• 한국약용작물학회:학술대회논문집
• /
• 2012.05a
• /
• pp.259-260
• /
• 2012

• 한국약용작물학회:학술대회논문집
• /
• 2012.05a
• /
• pp.257-258
• /
• 2012

• Fibers and Polymers
• /
• v.6 no.3
• /
• pp.181-185
• /
• 2005

Silk fibroin (SF) nanofibers were prepared by electrospinning and their application as an enzyme immobilization support was attempted. By varying the concentration of SF dope solution the diameter of SF nanofiber was controlled. The SF nanofiber web had high capacity of enzyme loading, which reached to $5.6\;wt\%$. The activity of immobilized a-chymotrypsin (CT) on SF nanofiber was 8 times higher than that on silk fiber and it increased as the fiber diameter decreased. Sample SF8 (ca. 205 nm fiber diameter) has excellent stability at $25^{\circ}C$ by retaining more than $90\%$ of initial activity after 24 hours, while sample SF11 (ca. 320 nm fiber diameter) shows higher stability in ethanol, retaining more than $45\%$ of initial activity. The formation of multipoint attachment between enzyme and support might increase the stability of enzyme. From these results, it is expected that the electrospun SF nanofibers can be used as an excellent support for enzyme immobilization.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.5
• /
• pp.815-818
• /
• 2003

Maltosyl(G2)-erythritol, produced by the transglycosylation reaction of erythritol with maltotriose by Bacillus stearothermophilus maltogenic amylase, was not utilized either as a substrate for lactic acid production or for water-insoluble glucan synthesis. An inhibition assay of dextransucrase and mutansucrase showed that the dental caries suppression effect of G2-erythritol was greater than that of erythritol.

• Korean Journal of Pharmacognosy
• /
• v.44 no.3
• /
• pp.235-241
• /
• 2013

Aucklandia lappa Decne (Compositae) has been used for treatment of abdominal pain, vomiting, diarrhea, chronic inflammation, and antibacterial effect. The quality of these herbs has been affected by many factors such as collection time, place, temperature, cultivation environment and manufacturing process. We used costunolide and dehydrocostuslactone as marker compounds for quality evaluation of rhizome of Aucklandia lappa. 66 samples of Aucklandia lappa were collected from those habitats in Korea and China. The developed HPLC-DAD method was applied to investigate for quality control of Aucklandia lappa samples. The average contents of the costunolide and dehydrocostuslactone were 2.3895% and 0.9258%, respectively. The principal component analysis (PCA) exhibited that classification of Aucklandia lappa according to origin not separated. Results of this study may be satisfactory applied to determination of content criteria of Aucklandia lappa.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.8
• /
• pp.8-17
• /
• 2019

In this study, a model reduction technique was used to develop a precise noise and vibration prediction model for the individual components of a driveline system. The dynamic reduced-order model generated by the Craig-Bampton method was applied to perform dynamic analysis of an electric agricultural power cart. The natural frequency and acceleration response results were analyzed according to the different number of dominant sub-structural modes contained in the reduced-order models. Through the analysis results, it was confirmed that a sufficient number of dominant sub-structures to satisfy the operating conditions should be selected to construct an optimal reduced-order model.

• BMB Reports
• /
• v.54 no.8
• /
• pp.431-436
• /
• 2021

In recent years, restoring anti-tumor immunity has garnered a growing interest in cancer treatment. As potential therapeutics, immune checkpoint inhibitors have demonstrated benefits in many clinical studies. Although various methods have been applied to suppress immune checkpoints to boost anti-tumor immunity, including the use of immune checkpoint inhibitors, there are still unmet clinical needs to improve the response rate of cancer treatment. Here, we show that acetate can suppress the expression of poliovirus receptor (PVR/CD155), a ligand for immune checkpoint, in colon cancer cells. We demonstrated that acetate treatment could enhance effector responses of CD8⁺ T cells by decreasing the expression of PVR/CD155 in cancer cells. We also found that acetate could reduce the expression of PVR/CD155 by deactivating the PI3K/AKT pathway. These results demonstrate that acetate-mediated expression of PVR/CD155 in cancer cells might potentiate the anti-tumor immunity in the microenvironment of cancer. Our findings indicate that maintaining particular acetate concentrations could be a complementary strategy in current cancer treatment.

• Macromolecular Research
• /
• v.17 no.12
• /
• pp.935-942
• /
• 2009

Silk is a textile material, as well as one of the oldest biomaterials. However, the recent progress of biomedical science and technology has led to the replacement of silk by various biomaterials based on synthetic polymers. Despite the wide variety of biomaterials available, these materials suffer certain limitations that prevent them from meeting the various demands of the medical field. Therefore, silk continues to attract considerable interest as a promising biomaterial. This paper explains the fundamentals of silk protein, and reviews the many applications of silk biomedical polymers.

• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.302-307
• /
• 2008

Novel amylase inhibitors were synthesized via transglycosylation by Thermotoga maritima glucosidase (TMG). TMG hydrolyzes acarbose, acarviosine-glucose, and maltooligosaccharide by releasing $^{14}C$-labeled glucose from the reducing end of each molecule. When TMG was incubated with acarviosine-glucose (the donor) and glucose (the acceptor), two major transfer products, compounds 1 and 2, were formed via transglycosylation. The structures of the transfer products were determined using thin-layer chromatography (TLC), high-performance ion chromatography (HPIC), and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopy. The results indicate that acarviosine was transferred to glucose at either C-6, to give a $\alpha-(1{\rightarrow}6$) glycosidic linkage, or at C-3, to produce an $\alpha-(1{\rightarrow}3$) glycosidic linkage. The transfer products showed a mixed-type inhibition against porcine pancreatic $\alpha$-amylase; therefore, they may be useful not only as inhibitors but also as acarbose transition-state analogs to study the mechanism of amylase inhibition.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.8
• /
• pp.1472-1478
• /
• 2008

The synthesis of a new series of 1$\beta$-methylcarbapenems having spiro[2,4]heptane moieties is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents at the pyrrolidine ring was investigated. Most of the compounds were found to be more active compared to imipenem against Gram-negative bacteria. A particular compound (IIIc) having 7-oxo-5- azaspiro[2,4]heptane moiety showed the most potent antibacterial activity.