• BMB Reports
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• v.42 no.9
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• pp.586-592
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• 2009

The bactenecin is an antibacterial peptide with an intramolecular disulfide bond. We recently found that homodimeric bactenecin exhibits more potent antibacterial activity than the monomeric form and retains its activity at physiological conditions. Here we assess the difference in the modes of antibiotic action of homodimeric and monomeric bactenecins. Both monomeric and dimeric bactenecins almost completely killed both Staphylococcus aureus and E. coli within 10-30 min at concentrations of $8-16\;{\mu}M$. However, exposure to liposomes elicited an increase in the fluorescence quantum yield from a tryptophan-containing monomeric analog, while the homodimeric analog showed a significant reduction in fluorescence intensity. Moreover, unlike the monomer, the homodimer displayed apparent membrane-lytic activity enabling release of various sized dyes from liposomes, and rapidly and fully depolarized the S. aureus membrane. Together, our results suggest that homodimeric bactenecin forms pores in the bacterial membrane, while monomeric one penetrates through the membrane to target intracellular molecules/organelles.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.551-557
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• 2014

In this study, we demonstrated multimodal nonlinear optical (NLO) microscopy integrated simultaneously with two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS) in order to obtain targeted cellular and label-free images in an immunofluorescence assay of the atherosclerotic aorta from apolipoprotein E-deficient mice. The multimodal NLO microscope used two laser systems: picosecond (ps) and femtosecond (fs) pulsed lasers. A pair of ps-pulsed lights served for CARS (817 nm and 1064 nm) and SHG (817 nm) images; light from the fs-pulsed laser with the center wavelength of 720 nm was incident into the sample to obtain autofluorescence and targeted molecular TPEF images for high efficiency of fluorescence intensity without cross-talk. For multicolor-targeted TPEF imaging, we stained smooth-muscle cells and macrophages with fluorescent dyes (Alexa Fluor 350 and Alexa Fluor 594) for an immunofluorescence assay. Each depth-sectioned image consisted of $512{\times}512$ pixels with a field of view of $250{\times}250{\mu}m^2$, a lateral resolution of $0.4{\mu}m$, and an axial resolution of $1.3{\mu}m$. We obtained composite multicolor images with conventional label-free NLO images and targeted TPEF images in atherosclerotic-plaque samples. Multicolor 3-D imaging of atherosclerotic-plaque structural and functional composition will be helpful for understanding the pathogenesis of cardiovascular disease.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.607-615
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• 2021

Cytokines are protein mediators that possess the ability to assist cell-to-cell communication in immune system-related activities. In general, pathogen endotoxins activate the release of inflammatory mediators, and with time, there is an increase in the cytokine levels in the body. Interleukin (IL)-6 mediates the acute-phase inflammatory response, and elevated IL-6 levels have been reported in peritoneal fluids of women with pelvic inflammation and endometriosis, thereby associating it with oocyte quality and infertility. To overcome subfertility or infertility in humans and animals, the present study was done to examine the effect of recombinant IL-6 on porcine oocytes matured in vitro and subsequently to determine the fertilization rate and embryo development. Porcine oocytes were incubated with varying concentrations of IL-6 (0 - 2 ㎍·mL^-1) for 44 h followed by in vitro fertilization and culturing of the oocytes. The oocytes or embryos were fixed with 3.7% paraformaldehyde (PFA) and stained with fluorescence dyes, and the meiotic spindle, chromosome organization, fertilization status and embryo development were subsequently assessed under a fluorescence microscope. We observed induction of an abnormal meiotic spindle alignment in the oocytes incubated with IL-6 compared to the control oocytes incubated without IL-6. Moreover, significantly decreased fertilization rates and embryo development were observed for oocytes incubated with IL-6 (p < 0.05). Thus, an increased IL-6 level during oocyte maturation could be associated with fertilization failure due to an aberrant chromosomal alignment and a disruption of the cortical granules. Taken together, our results indicate that successful assisted reproduction can be achieved by controlling the levels of inflammatory cytokines.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.420.2-420.2
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• 2016

