• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.411-417
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• 2004

Recently, instruments and systems related on biological technology have been enormously developed. Particularly, many researches for biological cell injection have been carried out. Usually, excessive contact force occurring when the end-effector and a biological cell contact might make a damage on the cell. Unfortunately, the excessive force could easily destroy the membrane and tissue of the cell. In order to overcome the problem, we proposed a new injection system for biological cell manipulation. The proposed injection system can measure the contact force between a pipette and a cell by using a force sensor. Also, we used vision technology to correctly guide the tip of the pipette to the cell. Consequently, the proposed injection system could safely manipulate the biological cells without any damage. This paper presents the introduction of our new injection system and design concepts of the new micro end-effector. Through a series of experiments the proposed injection system shows the possibility of application for precision biological cell manipulation such as DNA operation.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.146-151
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• 2013

This paper reveals the performance decrease and recovery of PEMFC when the contaminated fuel gas and air source with sulfur impurities such as hydrogen sulfide and sulfur dioxide were simultaneously introduced to anode and cathode, respectively. Three different GDLs were fabricated with different carbon black and activated carbon to prevent an introduction of sulfur compound impurities into MEA. components. The severity of $SO_2$ and $H_2S$ poisoning was depended on concentrations(3 ppm - 10 ppm) of sulfur impurities. Especially, cell performance degradation rate was rapid when MEA fabricated with CN-2 GDL because it had little porosity on GDL surface. Moreover, the cell performance can be recovered up to 90%-95% only with neat hydrogen and fresh air feeding.. Conclusively, MEA fabricated with porous CN-1 GDL showed the best cell performance and recovery efficiency during exposure to poisoning condition by simultaneous sulfur impurities.

• Korean Journal of Materials Research
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• v.22 no.5
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• pp.227-236
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• 2012

Ionomer is a thermoplastic that is composed of covalent bonds and ionic bonds. It is possible to use this material in processes such as injection molding or extrusion molding due to the material's high oil resistance, weatherproof characteristics, and shock resistance. In this study, a new ionomer having a multifunctional group was prepared by a stepwise neutralization system with the addition of acidic and salt additives. In step I, to increase the contents of the multifunctional group and the acid degree in ethylene acrylic acid (EAA), MGA was added to the ionomer resin (EAA). A new ionomer was prepared via the traditional preparation method of the ionic cross-linking process. In step II, metal salt was added to the mixture of EAA and MGA. The extrusion process was performed using a twin extruder (L/D = 40, size : ${\varphi}30$). Ionomer film was prepared for evaluation of gas permeability by using the compression molding process. The degree of neutralized and ionic cross-linked new ionomer was confirmed by FT-IR and XRD analysis. In order to estimate the neutralization of the new ionomer film, various properties such as gas permeation and mechanical properties were measured. The physical strength and anti-scratch property of the new ionomer were improved with increase of the neutralization degree. The gas barrier property of the new ionomer was improved through the introduction of an ionic site. Also, the ionic degree of cross-linking and gas barrier property of the ionomer membrane prepared by stepwise neutralization were increased.

• Polymer(Korea)
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• v.38 no.3
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• pp.293-298
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• 2014

We prepared hydrophilic porous supporters for the reinforced composite fuel cell membrane by radiation grafting of acrylonitrile (AN) and hydrophilic sodium allylsulfonate (SAS) into a porous polytetrafluoroethylene (PTFE) supporter. The physicochemical properties of the supporters prepared under various reaction conditions such as molar ratio of SAS/AN, monomer concentration, and irradiation dose were evaluated. FTIR was utilized to confirm the successful introduction of SAS/AN copolymer chains into the porous PTFE. The pores of the porous PTFE film were found to be decreased with an increase in the degree of grafting by using FE-SEM and gurley number. Furthermore, by analyzing the degree of grafting, contact angle, and TBO (toluidine blue O) uptake, the hydrophilicity of the prepared supporters was found to increase with an increase in the degree of grafting.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.4
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• pp.278-286
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• 2011

Introduction: This study examined the predictability of new bone formation in the pneumatized maxillary sinus using only fibrin-rich blocks with concentrated growth factors as an alternative to bone grafts. Materials and Methods: Maxillary sinus augmentation was performed in thirty-three patients with a deficient alveolar bone height (mean 3.9 mm). All patients were treated consecutively with sinus membrane elevation via the lateral window approach and panoramic radiograms and cone-beam computed tomograms were taken to evaluate the remaining bone height and the new bone formation in the maxillary sinus, before and after surgery. Four biopsy specimens were taken at the time of implant consolidation (after an average of five months healing) and were stained by H & E and Trichrome staining. Results: None of the patients had postoperative complications during implant consolidation. After an average of 5 months since sinus augmentation, newly formed bone was observed in all cases by a radiographic evaluation. In 4 biopsy samples, newly formed bone was observed along the floor of the replaced bony window. The osteoblast lining and well distinguished Osteocytes in the lacunas were observed in the newly formed bone. Of the 74 implants (4 different surfaced implants - resorbable blast media-surfaced (RBM), Hydroxyapatite (HA) coated, acid-etched, sintered porous-surfaced implant) placed, one RBM implant failed. The success rate was 98.6% after a mean of 15 months. Discussion: These results suggest that maxillary sinus augmentation using fibrin rich block with concentrated growth factors is a successful and predictable technique.

