• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1951-1964
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• 2016

1,4-Dioxane-degrading bacterial consortia were enriched from forest soil (FS) and activated sludge (AS) using a defined medium containing 1,4-dioxane as the sole carbon source. These two enrichments cultures appeared to have inducible tetrahydrofuran/dioxane and propane degradation enzymes. According to qPCR results on the 16S rRNA and soluble di-iron monooxygenase genes, the relative abundances of 1,4-dioxane-degrading bacteria to total bacteria in FS and AS were 29.4% and 57.8%, respectively. For FS, the cell growth yields (Y), maximum specific degradation rate ($V_{max}$), and half-saturation concentration ($K_m$) were 0.58 mg-protein/mg-dioxane, $0.037mg-dioxane/mg-protein{\cdot}h$, and 93.9 mg/l, respectively. For AS, Y, $V_{max}$, and $K_m$ were 0.34 mg-protein/mg-dioxane, $0.078mg-dioxane/mg-protein{\cdot}h$, and 181.3 mg/l, respectively. These kinetics data of FS and AS were similar to previously reported values. Based on bacterial community analysis on 16S rRNA gene sequences of the two enrichment cultures, the FS consortium was identified to contain 38.3% of Mycobacterium and 10.6% of Afipia, similar to previously reported literature. Meanwhile, 49.5% of the AS consortium belonged to the candidate division TM7, which has never been reported to be involved in 1,4-dioxane biodegradation. However, recent studies suggested that TM7 bacteria were associated with degradation of non-biodegradable and hazardous materials. Therefore, our results showed that previously unknown 1,4-dioxane-degrading bacteria might play an important role in enriched AS. Although the metabolic capability and ecophysiological significance of the predominant TM7 bacteria in AS enrichment culture remain unclear, our data reveal hidden characteristics of the TM7 phylum and provide a perspective for studying this previously uncultured phylotype.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.543-549
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• 2004

Chitosan has been widely researched as bone substitution materials and membranes in orthopedic/periodontal applications. Chitosan nanofiber membrane was fabricated by chitosan nanofiber using electrospinning technique. The structure of the membrane is nonwoven, three-dimensional, porous, and nanoscale fiber-based matrix. The aim of this study was to evaluate the biocompatibility of chitosan nanofiber membrane and to evaluate its capacity of bone regeneration in rabbit calvarial defect. Ten mm diameter round cranial defects were made and covered by 2 kinds of membranes (Gore-Tex membrane, chitosan nanofiber membrane) in rabbits. Animals were sacrificed at 4 weeks after surgery. Decalcified specimens were prepared and observed by microscope. Chitosan nanofiber membrane maintained its shape and space at 4 weeks. No inflammatory cells were seen on the surface of the membrane. In calvarial defects, new bone bridges were formed at all defect areas and fused to original old bone. No distortion and resorption was observed in the grafted chitosan nanofiber membrane. However bone bridge formation and new bone formation at the center of the defect could not be seen in Gore-Tex membranes. It is concluded that the novel membrane made of chitosan nanofiber by electrospinning technique may be used as a possible tool for guided bone regeneration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.5
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• pp.417-433
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• 2006

Purpose : Platelet rich plasma (PRP) is an autologous material with many growth factors, such as BMPs, PDGF, $TGF-{\beta}_1$, $TGF-{\beta}_2$, VEGF, and IGF, facilitating bone healing process. The prominent osteoconductive activity and the biodegradable nature of beta-tricalciumphosphate (${\beta}-TCP$) for bone grafts in animal experiments have been reported. The purpose of this study was to evaluate the effect of PRP on the osteogenesis of ${\beta}-TCP$. Materials & Methods : Two artificial calvarial bone defects were made in 32 rabbits which were divided into 2 groups. In one group of 16 rabbits, autogenous bone / ${\beta}-TCP$ was grafted on each side of cranial bone defect. In the other group of 16 rabbits, mixture of ${\beta}-TCP$ and PRP / PRP alone was grafted on each side of the cranial bone defect. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery. The specimens were harvested and examined histologically and immunohistochemically by the expression of BMP2/4/7, PDGF, VEGF and $TGF-{\beta}_1$. Results : The mean volume of new bone formation was significantly higher at 4, 8, 12 weeks in autogenous graft than that in ${\beta}-TCP$. The BMP2/4 expression was significantly higher at 4 weeks in autogenous bone graft and at 4 weeks in mixture of ${\beta}-TCP$ and PRP and at 12 weeks in ${\beta}-TCP$. The expression of BMP7, PDGF, VEGF and $TGF-{\beta}_1$ showed no significant difference in autogenous, ${\beta}-TCP$, mixture of ${\beta}-TCP$ and PRP, and PRP alone during grafted bone regeneration. Conclusion : The results showed that PRP had no additional value in promoting healing process of ${\beta}-TCP$ grafts.

