• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.467-480
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• 2002

The development of the female gametophyte of Corydalis albipetala, C. ambigua, C. filistipes, C. nobilis, C. solida, C. ophiocarpa have been comparatively investigated using laser scanning confocal microscope (LSCM) and light microscope. An archesporium was originated from one of the outmost parietal cells beneath the one-layered epidermis of protuberant nucellus, and acted directly as a megaspore mother cell (MMC). These species had linear tetrads after successional meiotic division during the megasprogenesis. A functional megasprore developed from one of the tetrad in the chalazal end, and the rest three being degenerated. The developmental type of the female gametophyte was monosporic in accordance with the Polygonum type. Prior to anthesis the female gametophyte was organized. So mature embryo sac was comprised a three-celled egg apparatus, three large antipodals were developed from the apex of each antipodal cell, and extended toward micropylar end to be contacted with egg apparatus. Two synergids were usually observed as degenerated condition, and in this time the apices of antipodal haustoria were connected with the degenerated synergids. The developmental characteristics of seven-nucleate female gametophytes were common in all the species investigated. But the shape of mature embryo sac was ovoidal in C. albipetala, C. filistipes, C. ophiocarpa and C. solida, reflexed in C. ambigua, and rather flattened ovoidal in C. nobilis. Also, the type of megasporangium was anatropous in all the species except C. ambigua with campylotropous ovule.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.261-266
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• 2011

As recent reports suggest that nanoparticles may penetrate into cell membrane and effect DNA condition, it is necessary to assay possible cytotoxic and genotoxic risk. Three different sizes of magnetic nanoparticle silica (MNP@$SiO_2$) (50, 100 and 200 nm diameter) were tested for cytotoxicity and DNA damage using L5178Y cell. MNP@$SiO_2$ had constant physicochemical characteristics confirmed by transmission electron microscope, electron spin resonance spectrometer and inductively coupled plasma-atomic emission spectrometer for 48 h. Treatment of MNP@$SiO_2$ induced dose and time dependent cytotoxicity. At 6 h, 50, 100 or 200 nm MNP@$SiO_2$ decreased significantly cell viability over the concentration of 125 ${\mu}g/ml$ compared to vehicle control (p<0.05 or p<0.01). Moreover, at 24 h, 50 or 100 nm MNP@$SiO_2$ decreased significantly cell viability over the concentration of 125 ${\mu}g/ml$(p<0.01). And treatment of 200 nm MNP@$SiO_2$ decreased significantly cell viability at the concentration of 62.5 ${\mu}g/ml$ (p<0.05) and of 125, 250, 500 ${\mu}g/ml$ (p<0.01, respectively). Furthermore, at 48 h, 50, 100 or 200 nm MNP@$SiO_2$ decreased significantly cell viability at the concentration of 62.5 ${\mu}g/ml$ (p<0.05) and of 125, 250, 500 ${\mu}g/ml$ (p<0.01, respectively). Cellular location detected by confocal microscope represented they were existed in cytoplasm, mainly around cell membrane at 2 h after treatment of MNP@$SiO_2$. Treatment of 50 nm MNP@$SiO_2$ significantly increased DNA damage at middle and high dose (p<0.01), and treatment of 100 nm or 200 nm significantly increased DNA damage in all dose compared to control (p<0.01). Taken together, treatment of MNP@$SiO_2$ induced cytotoxicity and enhanced DNA damage in L5178Y cell.

• The korean journal of orthodontics
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• v.44 no.4
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• pp.195-202
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• 2014

Objective: A low-viscosity resin (infiltrant) was used to inhibit the progression of white spot lesions (WSLs) and resolve associated esthetic issues. An alternative pretreatment was explored to increase the pore volume of the surface layer of the WSLs. Also, the penetration effects of the infiltrant were evaluated for various pretreatments. Methods: Sixty two artificial lesions were fabricated on bovine teeth. As a positive control, 15% HCl gel was applied for 120 seconds. Further, 37% $H_3PO_4$ gel was applied for 30 seconds using three methods. The samples were divided as follows: $H_3PO_4$ only group, $H_3PO_4$ sponge group, and $H_3PO_4$ brush group. The acid was gently rubbed with the applicators (i.e., a sponge or brush) throughout the application time. To compare the effects of resin infiltration, twenty paired halves of specimens were treated with an infiltrant (ICON$^{(R)}$). Results: Thicknesses of the removed surface layers and infiltrated areas were evaluated by confocal laser scanning microscope. The positive control and the 37% $H_3PO_4$ brush group failed to show significant differences in the removed thickness (p > 0.05); however, the mean percentage of the infiltrated area was higher in the 37% $H_3PO_4$ brush group ($84.13{\pm}7.58%$%) than the positive control ($63.51{\pm}7.62%$, p < 0.001). Scanning electron microscope observations indicate higher pore volumes for the 37% $H_3PO_4$ brush group than for the positive control. Conclusions: Application of 37% $H_3PO_4$ with a brush for 30 seconds increased the pore volume of WSL surface layers and the percentage of infiltrated areas in comparison to the use of 15% HCl for 120 seconds.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.339-347
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• 2012

