• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.611-618
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• 2007

We demonstrate the sol-gel coating technique of colloidal clusters for producing hollow micro-particles with complex morphologies. Cross-linked amidine polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion copolymerization of styrene and divinylbenzene. The amidine PS particles were self-organized inside toluene-in-water emulsion droplets to produce large quantities of colloidally stable clusters. These clusters were coated with thin silica shell by sol-gel reaction of tetraethylorthosilicate (TEOS) and ammonia, and the organic polystyrene cores were removed by calcination at high temperature to generate nonspherical hollow micro-particles with complex morphologies. This process can be used to prepare hollow particles with shapes such as doublets, tetrahedra, icosahedra, and others.

• Polymer(Korea)
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• v.37 no.4
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• pp.411-419
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• 2013

Various biomaterials have been widely used for biomedical applications, including bio-organs, medical devices, and clinical devices like vessel, blood pumps, artificial kidneys and hearts, even in contact with blood. The issue of blood compatibility has been studied intensively to prevent negative effects such as thrombosis due to the implanted devices. The use of lotus-leaf-like structured surfaces has been extended to an increasing number of applications such as contamination prevention and anticorrosion applications. Various methods such as template, sol-gel transition, layer-by-layer, and other methods, developed for the fabrication of lotus-leaf-like surfaces have been reported for major industrial applications. Recently, the non-wettable character of these surfaces has been shown to be useful for biomedical applications ranging from blood-vessel replacement to antibacterial surface treatment. In this review, we provide a summary of current and future research efforts and opportunities in the development and medical applications of lotus-leaf-like structure surfaces.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.178-184
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• 2010

The aim of this work is the fabrication of polyelectrolyte microcapsules composed of biocompatible polymers such as chitosan, heparin and alginate, to encapsulate the fluorescein isothiocyanate(FITC)-albumin, and to investigate the protein release behavior therefrom. Polyelectrolyte capsules with 4-layer structures could be prepared with biocompatible materials by oppositely charged adsorption using melamin-foramide as a template. Transmission electron microscope(TEM), scanning electron microscope(SEM) and optical microscope confirmed hollow capsule structures. Protein release before and after encapsulation was monitored with a UV-Vis spectrometer. Microcapsules have different behaviors depending on the kind of polyelectrolyte polymers, chitosan-heparin capsules or chitosan-alginate capsules. In conclusion, the polyelectrolyte multilayer shells can be switched between an open and closed state by means of tuning the pH value.

• Research in Plant Disease
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• v.23 no.2
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• pp.193-201
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• 2017

Major tomato viruses in Korea are Tomato chlorosis virus (ToCV), Tomato spotted wilt virus (TSWV), Cucumber mosaic virus (CMV), Pepper mottle virus (PepMoV), and Tomato mosaic virus (ToMV). RT-PCR conditions for the viruses were examined, especially in primer set and RT-PCR mixture. Total 46 primer sets from the unique sequence of the viruses were tested for nonspecific background products in a RT-PCR mixture without template. Among them 16 primer sets were applied to healthy tomato RNA, resulting the compatibility between RT-PCR mixture and primer set influenced RT-PCR to reduce nonspecific background products. Based on the combinations among cDNA synthesis parameters and RT-PCR mixtures, two reaction mixtures were finally selected for ToCV detection. The condition allowed to determine more specific primer sets; C029 (ToCV), C072 (TSWV), C070 (CMV), C048 (PepMoV), and C065 (ToMV). These primer sets are expected to be of use to specific detection of the major viruses in tomato plants.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.740-746
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• 2004

In order to identify the anti-inflammatory and analgesic properties of natural herbal extracts, widely used in the Korean traditional medicine, an in vitro screening system was designed using pGL3, a luciferase reporter vector, and the tumor necrosis factor (TNF)-α and cyclooxygenase (COX)-II as target genes. The promoter regions of each gene was generated by PCR using the human chromosome as template DNA, and inserted into pGL3 vector with Kpnl and Hindlll. The final construct was transfected into human myleomonocytic leukemia cells (U937) that could be differentiated and activated by phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide (LPS). Using this system, we tested the anti-inflammatory and analgesic effects of several herbal extracts being regarded to have the medicinal effects of diminishing the body heat and complementing Qi. The well-known chemicals of PD98059 and berberine chloride were used as controls of the transcriptional inhibitors of TNF-α and COX-II, respectively. Among them, Salvia miltiorrhiza (Dan-Sam) was found to exhibit the significant medicinal properties of anti-inflammatory and analgesic effects.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.375-375
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• 2012

