• Journal of Microbiology and Biotechnology
• /
• v.15 no.2
• /
• pp.254-258
• /
• 2005

We have conducted in vitro reconstitution study of ferritin from its subunits FerH and FerL. For the reconstitution, FerH was produced from an expression vector construct in Escherichia coli and was purified from a heat treated cell extract by using one-step column chromatography. FerL was expressed as inclusion bodies. The denatured form of FerL was obtained by a simple washing step of the inclusion bodies with 3 M urea. The reconstitution experiment was conducted with various molar ratios of urea-denatured FerH and FerL to make the ferritin nanoparticle with a controlled composition of FerH and FerL. SDS-PAGE analysis of the reconstituted ferritins revealed that the reconstitution required the presence of more than 40 molar$\%$ of FerH in the reconstitution mixture. The assembly of the subunits into the ferritin nanoparticle was confmned by the presence of spherical particles with diameter of 10 nm by the atomic force microscopic image. Further analysis of the particles by using a transmission electron microscope revealed that the reconstituted particles exhibited different percentages of population with dense iron core. The reconstituted ferritin nanoparticles made with molar ratios of [FerH]/[FerL]=l00/0 and 60/40 showed that 80 to $90\%$ of the particles were apoferritin, devoid of iron core. On the contrary, all the particles formed with [FerH]/[FerL]=85/ 15 were found to contain the iron core. This suggests that although FerH can uptake iron, a minor portion of FerL, not exceeding $40\%$ at most, is required to deposit iron inside the particle.

• Journal of Powder Materials
• /
• v.27 no.6
• /
• pp.490-497
• /
• 2020

The 3D printing process provides a higher degree of freedom when designing ceramic parts than the conventional press forming process. However, the generation and growth of the microcracks induced during heat treatment is thought to be due to the occurrence of local tensile stress caused by the thermal decomposition of the binder inside the green body. In this study, an alumina columnar specimen, which is a representative ceramic material, is fabricated using the digital light process (DLP) 3D printing method. DTG analysis is performed to investigate the cause of the occurrence of microcracks by analyzing the debinding process in which microcracks are mainly generated. HDDA of epoxy acrylates, which is the main binder, rapidly debinded in the range of 200 to 500℃, and microcracks are observed because of real-time microscopic image observation. For mitigating the rapid debinding process of HDDA, other types of acrylates PETA, PUA, and MMA are added, and the effect of these additives on the debinding rate is investigated. By analyzing the DTG in the 25 to 300℃ region, it is confirmed that the PETA monomer and the PUA monomer can suppress the rapid decomposition rate of HDDA in this temperature range.

• Korean Journal of Construction Engineering and Management
• /
• v.25 no.2
• /
• pp.36-44
• /
• 2024

This paper presents the application of Convolutional Neural Networks (CNNs) and Region of Interest (ROI) techniques for concrete crack analysis. Surfaces of concrete structures, such as beams, etc., are exposed to fatigue stress and cyclic loads, typically resulting in the initiation of cracks at a microscopic level on the structure's surface. Early detection enables preventative measures to mitigate potential damage and failures. Conventional manual inspections often yield subpar results, especially for large-scale infrastructure where access is challenging and detecting cracks can be difficult. This paper presents data collection, edge segmentation and ROI techniques application, and analysis of concrete cracks using Convolutional Neural Networks. This paper aims to achieve the following objectives: Firstly, achieving improved accuracy in crack detection using image-based technology compared to traditional manual inspection methods. Secondly, developing an algorithm that utilizes enhanced Sobel edge segmentation and ROI techniques. The algorithm provides automated crack detection capabilities for non-destructive testing.