In previous studies, methods for enhancing cellular response on the Hydroxyapatite coated implant surface were described. In this study, the changes of surface characteristics such as surface roughness, contact angle, surface energy and surface morphology were observed when Hydroxyapatite coated Ti discs were immersed in NaCl solution for various time. Hydroxyapatite coated Ti discs were immersed in 0.9% NaCl solution for 7, 14 and 21 days at $37^{\circ}C$. The control group comprises dry identical discs not immersed in a solution. (n=3) All discs were dried in air completely and the surface roughness was measured using confocal laser scanning microscopy(CLSM). Static contact angle was recorded by video contact angle analyzer after dropping distilled water on the surface. The surface energy was calculated from contact angles of the three liquids. Surface was observed using a field emission-scanning electron microscope(FE-SEM). As a result, the surface roughness of immersed Hydroxyapatite coated Ti discs increased significantly and the contact angle decreased comparing with control group discs. The surface energy of immersed discs increased except for discs immersed for 14 days.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.47-60
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• 2004

The permeability coefficients were calculated by the homogenization analysis method with sufficient consideration of fracture geometry dependent on aperture change. According to the results of aperture measurements using a confocal laser scanning microscope, apertures on each measuring point display different magnitudes, indicating that fracture walls can not be assumed as parallel feature. After construction of fracture model based on the aperture values measured on each pressure level, the homogenization analysis was conducted to compute permeability coefficients. The calculated permeability coefficients distribute in the ranges of $10^{-1}~10^{-3}cm/sec$. Most of the specimens show decreasing permeability coefficients with the increase of the applied pressure. However, the decreasing rates of permeability coefficients do not show a constant trend on each pressure level. This phenomenon is well matched to the observation results of Chae et al. (2003). It proves that aperture change strongly influences on permeability characteristics. Three sections of each specimen have all different values of permeability coefficient. It suggests that the variation of permeability coefficient depends sensitively on aperture magnitudes and characteristics of fracture geometry. It is very important to consider accurate fracture geometries for analysis of permeability characteristics in rock fractures bearing different aperture distribution. Therefore, it needs to consider sufficiently the fracture geometries for calculating the permeability coefficients of fractures.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.220-225
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• 2020

Hair is made of proteins containing various amino acids. Ultraviolet (UV) radiation is believed to be responsible for the most damaging effects of sunlight, and also plays an important role in hair aging. The purpose of this study was to investigate the changes in morphological and chemical structures after ultraviolet B (UVB) irradiation of human hair. The UVB-irradiated hair showed characteristic morphological and structural changes, compared to those of the normal hair. The result from a scanning electron microscope (SEM) equipped with an energy dispersive X-ray diffractometer (EDX) showed that the scale of UV-irradiated hair appeared to be rough and the amount of oxygen element was higher than that of the normal hair. Fluorescence and three dimensional (3D) topographical images were obtained by a confocal laser scanning microscope (CLSM). In 3D images, the green emission intensity of normal hair was much higher than that of fluorescing UVB-irradiated hair. The intensity of green emission reflects the intrinsic fluorescence of hair protein. Also, a fluorescent imaging method using fluorescamine reagent was used to identify the free amino groups resulting from a peptide bond breakage in UVB-irradiated hair. Strong blue fluorescence of UVB-irradiated hair, which indicates a very high level of amino groups, was observed by CLSM. Therefore, the fluorescamine as an extrinsic fluorescence could provide a useful tool to identify the peptide bond breakage in UVB-irradiated hair. Infrared image mapping was also employed to assess the cross-sections of normal and UVB-irradiated specimens to examine the oxidation of disulfide bonds. The degree of peak areas with strong absorbance for the disulfide mono-oxide was spread from the outside to the inside of hair. The spectroscopic techniques used alone, or in combination, launch new possibilities in the field of hair cosmetics.

• Composites Research
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• v.37 no.3
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• pp.204-208
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• 2024

De-icing/anti-icing fluid is essential for removing ice formation on aircraft. It chemically removes ice using organic solvents, which can cause damage to the topcoat surface in the process. In this study, glycol-based deicing/anti-icing fluid was used to remove ice, and the resulting damage to the topcoat was examined. USB microscope was used to observe the formation and growth of ice, while a confocal microscope was employed to observe the surface morphology after treatment with de-icing/anti-icing fluid. Additionally, coating thickness measurements and Fourier transform infrared (FT-IR) analysis were conducted to investigate the physical and chemical changes on the surface. The repeated application of de-icing/anti-icing fluid showed a reduction in the ice formation rate and an increase in the growth rate. Damage during the pressurization process and surface damage to the polyurethane topcoat caused by ethylene glycol were observed during the de-icing process. Although no chemical changes were detected, the analysis revealed that surface uniformity decreased, with physical damage such as cracks and undulations forming on the surface. It was confirmed that while de-icing/anti-icing fluid is effective in removing ice, it also causes surface damage.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.1-7
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• 2011

