• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.217-223
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• 1990

This study was undertaken to find out the changes of chemically modified egg albumen grl after heat treatment at $95^{\circ}C$ for 30 minutes or at $120^{\circ}C$ for 30 minutes. Acetylation and succinylation increased the hardness of egg albumen gel, it was rather higher at high heat treatment($120^{\circ}C$, 30min.) than at low heat treatment($95^{\circ}C$, 30min). The cohesiveness of egg albumen gel was improved remarkably by succinylation and maleylation at both low and high heat treatment. The lightness and yellowness of egg albumen gel were decreased by chemical modification. Initial heat denaturation temperature of egg albumen was increased by 11$^{\circ}C$ by acetylation, by $12.5^{\circ}C$ by maleylation and by ,$14.5^{\circ}C$ by succinylation.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.83-86
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• 2003

A reverse transcription polymerase chain reaction (RT-PCR) protocol was developed using two specific 22-mer primers located in coat protein gene of SPFMV. A 411 bp PCR-product was detected in virus infected plants as well as tissue culture raised sweet potato but not in healthy plants. For optimization of RT-PCR protocol, the optimum crude nucleic acid concentration, annealing temperature, primer concentration and numbers of PCR-cycle for maximum sensitivity and specificity were determined. The optimum condition for RT-PCR was as follows: RT-PCR reaction mixture was one-step mixture, containing 50 pmol of primer, 30 units of reverse transcriptase, 5 units of RNasin, and the crude nucleic acid extracts (200 ng). In RT-PCR, cDNA was synthesized at $42^{\circ}C$ for 45 min before a quick incubation on ice after pre-denaturation at $95^{\circ}C$ for 5 min. The PCR reaction was carried out for 40 cycles at $96^{\circ}C$ for 30 see, $63^{\circ}C$ for 30 sec, $72^{\circ}C$ for 1 min, and finally at $72^{\circ}C$ for 10 min. The viral origin of the amplified product was confirmed by sequencing, with the sequence obtained having $95-98\%$ homology with published sequence data for SPFMV. The benefits of this RT-PCR based detection of SPFMV would be simple, rapid and specific.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.329-335
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• 1984

The effect of peeling methods, spherecity and weight of potatoes and carrots on the peeling efficiency were investigated. The changes in the surface texture by peeling were estimated by Rheometer and were related to the changes in the microstructure. The optimum mechanical peeling conditions using abrasion type rotary peeler were 90 sec. at 300 rpm for potatoes, 70 sec. at 300 rpm for sweet potatoes and 60 sec. at 300 rpm for carrots. The peeling loss was influenced by the sphericity and weight of the sample. The optimum conditions for alkali peeling were 90 sec. immersion in boiling 10% NaOH solution for potatoes, 300 sec. in boiling 10% NaOH solution for sweet potatoes and 60 sec. in boiling 6% NaOH solution for carrots. Severe damage of surface structure was noticed by alkali peeling, demonstrated by denaturation of starch granules in the cell. The structural damage observed by microscope was related to the reduction of cutting force after peeling.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1611-1620
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• 2019

Objective: The aim was to investigate the influence of ultrasound and adenosine 5'-monophosphate (AMP) marination (UAMP) on tenderness and structure of myofibrillar proteins of beef. Methods: Five groups, the untreated meat (Control), deionized water marination (DW), ultrasound followed by DW (UDW), AMP marination (AMP), and ultrasound followed by AMP (UAMP) were studied. Myofibrillar fragmentation, cooking loss, shear force, thermograms, histological observation of meats and myofibrillar proteins properties were investigated in these different treatments. Results: The results showed that UAMP significantly increased myofibrillar fragmentation index from 152 (Control), 231 (AMP), and 307 (UDW) to 355 (p<0.05), respectively. The lowest cooking loss, shear force and peak denaturation temperature were observed in UAMP. In histological observation, UDW and UAMP had more fragmented muscular bundles than the others. Furthermore, a drastic increase in ${\alpha}$-helix and decrease in ${\beta}$-sheet of myofibrillar proteins was observed in UAMP, implying the disaggregation of protein samples. The synchronous fluorescence spectra of myofibrillar proteins in UAMP suggested the combination of ultrasound and AMP could accelerate the unfolding molecular structure and destroying hydrophobic interactions. The results of circular dichroism and synchronous fluorescence spectra for myofibrillar proteins coincided with the microstructures of beef. Conclusion: The results indicate that ultrasound combined with AMP improved meat tenderness not only by disruption in muscle integrity, increasing water retention, but also altering their spatial structure of myofibrillar proteins.

