• Journal of Periodontal and Implant Science
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• v.49 no.4
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• pp.258-267
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• 2019

Purpose: Increased bone regeneration has been achieved through the use of stem cells in combination with graft material. However, the survival of transplanted stem cells remains a major concern. The purpose of this study was to evaluate the viability of transplanted mesenchymal stem cells (MSCs) at an early time point (24 hours) based on the type and form of the scaffold used, including type I collagen membrane and synthetic bone. Methods: The stem cells were obtained from the periosteum of the otherwise healthy dental patients. Four symmetrical circular defects measuring 6 mm in diameter were made in New Zealand white rabbits using a trephine drill. The defects were grafted with 1) synthetic bone (${\beta}$-tricalcium phosphate/hydroxyapatite [${\beta}-TCP/HA$]) and $1{\times}10^5MSCs$, 2) collagen membrane and $1{\times}10^5MSCs$, 3) ${\beta}-TCP/HA+collagen$ membrane and $1{\times}10^5MSCs$, or 4) ${\beta}-TCP/HA$, a chipped collagen membrane and $1{\times}10^5MSCs$. Cellular viability and the cell migration rate were analyzed. Results: Cells were easily separated from the collagen membrane, but not from synthetic bone. The number of stem cells attached to synthetic bone in groups 1, 3, and 4 seemed to be similar. Cellular viability in group 2 was significantly higher than in the other groups (P<0.05). The cell migration rate was highest in group 2, but this difference was not statistically significant (P>0.05). Conclusions: This study showed that stem cells can be applied when a membrane is used as a scaffold under no or minimal pressure. When space maintenance is needed, stem cells can be loaded onto synthetic bone with a chipped membrane to enhance the survival rate.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.290-294
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• 2006

Inactivation rates of Salmonella enteritidis in vitro and in vivo were assessed using confocal microscopy and flow cytometry. S. enteritidis was inactivated with 1% (w/v) trisodium phosphate (TSP) and live cells, and inactive cells were distinguished by staining with fluorescent probe, LIVE/DEAD BacLight Bacteria Viability stain. After TSP treatment for 1 min, most of Salmonella cells changed from green (live cells) fluorescence to red (inactive cells) fluorescence, indication of effective sanitizing. Inactivation efficiency and contamination sites of S. enteritidis on chicken skin by TSP treatment were assessed using confocal laser microscopy. Precise flow cytometry histograms for viability changes of S. enteritidis. after TSP treatments were obtained. Efficiency of various sanitizer treatments on foodborne pathogens could be assessed using this method.

• Journal of Environmental Impact Assessment
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• v.16 no.4
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• pp.285-300
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• 2007

The purpose of this study was to ascertain the ecological state and problems of eco-bridges on Korean roads. The study was conducted from March to April 2007 by checking ecological factors and wildlife around the eco-bridges and habitats. 8 representative eco-bridges were selected by their bridge shape and condition of location. After field survey, we analyzed ideal trails for wildlife using field data, digital topology maps, satellite images, and land use map. In addition to trail analysis, we identified the propriety of the eco-bridges through Population Viability Analysis. Because of unsuitable location and management, we found that most of the bridges are not proper for wildlife dispersal. Moreover, in some habitats, we could expect that some local populations might be extinct without appropriate treatments.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.3
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• pp.207-214
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• 2009

Positron emission tomogrpahy (PET) represents the most advanced scintigraphic imaging technology. With the increase in availability of PET, the clinical use of PET has grown in medical fields. This can be employed for cardiovascular research as well as for clinical applications in patients with various cardiovascular disease. PET allows non-invasive functional assessment of myocardial perfusion, substrate metabolism and cardiac innervation and receptors as well as gene expression in vivo. PET is regarded as the gold standard for the detection of myocardial viability, and it is the only method available for the quantitative assessment of myocardial blood flow. This review focuses on the clinical applications of myocardial perfusion PET in coronary artery disease.