Purpose: The purpose of this study was to investigate the cutting efficiency of coarse grit diamond burs with air-turbine handpiece on natural tooth. Materials and methods: Four groups of coarse grit diamond bur were selected: Komet (A), Shofu (B), Premier (C), and Mani (D). The extracted maxillary central incisors were used, and ten cuts were made on each specimen, using the rotary diamond burs. The surface of each bur was measured at the upper, middle, and bottom of the bur with confocal laser scanning microscope and imaged with SEM. The data were analyzed with one-way ANOVA and t-test at the significance level of 0.05. Results: The surface roughness was measured. At the A diamond bur, the Sa values were $52.93\;{\mu}m$, $48.32\;{\mu}m$, $46.79\;{\mu}m$, $45.06\;{\mu}m$, and $43.43\;{\mu}m$ for control, test 1, 2, 3, and 4 respectively. The Sa values were $50.68\;{\mu}m$, $45.62\;{\mu}m$, $44.41\;{\mu}m$, $44.10\;{\mu}m$, and $42.46\;{\mu}m$ for B diamond bur, $58.02\;{\mu}m$, $55.53\;{\mu}m$, $52.22\;{\mu}m$, $48.26\;{\mu}m$, and $45.36\;{\mu}m$ for C diamond bur, and $50.11\;{\mu}m$, $46.73\;{\mu}m$, $45.46\;{\mu}m$, $42.58\;{\mu}m$, and $41.80\;{\mu}m$ for D diamond bur. Surface roughness after each bur use showed significant changes, but no significant difference was found in surface roughness change between bur systems. Conclusions: Surface roughness in the same bur system showed significant differences after each tooth preparation. However no statistically significant differences were found in surface roughness between bur systems. The SEM images between control and test 4 showed the abraded particles.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.288-297
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• 2010

The purpose of this study was to evaluate the effect of light cured fluoride-releasing materials on the inhibition of demineralization. In addition, the pattern of fluoride uptake of adjacent tooth structure was analyzed with EPMA. Eighty intact premolars were restored with $Filtek^{TM}$ Z250(control group, composite), Fuji Filling $LC^{TM}$(RMGI), Dyract $AP^{(R)}$ (compomer) and Beautifil II(giomer). Restored teeth were stored in distilled water for 30 days. Then sixty teeth(n=15) were exposed to demineralizing solution(pH 4.3). Demineralized teeth were bisected and polished. The specimens were observed with confocal laser scanning microscope. The depth of outer lesion and the thickness of inhibition zone were measured. Remained twenty teeth(n=5) were bisected for fluoride uptake analysis. The fluoride analysis were taken at enamel-restoration interface and dentin-restoration interface by electron probe micro-analyzer. The results are as follows: 1. The depth of outer lesion of Fuji Filling $LC^{TM}$ Dyract AP, Beautifil II was shallower than that of $Filtek^{TM}$ Z250 at the margin of restoration(p<0.05). 2. The thickness of caries inhibition zone of Fuji Filling $LC^{TM}$, Dyract AP, Beautifil II was greater than that of $Filtek^{TM}$ Z250 at the margin of restoration(p<0.05). 3. Fuji Filling $LC^{TM}$, Dyract AP, Beautifil II groups showed the greater fluoride uptake into enamel and dentine around restoration than $Filtek^{TM}$ Z250 group. 4. In dentin the difference of fluoride concentration were greater than in enamel, and Dyract AP showed the greatest fluoride concentration in dentin.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.138-148
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• 2004

Purpose: Regardless of the underlying diseases, the proteinuric condition demonstrates ultrastructural changes in podocytes with retraction and effacement of the highly specialized interdigitating foot processes. We examined the molecular basis for this alteration of the podocyte phenotypes, including quantitative and distributional changes of ZO-1 protein as a candidate contributing to the pathogenic changes in the barrier to protein filtration. Methods: To investigate whether high glucose and advanced glycosylation endproduct(AGE) induce podocyte cytoskeletal changes, we cultured rat GEpC under 1) normal glucose(5 mM=control) or 2) high glucose(30 mM) or 3) AGE-added or 4) high glucose plus AGE-added conditions. The distribution of ZO-1 was observed by confocal microscope and the change of ZO-1 expression was measured by Western blotting and RT-PCR. Results: By confocal microscopy, we observed that ZO-1 moves from peripheral cytoplasm to inner actin filaments complexes in both AGE-added and high glucose condition. In Western blotting, high glucose or AGE-added condition decreased the ZO-1 protein expression by 11.1%(P>0.05) and 2.3%(P>0.05), respectively compared to the normal glucose condition. High glucose plus AGE-added condition further decreased ZO-1 protein expression to statistically significant level(12%, P<0.05). No significant change was seen in the osmotic control. In RT-PCR, high glucose plus AGE-added condition significantly decreased the expression of ZO-1 mRNA by 12% compared to normal glucose condition. Conclusion: We suggest that both high glucose and AGE-added condition induce the cytoplasmic translocation and suppresses the production of ZO-1 at transcriptional level and these changes may explain the functional changes of podocytes in diabetic conditions.