• Food Science and Industry
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• v.53 no.3
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• pp.277-283
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• 2020

Microbial disinfection is essential to increase the preservation and safety of food. In general, thermal sterilization technology is most frequently used, but it often causes nutrient denaturation, and deterioration of food quality. Accordingly, non-thermal sterilization using a novel technology is emerging as an alternative technology. Among them, ultrasonic technology produces a disinfection effect by promoting the destruction of microorganisms by cavitation. Ultrasound technology alone has a low effect, so research is being actively conducted to develop an effective technology by applying as a hurdle technology with various other technologies. Ultrasound can be treated with various processes including traditional sterilization methods such as heating, high pressure, and chemical treatment, as well as novel technologies such as ultraviolet irradiation. Ultrasound assisted sterilization technology still remains at the laboratory level, requiring additional research such as the development of equipment for industrial application and establishment of an optimal process.

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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• pp.673-697
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• 2018

BACKGROUND: Cartilage tissue engineering (CTE) aims to obtain a structure mimicking native cartilage tissue through the combination of relevant cells, three-dimensional scaffolds, and extraneous signals. Implantation of 'matured' constructs is thus expected to provide solution for treating large injury of articular cartilage. Type I collagen is widely used as scaffolds for CTE products undergoing clinical trial, owing to its ubiquitous biocompatibility and vast clinical approval. However, the long-term performance of pure type I collagen scaffolds would suffer from its limited chondrogenic capacity and inferior mechanical properties. This paper aims to provide insights necessary for advancing type I collagen scaffolds in the CTE applications. METHODS: Initially, the interactions of type I/II collagen with CTE-relevant cells [i.e., articular chondrocytes (ACs) and mesenchymal stem cells (MSCs)] are discussed. Next, the physical features and chemical composition of the scaffolds crucial to support chondrogenic activities of AC and MSC are highlighted. Attempts to optimize the collagen scaffolds by blending with natural/synthetic polymers are described. Hybrid strategy in which collagen and structural polymers are combined in non-blending manner is detailed. RESULTS: Type I collagen is sufficient to support cellular activities of ACs and MSCs; however it shows limited chondrogenic performance than type II collagen. Nonetheless, type I collagen is the clinically feasible option since type II collagen shows arthritogenic potency. Physical features of scaffolds such as internal structure, pore size, stiffness, etc. are shown to be crucial in influencing the differentiation fate and secreting extracellular matrixes from ACs and MSCs. Collagen can be blended with native or synthetic polymer to improve the mechanical and bioactivities of final composites. However, the versatility of blending strategy is limited due to denaturation of type I collagen at harsh processing condition. Hybrid strategy is successful in maximizing bioactivity of collagen scaffolds and mechanical robustness of structural polymer. CONCLUSION: Considering the previous improvements of physical and compositional properties of collagen scaffolds and recent manufacturing developments of structural polymer, it is concluded that hybrid strategy is a promising approach to advance further collagen-based scaffolds in CTE.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1905-1911
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• 2020

Homoserine dehydrogenase (HSD) catalyzes the reversible conversion of ʟ-aspartate-4-semialdehyde to ʟ-homoserine in the aspartate pathway for the biosynthesis of lysine, methionine, threonine, and isoleucine. HSD has attracted great attention for medical and industrial purposes due to its recognized application in the development of pesticides and is being utilized in the large scale production of ʟ-lysine. In this study, HSD from Bacillus subtilis (BsHSD) was overexpressed in Escherichia coli and purified to homogeneity for biochemical characterization. We examined the enzymatic activity of BsHSD for ʟ-homoserine oxidation and found that BsHSD exclusively prefers NADP+ to NAD+ and that its activity was maximal at pH 9.0 and in the presence of 0.4 M NaCl. By kinetic analysis, Km values for ʟ-homoserine and NADP+ were found to be 35.08 ± 2.91 mM and 0.39 ± 0.05 mM, respectively, and the Vmax values were 2.72 ± 0.06 μmol/min-1 mg-1 and 2.79 ± 0.11 μmol/min-1 mg-1, respectively. The apparent molecular mass determined with size-exclusion chromatography indicated that BsHSD forms a tetramer, in contrast to the previously reported dimeric HSDs from other organisms. This novel oligomeric assembly can be attributed to the additional C-terminal ACT domain of BsHSD. Thermal denaturation monitoring by circular dichroism spectroscopy was used to determine its melting temperature, which was 54.8℃. The molecular and biochemical features of BsHSD revealed in this study may lay the foundation for future studies on amino acid metabolism and its application for industrial and medical purposes.