Various fields have been paid attention to upconversion nanoparticles (UCNPs) because of its unique optical properties. Moreover, to use the UC luminescent techniques through cell images for identified apoptosis/necrosis of cancer cells have been performed. They have been studied for a versatile biomedical application such as a biosensing tool, or delivery of active forms of medicines inside living cells. UCNPs have distinctive characteristics such as photoluminescence, special emission, low background fluorescence signal and good colloidal stability, which have many advantages compared with the organic dyes and quantum dots. UCNPs have not only a great potential for imaging (UC luminescence) but also therapies (photo-thermal therapy, PTT and photo-dynamic therapy, PDT) in cancer diagnostics. Therefore, we report the enhancement of upconversion red emission in NaYF4:Yb3+,Er3+ nanoparticles, synthesized via solid-state method with the thermal decomposition of trifluoroacetate as precursors and organic solvent at a high boiling point. The UCNPs have an emission in the field of near infrared wavelength, cubic shape and nano-size in length. In this study, we will further investigate it for cancer therapy with NIR optical detection onto the solid substrate.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.292-296
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• 2013

This study utilized an analysis method for detecting six microorganisms, such as Actinobacillus actinomycetemcomitans, Campylobacter rectus, Porphyromonas gingivalis, Tannerella forsythus, Treponema denticola, and Prevotella intermedia, triggering periodontal disease, using multiplex real-time polymerase chain reaction (PCR). The analysis including internal control was made by dividing the six species into two groups using four fluorescence dyes, and it was verified that there was no interference or cross-reaction between the target species and different kinds of oral microbial species. Qualitative and quantitative analyses were conducted on each microorganism in various samples, such as saliva and the plaque, using the multiplex real-time PCR and comparative analysis between periodontitis patients and healthy people, revealing obvious differences between them.

• Textile Coloration and Finishing
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• v.20 no.1
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• pp.8-15
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• 2008

We presented the modified decal-transfer lithography (DTL) and light stamping lithography (LSL) as new powerful methods to generate patterns of poly(dimethylsiloxane) (PDMS) on the substrate. The microstructures of PDMS fabricated by covalent binding between PDMS and substrate had played as barrier to locally control wettability. The transfer mechanism of PDMS is cohesive mechanical failure (CMF) in DTL method. In the LSL method, the features of patterned PDMS are physically torn and transferred onto a substrate via UV-induced surface reaction that results in bonding between PDMS and substrate. Additionally we have exploited to generate the patterning of rhodamine B and quantum dots (QDs), which was accomplished by hydrophobic interaction between dyes and PDMS micropatterns. The topological analysis of micropatterning of PDMS were performed by atomic force microscopy (AFM), and the patterning of rhodamine B and quantum dots was clearly shown by optical and fluorescence microscope. Furthermore, it could be applied to surface guided flow patterns in microfluidic device because of control of surface wettability. The advantages of these methods are simple process, rapid transfer of PDMS, modulation of surface wettability, and control of various pattern size and shape. It may be applied to the fabrication of chemical sensor, display units, and microfluidic devices.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.295-303
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• 2014

Purpose: This study aims to observe bleaching resulted from multipurpose contact lens solutions used to manage lenses with the subjects of colored contact lenses being distributed in Korea. Methods: The lenses have been worn for six months, and their refraction is 0.00D. Three types of colored contact lenses of which margin has been colored with a different manufacturing method have been adopted (type 1: pigment application method, type 2: chemical bonding process, type 3: sandwich method), and multipurpose solutions used were two types containing different components. Each of the colored contact lenses was stored in the multipurpose solutions for 20 days and went through vortexing for 15 seconds per day. Their fluorescence absorbance, surface roughness, brightness index, and color coordinate index were measured before and after the vortexing to see the degree of bleaching. Results: In the two types of multipurpose solutions, every type of the color contact lenses showed no statistically significant difference in their fluorescence absorbance value before and after the vortexing. Regarding surface image, the front surface of the lenses was smooth in every type, and about the back surface, type 3 indicated less protrusion than type 1 and 2. About the difference of color on the lens surface before and after the vortexing, type 3 showed significantly less difference than type 1 and 2; however, all fell into the permissible error. Conclusions: About the bleaching of colored contact lenses resulted from multipurpose solutions for soft contact lenses, there was no difference observed in terms of fluorescence absorbance and color. According to the methods of manufacturing dyes, however, there was difference in the protrusion of the posterior surface image.

