• The Korean Journal of Nuclear Medicine
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• v.39 no.5
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• pp.278-283
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• 2005

Purpose: In prior study, we synthesized $^{99m}Tc$-galactosylated chitosan (GC) and performed in vivo biodistribution study, showed specific targeting to hepatocyte. The aim of this study is to evaluate the labeling efficiency and cytotoxicity of modified galactosylated chitosan compounds, galactosyl methylated chitosan (GMC) and HYNIC-galactosylated chitosan (GCH). Materials and Methods: GC, GMC and GCH were synthesized and radiolabeled with $^{99m}Tc$. Then, they were incubated for 6 hours at room temperature and human serum at $37^{\circ}C$. Labeling efficiencies were determined at 15, 30 m, 1, 2, 3 and 6 h after radiolabeling. To evaluate cytotoxicity, MTT assay was performed in HeLa and HepG2 cells. Results: In comparison with them of $^{99m}Tc$-GC labeling efficiencies of $^{99m}Tc$-GMC were significantly improved (100, 97 and 89%) in acetone and 96.3, 95.8 and 75.6% in saline at 15 m, 1 and 6 h, respectively). Moreover, $^{99m}Tc$-GCH showed more improved labeling efficiencies (>95% in acetone and human serum and >90% in saline at 6 h). In MTT assay, cytotoxicity was very low and not different from that of controls. Conclusion: These results represent that these compounds are radiochemically compatible radiopharmaceuticals, can be used in hepatocyte specific imaging study and in vivo gene or drug delivery monitoring.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.1
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• pp.9-21
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• 2006

Foods and related substances from diverse sources known to have a potential for disease risk reduction are called functional foods, while nutraceuticals are bioactive compounds isolated from food and sold in dosage form. Nutraceutical and functional food industries are rapidly growing in recent years and most of the cases development of these functional materials involves certain biotransformation processes. A number of bioactive compounds has been identified up to date and isolated from seafood related products through enzyme-mediated hydrolysis. The enzymatic bioconversion process require suitable biocatalysts and appropriate bioreactor systems to incubate byproducts with digestive enzymes. Membrane bioreactor technology is recently emerging for the development of bioactive compounds from seafood processing byproducts.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.174-174
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• 1998

Twelve different derivatives were synthesised from chitin/chitosan[1, 2, 3]. Their structures have been determined by different physical methods. The bioassay screening on antifungal and antibacterial activities of all these compounds showed that most of them had significant activity and they can inhibite the growth of some fungi and bacterias : E. coli, S. pyogenes, F. oxysporum, P. oryzae, that caused the spoilage of fresh fruits and foods. Furthermore, all of these compounds are non-toxic (LD$\_$50/>50g/kg) and can be applied for food preservation.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.236-238
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• 2004

Functional porperties such as CL, VP and EM did not affected by the addition of chitosans, however, level and MW of chitosans affected textural properties of LFSs, resulting in harder and springer texture of LFSs containing 0.3% MME chitosan as compared to others, Approximately 9 flavor compounds were different between RFC and LFS, and the addition of chitosans did not affected volatile compounds in the LFSs.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.294-300
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• 2003

The anionic agent containing dichloro-s-triazinyl reactive group was synthesized and applied to the cotton fabrics to introduce covalent bonds. This attempt was expected to improve the affinities of cationic compounds, such as cationic dyes, chitosan, quaternary ammonium antimicrobial agents and metal ions, by the electrostatic attractive force. As expected, the anionic agent was reacted with cotton fabrics at room temperature. In order to examine the adsorptivity of the cationic compounds on to the anionized cotton fabrics, firstly a cationic dye(C. I. Basic Violet 7) was applied. The color strength of the dyeing of anioized cotton fabric was highly increased comparing to that of untreated fabric.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.311-318
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• 2010

Antimicrobial finishing of textiles has been found to be an economical way to prevent (or treat) skin disorders. Hence, this research effort was aimed at elucidating the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon six dermal reference microorganisms, as well as the influence of the interactions with cotton fabrics on said activity. Using 3 chitosans with different MWs, as well as two chitooligosaccharide (COS) mixtures, a relevant antimicrobial effect was observed by 24 h for the six microorganisms tested; it was apparent that the antimicrobial effect is strongly dependent on the type of target microorganism and on the MW of chitosan - being higher for lower MW in the case of E. coli, K. pneumoniae, and P. aeruginosa, and the reverse in the case of both Gram-positive bacteria. Furthermore, a strong antifungal effect was detectable upon C. albicans, resembling the action over Gram-positive bacteria. Interactions with cotton fabric resulted in a loss of COS activity when compared with cultured media, relative to the effect over Gram-negative bacteria. However, no significant differences for the efficacy of all the 5 compounds were observed by 4 h. The three chitosans possessed a higher antimicrobial activity when impregnated onto the fabric, and presented a similar effect on both Gram-positive bacteria and yeast, in either matrix. Pseudomonas aeruginosa showed to be the most resistant microorganism to all five compounds.

