• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.2
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• pp.155-161
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• 2012

Platelet-rich fibrin (PRF) is a strong but flexible fibrin including a enrich platelet which contain growth factors and cytokines. PRF can be made very simply and requires no artificial additives unlike platelet-rich plasma. While PRF is remodeled and released in the tissue, this induces cell growth, vascularization, collagen synthesis, osteoblast differentiation and an anti-inflammatory reaction. Taking advantage of these functions, PRF can stimulate regeneration of bone and soft tissue in a diverse number of ways during the course of hemostasis, wound coverage, preservation, and reconstruction of alveolar bone. Moreover, the use of PRF to improve bone regeneration has become a recent technique in implantology. In this study, through a literature review of PRF's existing clinical applications, we classified a range of potential PRF oral and maxillofacial surgery applications including preservation of extraction sockets, guided bone graft, sinus lift, dressing and periodontal treatment. This trial gave us chance to confirm the usefulness of PRF. Recently, updated clinical studies results concerning skin and tendon wound healing have become available. These results suggest that the usage of RPF will gradually expand.

• Food Science and Preservation
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• v.30 no.1
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• pp.42-51
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• 2023

This study aimed to characterize a lytic Salmonella Typhimurium-specific (ST) phage and its biofilm control capability against S. Typhimurium biofilm on polypropylene surface. ST phage was isolated, propagated, and purified from water used in a slaughterhouse. The morphology of ST phage was observed via transmission electron microscopy. Its bactericidal effect was evaluated by determining bacterial concentrations after the phage treatment at various multiplicities of infection (MOIs) of 0.01, 1.0, and 100. Once the biofilm was formed on the polypropylene tube after incubation at 37℃ for 48 h, the phage was treated and its antibiofilm capability was determined using crystal violet staining and plate count method. The phage was isolated and purified at a final concentration of ~11 log PFU/mL. It was identified as a myophage with an icosahedral head (~104 nm) and contractile tail (~90-115 nm). ST phage could significantly decrease S. Typhimurium population by ~2.8 log CFU/mL at an MOI of 100. After incubation for 48 h, biofilm formation on polypropylene surface was confirmed with a bacterial population of ~6.9 log CFU/cm². After 1 h treatment with ST phage, the bacterial population in the biofilm was reduced by 2.8 log CFU/cm². Therefore, these results suggest that lytic ST phage as a promising biofilm control agent for eradicating S. Typhimurium biofilm formed on food contact surfaces.

• Food Science and Preservation
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• v.30 no.3
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• pp.434-445
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• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.

• Food Science and Preservation
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• v.30 no.5
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• pp.797-810
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• 2023

Elaeagnus umbellata leaves have been reported to suppress inflammation, allergic responses, lung cancer proliferation and oral bacterial growth. Cadmium (Cd) is a heavy metal that has been found to cause many toxicities, including liver toxicity. The aim of this study was to evaluate the capacity of 70% ethanol extract of E. umbellata leaves (EUL) to protect human hepatocytes from Cd toxicity. After exposure of HepG2 cells to Cd at 10 𝜇M for 24 h, cell viability, expression levels of apoptosis- and antioxidant-related proteins, reactive oxygen species (ROS) accumulation and Cd uptake were assessed. EUL protected HepG2 cells from Cd-induced apoptosis as determined by MTT assay. A decrease in caspase-3 and p-p53 protein levels was observed in cells pretreated with EUL prior to Cd exposure. Furthermore, the Cd-induced increase in intracellular DCF fluorescence was attenuated by EUL, indicating that the Cd-induced apoptosis preventing effect was associated with the suppression of ROS accumulation. Moreover, EUL's effects on the inhibition of p38, JNK, and AKT phosphorylation also appear to be associated with protection against Cd toxicity. Moreover, EUL upregulated Cd-depressed expression of Nrf2, HO-1, catalase, and MT-1,2 proteins, suggesting that Cd uptake-induced apoptosis in HepG2 cells may be inhibited by EUL's antioxidative potential.

