• Journal of Ecology and Environment
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• v.48 no.3
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• pp.233-246
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• 2024

Background: In this research work, epilithic communities of diatoms in macrophytes are listed and described to evaluate the ecological conditions of the surface waters of the Chipoco River, whose basin has been exploited for agricultural and mining purposes, degrading natural ecosystems. The diatoms studied are found in calcareous tufa deposits developed in swampy environments where little of their benthic microbiota has been studied, despite the regional relevance of these calcareous formations within the manganese mining district. To describe the diatoms and evaluate the ecological condition of the surface waters, the Chipoco River was divided into three sectors (North, Center, and South) collecting a total of 15 samples along 10 km. For the taxonomic identification of diatoms, scanning electron microscopy techniques, consultations with specialists and specialized literature were used. To evaluate the ecological conditions of the Chipoco River, the linear correlation coefficient was used, where the relationships between diatom species and environmental variables were evaluated. Likewise, species diversity was determined by applying the Shannon-Wiener index and Simpson's dominance value (D) was calculated to detect diversity impoverishment processes. Results: Ten genera of diatoms were identified in bryophytes of the species Plagiomnium cuspidatum that grow on the banks of said river. The linear correlation coefficient indicated that physicochemical characteristics such as total dissolved solids, temperature, and calcium, and hydrochemical characteristics of the water intervene in the distribution and abundance of four diatoms Rhoicosphenia abreviate, Epithemia turgida, Calloneis bacillum and Achanthidium minutissimum in the different sectors studied. The Shannon-Wiener diversity indices and Simpson's dominance show that there is greater diversity and marked dominance of diatoms in the northern sector compared to the central and southern sectors. Conclusions: Agricultural and mining activities and the poor sanitary infrastructure of human settlements have caused the Chipoco River to have poor ecological quality.

• Korean Journal of Plant Taxonomy
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• v.31 no.3
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• pp.267-282
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• 2001

To examine the leaf epidermal microstructure of three genera (Scopolia s.s., Anisodus, AtroPanthe, including Przewalskia as an outgroup) in the genera Scopolia Jacq. s.l., leaves of 10 species (37 specimens) were investigated by the light microscopy (LM) and scanning electron microscopy (SEM). The stomata of studied taxa were 'amphistomatic type' and the size (guard cell) range was $18-64{\times}11-48{\mu}m$. The size of stomata is slightly differed from between the taxa; the smallest size of stomata were found in the monotypic genus, Przewalskia ($24-27{\times}16-17{\mu}m$), on the other hand the largest one was found in Anisodus carniolicoides ($62-64{\times}43-48{\mu}m$). The stomatal complex was mostly anomocytic (in Scopolia s.s., Anisodus taxa : A. luridus, A. carniolicoides, A. acutangulus) and sometimes anisocytic (in Anisodus tanguticus, Przewalskia, Atropanthe). The stomata is mostly crescent in shape, but rarely circular, especially in Przewalskia tangutica. The shapes of epidermal cells are similar in both adaxial and abaxial sides, and mostly undulate/sinuate polygonal anticlinal wall, but rarely arched in Przewalskia tangutica. The epicuticular wax was not well developed in most studied taxa, except Anisodus tanguticus which is well developed cuticular striae around the stomatal complex. The elongate-headed glandular trichomes were found in Scopolia s.s. and Przewalskia. While the taxa of Anisodus and Atropanthe have not any trichomes (i. e., glabrous), except Anisodus luridus, which has simple or sometimes branched (dendritic- type) non-glandular trichome. Finally, the systematic and ecological significance of the leaf micromorphological features (stomata complex, trichome, etc.) in identification and elucidation of Scopolia s.l. including Przewalskia, especially between or within the genera including among the species is also discussed.

• Journal of dental hygiene science
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• v.16 no.4
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• pp.284-292
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• 2016

