• The Plant Pathology Journal
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• v.29 no.1
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• pp.17-30
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• 2013

Barley stripe mosaic virus (BSMV) induces massive actin filament thickening at the infection front of infected Nicotiana benthamiana leaves. To determine the mechanisms leading to actin remodeling, fluorescent protein fusions of the BSMV triple gene block (TGB) proteins were coexpressed in cells with the actin marker DsRed: Talin. TGB ectopic expression experiments revealed that TGB3 is a major elicitor of filament thickening, that TGB2 resulted in formation of intermediate DsRed:Talin filaments, and that TGB1 alone had no obvious effects on actin filament structure. Latrunculin B (LatB) treat-ments retarded BSMV cell-to-cell movement, disrupted actin filament organization, and dramatically decreased the proportion of paired TGB3 foci appearing at the cell wall (CW). BSMV infection of transgenic plants tagged with GFP-KDEL exhibited membrane proliferation and vesicle formation that were especially evident around the nucleus. Similar membrane proliferation occurred in plants expressing TGB2 and/or TGB3, and DsRed: Talin fluorescence in these plants colocalized with the ER vesicles. TGB3 also associated with the Golgi apparatus and overlapped with cortical vesicles appearing at the cell periphery. Brefeldin A treatments disrupted Golgi and also altered vesicles at the CW, but failed to interfere with TGB CW localization. Our results indicate that actin cytoskeleton interactions are important in BSMV cell-to-cell movement and for CW localization of TGB3.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.246-253
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• 1998

Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri which possessed the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The binding sites of heavy metal in the cells were investigated by chemical modification of functional groups the cell walls. To determine the binding sites of heavy metal in the cells, electrochemical charge of amine and carboxyl groups in the cell walls of heavy metal-tolerant microorganisms were chemically modified. Chemical modifications of amine groups did not affect the heavy metal uptake as compared to native cell walls. In contrast, modifications of carboxyl groups drastically decreased heavy metal uptake as compared to native cell walls, and electron microscopy confirmed that the form and structure of the heavy metal uptake were different from those of native cell walls. The results suggested that the carboxyl groups were the major sites of heavy metal uptake in the heavy metal-tolerant microorganism cell.

• Journal of Mechanical Science and Technology
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• v.14 no.8
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• pp.861-866
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• 2000

Flow induced shape change is important for spatial interpretation of vascular response and for understanding of mechanotransduction in a single cell. We investigated the possible shapes of endothelial cell (EC) in a mathematical model and compared these with experimental results. The linearized analytic solution from the sinusoidal wavy wall and Stokes flow was applied with the constraint of EC volume. The three dimensional structure of the human umbilical vein endothelial cell was visualized in static culture or after various durations of shear stress (20 $dyne/cm^2$ for 5, 10, 20, 40, 60, 120min). The shape ratio (width: length: height) of model agreed with that of the experimental result, which represented the drag force minimizing shape of stream-lining. EC would be streamlined in order to accommodate to the shear flow environmented by active reconstruction of cytoskeletons and membranes through a drag force the sensing mechanism.

• Korean Journal of Microbiology
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• v.10 no.1
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• pp.29-34
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• 1972

The present study is of ultra-fine structure of Cryptococcus neoformans by means of electron microscopy and reveals the following : 1) In constrast to the bacteria, the normal Cryptococcus neofrmans contains nuclear enveloped with nuclear menbrane, mitochondria, endoplasmic reticulum, distinct cell wall and cell membrane, vacuoles and storage granules as observed in the eucaryotic cells. 2) In apparent cell walls and cell membrane with the appearance of electron transparent area (ETA) and changes of cell morphology were observed in the ultra-violet ray irradiated cell. 2) In apparent cell walls and cell membrance with the appreance of electron transparent area (ETA) and changes of cell morphology were observed in the ultra-violet ray irradiated cell. 3) Morphology changes and cytoplasmic element abnormality was increased with irradiated time. 4) Increase of electron transparent area was thought to be associated with degradation of cell.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.345-349
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• 2009

This study measured the amounts of uronic acid, total sugars, non-cellulosic neutral sugars, phenolic compounds as well as antioxidants activity in cell wall materials (CWM) derived from different parts of deodeok (Codonopsis lanceolata). The values of the uronic acid (UA): neutral sugars (NS) ratio in polymers extracted from the CWM of the flesh and skin were 4 and 6, respectively. The total sugar contents of the flesh and skin were 788.6 and 824.9 ${mu}g/mg$ of CWM, respectively. Galactose and arabinose were the main noncellulosic neutral sugars. The chemical structure of five phenolic compounds from the CWM were analyzed and identified as vanillic acid, p-OH-benzaldehyde, vanillin, ferulic acid, and 8-O-4' diferulic acid by HPLC spectral data. Among them, p-OH-benzaldehyde, vanillin, and 8-O-4' diferulic acid were the first compounds identified from the deodeok. The content of 8-O-4' diferulic acid in the skin CWM was 56.1 ${mu}g/g$ AIR (alcohol insoluble residue). The ethanol-NaOH fractions from CWM had the highest oxygen radical absorbance capacity (ORAC) activities, followed by the AIR fractions and ethanol fractions.