• Food Science and Preservation
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• v.31 no.3
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• pp.499-505
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• 2024

Patulin has been reported as a risk factor in various foods, especially apple juice. This study monitored residual patulin and polyphenolic content in apple juice during post-irradiation storage conditions. Response surface methodology (RSM) was applied to monitor the changes in dependent variables (Yn, patulin, and polyphenolics) as affected by independent variables, such as storage temperature (Xi, -20℃ to 20℃), irradiation dose (Xii, 0-2 kGy), and storage period (Xiii, 0-20 days), which were based on a central composite design. The predicted peak point resulted in the lowest residual patulin content of 58.42 ppb with the corresponding independent parameter conditions, such as 18.19℃ of storage temperature, 1.24 kGy of irradiation dose, and 13.42 days of storage period. The residual patulin content of 58.42 ppb is the minimum desirable level, representing a 91% reduction compared to the non-irradiated control (675.00 ppb). A maximum polyphenolics content (11.98 mg/g) was obtained under the predicted maximum conditions of 14.40℃, 0.78 kGy, and 3.4 days. The most influential parameter in reducing residual patulin content while maintaining polyphenolic content in apple juice was irradiation dose (p<0.01), which showed potential to be applied in controlling the patulin levels in apple juice.

• Food Science and Preservation
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• v.20 no.3
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• pp.419-423
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• 2013

The objective of this study was to characterize the bactericidal effect of 461nm visible-light LED on three common foodborne bacteria: Escherichia coli O157:H7, Staphylococcus aureus and Vibrio parahaemolyticus. Tests were conducted against pathogen strains that were treated with 461nm LED for 10 h at $15^{\circ}C$. The E. coli (ATCC 43894, ATCC 8739 and ATCC 35150) and the S. aureus (ATCC 27664, ATCC 19095 and ATCC 43300) had average reductions of 2.5, 6.6, 1.5, 2.5 and 2.0 log CFU/mL, respectively, after they were exposed for 10 h to 461nm LED light (p<0.05). In contrast, V. parahaemolyticus (ATCC 43969) had 6 log CFU/mL reductions after it was exposed for 4 h to 461nm LED light. The results showed that both the Gram-positive and Gram-negative bacteria were inactivated with 461nm LED light exposure. Also, the Gram-negative bacteria were more sensitive to the LED treatment than the Gram-positive bacteria. These results show the potential use of 461nm LED as a food preservation and application technology.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.6
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• pp.489-495
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• 2006

In recent years, there has been an interest to use Moringa oleifera as the natural coagulant due to cost, associated health and environmental concerns of synthetic organic polymers and inorganic chemicals. However, it is known that M. oleifera as the natural coagulant is highly biodegradable and has a very short shelf life. This research was carried out to investigate the effects of storage temperature, packaging methods, and freeze-drying on the preservation of M. oleifera seeds powders. Non freeze-dried M. oleifera was prepared into different packaging namely open container, closed container and vacuum packing, whilst, freeze-dried M. oleifera was stored in closed container and vacuum packing. Each of the packaging was stored at room temperature ($30\;to\;32^{\circ}C$) and refrigerator ($4^{\circ}C$). The turbidity removal efficiencies of stored M. oleifera were examined using jar test at monthly interval for 12 months. The results indicated that non freeze-dried M. oleifera kept in the refrigerator ($4^{\circ}C$) would preserve its coagulation efficiency. In addition, closed container and vacuum packing were found to be more appropriate for the preservation of non freeze-dried M. oleifera, compared to open container. Freeze-dried M. oleifera retained its high coagulation efficiency regardless the storage temperature and packaging method for up to 11 months. Besides, higher increment in zeta potential values for water coagulated with freeze-dried M. oleifera indicated the higher frequency of charge neutralization and better coagulation efficiency of freeze-dried M. oleifera, compared to non freeze-dried seeds. As a coagulant, M. oleifera did not affect the pH of the water after treatment.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.381-395
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• 2011