• Polymer(Korea)
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• v.29 no.1
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• pp.36-40
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• 2005

Poly(amino acid) derivatives have been widely investigated as a drug carrier in drug delivery system. Particularly,polysuccinimide (PSI) is one of the most promising drug carriers since it possesses suitable physicochemical characteristics for development of macromolecular prodrugs, due to biocompatibility and biodegradability. In this study, we deal with the synthesis of polyaspartamide having various functional groups such as methoxy-poly(ethylene glycol) (MPEG) via ring closing of PSI. PSI was synthesized by polyonensation polymerization of spartic acid. The variety of average molecular weight was confirmed with reacion time and catalyst content to observe the optimum condition of synthesis. MPEG, hydrophilic chain, was bonded to fabricate polymeric micell composed of hydrophilic and hydrophobic polymer. All materials were characterized by 1H-NMR, FT-IR and GPC. In addition, the formation of nanoparticle micelle as drug carrier were also examined. Micelle size was measured by ELS and AFM. The functionalized polysparamide formed nanoparticle micelle whose size ranged from 90 to 130 nm. In conclusion, we prepared polyaspartamide functionalized with PEG examined the possibility as drug carriers.

• Polymer(Korea)
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• v.32 no.6
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• pp.516-522
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• 2008

Biodegradable polymers have been used extensively as scaffolding materials to regenerate new tissues and the ingrowth of tissue have been reported to be dependent directly of the porosity, pore diameter, pore shape, and porous structure of the scaffold. In this study, porous poly (L-lactide-co-glycolide) (PLGA) scaffolds with five different pore sizes were fabricated to investigate the effect of pore sizes for AF tissue regeneration. Cellular viability and proliferation were assayed by MTT test. Hydroxyproline/DNA content of AF cells on each scaffold was measured. sGAG analyses were performed at each time point of 2 and 6 weeks. Scaffold seeded AF cells were implanted into the back of athymic nude mouse to observe the difference of formation of disc-like tissue depending on pore size in vivo. We confirmed that scaffold with $180{\sim}250{\mu}m$ pores displayed high cell viability in vitro and produced higher ECM than scaffold with other pore sizes in vivo.

• Journal of Life Science
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• v.29 no.3
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• pp.382-393
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• 2019

Wound care is a health industry concern affecting millions worldwide. Recent increase in metabolic disorders such as diabetes comes with elevated risk of wound-based complications. Treatment and management of wounds are difficult practices due to complexity of the wound healing process. Conventional wound dressings and treatment applications only provide limited benefits which are mainly aimed to keep wound protected from external factors. To improve wound care, recent developments make biopolymers to be of high interest and importance to researchers and medical practitioners. Biopolymers are polymers or natural origin produced by living organisms. They are credited to be highly biocompatible and biodegradable. Currently, studies reported biopolymers to exhibit various health beneficial properties such as antimicrobial, anti-inflammatory, hemostatic, cell proliferative and angiogenic activities which are crucial for effective wound management. Several biopolymers, namely chitosan, cellulose, collagen, hyaluronic acid and alginic acid have been already investigated and applied as wound dressing agents. Different derivatives of biopolymers have also been developed by cross-linking with other molecules, grafting with other polymers, and loading with bioactive agents or drugs which showed promising results towards wound healing without any undesired outcome such as scarring and physiological abnormalities. In this review, current applications of common biopolymers in wound treatment industry are highlighted to be a guide for further applications and studies.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.1-8
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• 2022

With the spread of COVID-19 worldwide, non-face-to-face services have grown rapidly, but at the same time, the problem of plastic waste is getting worse. Accordingly, eco-friendly policies such as carbon neutrality and sustainable circular economy are being promoted worldwide. Due to the high demand for eco-friendly products, the packaging industry is trying to develop eco-friendly packaging materials using PLA and PBAT and create new business models. On the other hand, Ulva australis occurs in large quantities in the southern seas of Korea and off the coast of Jeju Island, causing marine environmental problems. In this study, lactic acid was produced through dilute acid pretreatment, enzymatic saccharification, and fermentation processes to utilize Ulva australis as a new alternative energy raw material. In general, seaweeds vary in carbohydrate content and sugar composition depending on the species, harvest location, and time. Seaweed is mainly composed of polysaccharides such as cellulose, alginate, mannan, and xylan, but does not contain lignin. It is difficult to expect high extraction yield of the complex polysaccharide constituting Ulva australis with only one process. However, the fusion process of dilute acid and enzymatic saccharification presented in this study can extract most of the sugars contained in Ulva australis. Therefore, the fusion process is considered to be able to expect high lactic acid production yield when a commercial-scale production process is established.