• Parasites, Hosts and Diseases
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• v.39 no.1
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• pp.13-21
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• 2001

Pneumocystis carinii causes serious pulmonary infection in immuno-suppressed patients. This study was undertaken to observe the cytoskeletal proteins of P. carinii by immune-electron microscopy. P. carinii infection was experimentally induced by immunosuppression of Sprague-Dawley rats for seven weeks, and their lungs were used for the observations of this study. The gold particles localized actin, tropomyosin, and tubulin. The actin was irregularly scattered in the cytoplasm of the trophic forms but was much more concentrated in the inner space of the cell wall of the cystic forms called the inner electron-lucent layer No significant amount of tropomyosin was observed in either trophic forms or cystic forms. The tubulin was distributed along the peripheral cytoplasm and filopodia of both the trophic and cystic forms rather than in the inner side of the cytoplasm. Particularly, in the cystic forms, the amount of tubulin was increased and located mainly in the inner electron-lucent layer of the cell wall where the actin was concentrated as well. The results of this study showed that the cell wall of P carinii cystic forms is a structure whose inner side is rich in actin and tubulin. The location of the actin and tubulin in P. carinii suggests that the main role of these proteins is an involvement in the protection of cystic forms from the outside environment by maintaining rigidity of the cystic forms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.237-242
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• 2001

The stochiometric mix of evaporating materials for the CuGaSe$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CuGaSe$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 610$^{\circ}C$ and 450$^{\circ}C$, respectively The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuGaSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting Δ So and the crystal field splitting ΔCr were 91 meV and 249.8 meV at 20 K, respectively. From the Photoluminescence measurement on CuGaSe$_2$ single crystal thin film, we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton (D$^{\circ}$,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy 7f neutral acceptor bound excision were 8 meV and 35.2 meV, respectivity. By Haynes rule, an activation energy of impurity was 355.2 meV

• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.104-110
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• 2010

Cyclic deformations of polymer foam film are simulated using the finite element method. Material of polymer foam film is polypropylene (PP). The calculated polymer foam film is micro-scale thin film has cellular structure. The polymer foam film is used in ferro-electret applications. The polymer foam film is idealized to one cell structure as lens shaped stretched truncated octahedron model. Cyclic deformation is performed by uniaxial stretching. Stretching direction is perpendicular to plane of cellular film. Various cyclic strain amplitudes, pore wall thicknesses, pore shape are investigated to find deformation tendency of cellular structure. Consequently, cellular structure has various macroscopic stresses on cyclic deformation with various pore thickness and pore shape.

• The Journal of Korea Robotics Society
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• v.11 no.3
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• pp.133-139
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• 2016

Increasing interest of human health, building bio-database (Bio DB) has been become a hot issue in life science. Consequently, Single Cell Analysis (SCA) which can explain biodiversity of lives has been a significant factor for building Bio DB. In numerous studies from these analyses, they have been showed that mechanical properties of cells can serve explanation of biological heterogeneity and criterion of disease states. Therefore, measuring mechanical properties of cells have great potential to be used in bio-medical applications. However, traditionally, many researchers have undergone difficult and time consuming work because handling small sized cells usually requires high-skilled technique. Thus, this paper shows robotized stiffness measurement technique using fixed ended beam sensor, precision motorized stage and substrate which have wall structure.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.492-498
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• 2021

In this paper, the electromagnetic wave transmittance of the reinforced concrete structure wall was analyzed using the performance measurement system of electromagnetic wave shielding. Recently, electromagnetic wave shielding technologies on the reinforced concrete wall conditions have been studied, and the shielding effectiveness have been tested on unit cell size. However, the unit cell size tests have problems on that the measurement range for shielding performance is insufficient and it is difficult to reflect the real conditions of the concrete wall. Therefore, we constructed a shielding performance measurement system using a large sample of 2.2m × 2.2m like a real wall. To verify the measurement system, general reinforced concrete test samples were selected, and real shielding performance measurements and numerical analysis were proceeded. Test and numerical analysis results showed similar tendencies in the evaluation frequency range of 75MHz to 2GHz. Thus we validated the effectiveness of this shielding performance measurement system.