• Conservation Science in Museum
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• v.13
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• pp.13-22
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• 2012

The patterns for Jeogui and Pyeseul (patterns of the queen's ceremonial robe worn and a belt ornament covering knees in the front) as owned by National Museum of Korea were made in the early 20th century and both of them were colored on paper. Through a non-destructive analysis on pigments and dyes used on both the patterns, it was attempted to identify the coloring materials. As for the analysis of the coloring pigments, the XRF was used. As a result of the pigment analysis on the pattern for Jeogui, it is presumed that lead white was used for obtaining the white color, ink stick for black color, orpiment for yellow color, cinnabar and red lead for red color, copper and arsenical or a mixture of copper carbonate and orpiment for green color whereas brass seems to have been used for obtaining other colors. The pigments used for obtaining the colors of white, black, yellow and green on the pattern for Pyeseul are the same as those used on the pattern for Jeogui whereas the red pigments used on each of the two patterns are seen to be different. Although it may be difficult to identify the kinds of blue pigments that were used on the patterns for Jeogui and Pyeseul, a mixture containing lead white is presumed to be used as blue pigment. Also, as a result of the UV-Vis spectroscopic analysis performed on the blue hanji (traditional Korean paper) of the pattern for Jeogui, it was presumed to have been dyed with indigo.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.737-743
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• 2010

Coupling of 5-amino-1,3-diaryl-pyrazoles 1a-c with diazonium salts of different aryl amines gave a series of novel 1,3-diaryl-5-amino-4-arylazopyrazoles 3a-l. Such compounds could be also obtained by reaction of 5-amino-1,3-diaryl-4-nitroso- 1H-pyrazoles 2a-c with different aryl amines in alkaline medium. Oxidation of azo derivatives 3a-l with cupric acetate, in dimethyl formamide and stream of air, gave 2,4,6-triaryl-2,4-dihydropyrazolo [4,3-d]-1,2,3-triazoles 4a-l. and the fluorescence properties of the cyclic triazoles were studied. Diazotization of 5-amino-1,3-diaryl-1H-pyrazoles 1a-c by sodium nitrite in ortho-phosphoric acid followed by coupling with some aryl amines gave o-aminoazo compounds 5a-f. Cyclisation of compounds 5a-f in pyridine and cupric acetate gave the corresponding triazoles 6a-f. The coupling of compounds 6a-f with different aryl diazonium salts gave compounds 7a-j. The synthesized dyes were applied to polyesters as disperse dyes and the fastness properties were evaluated.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.95-105
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• 2008

Objectives : Although herbal medicines containing flavonoids have been reported to exert anti-tumor activities, it has not been explored whether Hwang-Jeong (Polygonati sibirici Rhizoma, PsR) exerts anti-tumor activity in human glioma. The present study was therefore undertaken to examine the effect of PsR on cell viability and to determine its underlying mechanism in A172 human glioma cells. Methods : Cell viability was estimated by MTT assay. Reactive oxygen species generation and mitochondrial membrane potential were measured by the fluorescence dyes. The phosphorylation of kinases was evaluated by western blot analysis and caspase activity was estimated using colorimetric assay kit. Results : PsR resulted in loss of cell viability in a dose- and time-dependent manner. PsR did not increase reactive oxygen species (ROS) generation and the PsR-induced cell death was also not affected by antioxidants, suggesting that ROS generation is not involved in loss of cell viability. Western blot analysis showed that PsR treatment caused rapid reduction in phosphorylation of extracellular signal-regulated kinase (ERK) without changes in p38 and Jun-NH2-terminal kinase (JNK). U0126, an inhibitor of ERK, increased the PsR-induced cell death, but inhibitors of p38 and JNK did not affect the cell death. PsR induced depolarization of mitochondrial membrane potential. Caspase activity was not stimulated by PsR and caspase inhibitors did not prevent the PsR-induced cell death. Conclusion : Taken together, these findings suggest that PsR results in human glioma cell death through caspaseindependent mechanisms involving down-regulation of ERK.