• Membrane Journal
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• v.32 no.2
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• pp.150-162
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• 2022

In the field of water treatment and pharmaceutical bio an alumina hollow fiber membrane used for mixture separation. However, due to the lack of strengths it is very brittle to handle and apply. Therefore, it is necessary to study and improve the bending strength of the membrane to 100 MPa or more. In this study, as the mixing ratio of the nano-particles increased to 0, 1, 3, and 5 wt%, the viscosity of the fluid mixture increased. The pore structure of the hollow membrane produced by interrupting the diffusion exchange rate of the solvent and non-solvent during the spinning process suppresses the formation of the finger-like structure and gradually increases the ratio of the sponge-like structure to improve the membrane mechanical strength to more than 100 MPa. As a result, an interparticle space was ensured to improve the porosity of the sponge-like structure with high permeability, and it showed excellent N2 permeability of about 100000 GPU and high water permeability of 3000 L/m² h. Therefore, it can be concluded, that the addition of γ-Al₂O₃ nanoparticles as sintering aid is an important method to enhance the mechanical strength of the α-alumina hollow fiber membrane to maintain high permeability.

• Fisheries and Aquatic Sciences
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• v.25 no.11
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• pp.579-586
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• 2022

Research on the potential biological activity of red alga Symphyocladia spp. has been limited to Symphyocladia latiuscula, which is widely used as a food ingredient in Korea. Here, we examined the biological activity of another species, Symphyocladia linearis, which is found in Korea and was reported as a new species in 2013. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antibacterial properties of a 70% ethanol extract of S. linearis. Antioxidant activity, which was evaluated using radical scavenging assays, revealed half maximal inhibitory concentration values for 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) of 34.57 and 11.70 ㎍/mL algal extract, respectively. Anti-inflammatory activity of the S. linearis ethanolic extract was evaluated using RAW 264.7 cells by measuring the inhibition of lipopolysaccharide-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. The potential cytotoxicity of NO and PGE₂ was first examined, confirming no toxicity at concentrations ranging from 10-100 ㎍/mL. NO production was inhibited 61.1% and 78.0% at 50 and 100 ㎍/mL S. linearis extract, respectively; and PGE₂ production was inhibited 69.1%, 83.2%, and 94.8% at 25, 50, and 100 ㎍/mL S. linearis extract, respectively. Thus, the S. linearis extract showed very strong efficacy against PGE₂ production. The cellular production of reactive oxygen species, measured using 2',7'-dichlorofluorescin diacetate fluorescence, was inhibited 48.8% by the addition of 100 ㎍/mL S. linearis extract. Antibacterial activity was evaluated using the disc diffusion method and minimum inhibitory concentration (MIC). S. linearis was effective only against gram-positive bacteria, exhibiting antibacterial activity against Staphylococcus aureus with a MIC of 256 ㎍/mL extract and against Bacillus cereus with a MIC of 1,024 ㎍/mL extract. Based on these results, we infer that a 70% ethanolic extract of S. linearis possesses strong anti-inflammatory properties, and therefore has the potential to be used in the prevention and treatment of inflammatory and immune diseases.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.227-239
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• 2022

Purpose: In our study, in order to find lactic acid bacteria (LAB) with multi-drug resistance to antibiotics, we isolated 140 strains from 15 types of kimchi commercially available in Korea and 20 types of Kimchi made at home from January to December in 2016, and investigated their H₂O₂ generating ability and multi-drug resistance to antibiotics. Methods: In order to observe the H₂O₂ generation ability of LAB, we performed the experiment with methods such as Rabe, Hillier, and Kang. To test the antibacterial susceptibility of LAB, we used the disc agar diffusion method using MRS agar (Difco, USA) according to the CLSI and WHO test methods. There are 18 types of antibiotic discs used. Results: Out of the total numbers of 140 strains, 6 strains of Ent. Faecium, 25 strains of L. plantarum, 1 strain of L. rhamnosus, 3 strains of L. sakei, 1 strain of L. acidophilus, 1 strains St. thermophilus, and 7 of unidentified strains generated H₂O₂. The antibiotic susceptibility of Ent. Faecium indicated SXT, OX, NA, and E; and the antibiotic susceptibility of L. plantarum indicated NA; and the antibiotic susceptibility of St. thermophilus indicated NA, CC, RA, CTT, CM, and P ; and the antibiotic susceptibility of L. rhamnosus indicated SXT, VA, NA and CTT; and the antibiotic susceptibility of 6 strains of L. sakei indicated SXT, OX, NOR, NA, CTT and CIP, all indicating antibiotic resistance. In the case of multi-drug resistance to antibiotics for 53 strains of L. antarum, 8-drug resistance was the most common with 25 strains, followed by 7-drug-resistant strains with 18 strains, 9-drug-resistant strains with 4 strains, 6-drug-resistant strains with 3 strains, 5-drug-resistant strains with 2 strains, and 17-drug-resistant strains with 1 strain. In the case of multi-drug resistance to antibiotics for Ent. Faecium 27 strains, 9-drug resistance was most commonly identified as 9 strains, 8-drug resistance was identified as 6 strains, 7- and 11 drug resistances were identified as 4 strains each, and 4- and 6-drug resistances were identified as 1 strain each. Conclusion: Ent. Faecium, L. plantarum, L. rhamnosus, L. sakei, and St. thermophilus, shown to have anantibacterial activity in previous studies on LAB and shown to have and H₂O₂ generating ability, antibiotic resistance and multi-drug resistance in this study, are expected to be able to play an excellent role for long-term inpatients to use as an alternative to antibiotics and to cope with emerging antibiotic resistance.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.125-133
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• 2023

