• Journal of Sensor Science and Technology
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• v.8 no.6
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• pp.476-480
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• 1999

PbSe thin films were grown using PLD method on the p-Si(100) substrate. To determine what crystalline structure of PbSe thin films have according to the growth temperature, the films were prepared under a substrate temperature changing between a room temperature and $400^{\circ}C$. As a result of analyzing XRD patterns of PbSe thin films prepared at various substrate temperatures and FWHM of PbSe(200) rocking curve, it was found that PbSe thin film obtained at the growth temperature of $200^{\circ}C$ was best crystallized. In addition, the surface morphology of PbSe thin film observed using AFM found itself having the most regularly arranged particles in case of growing the film at $200^{\circ}C$. The measurement of Hall effect indicated that PbSe thin films were n-type semiconductors and that current-voltage characteristic curve exhibit the typical p-n junction phenomenon. In addition, electric conductivity of PbSe thin films was found somewhat higher than that of general semiconductors.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.48-53
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• 2007

Pulverization characteristics of H-kenyaite in vibration mill and exfoliation property in epoxy of pulverized H-kenyaite was investigated by using XRD, SEM, TEM. and particle size analyzer. Pulverization was conducted for 0.5~5 h. The particle morphology of sample pulverized for 1 h preserved plate-shape. However, this plate-shape disappeared in the sample pulverized for 3 h. The XRD pattern of sample pulverized for 1 h showed the characteristic peak of H-kenyaite. However, the peak disappeared in samples pulverized above 3 h, indicating severe destruction of H-kenyaite structure. TEM analysis for the kenyaite/epoxy nanocomposites exhibited only gallery expansion of 3~5 nm in non-pulverized sample, but dramatical large expansion of 5~10 nm in the samples pulverized during 1 h. This results confirm that the pulverization of wide plates composed of H-kenyaite particle have largely affect on the formation of an exfoliated kenyaite-polymer nanocomposite.

• Food Science of Animal Resources
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• v.36 no.1
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• pp.37-43
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• 2016

Cardiovascular and cerebrovascular diseases seriously harm human health, and Bifidobacterium is the most beneficial probiotic in the gastrointestinal tract of humans. This work aimed to screen cholesterol-lowering Bifidobacterium from Guizhou Xiang Pig and evaluate its tolerance to oxygen, acid, and bile. Twenty-seven aerotolerant strains with similar colony to Bifidobacterium were isolated through incubation at 37℃ in 20% (v/v) CO₂-80% (v/v) atmospheric air by using Mupirocin lithium modified MRS agar medium, modified PTYG with added CaCO₃, and modified PTYG supplemented with X-gal. Ten strains with cholesterol-lowering rates above 20% (w/w) were used for further screening. The selected strains’ tolerance to acid and bile was then determined. A combination of colony and cell morphology, physiological, and biochemical experiments, as well as 16S rRNA gene-sequence analysis, was performed. Results suggested that BZ25 with excellent characteristics of high cholesterol-removal rate of 36.32% (w/w), as well as tolerance to acid and bile, was identified as Bifidobacterium animalis subsp. lactis. To further evaluate Bifidobacterium BZ25’s growth characteristic and tolerance to oxygen, culture experiments were performed in liquid medium and an agar plate. Findings suggested that BZ25 grew well both in environmental 20% (v/v) CO₂-80% (v/v) atmospheric air and in 100% atmospheric air because BZ25 reached an absorbance of 1.185 at 600 nm in 100% atmospheric air. Moreover, BZ25 was aerotolerant and can grow in an agar medium under the environmental condition of 100% atmospheric air. This study can lay a preliminary foundation for the potential industrial applications of BZ25.

