• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.647-656
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• 2011

In radioactive waste repositories constructed in underground, concrete member could be in contact with groundwater for a long time. However, this pure water creates concentration gradients which lead to the diffusion of Ca ions from the pore water and the degradation of underground concrete. Therefore, this study is aimed at investigating the alteration of pore structure and loss of compressive strength associated with dissolution. The results showed that as the leaching period became longer, the pore volume within 50 nm to 500 nm in diameter is greatly increased. Also, the volume of pores larger than 200 nm rapidly increased during initial leaching time and those below 200 nm gradually increased. Furthermore, the compressive strength gradually decreased with increase of degraded thickness. The residual strength of the degraded concrete with OPC was in the range of 33% to 58%.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1546-1550
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• 2007

This study aimed to provide basic information as the foundation for further studies on the assessment of velvet antler quality by investigating the changes in fatty acid, vitamin A and E, minerals and GAGs contents by development stage of antler in spotted deer (Cervus nippon). Twelve stags (aged 4 to 5 years) were divided into two groups and velvet antler harvested 40 days (FDG) and 60 days (SDG) after casting of the buttons from the previous set. Total saturated fatty acid was lower in FDG than SDG (p<0.05). Total monounsaturated fatty acid, conjugated linoleic acid (p<0.05), polyunsaturated fatty acid and ${\omega}$3 fatty acid were higher in FDG than SDG. The vitamin A content of FDG was higher than that of SDG, but the vitamin E content of FDG was lower than that of SDG (p<0.05). SDG had significantly higher calcium and phosphate content than FDG (p<0.05). The magnesium content showed a similar trend to the contents of calcium and phosphate, but there was no significant difference between SDG and FDG. Uronic acid content was higher in FDG than SDG but there was no significant difference. The contents of GAGs and sialic acid were significantly higher (p<0.05) in FDG than SDG. These results indicated that the longer stage of antler development had lower content of activating components and this lead to a decrease of antler quality.

• Korean Journal of Materials Research
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• v.20 no.7
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• pp.392-400
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• 2010

The electrospinning process was established as a promising method to fabricate nano and micro-textured scaffolds for tissue engineering applications. A BCP-loaded PCL micro-textured scaffold thus can be a viable option. The biocompatibility as well as the mechanical properties of such scaffold materials should be optimized for this purpose. In this study, a composite scaffold of poly ($\varepsilon$-caprolactone) (PCL)-biphase calcium phosphate (BCP) was successfully fabricated by electrospinning. EDS and XRD data show successful loading of BCP nano particles in the PCL fibers. Morphological characterization of fibers shows that with a higher loaded BCP content the fiber surface was rougher and the diameter was approximately 1 to 7 ${\mu}m$. Tensile modulus and ultimate tensile stress reached their highest values in the PCL- 10 wt% BCP composite. When content of nano ceramic particles was low, they were dispersed in the fibers as reinforcements for the polymer matrix. However, at a high content of ceramic particles, the particles tend to agglomerate and lead to decreasing tensile modulus and ultimate stress of the PCL-BCP composite mats. Therefore, the use of nano BCP content for distribution in fiber polymer using BCP for reinforcement is limited. Tensile strain decreased with increasing content of BCP loading. From in vitro study using MG-63 osteoblast cells and L-929 fibroblast like cells, it was confirmed that electrospun PCL-BCP composite mats were biocompatible and that spreading behavior was good. As BCP content increased, the area of cell spreading on the surface of the mats also increased. Cells showed the best adherence on the surface of composite mats at 50 wt% BCP for both L-929 fibroblast-like cells and MG-63 osteoblast cell. PCL- BCP composites are a promising material for application in bone scaffolds.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.214-220
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• 2013

The effects of different cations on its composition and flavor characteristics of pidan white and yolk produced with duck egg in comparison to its fresh egg were investigated. Mineral content such as calcium, magnesium, sodium and potassium were significantly increased in pidan yolk irrespective of its cations in pickle solution in comparison to the fresh yolk (P<0.05). It confirmed the migration of minerals from the pickling solution to the egg. However, calcium and magnesium was found lower in 0.2% $PbO_2$ treated pidan. Less pidan flavor compounds were generated in pidan white produced with the aid of 0.2% $PbO_2$. It confirmed that binding of lead prevent the maillard reaction in the pidan treated with $PbO_2$. Benzaldehyde, ketones, alcohol and acid found in the pidan white treated with 0.2% $ZnCl_2$ reveals that volatiles are generated most likely from maillard reaction. However, pidan yolk of both 0.2% $PbO_2$ and 0.2% $ZnCl_2$ showed higher generation of volatiles more likely from yolk lipids. Butanal, pentanal, hexanal, and heptanal are of those aldehydes found in 0.2% $ZnCl_2$ treated pidan yolk whereas hexanal is the only aldehyde detected in 0.2% $PbO_2$ treated pidan yolk. Thus, cations in the pickling solution affect the flavor characteristics of pidan white and yolk.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.189-195
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• 2010