Purpose : This study aimed to analyze the antibacterial activity of Liriope platyphylla ethanol extract (LPEE) against Streptococcus mutans and Porphyromonas gingivalis and to validate its potential for the prevention and treatment of dental caries, gingivitis, and periodontal disease. Methods : To verify the antibacterial effect of L. pulsatilla ethanolic extract (LPEE) against S. mutans and P. gingivalis, the disk diffusion method was used to determine the inhibition zones at concentrations of 50, 100, 200, and 300 mg/㎖. To determine the minimum inhibition concentration (MIC), the final dose of LPEE was .2, .4, .8, 1.6, 2.5, and 5.0 mg/㎖, and the minimum bactericidal concentration (MBC) was determined based on the MIC results. To confirm the growth inhibitory effect of LPEE on both pathogens, the absorbance was measured at 600 nm after each incubation for 0, 3, 6, 12, and 24 hr at concentrations of .8, 1.6, 2.5, and 5.0 mg/㎖. Results : The cytotoxicity of LPEE was evaluated and the cell viability was more than 70 % at 400 mg/㎖. Therefore, concentrations of 50, 100, 200, and 300 mg/㎖ were used in this study. The antimicrobial effect against S. mutans was seen at 100 mg/㎖ and grew in a concentration-dependent manner, while P. gingivalis was effective at 50 mg/㎖ with the dose dependency. The MIC was .8 mg/㎖ for both strains, and the MBC was 1.6 mg/㎖ with the same results. The growth inhibitory effect of LPEE on S. mutans and P. gingivalis was observed, even at low concentrations. Conclusion : The antibacterial effect of LPEE was evaluated through the analysis of MIC, MBC, and growth inhibition effect on S. mutans and P. gingivalis, which suggests LPEE might have the possibility of utilization as a preventive and therapeutic composition for oral diseases.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.169-181
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• 2007

Statement of problem: Titanium is well known as a proper metal for the dental restorations, because it has an excellent biocompatibility, resistance to corrosion, and mechanical property. However, adhesion between titanium and dental porcelains is related to the diffusion of oxygen to the reaction layers formed on cast-titanium surfaces during porcelain firing and those oxidized layers make the adhesion difficult to be formed. Many studies using mechanical, chemical and physical methods to enhance the titanium-ceramic adhesion have been actively performed. Purpose: This study meant to comparatively analyse the adhesion characteristics depending on different titanium surface coatings after coating the casts and wrought titanium surfaces with Au and TiN. Material and method: In this study, the titanium specimens (CP-Ti, Grade 2, Kobe still Co. Japan) were categorized into cast and wrought titanium. The wrought titanium was cast by using the MgO-based investment(Selevest CB, Selec). The cast and wrought titanium were treated with Au coating($ParaOne^{(R)}$., Gold Ion Sputter, Model PS-1200) and TiN coating(ATEC system, Korea) and the ultra low fusing dental porcelain was fused and fired onto the samples. Biaxial flection test was done on the fired samples and the porcelain was separated. The adhesion characteristics of porcelain and titanium after firing and the specimen surfaces before and after the porcelain fracture test were observed with SEM. The atomic percent of Si on all sample surfaces was comparatively analysed by EDS. In addition, the constituents of specimen surface layers after the porcelain fracture and the formed compound were evaluated by X-ray diffraction diagnosis. Result: The results of this study were obtained as follows : 1. The surface characteristics of cast and wrought titanium after surface treatment(Au, TiN, $Al_2O_3$ sandblasting) were similar and each cast and wrought titanium showed similar bonding characteristics. 2. Before and after the biaxial flection test, the highest atomic weight change of Si component was found in $Al_2O_3$ sandblasted wrought titanium(28.6at.% $\rightarrow$ 8.3at.%). On the other hand, the least change was seen in Au-Pd-In alloy(24.5at.% $\rightarrow$ 9.1at.%). 3. Much amount of Si components was uniformly distributed in Au and TiN coated titanium, but less amount of Si's was unevenly dispersed on Al2O3 sandblasting surfaces. 4. In X-ray diffraction diagnosis after porcelain debonding, we could see $Au_2Ti$ compound and TiN coating layers on Au and TiN coated surfaces and $TiO_2$, typical oxide of titanium, on all titanium surfaces. 5. Debonding of porcelain on cast and wrought titanium surface after the biaxial flection is considered as a result of adhesion deterioration between coating layers and titanium surfaces. We found that there are both adhesive failure and cohesive failure at the same time. Conclusion: These results showed that the titanium-ceramic adhesion could be improved by coating cast and wrought titanium surfaces with Au and TiN when making porcelain fused to metal crowns. In order to use porcelain fused to titanium clinically, it is considered that coating technique to enhance the bonding strength between coating kKlayers and titanium surfaces should be developed first.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.140-149
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• 1997