• Food Science and Preservation
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• v.30 no.2
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• pp.179-189
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• 2023

Consumers and industry experts frequently have negative perceptions of most chemical preservatives. Although most people concede that they cannot resolve global food waste issues without preservatives, they prefer products without chemical preservatives. Numerous emerging technologies is now surpassing conventional methods for mitigating microbial food deterioration in response to consumer demand and fundamental health and safety considerations, including biological antimicrobial systems such as using food-grade microorganisms and their metabolites primarily originating from microorganisms, plants, and animals. Microbial compounds, including bacteriocins, bacteriophages, and anti-fungal agents, plant extracts such as flavonoids and essential oils; and animal-originated compounds, such as lysozyme, chitosan, and lactoferrin, are considered some of the major bio-preservatives. These natural compounds can be used alone or with other preservatives to improve food safety. Hence, the use of microbes or their metabolic byproducts to extend the shelf life of foods while maintaining safety standards is known as bio-preservation. To manufacture and consume foods in a safe condition, this review primarily aims to broaden knowledge amongst industry professionals and consumers regarding bio-preservation techniques, bio-preservatives, their classifications, and distinctive mechanisms to enhance food safety.

• Mycobiology
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• v.45 no.4
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• pp.409-420
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• 2017

Foliar sprays of three plant resistance inducers, including chitosan (CH), potassium sorbate (PS) ($C_6H_7kO_2$), and potassium bicarbonates (PB) ($KHCO_3$), were used for resistance inducing against Erysiphe cichoracearum DC (powdery mildew) infecting okra plants. Experiments under green house and field conditions showed that, the powdery mildew disease severity was significantly reduced with all tested treatments of CH, PS, and PB in comparison with untreated control. CH at 0.5% and 0.75% (w/v) plus PS at 1.0% and 2.0% and/or PB at 2.0% or 3.0% recorded as the most effective treatments. Moreover, the highest values of vegetative studies and yield were observed with such treatments. CH and potassium salts treatments reflected many compounds of defense singles which leading to the activation power defense system in okra plant. The highest records of reduction in powdery mildew were accompanied with increasing in total phenolic, protein content and increased the activity of polyphenol oxidase, peroxidase, chitinase, and ${\beta}$-1,3-glucanase in okra plants. Meanwhile, single treatments of CH, PS, and PB at high concentration (0.75%, 2.0%, and/or 3.0%) caused considerable effects. Therefore, application of CH and potassium salts as natural and chemical inducers by foliar methods can be used to control of powdery mildew disease at early stages of growth and led to a maximum fruit yield in okra plants.

• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.347-357
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• 2015

This experiment was conducted to test the efficiency of environmentally friendly materials for controlling garlic leaf blight by Stemphylium botryosum. Fifty five kinds of environmental friendly control agents are obtained from commercial market and are tested for spore germination using 96 well plate and among them, five agents (copper-, sulfur-, medinal herb extract-, sulfur+sodium bicarbonate- and oligo chitosan based compound) are selected for field test from 2012 and 2013 year. With reference of 2012 year test result, copper and oligo chitosan based compounds are chosen as 2013 year test. When the first symptoms were appeared early May season and environmental friendly control agents are applied as prompt as possible, the control value of copper and oligo chitosan based agents are 54% and 90% respectively as compared to the occasion of chemical agent Antracol WP (propineb 70%) and yield of bulbs are increased by 16% and 34% against untreated control and marketable garlic bulb yield were 79% and 95% against Antracol WP treatment, respectively. From this result, oligo chitosan based compound can be a good organic control agent candidate for garlic leaf blight disease in organic garlic cultivation.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1719-1723
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• 2009

The LiFeP$O_4$ powder was synthesized by using the solid state reaction method with Fe($C_2O_4){\cdot}2H_2O,\;(NH_4)_2HPO_4,\;Li_2CO_3$, and chitosan as a carbon precursor material for a cathode of a lithium-ion battery. The chitosan added LiFePO4 powder was calcined at 350 ${^{\circ}C}$ for 5 hours and then 800 ${^{\circ}C}$ for 12 hours for the calcination. Then we calcined again at 800 ${^{\circ}C}$ for 12 hours. We characterized the synthesized compounds via the crystallinity, the valence states of iron ions, and their shapes using TGA, XRD, SEM, TEM, and XPS. We found that the synthesized powders were carbon-coated using TEM images and the iron ion is substituted from 3+ to 2+ through XPS measurements. We observed voltage characteristics and initial charge-discharge characteristics according to the C rate in LiFeP$O_4$ batteries. The obtained initial specific capacity of the chitosan added LiFeP$O_4$ powder is 110 mAh/g, which is much larger than that of LiFeP$O_4$ only powder.