• International Journal of Stem Cells
• /
• v.17 no.2
• /
• pp.141-146
• /
• 2024

Recent advancements in organoid technology have led to a vigorous movement towards utilizing it as a substitute for animal experiments. Organoid technology offers versatile applications, particularly in toxicity testing of pharmaceuticals or chemical substances. However, for the practical use in toxicity testing, minimal guidance is required to ensure reliability and relevance. This paper aims to provide minimal guidelines for practical uses of kidney organoids derived from human pluripotent stem cells as a toxicity evaluation model in vitro.

• Advances in concrete construction
• /
• v.6 no.4
• /
• pp.345-362
• /
• 2018

In this paper, mechanical and short-term durability properties of fly ash and slag based geopolymer concretes (FAGPC-SGPC) were investigated. The alkaline solution was prepared with a mixture of sodium silicate solution ($Na_2SiO_3$) and sodium hydroxide solution (NaOH) for geopolymer concretes. Ordinary Portland Cement (OPC) concrete was also produced for comparison. Main objective of the study was to examine the usability of geopolymer concretes instead of the ordinary Portland cement concrete for structural use. In addition to this, this study was aimed to make a contribution to standardization process of the geopolymer concretes in the construction industry. For this purpose; SGPC, FAGPC and OPC specimens were exposed to sulfuric acid ($H_2SO_4$), magnesium sulfate ($MgSO_4$) and sea water (NaCl) solutions with concentrations of 5%, 5% and 3.5%, respectively. Visual inspection and weight change of the specimens were evaluated in terms of durability aspects. For the mechanical aspects; compression, splitting tensile and flexural strength tests were conducted before and after the chemical attacks to investigate the residual mechanical strengths of geopolymer concretes under chemical attacks. Results indicated that SGPC (100% slag) is stronger and durable than the FAGPC due to more stable and strong cross-linked alumina-silicate polymer structure. In addition, FAGPC specimens (100% fly ash) showed better durability resistance than the OPC specimens. However, FAGPC specimens (100% fly ash) demonstrated lower mechanical performance as compared to OPC specimens due to low reactivity of fly ash particles, low amount of calcium and more porous structure. Among the chemical environments, sulfuric acid ($H_2SO_4$) was most dangerous environment for all concrete types.

• Journal of Ginseng Research
• /
• v.22 no.4
• /
• pp.274-283
• /
• 1998

It has generally been accepted that quality of ginseng should be determined not by the content of a single component but by composition and balance of total active principles. However, there still can be an exception with a product in which a given ginsenoside is used for the treatment of a specific disease. Although ginsenosides have been regarded to be major active components of ginseng and employed as index components for the quality control, it does not consistent with the traditional concept on ginseng quality creterion; main root has been more highly appreciated than the lateral or fine root. Content of ginsenosides in the lateral or fine root is much higher than that in main root. However, the ratio of protopanaxadiol (PD) and protopanaxatriol (PT) saponins existing in various part of ginseng root is greatly different. The ratio of PD/PT saponins in main root is well balanced but the thinner the root is the higher the ratio. Thus far, a total of 34 different kinds of ginsenosides have been isolated from Korean (red) ginseng, and their pharmacological activities were elucidated partly. Interestingly, different ginsenoside shows similar or contrary effects to each other in biological systems, thus indicating the significance of absolute content of single ginsenoside as well as compositional patterns of each ginsenoside. Therefore, pharmacological activities of ginseng should be determined as a wholly concept. In these regards, standardization of ginseng material (fresh ginseng root) should be preceded to the standardization of ginseng products because ginsenoside content and non-saponin active principles such as polysaccharides and nitrogen (N)-containing compound including proteins are significantly different from part to part of the root. In other words, the main root contains less ginsenosides than other lateral or fine roots. Contents of polysaccharides and N-containing compound in main root is higher. However, the quality control of ginseng products focused on non-saponin compounds has limitation in applying to the analytical method, because of the difficult chemical analysis of these compounds. Content of ginsenosides, and ratios of PD/PT and ginsenoside Rb,/Rg, are inversely proportional to the diameter of ginseng root. Therefore, these can be served as the chemical parameters for the indirect method of evaluating from what part of the root does the material originate. Furthermore, contents of polysaccharides and N-containing compounds show inverse relationship to saponin content. Therefore, it seems that index for analytical chemistry of saponin can be applied to the indirect method of evaluating not only saponin but also non-saponin compounds of ginseng. From these viewpoints, it is strongly recommended that quality of ginseng or ginseng products be judged not only by the absolute content of given ginsenoside but also by varieties and compositional balance of ginsenosides, including contents of non-saponin active principles.

