• Title/Summary/Keyword: light micrograph

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Characterization of the protocrystalline silicon multilayer solar cells (프로터결정 실리콘 다층막 태양전지의 특성 연구)

  • Kwon, Seong-Won;Kwak, Joong-Hwan;Myong, Seung-Yeop;Lim, Koeng-Su
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.145-148
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    • 2006
  • The protocrystalline silicon (pc-Si:H) multilayer solar cell is very promising owing to its fast stabilization with low degradation against light irradiation. However, the pc-Si:H multi layers have not extensively been investigated in detail on its material characteristics yet. We present the material characteristics of pc-Si:H multilayer using a transmission electron microscopy(TEM), and Raman spectroscopy. In addition, we present the superior light-soaking behavior of the pc-Si:H mutt i layer solar cell. A TEM micrograph shows that a pc-Si:H multilayer has a repeatedly layered structure and crystalline-like objects in a-Si:H matrix. A Raman spectra introduces improved short-range-order and medium-range-order in pc-Si:H multilayer. As a result the excellent metastability of the pc-Si:H multilayer solar cell is primarily due to the repeatedly layered structure that improves a structural order in absorber layer.

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Triterpenoid-Containing Liposome by Micelle-to-Vesicle Transition and Their Biological Activities

  • Kang, Hyung-Seok;Park, Ji-Eun;Nam, Gae-Won;Han, Sang-Hoon;Chang, Ih-Seop
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.319-329
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    • 2003
  • Ursolic acid (UA) and oleanolic acid (OA) are pentacyclic triterpenoids which are widely distributed in plants, and their derivatives are aglycones of many naturally occurring saponins. It is known that pentacyclic acids may possibly enhance the mechanical barrier functions of cell membranes in plants. Recently, it has been reported that OA and UA have interesting biological activities on skin, such as anti-inflammatory and anti-wrinkle activities. Since triterpenoids are extremely insoluble and their solubility problem limits skin-care application, OA and UA were encapsulated in liposomes via micelle-to-vesicle transition to overcome poorly soluble property and enhance biological efficacy. Optimal molar ratio of OA to lecithin was found to exist for producing liposomes of small hydrodynamic size and liposomal suspensions without recrystallized precipitation of OA. From electron micrograph and dynamic light scattering studies, reconstituted OA-containing liposomes without severe mechanical treatment showed small hydrodynamic size about 150 nm. Wide-angle X-ray diffraction coupled with dynamic light scattering revealed that optimal amount of OA in liposome was 25.4 mole %. In biological evaluation, OA-containing liposome significantly increased filaggrin and transglutaminase as markers of keratinocyte differentiation in epidermal layer of hairless mouse, whereas ursolic acid-containing liposome did not show noticeable increase of filaggrin and transglutaminase compared to empty liposome. It is concluded that nano-scaled liposomes containing triterpenoids were spontaneously prepared by vesicular transition from mixed micelle and liposomal triterpenoids can enhance skin absorption of triterpenoid and biological efficacy.

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EFFECT OF LASER IRRADIATION ON DENTIN SURFACE STRUCTURE AND SHEAR BOND STRENGTH OF LIGHT-CURED GLASS IONOMER. (상아질 표면 구조와 광중합형 글라스 아이오노머의 전단강도에 대한 레이저 조사의 효과)

  • Park, Mi-Ryoung;Kim, Jong-Soo;Kim, Yong-Kee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.25 no.1
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    • pp.76-92
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    • 1998
  • The purpose of this study was to evaluate the possible efficacy of Nd-YAG laser as a dentin conditioner by observing the laser irradiation dentin surface under scanning electron micrograph and measuring shear bond strength of restored light-cured glass ionomer mold. Fifty intact premolars were prepared for shear bond strength tests. The teeth were randomly divided into five groups as follows; Group I. no treatment Group II. 10% poly acrylic acid, 20 sec Group III. laser treatment 2 w, 20 Hz, 2 sec Group IV. laser treatment 2 w, 20 Hz, 5 sec Group V. laser treatment 2 w, 20 Hz, 10 sec Samples of each group were restored with light-cured glass ionomer cement after dentin conditioning and then measuring the shear bond strength of each specimen were measured using universal testing machine. Additional ten premolars were prepared for SEM analysis The result from the this study can be summarized as follows. 1. Shear bond strength of polyacrylic acid-treated group (II) was significantly higher than other groups (p<0.05). 2. No statistically significant difference could be found between three laser-treated groups (III, IV, V) in shear bond strength(p>0.05) 3. According to the result of observation under SEM, Polyacrylic acid was shown to have removed the smear layer effectively and opened the dentinal tubules, whereas the laser has produced the irregular surface mainly composed of melted and fused structure. The microcracks found in laser-treated groups increased in number with irradiation time and formed the regular mesh-type in 10 sec-irradiation group. 4. The ultrastructural change of dentin surface created by laser irradiation was found to the improper for bonding of the glass ionomer restorative materials. And the lower shear bond strength of laser irradiated group might have been due to the failure to form the suit able dentin surface for the glass ionomer to penetrated into and form the proper micromechanical retention.