• Animal Bioscience
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• v.35 no.2
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• pp.236-246
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• 2022

Objective: The objective of this study was to investigate the effect of dietary pumpkin (Cucurbita moschata) seed meal (PSM) on laying hens' performance, quality, fatty acids, cholesterol, antioxidant compounds and shelf life of eggs. Methods: Eighty Tetra SL laying hens, 50-week-old, were randomly divided into two equal groups, having 10 replicates with 4 birds in each. The control (CON) treatment was fed with basal diet, while experimental treatment was fed a diet with 9% PSM, for a 6 week period. Results: Dietary PSM significantly decreased average daily feed intake (p<0.05), with no significant effect on other performance parameters. The PSM, enriched the eggs with polyunsaturated fatty acids, especially α linolenic acid (0.33 vs 0.21 g/100 g) and linoleic acid (20.65 vs 18.37 g/100 g), whereas it reduced the amount of arachidonic acid with 3.91% and n-6/n-3 ratio in PSM eggs compared with CON. The inclusion of 9% PSM significantly (p<0.05) diminished the cholesterol concentration in yolk with 11.31% and in egg with 10.38%, in respect to the CON samples. The significantly (p<0.05) higher concentration of polyphenols and antioxidant compounds, determined in PSM eggs, proved to be effective on shelf life of eggs preserved at refrigerator (5℃) and room temperature (21℃) for 28 days, by delaying the lipid oxidation and protein denaturation. This effect was reflected in significantly (p<0.05) higher Haugh unit in eggs stored 28 days at 21℃ and lower albumen pH values for the overall storage time, both at 5℃ and 21℃, proving the antioxidant effect of pumpkin. Conclusion: Dietary PSM supplementation was significantly effective on average daily feed intake and egg quality by increasing some fatty acids while lowering the cholesterol concentration. Also, PSM proved to be effective improving shelf life of eggs for 28 days storage time.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.71-78
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• 2019

Objective : The purpose of the study was to identify expression profiling of miRNAs associated with cancers after treating allergen-removed Rhus Verniciflua Stokes and allergen-removed Rhus Verniciflua Stokes fumigaed Angelica gigas on leukemia cell lines. Methods : miRNA expression has been analyzed using miRNA array method through denaturation and hybridization after isolating the total RNA from leukemic cell line treated with 100 ㎍/㎖ of aRVS and aRVS-A each. Microarray expressions were interpreted as 'significant' on miRNAs when decreased less than 0.5 fold or increased more than 1.5 fold compared with the control group. Results : Among 158 miRNAs in total, 32 miRNAs were significantly presented in miRNAs expression. miRNA has been activated with a variety of genes for predicted targets, and the overexpressed miRNAs were categorized according to proliferation and metastasis of cancer in this study. The findings were reported that seven miRNAs (let-7b, miR-193a-5p, 296-3p, 26a, 22, 124a, 92b) showed significant expressions on proliferation and growth, seven miRNAs (miR-193a-5p, 26a, 200c, 183, 124a, 198, 210) presented meaningful expressions on invasion and metastasis, two miRNAs (let-7b, miR-210) were highly expressed on angiogenesis, five miRNAs (let-7b, miR-26a, 181d, 181c, 296-5p) related with apoptosis, and six miRNAs (let-7b, miR-200c, 183, 370, 124a, 191) were associated with prognosis of cancer and early diagnostic factors for cancer. Conclusion : The mechanism of miRNA takes a role in diagnosis, treatment, and prognotic factors for cancer as well. This study suggested that further detailed research on overexpression of specific miRNA should be carried out continuously in the future.

• Medical Lasers
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• v.7 no.1
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• pp.6-12
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• 2018

Introduction Energy-based devices allow for a more rapid and efficient ligation of blood vessels during operations. In the present study, we evaluated the feasibility of a laser as an alternative energy source for the vessel sealing system and determined the optimal condition of laser for an effective vessel sealing through histologic examination. Materials and Methods The arteries (5 mm diameter) harvested from porcine legs were compressed between two glass-slides to eliminate its luminal space and were irradiated with 1,470-nm diode laser under various sealing conditions, including laser power (5-30 W), irradiation time (5 or 10 seconds), and focus mode (focus or defocus). Subsequently, the irradiated vessels were fixed in 4% formaldehyde and then processed to paraffin block. The paraffinized sample was sectioned and stained with hematoxylin and eosin for histological evaluation. Results The extent of tissue change was positively correlated with duration and power of laser. In defocus mode, the irradiated vessels showed sufficient tissue denaturation for sealing effect without severe tissue destruction. Moreover, among the various conditions of irradiation, laser power between 15 and 20 W, as well as exposure time of 5 seconds were appropriate for sealing the blood vessels. Conclusion Adequate power and irradiation duration of laser can render blood vessels to be sealed effectively, although the higher power of laser may be required to cut the vessels.