• Korean Journal of Food Science and Technology
• /
• v.29 no.6
• /
• pp.1228-1235
• /
• 1997

This study was conducted to standardize the proper ingredient ratios of chinese cabbage kimchi by the sensory evaluation, chemical properties, and functional properties of antimutagenic effect and inhibitory effect on the growth of cancer cells from the ratios obtained from literatures. The standardized ratios of ingredient from the literatures was 13.0 of radish, 2.0 of green onion, 3.5 of red pepper powder, 1.4 of garlic, 0.6 of ginger, 2.2 of anchovy juice, 1.0 of sugar and the final salt concentration 2.7 in the proportion of 100 salted chinese cabbage. The standardized ratio of the ingredients exhibited better overall acceptability and less moldy smell and moldy flavor than any other ratio of ingredient in the sensory evaluation. The standardized kimchi with the above ratios of the ingredients, at final salt concentration of 2.5%, showed high reducing sugar contents and Leuconostoc sp. counts. All juices of the chinese cabbage kimchi showed not only high antimutagenicity against aflatoxin $B_1$ in Salmonella typhimurium TA100 but also strong inhibitory effect on the growth of AGS human gastric adenocarcinoma cells in SRB assay, especially these functional properties were the most effective at each standardized ratio of the ingredients. From the taste, chemical and functional properties, the standardized ratios of ingredients was 13.0 radish, 2.0 green onion, 3.5 red pepper powder, 1.4 garlic, 0.6 ginger. 2.2 anchovy juice, 1.0 sugar and the final salt concentration 2.5 in the proportion of 100 salted chinese cabbage.

• Journal of Ginseng Research
• /
• v.37 no.3
• /
• pp.349-354
• /
• 2013

Dried ginseng (DG) is in fact the representing ginseng product in the worldwide market. Although it is made in various packages depending on the processing method, size and age of DG, basic scientific data reporting the chemical components are limited. In this study, 4-year-old curved ginseng (CG), one of the domestic DG products, was selected for further investigation. Eighty-six samples of 30 and 50 piece-grade CG, which are the most widely distributed in the market, were collected for 5 yr. Their major components, such as moisture, total sugar, acidic polysaccharides, total phenolic compounds, and saponins, were analyzed to figure out the standard quality characteristics. The moisture content of all CG samples was less than 15%. The total water-soluble sugar contents were 22.9% to 47.8% and 23.2% to 49.5% in the 30 and 50 piece-grade CG, respectively. The acidic polysaccharide contents were 3.6% to 6.7% and 2.9% to 6.9% in the 30 and 50 piece-grade CG, respectively. The total phenolic compound content was 0.4% to 0.5% in CG, regardless of the piece-grade. The crude saponin content, which represents the active component of ginseng, was over 2% in all samples. In 30 piece-grade CG samples, the contents of major ginsenosides, Rb1, Rf, and Rg1, were 2.2 to 4.7 mg/g, 0.4 to 1.3 mg/g, and 1.6 to 4.0 mg/g, respectively. The ginsenoside contents in 50 piece-grade CG samples were 2.1 to 3.9 mg/g (Rb1), 0.5 to 1.2 mg/g (Rf), and 1.3 to 3.4 mg/g (Rg1). Overall, since there were relatively high standard deviation and coefficient of variation in all the chemical component contents that were assessed, we found some difficulties in showing the CG standard chemical component characteristics by average, standard deviation, and other statistical analysis factors.

• Korean Chemical Engineering Research
• /
• v.58 no.3
• /
• pp.416-423
• /
• 2020

Majority of over 100 kW capacity photo voltaic (PV) power generation system was constructed on the plate ground of soil. Rarely PV system installed on concrete or building but it usually be under 25 kW capacity. On the soil ground the weeds growen up and it's shadow influenced to decrease of amount of PV power generation. This work analysis the weeds shadow's effect to decrease of PV power generation with 100 kW capacity of real PV power generation system in Yeungnam University, Finally the weed shadow"s influence value through the real field monitoring Data is suggested for give a standard management time of weeds to avoid the negative influence on whole power plant. Moreover the hot spot which is generated by long term partial shallow on PV module also can detected with the result of this work. It also suggested as a standard value of monitoring Data.