Water extracts from 20 medicinal plants, traditionally used for postmenopausal symptoms in Korea, were examined for their vasorelaxant activity in isolated rat thoracic aorta rings precontracted with norepinephrine (NE). Among the 20 medicinal plants, Cornus officinalis (CoEx, 0.3 mg/mL), Schisandra chinensis (ScEx, 0.3 mg/mL), Erythrina variegate (EvEx, 0.3 mg/mL), and Epimedium koreanum (EkEx, 0.3 mg/mL) showed rapid relaxation of endothelium-intact aorta ($69\pm4%$, $40\pm3%$, $25\pm2%$, and $23\pm3%$ of active tone induced by NE, respectively). In contrast, the extracts of Erythrina variegata (EvEx), Angelica gigas (AgEx), Pueraria thunbergiana (PtEx), and EkEx lead to gradual (i.e., long-term) relaxation to baseline in endothelium-intact vessels. The time to complete relaxation was 20～40 min. These 6 plant extracts were selected for the investigation of possible underlying mechanisms. The CoEx-, ScEx-, or EkEx-induced rapid relaxations were virtually abolished by endothelium denudation, and were significantly inhibited by pretreatment with nitric oxide (NO) synthase inhibitor $N^G$-nitro-L-arginine (L-NNA, 10 ${\mu}M$), indicating that increased formation of NO might contribute to the endothelium-mediated relaxation. In long-term responses, the endothelium denudation did not affect PtEx-induced relaxation, whereas it delayed responses by EvEx and AgEx, and significantly inhibited the effect of EkEx. Among EvEx, AgEx, and PtEx, EvEx attenuated the $CaCl_2$-induced vasoconstriction in high-potassium depolarized medium, implying that EvEx is involved in inhibition of the extracellular calcium influx to smooth muscle through voltage dependent calcium channels. These results provide the scientific rationale for the interrelationships between the use of 20 medicinal plants and their effects on cardiovascular health in estrogen deficient conditions.

• Journal of Nutrition and Health
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• v.15 no.2
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• pp.98-106
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• 1982

This study was carried out to investigate the nutritional status of physically handicapped children with cerebral palsy in order to contribute to their welfare by studying their healthy status, nutrient intake, daily energy expenditure, and living environment. The survey was conducted at two rehabilitation institutions from May 25 to June 30, 1981. A special questionnaire was designed to investigate the living environment. The 24 hr. recall method was used in evaluation the nutrient intake of 67 children. Anthropometric measurement was made of height, weight, chestgirth, upper-arm circumference, and triceps skinfold thickness. The biochemical status of the children with cerebral palsy was assessed with measurement of hemoglobin and hematocrit. The results may be summarized as follows : 1. The children with cerebral palsy, the intakes of all nutrients except vitamin A, thiamin, and ascorbic acid were lower than Korean recommend dietary allowances (1980). They had significantly higher intakes of vitamin A and calcium than the normal children, but the calcium intake was low as 62% of the Korea RDA. 2. All the children with cerebral palsy were very short and low weight in comparison with the accepted standards, but chestgirth was above the accepted standards for Korean school children. 3. The average hemoglobin value was 12.2gm%, hematocrit 39.3%, and mean corpuscular hemoglobin concentration (MCHC) 31.1%. 4. The possible etiological factors of cerebral palsy were, prenatal factors 16%, natal 44.9%, postnatal 27.5%, and unknown 11.6%. Eighty four percent of the children showed their first symptoms within the first year after birth. 5. Thirty percent of the parents said that the handicapped children lead to marital problems, and 84.1% of the parents mentioned that medical expenses for the children influenced their family finances.

• Journal of dental hygiene science
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• v.21 no.4
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• pp.243-250
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• 2021

Background: Endodontic sealers or their toxic components may become inflamed and lead to delayed wound healing when in direct contact with periapical tissues over an extended period. Moreover, an overfilled sealer can directly interact with adjacent tissues and may cause immediate necrosis or further resorption. Therefore, the treatment outcome conceivably depends on the endodontic sealer's biocompatibility and osteogenic potential. This study aimed to evaluate the cell viability and osteogenic effects of four different sealers in osteoblastic cells. Methods: AH Plus (resin-based sealer), Pulp Canal Sealer EWT (zinc oxide-eugenol sealer), BioRoot RCS (calcium silicate-based sealer), and Well-Root ST (MTA-based calcium silicate sealer) were mixed strictly according to the manufacturer's instructions, and dilutions of sealer extracts (1/2, 1/5 and 1/10) were determined. Cell viability was measured using the water-soluble tetrazolium-8 (WST-8) assay. Differentiation was assessed by alkaline phosphatase (ALP) activity and mineralized nodule formation by Alizarin Red S staining. Results: The cell viability of the extracts derived from the sealers excluding Well-Root ST was concentration dependent, with sealer extracts having the least viability at a 1/2 dilution. At sealer extract dilution of 1/10, the test groups showed the same survival rate as that control group, with the exception of BioRoot RCS. Among all experimental groups, BioRoot RCS showed the highest cell viability after 48 hours. The ALP activity was significantly higher in a concentration-dependent manner. Furthemore, all four materials promoted ALP activity and mineralized nodule formation compared to the control at 1/10 dilutions. Conclusion: This is the first study to highlight the differences in biological activity of these four materials. These results suggest that the composition of root canal sealers appears to alter the form of biocompatibility and osteoblastic differentiation.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.4
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• pp.311-323
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• 2023