• Applied Microscopy
• /
• v.42 no.1
• /
• pp.1-7
• /
• 2012

The possibility of nanoparticles (NPs) in biotechnology had been discussed by biomedical investigators. Here we report to suggest a solution and problems when using electron microscopy to determine the distribution of quantum dots (QDs) nanoparticles that penetrate skin. The results of this study showed that NPs were able to penetrate stratum corneum (SC) and sebocyte via hair follicle. However, we have found artifacts such as nanoparticles that are produced from combination of free fatty acid and osmium tetroxide during specimen preparation. It is usually difficult to identify NPs. Therefore, we tried to resolve these problems by comparing the cross-correlation image pattern that are derived from the images of sample that had been processed differently. This method can contribute to more accurate interpretation and minimal errors during the analysis using quantum dot as tracer.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1993.05a
• /
• pp.89-89
• /
• 1993

The laryngeal epithelial cell kinetics of 26 laryngeal lesions(invasive squamous cell carcinoma 14, epithelial hyperplasia 5, laryngeal nodule 7) were studied by immunehistochemical analysis with the monoclonal antibody Ki-67, which reacts with nuclear antigen in proliferating cells using paraffin embedded tissue. For DNA analysis, touch implint with fresh biopsy specimens were stained with feulgen and analyzed by image analyzer in 22 cases. 1) The proportion of Ki-67-positive cells were 32.65$\pm$ 11.59% in invasive squamous cell ca, 20.14$\pm$3.38% in epithelial hyperplasia lesion and 11.66$\pm$3.02% in laryngeal nodule. 2) DNA aneuploidy was found in 7 cases of 10(70%) invasive squamous cell carcinomas, 2 cases of 5(40%) epithelial hyperplasia lesions and all cases of laryngeal 3) Proliferation index(S phase+G2/M phase) show 23.42$\pm$11.33% in squamous cell carcinoma, 13.09$\pm$ 10.90% in epithelial hyperplasia lesion and 4.50$\pm$1.19% in laryngeal nodule. As the results, measuring the DNA content from touch imprint method together positivity of Ki-67 antibody from the microtissue during the laryngeal microscopic surgery, cell kinetics can be assessed as an effort of deciding the prognosis and provide a key to the management of precancerous lesions.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.2
• /
• pp.153-165
• /
• 1997

In male reproducible health, fertility and IVF (in-vitro fertilization), semen analysis has been most important. Semen analysis can be divided into concentration, motional and morphological analysis of sperm. The existing method which was developed earlier to analyze semen concentrated on the sperm motility analysis. To provide more useful and precise solutions for clinical problems such as infertility, semen analysis must include sperm morphological analysis. But the traditional tools for semen analysis are subjective, imprecise, inaccurate, difficult to standardize, and difficult to reproduce. Therefore, with the help of development of microcomputers and image processing techniques, we developed a new sperm morphology analyzer to overcome these problems. In this study the agreement on percent normal morphology was studied between different observers and a computerized sperm morphology analyzer on a slide-by-slide basis using strict criteria. Slides from 30 different patients from the SNUH andrology laboratory were selected randomly. Microscopic fields and sperm cells were chosen randomly and percent normal morphology was recorded. The ability of sperm morphology analyzer to repeat the same reading for normal and abnormal cells was studied. The results showed that there was no significant bias between two experienced observers. The limits of agreement were 4.1%${\sim}$-3.8%. The Pearson correlation coefficient between readers was 0.79. Between the manual and sperm morphology analyzer, the same findings were reported. In this experiments the slides were stained by two different methods, PAP and Diff-Quik staining methods. The limits of agreement were 7.2%${\sim}$-5.7% and 6.0%${\sim}$-6.3%, respectively. The Pearson correlation coefficients ware 0.76 and 0.91, respectively. The limits of agreement was tighter below 20% normal forms. In the experiments of repeatability, 52 cells stained by PAP and Diff-Quik staining methods were analyzed three times in succession. Estimating pairwise agreement, the kappa statistic for the pairs were 0.76, 0.81, 0.86, and 0.75, 0.88, 0.88 respectively. In this study it was shown that there was good agreement between manual and computerized assessment of normal and abnormal cells. The repeatability and agreement per slide of computerized sperm morphology analyzer was excellent. The computer's ability to classify normal morphology per slide is promising. Based on results obtained, this system can be of clinical value both in andrology laboratories and IVF units.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.16 no.1
• /
• pp.46-52
• /
• 2008

Oils and chlorinated solvents leaking to the subsurface are entrapped in the soil pore and these are called as nonaqueous phase liquids (NAPL). NAPL entrapped in porous media acts as a continuous source for surface and ground water contamination. This study visualized dissolution of trichloroethylene (TCE) entrapped in porous media and quantified the velocity of TCE dissolution using an image analysis technique. As the water velocity increased, the level of dissolution increased. The results imply that a TCE contaminated region having a high infiltration rate and groundwater velocity may result in severe groundwater contamination. Microscopic images of TCE entrapped in porous media showed that TCE present in the preferential flow paths was easily dissoluted into the water phase. However, TCE present in the stagnant flow region was visualized for long time. The results imply that TCE would be still present in the soil if TCE is detected in goundwater.

