• Journal of Microbiology
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• v.34 no.4
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• pp.384-386
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• 1996

Application of polyacrylamide gel (PAG) instead of agar to solid cultures of Streptomyces spp. was studied. The improved media were prepared by 1) gelling 20 ml of 5% acrylamide in a glass petri dish at room temperature, 2) washing by running water for more than 8 hr to remove residual reaction reagents, 3) drying at 5$0^{\circ}C$ for 12 hr to make a gel film, 4) autoclaving at 121$^{\circ}C$ for 15 min, and 5) swelling gel for about 4 hr by adding sterile liquid medium. In PAG media there were no differences from the observation of morphological characteristics showing during the cellular differentiation on agar media, whereas the ability to utilize carbohydrates differed somewhat from agar media. Agar media thus were little favorable for biochemical tests which the growth was determined depending on the formation of colony, but washed PAG was superior to serve as a solidifying agent.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.79-82
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• 2007

Recently, the use of ALC has became increasingly popular. ALC is a unique building material. Because of its cellular nature, it is lightweight, self-insulating, sound and fireproof, as well as insect and mold resistant. Furthermore, ALC is free of VOCs and various fibers associated with wood and glass wool construction. However, ALC have high water absorption, low compressive strength and popout the origin of the low surface strength in its properties. These properties make troubles under construction such as cracking and popout. Thus, this study is to improve the fundamental strength by controls of increasing of admixtures, and grain size. Admixtures make use of metakaolin, silica fume, sodium silicate and sodium hydroxide. From the test result, the ALC using admixture have a good fundamental properties compared with plain specimen. Compressive strength, specific strength and abrasion's ratio were improved depending on increasing admixtures ratio's, and grain size.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.524-530
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• 2013

In this study, we describe the most expected behavior of cells on the modified surface and the correlation between the modified substrates and the response of cells. The physicochemical characteristics of substrates played an essential role in the adhesion and proliferation of cells. Glass and polymer substrates were modified using air plasma oxidation, and the surfaces were coated with self-assembled monolayer molecules of silanes. The PDMS substrates embedded with parallel micropatterns were used for evaluation of the effect of topologically modified substrate on cellular behaviour. BALB/3T3 fibroblast cells were cultured on different surfaces with distinct wettability and topology, and the growth rates and morphological change of cells were analyzed. Finally, we found the optimum conditions for the adhesion and proliferation of cells on the modified surface. This study will provide insight into the cell-surface interaction and contribute to tissue engineering applications.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.239-243
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• 2006

This research compared growth and flowering of potted $Viola{\times}wittrockiana$ 'Majestic GT Scarlet Shadow' in various mixtures of recycled perlite and cellular glass foam (CGF). The crop was cultured in a mat subirrigation system. Numbers of leaves, opened flowers, flower buds, and branches, fresh and dry weights of shoot, leaf area, and total chlorophyll concentration were the greatest in plants grown in the medium of used perlite + granular rockwool+ peatmoss (25:50:25, v/v/v). Plant height and length of the longest root were the highest and longest, respectively, in plants grown in the medium of CGF+peatmoss (25:75, v/v). The medium of CGF+peatmoss (25:75, v/v) was better than the medium of used perlite+peatmoss (25:75, v/v) in plant growth. The medium of CGF + granular rockwool (25:75, v/v) was poorer than the medium of recycled perlite + granular rockwool (25:75, v/v).

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.141-147
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• 2010

Liquefied natural gas(LNG) is natural gas that has been converted temporarily to liquid form for ease of storage and transport it. Natural gas is the worlds cleanest burning fossil fuel and it has emerged as the environmentally preferred fuel of choice. In Korea, the demand of this has been increased since the first import from the Indonesia in 1986. LNG takes up about 1/600th the volume of natural gas in the gaseous state by cooling it to approximately $-162^{\circ}C(-260^{\circ}F)$. The reduction in volume therefore makes it much more cost efficient to transport and store it. Modern LNG storage tanks are typically the full containment type, which is a double-wall construction with reinforced concrete outer wall and a high-nickel steel inner tank, with extremely efficient insulation between the walls. The insulation will be installed to LNG outer tank for the isolation of cryogenic temperature. The insulation will be installed in the base slab, wall and at the roof. According to the insulation's arrangement, the different aspects of temperature transmission is shown around the outer tank. As the result of the thermal & stress analysis, by the installing cellular glass underneath the perlite concrete, the temperature difference is greatly reduced between the ambient temperature and inside of concrete wall, also reducing section force according to temperature load.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.605-621
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• 1993

The gingival hyperplasia refers to an increase in the size of the gingival tissue produced by an increase in the number of its component cells. In order to investigate the cellular change in epithelium and subepithelial tissue of noninflammatory gingival hyperplasia, the gingival tissues were surgically obtained from the patients with dilantin gingival hyperplasia and idiopathic gingival hyperplasia. The excised tissue samples were fixed in neutral formalin for 6-24 hours, embedded with paraffin, sectioned at $4-6{\mu}m$ in thickness, mounted on glass slides coated with 3-aminopropyltriethoxysilane(Sigma Chemical Co., St. Louis, MO, U.S.A.) and immunocytochemically processed by Avidin-Biotin peroxidase complex method for detecting proliferating cell nuclear antigen, tenascin and collagen type IV. Monoclonal mouse anti-human PCNA antibody(Oncogene Science, Uniondale, NY, U.S.A., 1 : 250,000), monoclonal mouse anti-human tenascin antibody(Chemicon-International Inc., Temecula, CA, U.S.A., 1:5,000), and monoclonal mouse anti-human collagen type IV(Dakopatts, Glostrup, Denmark, 1: 50) were used as primary antibodies. The results were as follows: 1. In non-inflammatory gingival hyperplasia, the positive reaction to proliferating cell nuclear antigen was localized in the basal cell layer of gingival epithelium and well-developed rete pegs. 2. The positive reaction to tenascin was shown in the connective tissue subjacent to basament membrane of gingival tissue, and especially strong positive reaction was noted in the tip portion of connective tissue projections. 3. The positive reaction to collagen type IV was localized along the basement membranes of gingival epithelium and blood vessels. The results suggest that connective tissue enlargement may affect the proliferation of gingival epithelium.

