• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1235-1240
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• 2010

Wire-woven Bulk Kagome (WBK) is fabricated by assembling helically formed wires in six directions. To date, WBK samples have been assembled manually. For industrial application, the assembly process must be automated. Furthermore, if WBK is to be fabricated using flexible wires that cannot maintain their helical shape during fabrication, a specialized automatic machine, i.e., a loom needs to be developed. In this work, we designed and constructed a loom for fabricating WBKs using flexible wires. This loom is operated by one rotation of the upper plate, two translations of the insertion device, and insertion of wires. So-called "comb devices" are placed between multiple layers of Kagome nets to prevent the wires that are already in place from getting entangled with those that are being inserted. This loom can be also used to fabricate semi-WBKs composed of helically formed wires and rigid straight wires.

• Molecules and Cells
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• v.39 no.10
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• pp.768-775
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• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.114-119
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• 2001

Many isolates from different forest soil layers did not show appreciable growth on full strength of the conventional nutrient broth (NB medium) but grow on its 100-fold dilution (DNB medium). These isolates were divided into four types according to organic nutrient concentration in the growth medium from $1^{-1}\;to\;10^{-4}$dilution of normal NB medium. Oligotrophic bacteria were type II and type IV which grew in $10^{-4}$ dilution of NB (1 mg C/l) medium. Sixty strains were isolated for obligate oligotrophic bacteria. Chemotaxonomic and phylogenetic characteristics of eleven isolates of acetylene-reducing (nitrogen-fixing) oligotrophic bacteria from forest soil were investigated. They showed similar characteristics: the cellular fatty acid mainly consisted of straight-chain unsaturated $C_{18:1}$ (60-84% of total fatty acids). Ubiquinone Q-10 and a high guanine plus-cytosine content(61-64 mol%) were found. Eleven isolates of nitrogen-fixing oligotrophic bacteria were found to be closely related by full 16S rDNA sequence simility and many common taxonomic traits. Analysis of full 16S rDNA sequences of eleven isolates indicated that they were more closely related to Bradyrhizobium (similarity values: 98.1-98.8%), Agromonas, Nitrobacter, and Afipia.

• Laser Solutions
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• v.11 no.4
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• pp.29-34
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• 2008

Ultraviolet laser micromachining has increasingly been applied to the electronics industry where precision machining of high-density, multi-layer, and multi material components is in a strong demand. Due to the ever-decreasing size of electronic products such as cellular phones, MP3 players, digital cameras, etc., flexible printed circuit board (FPCB), multi-layered with polymers and metals, tends to be thicker. In present, multi-layered FPCBs are being mechanically cut with a punching die. The mechanical cutting of FPCBs causes such defects as burr on layer edges, cracks in terminals, delamination and chipping of layers. In this study, the laser cutting mechanism of FPCB was examined to solve problems related to surface debris and short-circuiting that can be caused by the photo-thermal effect. The laser cutting of PI and FCCL, which are base materials of FPCB, was carried out using a pico-second laser(355nm, 532nm) and nano-second UV laser with adjusting variables such as the average/peak power, scanning speed, cycles, gas and materials. Points which special attention should be paid are that a fast scanning speed, low repetition rate and high peak power are required for precision machining.

• The Korean Journal of Cytopathology
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• v.18 no.1
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• pp.29-35
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• 2007