• East Asian Journal of Business Economics (EAJBE)
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• v.8 no.4
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• pp.45-65
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• 2020

Purpose - This paper is to analyze the system and the models of financial analysis in the assessment of economic consistency and the creditability of borrower. To test the process of complex express-analysis, it is utilized by the concentric matrix models by using the matrix of 5×5.. Research design, data, and methodology - The estimation of economic consistency, the creditworthiness, the complex express-analysis with application of concentric matrix models were carried out on the basis of data of the report for the 2017 of corporations POSCO and in the first half of the 2018 Daewoo Shipbuilding & Marine Engineering of South Korea. Results - This paper focused on the unbalance of the corporate financial structure (capital, receivable) and the assessment of sustainability development, taking into account the liquidity, solvency, financial sustainability and economic viability of the enterprise. Conclusions - this paper also consider the theoretical means of regulating receivables. The material is presented in the pedagogical context and appendix of the conclusion.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.327-327
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• 2000

In the 1990's several economically important marine fisheries collapsed or showed signs of extreme hardship owing to overcapitalization and excessive fishing pressure on the resources. Public concern was raised and demands voiced for more prudent fishery management practices. The United Nations responded and developed international guidelines, such as the FAO Code of Conduct for Responsible Fishing and the UN Straddling Fish Socks and Highly Migratory Fish Stocks Agreement These guidelines task fishery managers to take prudent steps to ensure the long-term viability of fisheries and fishery resources. Included in the guidelines are two particular demands that will challenge stock assessment scientists in the new millennium. They are application of the precautionary approach and the inclusion of ecological considerations in assessments and management advice. High-lighted in the presentation are examples from the central-western Pacifi skipjack tuna fishery and the eastern Pacific thresher shark fishery where insufficien information is affecting stock assessments. The shortcomings are further linked t the new challenges of applying the precautionary approach, such as reference points, and ecological considerations, such as predator-prey and oceanographic-regime shift.(omitted)

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.157-163
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• 2007

Tetrabromobisphenol A (TBBPA) is the most widely used BFR (brominated flame retardants) as a reactive flame retardant in printed circuit boards, and as additive applications in several types of polymers. The purpose of this study is to assess the adverse effects of TBBPA on the benthic amphipod (Hyalella azteca). Results on the acute toxicity of TBBPA using Hyalella azteca showed that NOEC and LOEC are 100mg/kg and 200mg/kg, respectively. In addition, when chronic toxicity of TBBPA was investigated at the concentration ranges between 0.01 to 100mg/kg, it was found that NOECs are $10mg/kg(fecundity){\sim}100mg/kg(viability)$, respectively. Significant fecundity inhibition was appeared at 100mg/kg of TBBPA, however, this concentration did not show severe adverse effect on weight increment. The values of PNEC were determined as 0.1mg/kg (fecundity) and 1mg/kg (lethal effect), respectively, using a safety factor suggested by EU and OECD.

• Reproductive and Developmental Biology
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• v.28 no.3
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• pp.167-172
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• 2004

