Cyprinus carpio after exposure against muddy water caused by riverbed disturbance with various rearing condition. The gill of C. carpio showed abnormal shapes in its secondary lamellae and a rough surface with impure debris after exposed to muddy water for 80 days. In addition, the gills showed the edema, the exfoliation of epithelial cell, and the fusion of the secondary lamellae. Using 20 ACPs, 24 differentially expressed genes (DEGs) exposed to muddy water for 80 days were identified. 17 genes among them were up-regulated, while 7 genes were down-regulated in preterm deliveries. A BLAST searches revealed that 3 genes were revealed known genes as calcium transporter 1 (TRPV6) mRNA, macha mRNA for putative puroindoline b protein, and Efnb3 protein-like. Therefore, it is considered that Efnb3 gene from gill would be a useful indicator for neurobehavioral changes in fish influenced by muddy water.

• Journal of the Korea Institute of Building Construction
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• v.22 no.4
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• pp.415-423
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• 2022

As human factors are the most important cause of construction accidents, it is important to reduce human error in construction work to reduce accidents. However, the error forcing context in organizational situations acts as a factor behind human error. Therefore, fatal construction accidents were analyzed using the m-SHEL model, which can identify the factors behind human errors. Through such analysis, it was found that there are differences in the detailed factors behind human errors according to the type of fatal accidents in construction, This study is meaningful in that it confirmed through accident cases that it is important to understand and respond to organizational situations in order to reduce human error in construction work.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.169-176
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• 1996

Tuberculous cervical lymphadenitis is still an important cause of neck mass in Korea. Tuberculosis is an important differential diagnosis in patients of cervical lymphadenopathy. Rapid and sensitive test for the diagnosis of tuberculosis is essential for the approapiate treatment. Up to now, conventional diagnostic methods for M. tuberculosis were acid-fast bacilli(AFB) stain and culture of M. tuberculosis. The direct microscopic examination of AFB by Ziehl-Neelsen stain is rapid, but often negative. The culture for M. tuberculosis is time-consuming, taking 4 to 8 weeks. Recently various methods to detect Mycobacterial DNA, including PCR and restriction fragment length polymorphism(RFLP) analysis have been reported. Here we represent a simple method for the confirmation of M. tuberculosis and exclusion of the other Mycobacterial species by RFLP analysis and silver staining of polyacrylamide gel electrophoresis after nested PCR for a repetitive DNA sequence(IS986) specific for M. tuberculosis from fresh or paraffin-embedded biopsy specimens. This result leads us to conclude that this method is simple, rapid and possibly applicable to confirm M. tuberculosis and rule out the other Mycobacteria species from the clinical specimens in the clinical laboratories.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.1
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• pp.87-98
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• 1998

This study was undertaken to determine whether Bombycis Corpus extract (Bom) has antioxidant action. Kidney tissues were exposed to t-butylhydroperoxide (t-BHP) to induce oxidative stress. Lipid peroxidation was estimated by measuring malondialdehyde, a product of lipid peroxidation, and cell injury was estimated by measuring lactate dehydrogenase (LDH) release in rabbit renal cortical slices. t-BHP increased lipid peroxidation and LDH release in a dose-dependent manner over the concentration range of 0.1-1 mM. Such effects of t-BHP on lipid peroxidase and LDH release were prevented by 0.5% Bom. When tissues were treated with t-BHP in the presence of various concentrations of Bom, lipid peroxidation and LDH release were dose-dependently inhibited by Bom. Bom at 1 and 2% concentrations inhibited lipid peroxidation and LDH release in normal tissues. Bom at 2% concentration increased glutathione peroxidase activity in tissues treated or untreated with 1.0 mM t-BHP. However, catalase activity was not altered by addition of Bom. Bom inhibited generation of reactive oxygen species. These results indicate that Bom inhibits lipid peroxidation and cell injury in tissues treated with or without oxidant and this effect is, at least in part, attributed to increased activity of glutathione peroxidase and a direct sacvenging action.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.75-81
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• 2016

The recent radiation therapy field can provide treatment which guarantees a high degree of accuracy, due to patient set-up using various image guided radiation therapy(IGRT) instruments. But the additional absorbed dose to patient's normal tissues is increasing. Therefore, this study measured the absorbed dose to surrounding normal tissues which is caused by patient set-up using OBI, CBCT, ExacTrac, among various IGRT instruments. The absorbed dose to the head, the chest, the abdomen, and the pelvis from CBCT was 12.57 mGy, 20.82 mGy, 82.93 mGy, and 52.70 mGy, respectively. Also, the absorbed dose from OBI and ExacTrac ranged from 0.76 to 8.58 mGy and from 0.14 to 0.63 mGy, respectively. As a result, CBCT's absorbed dose was far higher than other instruments. CBCT's surface dose was far higher than others, too, but OBI's entrance skin dose was almost the same as CBCT's.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.192-196
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• 2004