• Applied Microscopy
• /
• v.35 no.4
• /
• pp.16-23
• /
• 2005

Peroxiredoxins (Prxs) are a superfamily of thiol-specific antioxidant proteins present in all organism and involved in the hydroperoxide detoxification of the cell. To determine the structural organization of yeast-Prx, electron microscopic analysis was performed. The average images of yeast-Prxs revealed three different structure, i.e. spherical-shaped structure, ring-shaped structure and irregularly-shaped small particles. In order to analyze the conformational change of yeast-Prx by reduction and oxidation, Prxs were subjected to DTT and $H_2O_2$. In presence of DTT, yeast-Prx showed a high tendency to form a decamer. However, they changed into dimeric or spherical structure in the oxidized state. Here we also show ionic interaction between dimeric subunits is primarily responsible for yeast-Prx oligomerization.

• The Korea Journal of Herbology
• /
• v.31 no.4
• /
• pp.71-77
• /
• 2016

Objectives : Adipogenesis was defined as a differentiation process of preadipocytes into the adipocytes. Thus, to control of this process can be one of the most important strategies to prevent obesity. Korean ginseng(Panax ginseng C.A. Meyer) is one of the most widely used medicinal herbs. Although multiple biological activities of Korean ginseng, particularly ginsenosides, have been known, the anti-adipogenic role and function of polysaccharides from Korean ginseng are still unclear. In this study, we examined anti-adipogenic activity of polysaccharides and its molecular basis mechanisms are further investigated.Methods : The cytotoxicity of KGP in 3T3-L1 was evaluated by MTT assay. Anti-adipogenic effect of KGP was examined by Oil Red O (ORO) staining and microscopy observation in 3T3-L1 mature adipocytes. The mRNA expression levels of adipogenic transcriptional factors were analyzed by reverse transcription-polymer chain reaction (RT-PCR). To elucidate the adipogenic molecular mechanism of KGT, SB431542 (TGF-β specific inhibitor) was used.Results : We found that polysaccharides showed no effect on the viability of 3T3-L1 preadipocytes. Dose dependent inhibitory effect of polysaccharides on 3T3-L1 adipogenesis was observed as judged by ORO staining and microscopic image analysis. To obtain further mechanistic insight into anti-adipogenic function of polysaccharides, we then tested the effect of polysaccharides treatment on the adipogenic marker genes. The mRNA expressions level of C/EBPα, PPARγ, C/EBPβ, and fatty acid synthase (FAS) were dose-dependently inhibited by KGP treatment in 3T3-L1 mature adipocytes.Conclusions : In conclusion, these findings suggest that the KGP could be used in treatment of obesity and overweight related diseases.

• Journal of Periodontal and Implant Science
• /
• v.40 no.2
• /
• pp.49-55
• /
• 2010

Purpose: The purpose of this study was to preliminarily evaluate the influence of diabetes mellitus (DM) on periodontal tissue without establishment of periodontitis. Methods: Seven-week-old db/db mice were used for the diabetic experimental group and systematically healthy mice of the same age were used as controls. After 1 week of acclimatization, the animals were sacrificed for hard and soft tissue evaluation. The pattern of bone destruction was evaluated by stereomicroscope evaluation with alizarin red staining and radiographic evaluation by microscopic computerized tomography images. Histological evaluation was performed with hematoxylin and eosin stain for evaluation of soft tissue changes. Results: In both stereomicroscope evaluation and radiograph image analysis, aggressive form of bone destruction was observed in diabetic animals when compared to the systematically healthy controls. In histological evaluation, apical migration of junctional epithelium with slight inflammatory cell infiltration was observed with disarrangement of connective tissue fibers. Conclusions: Within the limits of this study, diabetic animals presented distortion in periodontal attachment and an aggressive bone loss pattern when compared to the healthy controls, suggesting that DM has an independent effect on periodontal tissue destruction irrespective of the presence or absence of periodontal disease.