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Proposal of a New Estimation Method of Colonization Rate of Arbuscular Mycorrhizal Fungi in the Roots of Chengiopanax sciadophylloides

  • Deguchi, Seitaro;Matsuda, Yosuke;Takenaka, Chisato;Sugiura, Yuki;Ozawa, Hajime;Ogata, Yoshimune
    • Mycobiology
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    • v.45 no.1
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    • pp.15-19
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    • 2017
  • This study proposed a rapid method to quantify the colonization rate of arbuscular mycorrhizal fungi (AMF) in plant roots. The method involved the use of an image analysis software (WinRHIZO Pro). The colonization rate is defined as the ratio of the fungal body to the plant root area in a micrograph. Three seedlings of Chengiopanax sciadophylloides, a woody species that accumulates radiocesium, were collected from a secondary forest in the Yamakiya district of Kawamata, Fukushima Prefecture during May-September 2014. The colonization of AMF structures was examined under a light microscope, and the percentage of colonization was determined using the WinRHIZO method. The superiority of the new method was verified by comparing with a modified grid-line intersect method. The colonization of AMF was confirmed in all the seedlings, and a significant coefficient of determination ($R^2=0.94$) was found with both the methods. The results suggested that the WinRHIZO method is reliable for estimating the colonization of AMF in C. sciadophylloides.

Aggregation-induced photoluminescence enhancement of polymetalloles by energy migration (에너지 전달을 이용한 Polymetalloles의 응집에 의해 유도되는 광발광성의 증가)

  • Kwon, Hyung-Jun;Jung, Dae-Hyuk;Song, Jin-Woo;Jang, Seung-Hyun;Kim, Bum-Seok;Kwon, Yong-Hee;Cho, Sung-Dong;Sohn, Hong-Lae
    • Journal of Sensor Science and Technology
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    • v.15 no.5
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    • pp.303-308
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    • 2006
  • Aggregation-induced emissions of polymetalloles have been investigated since they are very attractive in their possible optoelectronic applications such as P-LED's and Sensors. Size of nanoparticulates was measured by using scanning electron micrograph and was about 200-300 nm. Phenylmethylpolysilane (PMPS) and polymetalloles emit the light at 360 nm and 520 nm, respectively. However, the aggregates of polymetallole containing PMPS exhibit an enhanced emission band at 520 nm, indicating that the energy transfer occurs from PMPS to polymetalloles in aggregates. Emission intensity of PMPS/polymetallole nanoparticulates at 520 nm increases depending on the aliquot of PMPS.

Improving the Dyeability of Gelatin Pretreated Cotton Fabrics Dyeing with Cochineal in Ethanol-Water Mixture (젤라틴 전처리 면직물의 에탄올-물 혼합용매에 의한 코치닐 염색성 향상)