Water supplied through dental unit waterlines (DUWLs) has been shown to contain high number of bacteria. To reduce the contamination of DUWLs, it is essential to develop effective disinfectants. It is, however, difficulty to obtain proper DUWL samples for studies. The purpose of this study was to establish a simple laboratory model for reproducing DUWL biofilms. The bacteria obtained from DUWLs were cultured in R2A liquid medium for 10 days, and then stored at $-70^{\circ}C$. This stock was inoculated into R2A liquid medium and incubated in batch mode. After 5 days of culturing, it was inoculated into the biofilm formation model developed in this study. Our biofilm formation model comprised of a beaker containing R2A liquid medium and five glass rods attached to DUWL polyurethane tubing. Biofilm was allowed to form on the stir plate and the medium was replaced every 2 days. After 4 days of biofilm formation in the laboratory model, biofilm thickness, morphological characteristics and distribution of the composing bacteria were examined by confocal laser microscopy and scanning electron microscopy. The mean of biofilm accumulation was $4.68{\times}10^4$ colony forming unit/$cm^2$ and its thickness was $10{\sim}14{\mu}m$. In our laboratory model, thick bacterial lumps were observed in some parts of the tubing. To test the suitability of this biofilm model system, the effectiveness of disinfectants such as sodium hypochlorite, hydrogen peroxide, and chlorhexidine, was examined by their application to the biofilm formed in our model. Lower concentrations of disinfectants were less effective in reducing the count of bacteria constituting the biofilm. These results showed that our DUWL biofilm laboratory model was appropriate for comparison of disinfectant effects. Our laboratory model is expected to be useful for various other purposes in further studies.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.283-289
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• 2017

The water discharged from dental unit waterlines (DUWLs) is heavily contaminated with bacteria. The development of efficient disinfectants is required to maintain good quality DUWL water. The purpose of this study was to establish a DUWL biofilm model using well-plates to confirm the effectiveness of disinfectants in the laboratory. Bacteria were obtained from the water discharged from DUWLs and incubated in R2A liquid medium for 10 days. The bacterial solution cultured for 10 days was made into stock and these stocks were incubated in R2A broth and batch mode for 5 days. Batch-cultured bacterial culture solution and polyurethane tubing sections were incubated in 12-well plates for 4 days. Biofilm accumulation was confirmed through plating on R2A solid medium. In addition, the thickness of the biofilm and the shape and distribution of the constituent bacteria were confirmed using confocal laser microscopy and scanning electron microscopy. The average accumulation of the cultured biofilm over 4 days amounted to $1.15{\times}10^7CFU/cm^2$. The biofilm was widely distributed on the inner surface of the polyurethane tubing and consisted of cocci, short-length rods and medium-length rods. The biofilm thickness ranged from $2{\mu}m$ to $7{\mu}m$. The DUWL biofilm model produced in this study can be used to develop disinfectants and study DUWL biofilm-forming bacteria.

• Research in Plant Disease
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• v.12 no.1
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• pp.15-19
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• 2006

This study was carried out to know pathogenicity of the pathogen isolated in several location of Korea and penetration mechanism of the Pseudocercospora vitis ($(L\acute{e}v)$.) Speg. Inoculation tests at room temperature were performed on both sides of leaves with different isolates of the fungus. The typical symptoms appeared on the abaxial leaf surface, but no symptom was observed on the adaxial leaf surface with all isolates. The average incubation period was nine days, since all symptoms appeared from 8 to 10 days after inoculation. In order to know the mechanism of invasion of P. vitis to grapevine, the behavior of penetration hyphae through stomata were compared in two cultivars having different level of resistance. In order to know the mechanism of resistance of grape vine to P.vitis, two cultivars having different level of resistance were compared by counting the numbers and measuring size of the stomata per leaf. In a susceptible cultivar Campbell Early, the number of stomata was more than that of a resistance cultivar 'Kyoho'. In a susceptible cultivar 'Campbell Early', the fungus entered readily into stomata after inoculation. However, in a resistant cultivar 'Kyoho', the fungus seemed to pass over or surrounded only the guard cells. In comparison of height of guard cells of stomata between the two cultivars, significant differences were observed by scanning electron microscopy and light microscopy. The height of guard cells of 'Campbell Early' showed a little higher than those of 'Kyoho' known to be resistant to the fungus.

• Journal of Chest Surgery
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• v.36 no.4
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• pp.229-241
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• 2003