This study was performed to examine the correlations among dog sperm viabilities evaluated by flow cytometry, by microscopic evaluation (ME), by carbo-xifluorescein diacetate and propidium iodide (CFDA/PI) and by hypoosmotic swelling (HOS) test. Semen were collected from 5 dogs ranging in age from 2 to 4 years. Each ejaculate was divided into 3 aliquots and different proportions of freeze-killed cells were added to each aliquot (1:0, 1:1 and 1:3). In the other experiment, semen was extended with Sweden extender containing 5% glycerol and equex STM paste, and frozen using liquid nitrogen vapor. Fresh and frozen-thawed dog sperm viability were assessed by flow cytometry using PI staining method. The accuracy of flow cytometry was evaluated by comparing with other classic assessments, microscopic evaluation, epifluorescence microscopic analysis using CFDA/PI, and HOS test. High correlations of sperm viabilities were found among flow cytometry, epifluorescence evaluation, HOS test (p<0.01) in fresh semen. Especially, sperm viability assessed by HOS test was highly correlated with viability by flow cytometry in all the ratios of live and dead spermatozoa, 1:0, 1:1 and 1:3 (p<0.01). The viability evaluated by ME were significantly correlated with that by flow cytometry in ratios of 1:0 and 1:3 (p<0.05) however, there was no significance in ratio of 1:1. The viability evaluated by C/p were highly correlated with that by flow cytometry in ratio of 1:0 and 1:1 (p<0.01) and significantly correlated in ratio of 1:3 (p<0.05). In frozen-thawed spermatozoa, the viability determined by HOS test was considerably correlated with that by flow cytometry (p<0.01). There was significant correlation between the viabilities by ME and by flow cytometry (p<0.05). But the viability evaluated by CFDA/PI was not correlated with viability by flow cytometry. The result from this study validate the use of flow cytometry as a precise method for assessing the viability of fresh and frozen-thawed dog spermatozoa.

• Environmental Engineering Research
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• v.17 no.1
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• pp.35-39
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• 2012

In this study, multiparametric flow cytometry (FCM) was installed to enumerate the diagnosis of Pseudomonas aeruginosa ATCC 10145 and Escherichia coli K12 (IFO 3301). The nucleic acids (DNA/RNA) were double stained by a LIVE/DEAD bacLight viability kit, involving green SYTO 9 and red propidium iodide (PI), based on the permeability of two chemicals according to the integrity of plasma membrane. As the results showed, the gate for dead bacteria was defined as the range of $0.2{\times}10^0$ to $6.0{\times}10^1$ photo multiplier tube (PMT) 2 fluorescence (X-axis) and $2.0{\times}10^0$ to $2.0{\times}10^2$ PMT 4 fluorescence (Y-axis), and the gate for live bacteria was defined as the range of $6.0{\times}10^0$ to $6.0{\times}10^2$ PMT 2 fluorescence (X-axis) and $2.0{\times}10^0$ to $4.0{\times}10^2$ PMT 4 fluorescence (Y-axis). In the comparison of the number of the tested bacteria detected by FCM (viability assessment) and plate culture (cultivability assessment), the number of bacteria detected by FCM well represented the number of bacteria that was detected by the colony forming unit (CFU) counting method when bacteria were exposed to isopropyl alcohol and silver/copper cations. Consequently, it is concluded that the application of FCM to monitor the functional effect of disinfectants on the physiological status of target bacteria can offer more rapid and reliable data than the plate culture colony counting method.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.749-758
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• 2023

An understanding of safety problems pursuant to environmental release of GM (Genetically Modified) crops is considered important. Among the recognized safety problems, the possibilities of weediness and ecosystem invasion are constantly being validated. We herein compared the growth characteristics and germination rate of soybeans formed by hybridization with vitamin A-enhanced soybeans carrying an introduced gene that increases β-carotene content. We also examined overwintering, survival, and weed competitiveness to evaluate hybrid ecological impact on long-term unmanaged cultivatable land. These studies revealed that the hybrid soybeans exhibited intermediate growth characteristics and germination rate compared with the vitamin A-enhanced soybeans and wild soybeans, or exhibited traits similar to those of the maternal strain. Overwintering experiments were conducted by planting seeds at depths of 0, 5, 10, and 20 cm and recovering them after three or five months. After five months, all seeds at depths more than 5 cm lost viability. Among seeds recovered after three months, only wild soybeans retained viability at depths of more than 5 cm. Survival and weed competitiveness were assessed by sowing each type of seed and performing no irrigation, or pest or weed control. Quantitative assessment of numbers of individual soybean plants that appeared in the experimental plot revealed that all plants germinated after sowing, but only wild type plants survived overwintering. These studies suggest that both GM soybeans and hybrid soybeans cannot survive in uncultivated land even if they are released into the environment, which indicates less possibility of ecosystem invasion and weediness.