Present work aims to establish an integrated management system of environmental data base for nine typical wind holes or air holes in Korea. It basically deals with definition, geographical distribution, morphological pattern, physical characteristics and anthropogenic environments of wind hole to propose systematic preservation strategy of their periglacial landscape and flora, which are known to be sensitive to global warming. Wind hole, in which cool air blows out during the summer, but mild air comes out during the winter from a cave or hole, is frequently found on northwest- and north-facing slopes on the terminal point of steep talus, block field, and block stream, and can be categorized into three types, i.e., talus, cave and sink types. Environmental characteristics of nine wind holes are analyzed on the basis of their geology, landform, climate, soil, hydrology, vegetation, road, footpath, land-use, and management system, and relevant DB are prepared. Wind hole areas with unique landscape and ecological values need to be designated as a nature reserve, and zoning of core, buffer, and transitional zones are required for the multi-dimensional preservation of periglacial landscape and ecosystem. Phytogeographical values of glacial relict plants, including mountain cranberry(Vaccinium vitis-idaea) at its global southernmost limit at Bangnaeri wind hole, Hongchon County, Gangwon Province of Korea are discussed in detail as a floristic refugia in connection with climate change during the Pleistocene Epoch and potential in-situ and ex-situ preservation sites in the future.

• The Korean Journal of Archival Studies
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• no.39
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• pp.3-43
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• 2014

This paper showed results of the risk management project in detail which was conducted by National Archives of Korea(NAK) in 2010. In the project NAK examined its long-term preservation business of electronic records using DRAMBORA(Digital Repository Audit Method Based on Risk Assessment). NAK has defined 44 different risk elements related to its business activities, assessed and classified them into several grades according to the severity calculated by risk probability score and risk potential impact score, and developed precise management plans for two of the most serious risks. This paper introduced the management plan for one of them. The risk was numbered with NR04 and described by 'Loss of integrity of records information'. This paper explained mitigation strategies, contingency organization, disaster control responsibilities, and personal mission cards for the NR04. This paper planned to give comprehensive understandings to Records Management Organizations about the risk management approaches as an effective way for business management through the case study.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.41-51
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• 2012

To select 10 representatives for the ecotourism networks around the areas bordering national rivers in Korea, the spatial ranges for ecotourism have been established, the ecotourism potential analyzed, and the ecotourism resources information collected by the Regional Environmental Offices and the Korea National Park Service has undergone reviews, amendments, supplements, and verification processes through familiarization tour previews, and the following main results have been derived. First, the spatial ranges of the eco-tourism networks have been set as the watershed areas that include areas around the four major rivers and the rivers. Second, the areas with high potential value for ecotourism were selected through the analysis of ecotourism potential. Since EGIS was used for the analysis, it was inevitable that insufficient amount of localized information was reflected, and the use of the results as reference for the potential would be feasible. Third, it was possible, by reviewing, amending and complementing the results of ecological resource information collected by the Regional Environmental Offices and the Korea National Park Service, to select 50 representative ecological resources around the national rivers. The selected resources were considered for the adjacency, attractiveness of ecological resources, and uniqueness of the national rivers, and they were derived by screening expert advice, official opinion, and geographical analysis information. Fourth, 10 representative ecotourism networks based on watershed areas were selected, and suitable themes were given based on the resource characteristics. Fifth, the appropriateness for ecotourism has been confirmed, with the familiarization tour previews and survey results, preservation of the future ecotourism resources, and the establishment of the foundation as the basis. In the future, the remaining 9 ecotourism networks would also need to undergo a verification process such as familiarization tours. It is deemed that, through future ecotourism contests, if the programs that select locally-pioneered tourism programs resulting from the capacities of local entities and residents, then it would be more effective in discovering resources that are more localized and of higher regional value.