Background:Autogenous vein is the preferred vascular graft for patients who require coronary artery bypass surgery or peripheral arterial bypass surgery. When an autogenous vein is not available, an allograft saphenous vein can be used as an alternative conduit. Although arterial homograft has been under investigation since the beginning of this century, the viability of endothelial cells and the optimum mode of storage for the venous and arterial allografts is controversial. In addition, with the recently gained knowledge of vascular endothelial functions, such as the production of nitric oxide or thrombomodulin, the viability and antigenicity of endothelial cells are being studied again. The purpose of this study was to evaluate the viability of endothelial cells in the preserved human saphenous veins. Material and Method: The veins were stored in a $4^{\circ}C$ RPMI (Roswell Park Memorial Institute) 1640 solution including 10% fetal calf serum, for one, three, five, seven or fourteen days. After the completion of the storage period, the veins were divided into two groups: Group I: studied immediately at $4^{\circ}C$ (cold) storage (I-1, I-3, I-5, I-7, I-14), and Group II: studied after storage at $-196^{\circ}C$ liquid nitrogen tank (cryopreservation) in an RPMI 1640 solution containing 10% DMSO for two weeks (II-1, II-3, II-5, II-7, II-14). Light microscopy and scanning electron microscopy (SEM), frypan blue exclusion testing, and thrombomodulin immunohistochemistry were performed. Result: In a morphometric study using SEM, there was statistically significant increase in Gundry Score in Groups I-7, I-14, II-5, II-7, and II-14 and showed cellular destruction (p<0.05). In the thrombomodulin immunohistochemistry study, there was reactivity in Groups I-1, I-3, and I-5, but the cryopreserved group revealed decreased reactivity (p<0.05). The trypan blue exclusion testing also showed superior viability in cold storage Group I. Conclusion: Venous allografts preserved in a $4^{\circ}C$ RPMI 1640 solution showed well preserved endothelial cellular integrity and thrombomodulin expression at up to seven days of preservation. Although cryopreservation of venous allografts stored in 10% DMSO -RPMI 1640 solution maintained the endothelial cellular structure on SEM, immunohistochemistry from the thrombomodulin and trypan blue exclusion testing showed decreased viability, It remains to be seen whether the decreased thrombomodulin reactivity could be restored, and what the nature to the relationship is between thrombomodulin and long-term patency of allografts.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.307-327
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• 2008

Geochemical study on the rocks and minerals of the Gyeongju low and intermediate level waste repository was carried out in order to provide geochemical data for the safety assessment and geochemical modeling. Polarized microscopy, X-ray diffraction method, chemical analysis for the major and trace elements, scanning electron microscopy(SEM), and stable isotope analysis were applied. Fracture zones are locally developed with various degrees of alteration in the study area. The study area is mainly composed of granodiorite and diorite and their relation is gradational in the field. However, they could be easily distinguished by their chemical property. The granodiorite showed higher $SiO_2$ content and lower MgO and $Fe_2O_3$ contents than the diorite. Variation trends of the major elements of the granodiorite and diorite were plotted on the same line according to the increase of $SiO_2$ content suggesting that they were differentiated from the same magma. Spatial distribution of the various elements showed that the diorite region had lower $SiO_2,\;Al_2O_3,\;Na_2O\;and\;K_2O$ contents, and higher CaO, $Fe_2O_3$ contents than the granodiorite region. Especially, because the differences in the CaO and $Na_2O$ distribution were most distinct and their trends were reciprocal, the chemical variation of the plagioclase of the granitic rocks was the main parameter of the chemical variation of the host rocks in the study area. Identified fracture-filling minerals from the drill core were montmorillonite, zeolite minerals, chlorite, illite, calcite and pyrite. Especially pyrite and laumontite, which are known as indicating minerals of hydrothermal alteration, were widely distributed in the study area indicating that the study area was affected by mineralization and/or hydrothermal alteration. Sulfur isotope analysis for the pyrite and oxygen-hydrogen stable isotope analysis for the clay minerals indicated that they were originated from the magma. Therefore, it is considered that the fracture-filling minerals from the study area were affected by the hydrothermal solution as well as the simply water-rock interaction.

• Applied Microscopy
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• v.36 no.3
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• pp.165-172
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• 2006

Secretory leukocyte protease inhibitor (SLPI) involves tissue protection against the destructive action of neutrophil elastase at the site of inflammation. Several studies on new functions of SLPI have demonstrated that SLPI may play a primary role in innate immunity than protease inhibitor, To identify the function of SLPI by lipopolysaccharide (LPS) stimulation in the embryonic fibroblast (NIH3T3) cells. we studied the expression of SLPI compared to other growth factors involving the LPS treatment. To address this, we performed the reverse transcriptase polymerase chain reaction (RT-PCR) and Western blots for the detection of mRNA and protein expression of the SLPI and some growth factors such as VEGF. bFGF, and PDGF-BB after LPS stimulation. NIH3T3 cells were exposed 100 ng/mL Escherichia coli LPS for 30min, 60min, 90min, 24h, and 48h, respectively. The result of RT-PCR showed that SLPI and VEGF mRNA was expressed strongly in NIH3T3 without related to LPS stimulation. mRNA of bFGF was weakly expressed such as the expression of the control. PDGF mRNA expression gradually increased follows at time course. However, SLPI protein level was increased in lysates and culture medium by LPS stimulation. Phase contrast microscopic and scanning electron microscopic observation showed that the increased cell number and cytoplasmic enlargement of the NIH3T3 cells. Therefore, it suggests that the LPS upregulates SLPI expression in NIH3T3 cells. Moreover, secreted SLPI may stimulate cell proliferation and migration.