In order to measure cellular physiological activity including ion channel activity, protoplasts were isolated from the root tissue of tomato plant. The general methods recommended were not efficient enough to make protoplasts from the root tissue. Among various conditions tested, we found that a two-step treatment of osmosis is very efficient for the isolation of protoplasts. In this procedure, root tissues were preincubated in a solution containing 300 mM sorbitol for 30 min. Then, they moved to the reaction solution containing 700 mM sorbitol as well as cell wall-digesting enzymes. The formation of protoplast was greatly increased by this method. In order to find the optimal condition of the two-step method, various conditions of pH, osmotic pressure, incubation time, and the concentrations of cell wall-digesting enzymes were tested. The yield of protoplast isolation was maximal at pH 5.0 after 2 hr incubation. Mixed enzymes of 3% cellulase, 1 % macerozyme, and 0.1 % pectolyase showed maximal protoplast isolation. The physiological activity of isolated protoplast evaluated by measuring the cellular ATPase activity was as high as that measured from the preparation of root tissue. The protoplasts isolated by this method were remained healthy up to 4 hrs which is enough time to measure the cellular physiological activity. These results show that the two-step treatment of osmotic pressure was successful to obtain high yield of healthy protoplast from tomato root tissue.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.349-357
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• 1997

Epidermal growth factor(EGF), a single chain polypeptide of 53 amino acids with a molecular weight of 6,045 Da, was first isolated from the male mouse submandibular glands. EGF stimulates cellular proliferation and differentiation in several tissues and accelerates the rate of wound healing. EGF is bound to the specific receptor(EGFR) on the cell membrane of its target cell. EGFR is a transmembrane glycoprotein with a molecular weight of 170,000 Da and is detectable on a large variety of cell types and tissues. The authors investigated the expression of EGFR in the normal and inflamed human gingival epithelium to study the role of EGFR in the inflammation of the gingival epithelium, and the expression of EGFR in the dental follicle by using in situ mRNA hybridization and immunohistochenistry. The results weree as follows : 1. The expression of EGFR mRNA in the normal gingival epithelium on in situ mRNA hybridization was mainly localized on the basal cell layer, and the spinous layer was weakly positive The granular and cornified layers were negative 2. The expression of EGFR protein in the normal gingival epithelium on inmunohistochemistry was localized on the cornified and granular layers, and the spinous layer was weakly positive. The basal cell layer was completely negative 3. The expression of EGFR mRNA in the inflamed gingival epithelium on in situ mRNA hybridization was evenly and homogeneously distributed in the whole layers of the gingival epithelium except the cornified layer. The staining intensity appeared to increase progressively from the basal cell layer to the cornified layer. 4. The expression of EGFR protein in the inflamed gingival epithelium on immunohistochemistry was evenly and homogeneously distributed in the whole layers of the gingival epithelium. The staining intensity appeared to increase progressively from the cornified layer to the basal cell layer. 5. Strong positive reaction was seen in the epithelial cell rests of Malassez, whereas only background staining was seen in other cells of the dental follicle. In conclusion, the up-regulation of EGFR in the inflamed gingival epithelium and the high amounts of EGFR in the epthelial cell rests of Malassez in the dental follicle can be regarded as responses to the possible damages to the oral environment to maintain the homeostatic conditions.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.361-362
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• 2023

본 연구는 공공 조직 및 인사 관리의 새로운 패러다임으로서 서비스 중심적 접근법을 제시하였다. 특히 코로나19 팬데믹 이후의 불확실하고 경쟁적인 환경에서는 파편화된 데이터를 마이크로 서비스화하고 동적으로 재조합하는 것이 중요하며, 이를 실현하기 위한 모델로 KISTI의 ScienceON API Gateway와 시나리오 활용 서비스를 참고하였다. 이러한 접근법은 조직 및 인사 관리의 투명성과 효율성을 높이며, 서비스-이용자 간 상호작용을 강화하고, 조직의 변화를 촉진하는 데 기여할 것으로 기대된다.

• Journal of Biomedical Engineering Research
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• v.21 no.6
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• pp.575-581
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• 2000

본 논문에서는 척추침생검 시뮬레이터에서 사용의 햅틱 디바이스인 PHANToM(sup)TM을 이용하여 사실적인 힘을 구현하는 방법을 보여준다. PHANToM(sup)TM은 툴의 끝부분에서 좌표축 방향으로만 힘을 낼 수 있는 단점이 있으며, 시스템의 구동장치의한계로 인하여 딱딱한 물체에 닿을 때 불안정한 특성을 보인다. 또한 좁은 영역 안에서 복잡한 조직들로 인한 급격한 강도 변화도 시스템의 불안정을 초래한다. 모사되는 힘은 두가지 성분으로 나뉜다. 하나는 바늘이 삽입될 때 바늘의 길이 방향으로 느껴지는 힘으로 생체 조직의 모델을 통해 값이 구해진다. 다른 하나는 바늘이 피부를 뚫고 지나간 이후에 바늘이 초기 삽입 방양을 유지 시켜주는 회전방향 힘으로 피봇을 이용하여 구현하였다. 불안정성 문제와 바늘이 튀어나오는 문제는 램핑 필터와 시간변수를 이용하여 제거하였다. 침생검 과정은 생체조직의 탄성 변형뿐 아니라 파괴가 일어나는 변형이므로 사실적인 힘을 구현하기 위해서 실험 데이터를 이용하여 삽입 깊이에 따라 탄성 계수와 마찰 상수가 변하는 모델을 제안하였다.