• Journal of the Korean Institute of Gas
• /
• v.17 no.6
• /
• pp.73-82
• /
• 2013

With remarkable development of industry and technology, various chemical articles are developed to improve the quality of human life, yet some of chemicals are hazardous to human and the environment. However, safety control of chemical articles such as transportation, storage, and handling is emerging as a major issue lately. The road transportation needs well-organized safety management system, especially it has high probability of accidents. In this research, we point out problems in current state and related regulation of transportation of dangerous goods to compare the regulation in UN-RTDG. In addition, we suggest the enhancement law, the plan for standardization of classification in road transportation of dangerous goods and harmonization of labeling in transportation of dangerous goods to contribute to human health and environment protection.

• Journal of the Korean Society of Tobacco Science
• /
• v.30 no.1
• /
• pp.14-24
• /
• 2008

The objective of this study was to determine the effect of smoking conditions on the in vitro toxicological activity of mainstream smoke. The 2R4F reference cigarette was machine-smoked by International Organization for Standardization(ISO) and Canadian Intense(CI) conditions. Smoke was analysed for chemical composition and in vitro toxicity. The cytotoxic potencies of both the total particulate matter(TPM), which were collected in Cambridge filter pad, and gas/vapor phase(GVP), which was bubbled through in phosphate-buffer saline in a gas-washing bottle, were assessed neutral red up take assay with chinese hamster ovary(CHO) cells. The assessment for genotoxicity of TPMs generated under ISO and CI conditions was determined using Salmonella mutagenicity assay and in vitro micronucleus assay. When calculated on an equal TPM basis, in vitro toxicity of TPM obtained under CI condition was decreased compared to TPM generated under ISO condition. The results of chemical composition analyses revealed that the lower toxicological activity under CI condition than that of ISO condition could be explained by the decreased in the contents of phenols, N-nitrosoamines and aromatic amines of TPM on an equal TPM basis.

• Applied Chemistry for Engineering
• /
• v.20 no.4
• /
• pp.355-362
• /
• 2009

Fuels based on petroleum will eventually run out in the near future. DME (Di-methyl Ether) is a clean energy source that can be manufactured from various raw materials such as natural gas, coal as well as biomass. As DME has no carbon-carbon bond in its molecular structure and is an oxygenate fuel, its combustion essentially generates no soot as well as no SOx. Because the physical properties of DME are similar to those of LPG, the LPG distribution infrastructure can be converted to use with DME. DME has such high cetane number of 55~60 that it can be used as a diesel engine fuel. Practical use of DME as a next-generation clean fuel or next-generation chemical feedstock is advancing in the fields of power generation, diesel engines, household use, and fuel cells, among others. The purpose of this paper is review the characteristics, standardization, status of research and development in domestic and foreign countries of DME.

• Korean Journal of Environmental Agriculture
• /
• v.29 no.2
• /
• pp.165-175
• /
• 2010

A gas chromatographic (GC) method was developed to determine residues of captan, folpet, captafol, and chlorothalonil, known as broad-spectrum protective fungicides for the official purpose. All the fungicide residues were extracted with acetone containing 3% phosphoric acid from representative samples of five agricultural products which comprised rice, soybean, apple, pepper, and cabbage. The extract was diluted with saline, and dichloromethane partition was followed to recover the fungicides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were then determined by gas chromatography using a DB-1 capillary column with electron capture detection. Reproducibility in quantitation was largely enhanced by minimization of adsorption or thermal degradation of analytes during GLC analysis. Mean recoveries generated from each crop sample fortified at two levels in triplicate ranged from 89.0~113.7%. Relative standard deviations (RSD) were all less than 10%, irrespective sample types and fortification levels. As no interference was found in any samples, limit of quantitation (LOQ) was estimated to be 0.008 mg/kg for the analytes except showing higher sensitivity of 0.002 mg/kg for chlorothalonil. GC/Mass spectrometric method using selected-ion monitoring technique was also provided to confirm the suspected residues. The proposed method was reproducible and sensitive enough to determine the residues of captan, folpet, captafol, and chlorothalonil in agricultural commodities for routine analysis.