• Composites Research
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• v.36 no.5
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• pp.297-302
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• 2023

There are several methods for shaping foams, but the most commonly used methods involve the use of resin mixed with a foaming agent, which is then foamed under high temperature and pressure in the case of compression foaming, or foamed under high temperature without applying pressure in the case of atmospheric foaming. The polymers used for foaming require design and analysis of optimal foaming conditions in order to achieve foaming under ambient pressure. Environmentally friendly bio-based polymers face challenges when it comes to foaming on their own, which has led to ongoing research in blending them with resins capable of traditional foam production. This study investigates changes in the characteristics of bio-based polymer-EVA blend foams based on variations in the content of bio-based polymers and explores the optimal foaming conditions according to crosslinking. The correlation between foaming characteristics and mechanical properties of the foams was examined. Through this research, we gained insights into how the content of bio-based polymers affects the properties of foams containing bio-based polymers and identified differences between ambient pressure and high-pressure foaming processes. Additionally, the feasibility of commercializing bio-based polymer-EVA composite foams was confirmed.

• IMMUNE NETWORK
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• v.22 no.5
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• pp.42.1-42.20
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• 2022

Vaccination with tumor peptide epitopes associated with MHC class I molecules is an attractive approach directed at inducing tumor-specific CTLs. However, challenges remain in improving the therapeutic efficacy of peptide epitope vaccines, including the low immunogenicity of peptide epitopes and insufficient stimulation of innate immune components in vivo. To overcome this, we aimed to develop and test an innovative strategy that elicits potent CTL responses against tumor epitopes. The essential feature of this strategy is vaccination using tumor epitope-loaded nanoparticles (NPs) in combination with polyinosinic-polycytidylic acid (poly-IC) and anti-PD1 mAb. Carboxylated NPs were prepared using poly(lactic-co-glycolic acid) and poly(ethylene/maleic anhydride), covalently conjugated with anti-H-2K^b mAbs, and then attached to H-2K^b molecules isolated from the tumor mass (H-2^b). Native peptides associated with the H-2K^b molecules of H-2K^b-attached NPs were exchanged with tumor peptide epitopes. Tumor peptide epitope-loaded NPs efficiently induced tumor-specific CTLs when used to immunize tumor-bearing mice as well as normal mice. This activity of the NPs significantly was increased when co-administered with poly-IC. Accordingly, the NPs exerted significant anti-tumor effects in mice implanted with EG7-OVA thymoma or B16-F10 melanoma, and the anti-tumor activity of the NPs was significantly increased when applied in combination with poly-IC. The most potent anti-tumor activity was observed when the NPs were co-administered with both poly-IC and anti-PD1 mAb. Immunization with tumor epitope-loaded NPs in combination with poly-IC and anti-PD1 mAb in tumor-bearing mice can be a powerful means to induce tumor-specific CTLs with therapeutic anti-tumor activity.

• The Korean Journal of Franchise Management
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• v.2 no.2
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• pp.45-69
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• 2011

A basic function of packaging is preservability, delivery, subdivision, aesthetic and serviceability on packaging. Originally, the function and necessity of packaging is on preservability, but today it is expending before. then packaging is focusing on sales promotion. Although it is hard to say production itself, it could does when it is made. also, it is important for product to be goods when packaging and its materials are identification on matching each other. The role of packaging design is a core factor that satisfy consumer a various of needs and wants. In the past, the role of food packaging design is just preservability and delivery on product. but then, nawaday it is asked a various role. Not only present products have to get inherency but also have added value. That is, advanced technologies, information, and richness from materials which are diversity for coming a extention of choice. currently, food packaging design shouldn't have stayed on just packaging which cover beautiful. Packaging design is a symbolic sign. It is importance for manager to do R&D, producing, and distribution, also for consumer who use and buy the product whether manager and consumer think package design is a main mediation. This day, food design pay attention to be asking consumer's a number of sensitivity. It is the reason that the package is importance and exist. This article is to examine preservability, delivery, subdivision, aesthetic, serviceability, and environmental orientation in order to develop and show a method and theories to find package design in food industry the reason that why sales promotion and its profit increase. Consequently, draw on the function of package design effects the benefit on product is distribution. Green Design on the food packages by combining recycled and biodegradable food packages for the development of practices and long life to the look of the food package design practices.