• Biomedical Science Letters
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• v.15 no.1
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• pp.37-45
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• 2009

Insect cell cultures have become important tools in the production of biological substances for use in a variety of research, human and veterinary medicine, and pest control applications. These applications often require the introduction of foreign DNA into the cells and have generally used methods originally developed for use with human and other mammalian cell cultures. While these methods can be successfully employed, they are often less efficient with insect cells and frequently involve complex procedures or require specialized equipment. Even when they do work, they may require substantial modification because of differences in the culture medium or growth patterns of insect cells. In this study, We have optimized transfection conditions of Sf9 cell line using insect expression vector pIZT/V5-His which expresses green fluorescent protein effectively. Human stem cell factor (hSCF) is a glycoprotein that plays a key role in hematopoiesis acting both as a positive and negative regulator, often in synergy with other cytokines. It also plays a key role in mast cell development, gametogenesis, and melanogenesis. It can exist in membrane-bound form and in proteolytically released soluble form. As determined by an enzyme-linked immunosorbent assay performed, hSCF level in supernatant averaged 995ng/ml. The human hSCF was partially purified by immunoaffinity chromatography and analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The results show that the hSCF has N-linked carbohydrate and corresponds to the soluble form, at or about 223 amino acids in length. The findings suggest functional importance for soluble hSCF in cells.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.707-714
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• 2023

Plant-derived insecticide-neonicotinoid insecticides (NIs) played a crucial role in the development of agriculture and food industry in recent years. Nevertheless, synthesis of these nitrogen-containing heterocyclic compounds with an effective and greener routing remains challenging especially to the notion raise of "green chemistry" and "atom economy". While bio-catalyzed methods mediated by nicotinate dehydrogenase (NDHase) then provide an alternative. The current review mainly focuses on the introduction of sources, components, structure, catalytic mechanism and applications of NDHase. Specifically, NDHase is known as nicotinic acid hydroxylase and the sources principally derived from phylum Proteobacteria. In addition, NDHase requires the participation of the electron respiratory chain system on the cell membrane. And the most important components of the electron respiratory chain are hydrogen carrier, which is mainly composed of iron-sulfur proteins (Fe-S), flavin dehydrogenase (FAD), molybdenum binding protein and cytochromes. Heterologous expression studies were hampered by the plasmid and host with high efficiency and currently only Pseudomonas entomophila L48 as well as Comamonas testosterone was successfully utilized for the expression of NDHase. Furthermore, it is speculated that the conjugate and inductive effects of the substituent group at position 3 of the substrate pyridine ring exerts a critical role in the hydroxylation reactions at position 6 concerning about the substrate molecular recognition mechanism. Finally, applications of NDHase are addressed in terms of pesticide industry and wastewater treatment. On conclusion, this critical review would not only deepen our understanding of the theory about NDHase, but also provides the guideline for future investigation of NDHase.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.302-311
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• 2004

Comamonas testosteroni (formerly Pseudomonas sp.) NCIMB 10643 can grow on biphenyl and alkylbenzenes $(C_2-C_7)$ via 3-substituted catechols. Thus, to identify the genes encoding the degradation, transposon-mutagenesis was carried out using pAG408, a promoter-probe mini-transposon with a green fluorescent protein (GFP), as a reporter. A mutant, NT-1, which was unable to grow on alkylbenzenes and biphenyl, accumulated catechols and exhibited an enhanced expression of GFP upon exposure to these substrates, indicating that the gfp had been inserted in a gene encoding a broad substrate range catechol 2,3-dioxygenase. The genes (2,826 bp) flanking the gfp cloned from an SphI-digested fragment contained three complete open reading frames that were designated bphCDorfl. The deduced amino acid sequences of bphCDorfl were identical to 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC), 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (BphD), and OrfI, respectively, that are all involved in the degradation of biphenyl/4-chlorobiphenyl (bph) by Ralstonia oxalatica A5. The deduced amino acid sequence of the orfl revealed a similarity to those of outer membrane proteins belonging to the OmpW family. The introduction of the bphCDorfl genes enabled the NT-l mutant to grow on aromatic hydrocarbons. In addition, PCR analysis indicated that the DNA sequence and gene organization of the bph operon were closely related to those in the bph operon from Tn4371 identified in strain A5. Furthermore, strain A5 was also able to grow on a similar set of alkylbenzenes as strain NCIMB 10643, demonstrating that, among the identified aromatic hydrocarbon degradation pathways, the bph degradation pathway related to Tn4371 was the most versatile in catabolizing a variety of aromatic hydrocarbons of mono- and bicyclic benzenes.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1343-1349
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• 2012

Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.