• Korean Journal of Plant Taxonomy
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• v.34 no.2
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• pp.97-118
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• 2004

A comparative anatomical and ultrastructural study was undertaken to investigare on the leaf epidermis by light microscopy (LM) and scanning electron microscopy (SEM). On the basis of results from this study, it was grasped major characters of taxa and variation range of each character on the level of species, section and subgenus respectively. The shape of leaf epidermal cell was oblong to linear, which was varied by each taxon. Epidermal cell of taxa in sects. Microscordum, Anguinum, and Rhizirideum, which had wide leaf blade, oblong instead of linear shape in others examined taxa in this study. The leaf of taxa in sect. Anguinum was hypostomatic, while the rest of taxa had amphistomatic leaf. This was also one of characters which could discriminate taxa of sect. Anguinum from others. The guard cell in investigated taxa had not so much variation in the respect of its size. The number of stomata per unit area reduced by increasing size of epidermal cell, the fewest number of stomata per unit area was found in the taxa of sect. Anguinum. The type of stomatal apparatus of observed all taxa was anomocytic. It was found to know ultrastructural variation in the epidermal cell, like as patterns of sculpture on the cell wall, and features of deposition of wax by SEM. There were no depositions of wax in the taxa of sect. Microscordum and Anguinum, but fine thread-like structures which were parallel or cross to axis was found on the surface of epidermal cell respectively. The patterns of sculpture on the cell were prominent straight in sects. Recticulato-bulbosa and Rhizirideum, discontinuous line in the sect. Oreiprason. The epicuticular wax had been deposited on the surface of its epidermal cell in all taxa except sects. Microscordum and Anguinum.

• Korean Journal of Plant Taxonomy
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• v.33 no.4
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• pp.421-433
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• 2003

To examine the leaf epidermal microstructure, nine species in five genera (Daphne L. - 4 spp., Diarthron Turcz. - 1 sp., Edgewarthia Meisn. - 1 sp., Stellera L. - 1 sp., Wikstroemia Endl. - 2 spp.) of the Korean Thymelaeaceae were investigated by light microscopy (LM) and scanning electron microscopy (SEM). The stomata of stuo야ed taxa were 'hypostomatic type' and the size range of guard cell was $13.8-34.4{\times}8.7-22.9{\mu}m$: the smallest size of stomata was found in Diathran linifolium ($15.9{\pm}2.6{\times}10.0{\pm}1.3{\mu}m$), while the largest one was measured to Daphne adara ($32.8{\pm}1.6{\times}20.7{\pm}1.3{\mu}m$). The stomatal complex was anomocytic in the most studied taxa, except Daphne kiusiana by having combined with anisocytic together. The shapes of epidermal cells are undulate anticlinal wall. The size range of epidermal cell was $20.7-61.0{\mu}m$; the smallest size of epidermal cell was found in Stellera charnaejasme ($26.0{\pm}1.9{\mu}m$), on the other hand the largest one was found in Edgeworthia chrysantha ($53.6{\pm}3.1{\mu}m$). The well-developed flaky epicuticular waxes can be divided three kinds of pattern - (1) smooth in comparison, not entire platelets and scattered, (2) isolated flake-like platelets, mostly paralleled, sparsely, (3) flake-like platelets, flat, membraneous, protruding from the surfaces at varying angles and densely. Two types of trichome are recognized; (1) Type I: uniseriate trichome of striate surface (D. genkwa, Diarthron linifalium, E. chrysantha, W. ganpi and W. trichotama), (2) Type II: multicellular trichome of papillose surface, uncinated 3-4 nodes (Diathron linifolium). Finally, the systematics significance of the leaf micromorphological features in identification and elucidation of Korean Thymelaeaceae, especially between or within the genera including among the species is also briefly discussed.