• Polymer(Korea)
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• v.31 no.4
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• pp.329-334
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• 2007

Osmotic pellet system, which is one of the oral drug delivery systems, has been developed to improve manufacturing process, reduce product cost and other problems of osmotic tablet systems. Osmotic pellet is consisted of water swellable seed layer, drug layer, and membrane layer. Among them, the membrane layer plays an important role in a control of the drug release. In this work, we examined the effect of ratio for Eudragit RL and RS on the drug release behavior. Osmotic pellet with nifedipine as a model drug was easily obtained in a good yield by fluidized bed coater. Osmotic pellet showed round morphology with a range of size $1300{\sim}1500\;{\mu}m$. In the experiment of nifedipine release, the release amount increased with the increase of the ratio of Eudragit. This is due to the fact that Eudragit RL contains more hydrophilic quaternary ammonium group than Eudragit RS. Additionally, the release amount was retarded with increasing the membrane thickness. There are no differences in the release amount measured at the different pH 1.2, 6.5, 6.8, and 7.2. In conclusion, it was found that the drug release from osmotic pellets depended on the composition ratio and coating thickness of membrane layer.

• Journal of the Korean Ceramic Society
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• v.54 no.1
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• pp.9-22
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• 2017

Many new functional materials have been studied for efficient production and storage of energy. Many new materials such as sodium-based and sulfide-based materials have been proposed for energy storage, but research on Li batteries is still dominant. Due to the influence of environmental concerns regarding nuclear energy, interest in and research on fusion power are steadily increasing. For the commercialization of nuclear fusion, a design standard based on a considerable level of physical analysis and modeling is proposed. Nevertheless, limitations of existing materials in nuclear fusion environments limit practical applications. Tritium propagation material for continuous fusion reaction is one of the core materials, and therefore research on this material is being carried out intermittently. The key material for Li-based energy storage and tritium generation is the functional material Li-M-O. In this review, a structural description of functional Li-M-O system materials and technical trends for its applications are introduced.

• Nuclear Engineering and Technology
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• v.42 no.3
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• pp.305-312
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• 2010

The protection sequence of an AC/DC converter for an ITER PF coil system is developed in this study. Possible faults in the coil system are simulated and the results reflected in the design of a sequence to protect the coil and converter. The inductances of the current sharing reactors and thyristor numbers in parallel with the bridge arms are optimized with the designed protection sequence.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1386-1388
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• 2012

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.65-72
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• 2014

Plant cells from which the cell walls have been enzymatically or mechanically removed are called protoplasts. The protoplasts are theoretically totipotent and can be used as sources of somatic cell fusion in practical breeding programs. Wild Solanum species have often been used as sources of important agricultural traits including diverse disease resistance. However, they cannot often be directly applied to breeding programs due to their sexual incompatibility with S. tuberosum. Somatic hybridization via protoplast fusion is one of the ideal methods to overcome this limitation and to introgress certain traits into S. tuberosum. This technique has still widely been used in potato since the first fusion was reported in 1970s. Therefore, this review highlights general perspectives of protoplast fusion and discusses the application of protoplast fusion in potato breeding.

• Journal of Korean Society for Quality Management
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• v.49 no.1
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• pp.1-15
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• 2021

Purpose: The purpose of this study was to propose a sensor fusion algorithm that integrates vehicle motion sensor(VMS) into the hybrid navigation system. Methods: How to evaluate the navigation performance was comparison test with the hybrid navigation system and the sensor fusion method. Results: The results of this study are as follows. It was found that the effects of the sensor fusion method and α value estimation were significant. Applying these greatly improves the navigation performance. Conclusion: For improving the reliability of navigation system, the sensor fusion method shows that the proposed method improves the navigation performance in a combat vehicle.