This study purposed to evaluate a $CellPrep^{(R)}$ (CP) of liquid-based cytology (LBC) to search for a less expensive and automated alternative cytologic preparation technique applicable to usually encountered cytologic specimens. Cervicovaginal direct-to-vial split samples from 457 gynecologic patients, 40 body fluid samples, and 34 urine samples were processed with the CP technique and the results were compared with those of currently used $ThinPrep^{(R)}$ (TP) method. Both CP and TP methods provide evenly distributed thin layers of cells with little cellular overlaps or significant obscuring elements in most of cases. Staining quality of both preparations showed a little difference due to the difference of fixative solutions without significant distractions in cytologic interpretation. On the supposition that TP was a gold standard, sensitivity, specificity, positive predictive value, and negative predictive value of CP cytology were 89%, 98%, 86%, and 99% in the cervicovaginal smear, 89%, 82%, 80%, and 90% in body fluid, and all of these values were 100% in urine samples. To testify the availability of immunohistochemistry on CP preparations, cytokeratin, vimentin, and Ki-67 were applied on body fluid specimens, and all of these antibodies were specifically stained on targeted cells. Conclusively, the CP method gave comparable results to those of TP in terms of smear quality and cytologic diagnostic evaluation, and was available on immunohistochemistry. The CP method could offer a cost-effective and automated alternative to the current expensive techniques of liquid-based cytology on popular cytologic materials including cervicovaginal, body fluid, and urine specimens.

• Molecules and Cells
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• v.22 no.1
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• pp.44-50
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• 2006

We investigated the possible role of p38 MAPK and $ET_B$ receptors in ET-1 induction of cyclooxygenase-2 (COX-2) and prostaglandin $E_2$ ($PGE_2$) in cultured feline esophageal smooth muscle cells (ESMC). Confluent layers of ESMC were stimulated with 10 nM ET-1 and expression of COX-1 and COX-2, involvement of receptors, and activation of p38 MAPK, were examined by Western blot analysis. Levels of $PGE_2$ induced by ET-1 were measured by Elisa. Using $ET_A$and $ET_B$ antagonists (BQ-123 and BQ-788, respectively), the contribution of the ET receptors to COX-1 and COX-2 expression induced by ET-1 was determined. Western blot analysis revealed that treatment of ESMC with ET-1 resulted in transient expression of COX-2 and activation of p38 MAPK. Activation of p38 MAPK was maximal after 1 h. SB202190, a p38 MAPK inhibitor, reduced expression of COX-2, but not COX-1. ET-1-induced release of $PGE_2$ was also blocked by SB202190. COX-2 expression was upregulated only via the $ET_B$ receptor, and COX-1 expression was not affected by either antagonist. Taken together, our data suggest that ET-1 causes p38 MAPK-dependent expression of COX-2 by interacting with $ET_B$ receptors on ESMC.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.915-920
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• 1995

This study was performed to investigate the effect of aluminum compound on the aluminum contents and histological change in brain tissue of rats. Seventy five male Sprague-Dawley strains were divided into five groups consisting of the control, 250 ppm $AlCl_3$ group, 500 ppm $AlCl_3$ group, 250 ppm $Al_2(SO_4)_3$ group, 500 ppm $Al_2(SO_4)_3$ group and kept on the diet for 2 weeks. The weight gain was increased by administration of $AlCl_3$ but decreased by administration of $Al_2(SO_4)_3$ as compared to control group. The aluminum contents in brain tissue of each group; 250 ppm $AlCl_3$ group, 500 ppm $AlCl_3$ group, 250 ppm $Al_2(SO_4)_3$ group and 500 ppm $Al_2(SO_4)_3$ group were 64.63, 102.21, 132.64 and 180.41 ppm, respectively. Aluminum accumulation in brain tissue was higher with administration of $Al_2(SO_4)_3$ than with administration of $AlCl_3$. In $AlCl_3$ administration group, multiple small intracytoplasmic granules and microvacuole were seen in large pyramidal cells of cortex and granulovacuolar degeneration. In $Al_2(SO_4)_3$ administration group revealed pollagis pallor, cellular pyknosis, microcavitation resulted from edema in deeper cortical layers were observed. Blue-pigmentation which represents the accumulation of aluminum was noted In granulovacuolar degeneration site in $Al_2(SO_4)_3$ administration group.

• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.67-71
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• 2009

A 10-year old female Yorkshire terrier with nasal discharge and swelling was referred to the local animal hospital. Abnormal mass of right nasal cavity was detected in physical examination and radiography. According to the radiographs of the head, there was an evidence of bony destruction in right nose. Oronasal fistula was detected in right maxillary canine teeth. After surgical excision, the sample of nasal mass was refereed to Pathology Department of Veterinary Medicine in Jeju National University. Grossly, the enlarged mass was soft and 3 ${\times}$ 3 cm in size. Histopathologically, the neoplastic mass was composed of tubular to tubulopapillary structures which were lined by single to 6~7 layers of cuboidal to ciliated columnar cells. These neoplastic cells showed invasive tendency to adjacent normal parenchyma. They had uniform, round to oval nuclei, cytoplasm with small vacuoles and indistinct cellular margin. The number of mitotic figures was varied in different areas, ranged from 0 to 4 per high power field. Necrotic foci and infiltration of inflammatory cells including neutrophils, lymphocytes, and plasma cells also presented in the mass. Immunohistochemically, the neoplastic cells demonstrated strong positive reaction for cytokeratin (CK) 18 but were negative for CK 7 and 8. Based on the gross, histopathology and immunohistochemistry, this mass was diagnosed as nasal adenocarcinoma originated from respiratory epithelium.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.281-286
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• 2013

Salmonella Gallinarum (SG) is known as an important pathogen that causes fowl typhoid in chickens. To investigate SG outer-membrane proteins (OMPs) as a vaccine candidate, we used proteomic mapping and database analysis techniques with extracted OMPs. Also, extracted OMPs were evaluated in several aspects to their safety, immune response in their host and protective effects. Our research has established a proteomic map and database of immunogenic SG-OMPs used as inactive vaccine against salmonellosis in chickens. A total of 22 spots were detected by 2-dimensional gel electrophoresis and immunogenic protein analysis. Eight spots were identified by Matrix-Assisted Laser Desorption/Ionization-Time of Flight-Mass spectrometry (MALDI-TOF-MS) and peptide mass fingerprinting (PMF) and categorized into four different types of proteins. Among these proteins, OmpA is considered to be an immunogenic protein and involved in the hosts' immune system. To estimate the minimum safety dose in chickens, 35 brown layers were immunized with various concentrations of OMPs, respectively. Consequently, all chickens immunized with more than a $50{\mu}g$ dose were protected against challenges. Moreover, intramuscular administration of OMPs to chickens was more effective compared to subcutaneous administration. These results suggest that the adjuvanted SG-OMP vaccine not only induces both the humoral and cellular immune response in the host but also highly protects the hosts' exposed to virulent SG with $50{\mu}g$ OMPs extracted by our method.

• Restorative Dentistry and Endodontics
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• v.37 no.1
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• pp.34-40
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• 2012

Objectives: The aim was to confirm the stem cell-like properties of the dental pulp stromal cells and to evaluate the morphologic changes during in vitro chondrogenesis. Materials and Methods: Stromal cells were outgrown from the dental pulp tissue of the premolars. Surface markers were investigated and cell proliferation rate was compared to other mesenchymal stem cells. Multipotency of the pulp cells was confirmed by inducing osteogenesis, adipogenesis and chondrogenesis. The morphologic changes in the chondrogenic pellet during the 21 day of induction were evaluated under light microscope and transmission electron microscope. TUNEL assay was used to evaluate apoptosis within the chondrogenic pellets. Results: Pulp cells were CD90, 105 positive and CD31, 34 negative. They showed similar proliferation rate to other stem cells. Pulp cells differentiated to osteogenic, adipogenic and chondrogenic tissues. During chondrogenesis, 3-dimensional pellet was created with multi-layers, hypertrophic chondrocyte-like cells and cartilage-like extracellular matrix. However, cell morphology became irregular and apoptotic cells were increased after 7 day of chondrogenic induction. Conclusions: Pulp cells indicated mesenchymal stem cell-like characteristics. During the in vitro chondrogenesis, cellular activity was superior during the earlier phase (within 7 day) of differentiation.