Purpose : Kawasaki Disease(KD) is a febrile disease with acute multisystemic vasculitis which is seen commonly in early childhood. The cause and etiologic agents are still unknown to identify using ordinary bacterial and viral culture, but the clinical labaratory studies suggest that KD is one of autoimmune disorder caused by infectious agents, but that is not proved yet. The study was performed to investigate the IgG subclasses in acute stage of KB before treatment of IVIG(Intravenous immunoglobulin). Method : The 35 cases in acute stage of KD before treatment of IVIG who were hospitalized from jan. 1995 to dec. 1996. The obtained sera were measured level of total IgG, IgM, IgA, IgE and IgG subclasses IgGl, IgG2, IgG3, IgG4 by using EIA and SRID method. Results : 1) The sex ratio is male to female is 1.5: 1.0, and male is prone to infected. 2) Total IgG, IgM, IgA and IgE level is normal range with age adjusted, but few cases are shown slight high level of total IgG compare to normal range of age adjusted. 3) acute phage reactants such as CRP, C3, ESR are all increased in acute stage of cases. 4) IgG subclasses IgGl, IgG2, IgG3 are shown normal range of age adjusted, but remarkably low level of IgG4 in all of cases. Conclusions : The low level of IgG4 is able to increasing the incidence of KD, and may use early diagnostic tools combine with other clinical symptoms and signs. But the resulsts of reported studies are different to each other, so it needs more times and cases to get final evaluation of changes of serum immnunoglobulin levels correlate to increase the incidence of high risk group of KD patients.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.1
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• pp.39-52
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• 2007

Quantitative analysis on release behavior of the $^{85}Kr\;and\;^{14}C$ fission gases from the spent fuel material during the voloxidation and OREOX process has been performed. This thermal treatment step in a remote fabrication process to fabricate the dry-processed fuel from spent fuel has been used to obtain a fine powder The fractional release percent of fission gases from spent fuel materials with burn-up ranges from 27,000 MWd/tU to 65,000 MWd/tU have been evaluated by comparing the measured data with these initial inventories calculated by ORIGEN code. The release characteristics of $^{85}Kr\;and\;^{14}C$ fission gases during the voloxidation process at $500^{\circ}C$ seem to be closely linked to the degree of conversion efficiency of $UO_2\;to\;U_3O_8$ powder, and it is thus interpreted that the release from grain-boundary would be dominated during this step. The high release fraction of the fission gas from an oxidized powder during the OREOX process would be due to increase both in the gas diffusion at a temperature of $500^{\circ}C$ in a reduction step and in U atom mobility by the reduction. Therefore, it is believed that the fission gases release inventories in the OREOX step come from the inter-grain and inter-grain on $UO_2$ matrix. It is shown that the release fraction of $^{85}Kr\;and\;^{14}C$ fission gases during the voloxidation step would be increased as fuel burn-up increases, ranging from 6 to 12%, and a residual fission gas would completely be removed during the OREOX step. It seems that more effective treatment conditions for a removal of volatile fission gas are of powder formation by the oxidation in advance than the reduction of spent fuel at the higher temperature.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.4-21
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• 2019