Graphene is a sp2-hybridized carbon sheet with an atomic-level thickness and a wide range of graphene applications has been intensely investigated due to its unique electrical, optical, and mechanical properties. In particular, hybrid graphene structures combined with various nanomaterials have been studied in energy- and sensor-based applications due to the high conductivity, large surface area and enhanced reactivity of the nanostructures. Conventional metal-catalytic growth method, however, makes useful applications difficult since a transfer process, used to separate graphene from the metal substrate, should be required. Recently several papers have been published on direct graphene growth on the two dimensional planar substrates, but it is necessary to explore a direct growth of hierarchical nanostructures for the future graphene applications. In this study, uniform graphene layers were successfully synthesized on highly dense dielectric nanowires (NWs) without any external catalysts. We also demonstrated that the graphene morphology on NWs can be controlled by the growth parameters, such as temperature or partial pressure in chemical vapor deposition (CVD) system. This direct growth method can be readily applied to the fabrication of nanoscale graphene electrode with designed structures because a wide range of nanostructured template is available. In addition, we believe that the direct growth growth approach and morphological control of graphene are promising for the advanced graphene applications such as super capacitors or bio-sensors.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.384-391
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• 2009

Previously, two events (H15 and B20) of transgenic pepper (Capsicum annuum L.) that enhanced resistance to Cucumber mosaic virus (CMV) by the introduction of CMV coat protein (CP) gene were constructed. Presently, a single copy number of the CP gene was revealed in H15 and B20 by Southern blot. To predict possible unintended effects due to transgene insertion in an endogenous gene, we carried out sequencing of the 5'-flanking region of the CP gene and a Blastbased search. The results revealed that insertion of the transgene into genes encoding putative proteins may occur in the H15 and B20 transgenic event. Mutiplex polymerase chain reaction (PCR) for simultaneous detection and identification of transgenic pepper was conducted with a set of nine primers. Both transgenic event were differentiated from non-transgenic event by the presence of 267 bp and 430 bp PCR products indicative of CP gene specific primer pairs and primer pairs targeting the CP gene and 35S promoter. H15 and B20 uniquely possessed a 390 bp and 596 bp PCR product, respectively. The presence of a 1115 bp product corresponding to intrinsic pepper actin gene confirmed the use of pepper DNA as the PCR template. The primer set and PCR conditions used presently may allow the accurate and simple identification of CMV resistant transgenic pepper.

• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.3.1-3.6
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• 2009

Introduction: GTPases known as translation factor play a vital role as ribosomal subunit assembly chaperone. The bacterial Obg proteins ($Spo{\underline{0B}}$-associated ${\underline{G}}TP$-binding protein) belong to the subfamily of P-loop GTPase proteins and now it is considered as one of the new target for antibacterial drug. The majority of bacterial Obgs have been commonly found to be associated with ribosome, implying that these proteins may play a fundamental role in ribosome assembly or maturation. In addition, one of the experimental evidences suggested that Bacillus subtilis Obg (BsObg) protein binds to the L13 ribosomal protein (BsL13) which is known to be one of the early assembly proteins of the 50S ribosomal subunit in Escherichia coli. In order to investigate binding mode between the BsObg and the BsL13, protein-protein docking simulation was carried out after generating 3D structure of the BsL13 structure using homology modeling method. Materials and Methods: Homology model structure of BsL13 was generated using the EcL13 crystal structure as a template. Protein-protein docking of BsObg protein with ribosomal protein BsL13 was performed by DOT, a macro-molecular docking software, in order to predict a reasonable binding mode. The solvated energy minimization calculation of the docked conformation was carried out to refine the structure. Results and Discussion: The possible binding conformation of BsL13 along with activated Obg fold in BsObg was predicted by computational docking study. The final structure is obtained from the solvated energy minimization. From the analysis, three important H-bond interactions between the Obg fold and the L13 were detected: Obg:Tyr27-L13:Glu32, Obg:Asn76-L13:Glu139, and Obg:Ala136-L13:Glu142. The interaction between the BsObg and BsL13 structures were also analyzed by electrostatic potential calculations to examine the interface surfaces. From the results, the key residues for hydrogen bonding and hydrophobic interaction between the two proteins were predicted. Conclusion and Prospects: In this study, we have focused on the binding mode of the BsObg protein with the ribosomal BsL13 protein. The interaction between the activated Obg and target protein was investigated with protein-protein docking calculations. The binding pattern can be further used as a base for structure-based drug design to find a novel antibacterial drug.