• Journal of Korea Foundry Society
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• v.23 no.5
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• pp.276-285
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• 2003

In the undercooled melt of $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy, the solidification behavior including nucleation and growth of crystals at the micrometer level has been observed in-situ by use of a confocal scanning laser microscope combined with an infrared image furnace. The $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy specimens were cooled from the liquid state to glass transition temperature. 575 K, at various cooling late under a helium gas flow. According to the cooling rate, the morphologies of the solidification front are changed among various types, irregular jog like front, columnar dendritic front, cellular grain, star like shape jog and fine grain, etc. The velocities of the solid-liquid interface are measured to be $10^{-5}{\sim}10^{-8}$ m/s which are at least two orders higher than the theoretical crystal growth rates. Combining the morphologies observed in terms of cooling rates and their solidification behaviors, we conclude that phase separation takes place in the undercooled molten $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy. The continuous cooling transformation (CCT) diagram was constructed from solidification onset time at various linear cooling conditions with different rate. The CCT diagram suggests that the critical cooling rate for glassy solidification is about 1.5 K/s, which is in agreement with the previous calorimetric findings.

• The Korean Journal of Nuclear Medicine
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• v.37 no.1
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• pp.43-52
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• 2003

Microarray technology allows the simultaneous analysis of gene expression patterns of thousands of genes, in a systematic fashion, under a similar set of experimental conditions, thus making the data highly comparable. In some cases arrays are used simply as a primary screen loading to downstream molecular characterization of individual gene candidates. In other cases, the goal of expression profiling is to begin to identify complex regulatory networks underlying developmental processes and disease states. Microarrays were originally used with ceil lines or other simple model systems. More recently, microarrays have been used in the analysis of more complex biological tissues including neural systems and the brain. The application of cDNA arrays in neuropsychiatry has lagged behind other fields for a number of reasons. These include a requirement for a large amount of input probe RNA In fluorescent-glass based array systems and the cellular complexity introduced by multicellular brain and neural tissues. An additional factor that impacts the general use of microarrays in neuropsychiatry is the lack of availability of sequenced clone sets from model systems. While human cDNA clones have been widely available, high qualify rat, mouse, and drosophilae, among others are just becoming widely available. A final factor in the application of cDNA microarrays in neuropsychiatry is cost of commercial arrays. As academic microarray facilitates become more commonplace custom made arrays will become more widely available at a lower cost allowing more widespread applications. in summary, microarray technology is rapidly having an impact on many areas of biomedical research. Radioisotope-nylon based microarrays offer alternatives that may in some cases be more sensitive, flexible, inexpensive, and universal as compared to other array formats, such as fluorescent-glass arrays. In some situations of limited RNA or exotic species, radioactive membrane microarrays may be the most practical experimental approach in studying psychiatric and neurodegenerative disorders, and other complex questions in the brain.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.412-421
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• 2023

Ultrasound brain stimulation is spot-lighted by its capability of inducing brain cell activation in a localized deep brain region and ultimately treating impaired brain function while the efficiency and directivity of neural modulation are highly dependent on types of stimulus waveforms. Therefore, to optimize the types of stimulation parameters, we propose a cell-cultivable ultrasonic transducer having a series stack of a spin-coated polymer piezoelectric element (Poly-vinylidene fluoride-trifluorethylene, PVDF-TrFE) and a parylene insulating layer enhancing output acoustic pressure on a glass-coverslip which is commonly used in culturing cells. Due to the uniformity and high accuracy of stimulus waveform, tens of neuronal cell responses located on the transducer surface can be recorded simultaneously with fluorescence microscopy. By averaging the cell response traces from tens of cells, small changes to the low intensity ultrasound stimulations can be identified. In addition, the reduction of stimulus distortions made by standing wave generated from reflections between the transducers and other strong reflectors can be achieved by placing acoustic absorbers. Through the proposed ultrasound transducer, we could successfully observe the calcium responses induced by low-intensity ultrasound stimulation of 6 MHz, 0.2 MPa in astrocytes cultured on the transducer surface.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.725-730
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• 2017

A heteronemertean, Yininemertes pratensis, was collected in Han River Estuary, South Korea. This estuarine nemertean has been known by the local fishermen for harmful effects to the glass eels, juveniles of Japanese eel Anguilla japonica, migrating to fresh water. The present study confirmed the neurotoxic effects of this heteronemertean ribbon worm at the cellular level. Derivative types of neurotoxic tetrodotoxin (TTX), 5,11-dideoxy TTX (m/z 288) and 11-norTTX-6(S)-01 (m/z 305.97), were identified through HPLC and MALDI-TOF MS. However, significant neurotoxicity was confirmed in the fraction containing an undefined molecule corresponding to the 291.1 (m/z) peak, when tested in rat primary astrocytes and dorsal ganglion cells. This study is the first to report neurotoxins of the estuarine nemertean, fairly abundant in the Han River estuary, and suggests the long-term monitoring of population dynamics and surveillance of the toxicity in this river estuary.