In this paper, 23 Silla gold earrings from the sixth and seventhand centuries, excavated from the Yeongnam region, were analyzed. Based on the silver content of the gold plate, they were classified into three types. The classifications included type I(20-50wt%), type II(10-20wt%) and type III (less than 10wt%). In the analysis process, the composition and morphological differences were identified on the surface of the gold plate. In the case of type I and II earrings, it was observed that the fine holes were concentrated in a relatively higher part of the gold content. The causes of the difference in the surface composition of the gold plate were divided into four categories: 1) surface treatment, 2) thermal diffusivity in the manufacturing process, 3) differences in composition of alluvial gold, and 4) the refining method of gold. It is possible that depletion gilding was attempted to increase the gold content while intentionally removing the other metals from the surface of the gold alloy in the portion where the gold deposit is relatively concentrated on the surface of the gold plating. The highest copper content was detected in the earring with the highest gold content of the analyzed earrings, and it was assumed that thermal diffusion had occurred between the gold plate and the metal rod during the manufacturing process rather than intentional addition. Copper was detected only in the thin ring earring type, and copper was not detected in the thick ring earring type or pendant type. It also proves that this earring has a high degree of tightness at higher temperatures, as there was an invisible edge finish on other earrings and horizontal wrinkles on the gold plate surface. In terms of the material of the gold plate, we examined whether the silver content of the gold plate was natural gold or added by alloy through analyzing the alluvial gold collected in the region. As a result of the analysis, it was found that on average about 13wt% of silver is included. This suggests that type II is natural gold, type III is refined gold, and type I seems to have been alloyed with natural gold. Here, we investigated the refining method introduced in the ancient literature, both at home and abroad, about the possibility of alloying silver after the refining process of type III earrings and then making pure gold. It was found that from ancient refining methods, silver which had been present in the natural gold was removed by reacting and combining with silver chloride or silver sulfide, and long-term efforts and techniques were required to obtain pure gold through this method. Therefore, it was concluded that the possibility of adding a small amount of silver in order to increase strength after making pure gold through a refining process is low.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.16-19
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• 2019

A thinner film has superior electrical properties and a better amorphous structure. Amorphous structures can be effective in improving conductivity through a depletion effect. Research is needed on the Schottky contact, where potential barriers are formed, as a way to identify these characteristics. $SiO_2/SnO_2$ thin films were prepared to examine the amorphous structure and Schottky contact, $SiO_2$ thin films were prepared using Ar = 20 sccm. $SnO_2$ thin films were deposited using mixed gas with a flow rate of argon and oxygen at 20 sccm, and $SnO_2$ thin films were added by magnetron sputtering and treated at $100^{\circ}C$ and $150^{\circ}C$. To identify the conditions under which the amorphous structure was constructed, the XRD patterns were investigated and C-V and I-V measurements were taken to make Al electrodes and perform electrical analysis. The depletion layer was formed by the recombination of electrons and holes through the heat treatment process. $SiO_2/SnO_2$ thin films confirmed that the pores were well formed when heat treated at $100^{\circ}C$ and an electric current was applied over the micro area. An amorphous $SiO_2/SnO_2$ thin film with heat treatment at $100^{\circ}C$ showed no reflection at $33^{\circ}\;2{\theta}$ in the XRD pattern, and a reflection at $44^{\circ}2\;{\theta}$. The macroscopic view (-30 V

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.611-620
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• 2007

The current study was designed to define whether a blend of prunus mume extract(25%) containing lactic acid(75%) and grape seed extract(10ppm) could affect in vitro antimicrobial activity and growth performance, intestinal microflora, plasma biochemical profiles and digestive enzymes activities in broiler chickens. In paper disc agar diffusion test, we clearly observed antimicrobial activity against E. coli in response to prunus mume extract or a blend of prunus mume extract. For in vivo test, a total of ninety six 3-d-old male broiler chicks were assigned to basal diet(CON), basal diet supplemented with antibiotics (ANTI) and 0.5% a blend of prunus mume extract(PRNUS) until 35 days of age. Throughout the entire experimental period(3-35 days), there were no differences in BW and FCR between the birds fed the basal diet with antibiotics and the diet supplemented with a blend of prunus mume. However, ANTI group showed a significant increase in BW and total gain compared to CON group. The weights of digestive organs such as the pancreas and mucosal tissues were not affected by dietary treatments. There was no difference in plasma levels of glucose, cholesterol, AST and ALT activity. However, triglyceride in plasma increased(P<0.05) in the birds fed the diet supplemented with 0.5% a blend of prunus mume extract compared to those fed antibiotics supplemented diet. The activities of pancreatic trypsin and amylase, and intestinal hydrolase including disaccharidase were not affected by dietary treatment. The colony forming units(CFU) of lactobacillus in the lower ileal-cecum of the birds fed the diet supplemented with a blend of prunus mume extract was significantly(P<0.05) higher than that of birds fed antibiotic supplemented diet without affecting the CFU of E. coli. In conclusion, the birds fed the diet supplemented a blend of prunus mume as an alternative to antibiotics showed a similar growth performance and an significant increase in lactobacillus population compared with the birds fed basal and antibiotics supplemented diets.