• International Journal of Computer Science & Network Security
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• v.23 no.4
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• pp.39-47
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• 2023

This study compares various transformation techniques for multifocus image fusion. Multi-focus image fusion is a procedure of merging multiple images captured at unalike focus distances to produce a single composite image with improved sharpness and clarity. In this research, the purpose is to compare different popular frequency domain approaches for multi-focus image fusion, such as Discrete Wavelet Transforms (DWT), Stationary Wavelet Transforms (SWT), DCT-based Laplacian Pyramid (DCT-LP), Discrete Cosine Harmonic Wavelet Transform (DC-HWT), and Dual-Tree Complex Wavelet Transform (DT-CWT). The objective is to increase the understanding of these transformation techniques and how they can be utilized in conjunction with one another. The analysis will evaluate the 10 most crucial parameters and highlight the unique features of each method. The results will help determine which transformation technique is the best for multi-focus image fusion applications. Based on the visual and statistical analysis, it is suggested that the DCT-LP is the most appropriate technique, but the results also provide valuable insights into choosing the right approach.

• Biomolecules & Therapeutics
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• v.29 no.3
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• pp.282-289
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• 2021

A novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), caused a worldwide pandemic. Our aim in this study is to produce new fusion inhibitors against SARS-CoV-2, which can be the basis for developing new antiviral drugs. The fusion core comprising the heptad repeat domains (HR1 and HR2) of SARS-CoV-2 spike (S) were used to design the peptides. A total of twelve peptides were generated, comprising a short or truncated 24-mer (peptide #1), a long 36-mer peptide (peptide #2), and ten peptide #2 analogs. In contrast to SARS-CoV, SARS-CoV-2 S-mediated cell-cell fusion cannot be inhibited with a minimal length, 24-mer peptide. Peptide #2 demonstrated potent inhibition of SARS-CoV-2 S-mediated cell-cell fusion at 1 µM concentration. Three peptide #2 analogs showed IC50 values in the low micromolar range (4.7-9.8 µM). Peptide #2 inhibited the SARS-CoV-2 pseudovirus assay at IC50=1.49 µM. Given their potent inhibition of viral activity and safety and lack of cytotoxicity, these peptides provide an attractive avenue for the development of new prophylactic and therapeutic agents against SARS-CoV-2.

• Polymer(Korea)
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• v.31 no.1
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• pp.14-19
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• 2007

Demineralized bone particle (DBP) has been used as one of the powerful inducers of bone and cartilage tissue specialization. In this study, we fabricated DBP/PLGA scaffold for tissue engineered disc regeneration. We manufactured dual-structured scaffold to compose inner cylinder and outer doughnut similar to nature disc tissue. The DBP/PLGA scaffold was characterized by porosity, wettability, and water uptake ability. We isolated and cultured nucleus pulposus (NP) and annulus fibrosus (AF) cells from rabbit intervertebral disc. We seeded NP cells into the inner core of the hybrid scaffold and AF cells into the outer portion of it. Cellular viability and proliferation were assayed by 3-(4,5-dimethylthiazole-2-yl) -2,5- diphenyltetrazolium -bromide (MTT) test. PLGA and PLGA/DBP scaffolds were implanted in subcutaneous of athymic nude mouse to observe the formation of disc-like tissue in vivo. And then we observed change of morphology and hematoxylin and eosin (H&E). Formation of disc-like tissue was better DBP/PLGA hybrid scaffold than control. Specially, we confirmed that scaffold impregnated 20 and 40% DBP affected to proliferation of disc cell and formation of disc-like tissue.

• Polymer(Korea)
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• v.32 no.1
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• pp.26-30
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• 2008

This study was designed to investigate the effect of hybridization of synthetic/natural materials for annulus fibrosus (AF) tissue regeneration in vitro and in vivo. The synthetic/natural hybrid scaffolds were prepared using PLGA (poly (lactic-co-glycolic) acid), SIS (small intestinal submucosa) and DBP (demineralized bone particles). PLGA, PLGA/SIS(20%), PLGA/DBP(20%) and PLGA/SIS (10%)/DBP (10%) scaffold were manufactured by solvent casting/salt leaching method. Compressive strength was measured. Rabbit AF cells were isolated, cultured and seeded into experimental groups. Hydroxyproline production and DNA quantity of AP cells on each scaffold was measured at 2, 4 and 6 weeks after in vitro culture. Cell-scaffold composites were implanted subcutaneously into athymic mice. After 1,4 and 6 weeks postoperatively, specimens were taken and H&E, Safranin-O and type I collagen staining were carried out concerning formation of cartilagenous tissue. In vitro PLGA/SIS scaffold was evaluated for total collagen content (bydroryproline/DNA content) and PLGA scaffold was evaluated for compressive strength.