• Polymer(Korea)
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• v.26 no.1
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• pp.28-36
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• 2002

In this study, we synthesized novel thiophene derivatives by the protection of the carboxyl group of 3-thiophene acetic acid with differently substituted benzyl groups. While 3-thiophene acetic acid is not electro-polymerizable, the modified monomers can be easily electro-oxidized to form stable electroactive polymers. The protecting groups can be easily removed in the solid state and the desired reactive carboxyl group can be introduced on the polymer surface. SEM observations show that obtained polymer films show a very good film surface and homogeneous morphology on the Pt electrode. After introduction of macromonomer, FT-IR spectrum shows new absorption bands at 1650 and $1550 cm^{-1}$, which is consistent with the formation of an amide bond. Electroactivity measurements were examined by cyclic voltammogram(CV). These polymers showed the characteristic electrochemical behavior of poly(3-alkylthiophene)s with reversible redox transition in the range of 0.7-0.9 V.

• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.942-952
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• 2013

Monoliths are functional porous materials with a three-dimensional continuous interconnected pore structure in a single piece. A monolith with uniform shape based on poly(${\gamma}$-glutamic acid) (PGA) has been prepared via a thermally induced phase separation technique using a mixture of dimethyl sulfoxide, water, and ethanol as solvent. The morphology of the obtained monolith was observed by scanning electron microscopy and the surface area of the monolith was evaluated by the Brunauer Emmett Teller method. The effects of fabrication parameters such as the concentration and molecular mass of PGA and the solvent composition have been systematically investigated. The PGA monolith was cross-linked with hexamethylene diisocyanate to produce the water-insoluble monolith. The addition of sodium chloride to the phase separation solvent affected the properties of the cross-linked monolith. The swelling ratio of the cross-linked monolith toward aqueous solutions depended on the buffer pH as well as the monolith fabrication condition. Copper(II) ion was efficiently adsorbed on the cross-linked PGA monolith, and the obtained copper-immobilized monolith showed strong antibacterial activity for Escherichia coli. By combination of the characteristic properties of PGA (e.g., high biocompatibility and biodegradability) and the unique features of monoliths (e.g., through-pore structure, large surface area, and high porosity with small pore size), the PGA monolith possesses large potentials for various industrial applications in the biomedical, environmental, analytical, and separation fields.

• The KIPS Transactions:PartB
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• v.14B no.3 s.113
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• pp.153-162
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• 2007

Sasang medicine is peculiar medicine that constitution of a human classify four types and differ treatment method by physical constitution. In this way the most important thing is very difficult problem that classification of Sasang constitution and discriminate correctly. Therefore, in this paper targets diagnosis medical appliances development of hybrid form that can behave constitution classification and sees among for this paper to propose about method to grasp characteristic that is morphology about eye, nose, ear and mouth be based on appearance and manner of speaking. In this paper, classified and verified this for Sasang constitution through the QSCC II program at 1 step and present method that more exactly and conveniently analyzing measure each physical constitution feature by survey about eye, nose, ear and mouth at 2 steps. Also, extraction and analyze and verified main area of physical constitution classification based on front face and side face at 3 steps. Such propose method to extraction the principal face region based on face color from front face and side face for correct physical constitution classification diagnosis appliance development through experiment consideration and verification process.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.47-53
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• 1996

We examined the expression of the heat shock proteins (HSPs) and glucose-regulated proteins (GRPs) during phorbol 1 2-myristate 1 3-acetate (PMA)-induced megakaryocytic differentiation of human er"'throleukemia K562 cells. PMA-treated K562 cells showed a cell growth arrest and alteration in morphology and patterns of gpllIa and c-myc expression, characteristic of megakaryocytic differentiation. During the megakaryocytic differentiation, HSP9OA, HSP9OB, and HSP28 mRNA and protein levels markedly decreased, while GRP78/B and GRP94 mRNA levels were enhanced. On the other hand, HSP7OA and HSP7OB mRNA levels were reduced, but HSP7O protein levels were not changed by PMA treatment. These results suggest specific roles for the HSPs and GRPs in K562 cell proliferation and megakaryocic differentiation.tion.