Ion homeostasis, which is regulated by ion channels, is crucial for intracellular signaling. These channels are involved in diverse signaling pathways, including cell proliferation, migration, and intracellular calcium dynamics. Consequently, ion channel dysfunction can lead to various diseases. In addition, these channels are present in the plasma membrane and intracellular organelles. However, our understanding of the function of intracellular organellar ion channels is limited. Recent advancements in electrophysiological techniques have enabled us to record ion channels within intracellular organelles and thus learn more about their functions. Autophagy is a vital process of intracellular protein degradation that facilitates the breakdown of aged, unnecessary, and harmful proteins into their amino acid residues. Lysosomes, which were previously considered protein-degrading garbage boxes, are now recognized as crucial intracellular sensors that play significant roles in normal signaling and disease pathogenesis. Lysosomes participate in various processes, including digestion, recycling, exocytosis, calcium signaling, nutrient sensing, and wound repair, highlighting the importance of ion channels in these signaling pathways. This review focuses on different lysosomal ion channels, including those associated with diseases, and provides insights into their cellular functions. By summarizing the existing knowledge and literature, this review emphasizes the need for further research in this field. Ultimately, this study aims to provide novel perspectives on the regulation of lysosomal ion channels and the significance of ion-associated signaling in intracellular functions to develop innovative therapeutic targets for rare and lysosomal storage diseases.

• Journal of Conservation Science
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• v.33 no.5
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• pp.371-380
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• 2017

To investigate the pigments used in modern and contemporary oil paintings, thirty-two paintings by Jiho Oh and Bonung Gu were selected. The white pigment found in the ground and painting layers was identified as lead white (hydrocerussite), zinc white (zinc oxide), titanium white (titanium dioxide in anatase or rutile forms), calcite (calcium carbonate), and barite (barium sulfate). Further, this indicated that pigments differ according to the artist and date of the painting's creation. However, both Oh and Gu used zinc white during the modern and contemporary period, while lead white was replaced by titanium white, barite and calcite. Compared with the overseas studies on pigments and oil paints, the change patterns of pigments were the same with them but the periods of the use were partially different. It seems to be due to the fact that South Korea is linked to the historical background of the art material which was imported from Japan instead of Western countries. Therefore, it is inevitable that any change in the white pigments used for domestic oil paintings occurred at a different time from global transitions. If the results of this study are used in the analysis of art works it is suggested that a database recording such aspects as material properties of oil paints, artistic techniques, and chronology would become important for future conservation science and the study of art history.

• Journal of the Korean Ceramic Society
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• v.16 no.1
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• pp.31-37
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• 1979

The middle point of composition within the system $MgO-Al_2O_3-SiO_2$ has been studied for applicability as ceramics dielectrics. A Kyul Sung Tale of high purity, magnesia clinker of Sam-wha chemical company, C.P. aluminium oxide, calcium carbonate, red lead, barium carbonate which was made into frit were used the raw materials. A number of steatite ceramics were prepared under carefully controlled condition and the water absorption, linear shrinkage, power factor, dielectric constant and dielectric loss were measured at elevated temperature. When we used magnesia clinker as flux, the quantity of this flux was 0.05mole, sintering temperature was continued for 2 hrs. at 1, 27$0^{\circ}C$. From this conditions, we could get the data whose power factor was 0.142%, water absorption was zero, linear shrinkage was 8.76%, dielectric constant was 5.63, dielectric loss was 0.00799. When we used red lead as flux, the quantity of this flux was 0.033mole and 0.066mole, sintering temperature was continued for 2hrs. at 1, 26$0^{\circ}C$. From this conditions, we could get the data whose water absorption was zero, linear shrinkage was 8.03%, and 8.48%, power factor was 0.136% and 0.062%, dielectric loss was 0.0072 and 0.0037. When we used barium carbonate made into frit as flux, the quantity of this flux was 0.02mole, sintering temperature was continued for 2hrs. at 1, 27$0^{\circ}C$. From this conditions, we could get the data whose water absoption was zero, linear shrinkage was 8.44%, power factor was 0.138%, dielectric constant was 5.69, dielectric loss was 0.0074.