• Journal of Korean Academy of Nursing
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• v.29 no.6
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• pp.1455-1468
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• 1999

The purpose of this study was to investigate the objectives and contents of basic medical sciences at department of nursing in college of nursing, and junior college of nursing, thus ultimately providing the basic data to standardize the curriculum of the basic medical sciences in nursing education. Seventy eight professors who were in charge of teaching basic medical sciences to at 22 colleges of nursing/ department of nursing, and 20 junior colleges of nursing responded to the questionnaires that consisted of the questions regarding objectives and contents, of basic medical sciences. Based on the description of objectives, the description related to nursing, nurse, nursing science was cathegorized as on objective applicable to nursing science, the description related to medicine or clinical medicine as medical model, the description without description related to medicine was cathegorized as knowledge acquisition. The number of schools corresponding to each category were summerized in descending order. The objectives of basic medical sciences were categorized by concepts and number of schools corresponding to the categorized concept. The findings of the study are as follows ; 1. The subjects of basic medical science identified were physiology, anatomy, biochemistry, pathology, microbiology, and pharmacology in most colleges of nursing and junior colleges. Two colleges of nursing/department of nursing (9.1%) and 19 junior colleges of nursing(95%) did not offer biochemistry, 1 college of nursing /department of nursing(5%) did not offer pathology & pharmacology. 2 junior colleges of nursing (10%) did not offer pharmacology, 1 junior college of nursing(5%) did not offer pathology. The other 1 junior college of nursing did not offer microbiology. 2. Objectives of physiology were to acquire knowledge and understanding on human function in both 6 (50%) colleges and 5 junior colleges. Objectives of anatomy were to acquire knowledge on human structure in both 4 (57%) colleges and 2 (50%) junior colleges; knowledge applicable to nursing sciences in both 3 (42.8%) colleges and 2 (50%) junior colleges. Objectives of biochemistry was to obtain knowledge and understanding on biochemistry, and understanding of basic concepts about biochemistry. Objectives of pathology were to obtain knowledge and understanding on pathology in both 4 (57.1%) colleges and 5(62.5%) junior colleges. Objectives of microbiology were to acquire knowledge and understanding on microbiology in both 5(83.8%) colleges and 6(85.7%) junior colleges. Objectives of pharmacology were to acquire knowledge on pharmacology in both 7(100%) colleges and 8(100%) junior colleges. 3. Contents of physiology in 19 (100%) schools were membrane transport, digestion, circulation, nervous system and respiration. In 16(84.2%) were kidney and muscle, that in 13(68.4%) were endocrine physiology. In 11(57.9%) were introduction and that in 9(47.4%) were structure and function of cells. Contents of anatomy in 11(100%) schools were skeletal system, muscle system, digestive system, circulatory system, concepts regarding human structure. In 10(90.9%) schools were endocrine system and nervous system, and in 5(45.5%) schools were blood, urinary system and cell. Contents of biochemistry in 6(100%) schools were history of biochemistry, body regulating factor, bioenergy, health and nutrition, nutrition of cell, energy production system. In 5(83.3%) schools were metabolism of protein and carbohydrate and enzyme, and in 3(50%) schools were metabolism of energy and fat. Contents of microbiology in 13(100%) schools were environment and influenc of bacteria, virus, G(-) rods, purulent cocci, G(+) rods. In 10 (76.9%) were immunity, diphtheria, enterobacteria, and in 9(69.2%) were spirochete, rickettsia and clamydia, and that in 6(46.2%) were sterilization and disinfection. Contents of pathology in 14(100%) schools were cell injury and adaptation, inflammation, respiratory diseases, circulatory diseases. In 10(71.4%) were neurological disorders, in 8(57.1%) were immunity and disease, and in 7 (50%) were tumor and progressive changes. Contents of pharmacology in 15(100%) were cardivascular drugs, introduction to pharmacology, hypnotics, analgesics, local anesthetics, an ticonvulsants. In 12(80%) were drugs activity on sympathetic and parasympathetic nervous system, and in 11(73%) were sulfa drugs, antibiotics, drug abuse and addiction.