• Korean Journal of Plant Taxonomy
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• v.48 no.3
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• pp.185-194
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• 2018

A comparative floral morphological study of 19 taxa in Persicaria sect. Cephalophilon with four taxa related to Koenigia was conducted to evaluate the taxonomic implications. The flowers of P. sect. Cephalophilon have (four-)five-lobed tepals; five, six, or eight stamens, and one pistil with two or three styles. The size range of each floral characteristic varies according to the taxa; generally P. humilis, P. glacialis var. glacialis and Koenigia taxa have rather small floral sizes. The connate degrees of the tepal lobes and styles also vary. The tepal epidermis consists of elongated rectangular cells with variation of the anticlinal cell walls (ACWs). Two types of glandular trichomes are found. The peltate glandular trichome (PT) was observed in nearly all of the studied taxa. The PT was consistently distributed on the outer tepal of P. sect. Cephalophilon, while Koenigia taxa and P. glacialis var. glacialis had this type of trichome on both sides of the tepal. P. criopolitana had only long-stalked pilate-glandular trichomes (LT) on the outer tepal. The nectary is distributed on the basal part of the inner tepal, with three possible shapes: dome-like, elongated, and disc-like nectary. The nectaries are always accompanied by elongated or spheroidal papillae. Various combinations of floral characters (e.g., the numbers of stamens and styles, the stigma shape, the nectary shape, ACWs, cuticular striation and the trichome type and distribution) of P. sect. Cephalophilon are useful when attempting to recognize the infrasectional levels of P. sect. Cephalophilon recently proposed. Here, we describe the floral characteristics in detail and discuss the taxonomic significance of the floral characters.

• Development and Reproduction
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• v.14 no.3
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• pp.155-162
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• 2010

The trophectoderm is one of the earliest cell types to differentiate in the forming placenta. It is an important for the initial implantation and placentation during pregnancy. Trophoblast stem cells (TBSCs) develop from the blastocyst and are maintained by signals emanating from the inner cell mass. However, several limitations including rarity and difficulty in isolation of trophoblast stem cells derived from blastocyst still exist. To establish a model for trophoblast differentiation, we isolated TBSCs from human term placenta ($\geq$38 weeks) and characterized. Cell cycle was analyzed by measuring DNA content by FACS analysis and phenotype of TBSCs was characterized by RT-PCR and FACS analysis. TBSCs have expressed various markers such as self-renewal markers (Nanog, Sox2), three germ layer markers (hNF68, alpha-cardiac actin, hAFP), trophoblast specific markers (CDX-2, CK7, HLA-G), and TERT gene. In FACS analysis, TBSCs isolated from term placenta showed that the majority of cells expressed CD13, CD44, CD90, CD95, CD105, HLA-ABC, cytokeratin 7, and HLA-G. Testing for CD31, CD34, CD45, CD71, vimentin and HLA-DR were negative. TBSCs were shown to decrease the growth rate when cultured in conditioned medium without FGF4/heparin as well as the morphology was changed to a characteristic giant cell with a large cytoplasm and nucleus. In invasion assay, TBSCs isolated from term placenta showed invasion activities in in vivo using nude mice and in vitro Matrigel system. Taken together, these results support that an isolation potential of TBSCs from term placenta as well as a good source for understanding of the infertility mechanism.

• Polymer(Korea)
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• v.35 no.3
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• pp.265-271
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• 2011

Graphene oxide (GO) was prepared by the Hummers and Offeman method from graphite. Reduced graphene oxide (EGO) and functionalized graphenes were synthesized from GO by using hydrazine hydrate and amine-functionalized alkyl groups, respectively. The structures of the GO, EGO, and functionalized graphenes were identified by FTIR and $^{13}C$ NMR. In addition, we examined the thermal stability, morphology and dispersibility of the materials in various organic solvents. AFM disclosed that GO and RGO consisted of one- or two-layer graphene regions throughout the film. However, the functionalized graphene films showed average thicknesses of 2.26~3.30 nm, The thermal stability of the functionalized graphenes was poorer than that of the EGO. The functionalized graphenes were well dispersed in toluene or chloroform, as evidenced by the lack of the characteristic graphite reflection in the solutions.