  • Ha, Su Young;Jang, Jeong Dae
    • Textile Coloration and Finishing
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    • v.31 no.3
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    • pp.127-134
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    • 2019
  • Cotton fabrics were treated with gelatin to improved their dyeability, color strength toward cochineal dye. Gelatin were used as the protein. Gelatin is containing a large number of hydrophilic groups. Pad-dry-cure method was used for the treatment process(10g/L concentration). The scanning electron micrograph showed the gelatin was deposited on the surface of cotton. Pretreated fabrics were mordanted with 10%(owf) alum. Then the fabrics were dyed with cochineal. Compared with original cotton fabric the K/S value with cochineal dyes was significantly improved on gelatin modified cotton. Treating cotton with 10g/L concentration gelatin offered higher cochineal adsorption. The dyeability of pH 4 yielded the highest color strength. In dyebaths of a ratio of ethanol and water such as; 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, 0:10, fabrics were dyed. The ratio of ethanol and water had powerful effects on solution polarity. Cochineal dye uptake showed maximum value, when the proportion of ethanol and water was 9:1. Dyeing at increased temperatures and with increased time resulted in higher dye uptake and reddish-purple color(5RP). The washing fastness was 1-2grade, and the fastness to light was 2-3grade.

Effects of Dietary Xylooligosaccharides on Hepatic HMG-CoA Reductase Activity and Morphological Exchange of liver in Rats Fed High Fat Diets (고지방 식이를 섭취한 흰쥐에 있어서 Xylooligo당이 간의 HMG-CoA Reductase 활성 및 간조직의 형태학적 변화에 미치는 영향)

  • 손효현;이순재
    • Journal of Nutrition and Health
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    • v.35 no.10
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    • pp.1015-1022
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    • 2002
  • This study was conducted to examine the effects of dietary xylooligosaccharides on hepatic HMG-CoA reductase activity and morphological exchange of liver in rats fed high fat diet. Sprague-Dawley male rats weighing 100 $\pm$ 10 g were randomly divided into four groups, two normal diets and two high fat diets containing 1% cholesterol and 10% lard. Two normal diets were classified into a basal diet (normal group) and 10% xylooligosaccharide diet (NX group). The high fat diet groups were classified into a HF group without xylooligosaccharides diet and HFX group supplemented 10% xylooligosacchride diet. Experimental diets were fed ad libidum to the rats for 4 weeks and then they were sacrificed. The body weight of high fat diet (HF group) was increased more than that of normal group, but it was significantly decreased by xylooligosacchrides supplementation. The food intake was not significantly different among the all groups. The weight of liver, small intestine and cecum of all xylooligosaccharide supplemented groups were significantly heavier than those of normal and HF groups. The activity of hepatic HMG-CoA reductase, a rate limiting enzyme of cholesterol biosynthesis, in xylooligosaccharide supplemented groups was higher than that of HF group. Light micrographs revealed that the structures of hepatocytes in xylooligosaccharide supplemented groups were preserved well, compared to HF group. The xylooligosaccharide supplementation exerted a lipid-lowering action by decreasing cholesterol and triglycerides contents in hepatic tissue. In conclusion, the activity of hepatic HMG-CoA reductase and damage of liver in rats fed high fat diets were improved by dietary xylooligosaccharides.

The applicable evaluation of biodegradable polymer coated-mulching paper for afforestation seedlings (생분해성 고분자 코팅 조림묘목용 mulching mat 원지의 적용성 평가)

  • Lee, Geum-Ja;Yoo, Yeong-Jeong;Ko, Seung-Tae;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.1
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    • pp.54-63
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    • 2010
  • Recently, as the function of largest supplier of biomass for "low carbon green growth", the necessity for systematic management of afforestation areas is emphasizing. The forestation of seedling, besides the afforestation cost itself, is required some additional follow-up management costs, like mowing and fertilizing of forestation area, and removal of bindweed. The mulching mat for afforestation seedlings is available for rooting of little seedlings as well as initial forestation expenses. Mulching technique is also used to control soil temperature and moisture by covering the surface of ground. In this study, the paper based-mulching film coated with biodegradable polymer and functional additive was specially produced using laboratory bar coater, and analyzed for its degradable behavior. Coating colors were prepared by dissolving PE (polyester) 80 % and PLA(polylactic acid) 20 % in chloroform and finally applied to handsheet prepared by preceding study conditions. Base paper and polymer-coated paper were artificially aged by 2 kinds of degradation methods, which are soil degradation by microorganism and light degradation by 257 nm UV wavelengths. Strength property, oxidation index and morphological property were evaluated by reduction rates of tensile strength, FTIR spectra ratio of carboxyl and carbonyl group and SEM micrograph. As these results, polymer coated-paper was superior to base paper in degradation behaviors, having results with lower reduction rate of strength properties.

Cell Biological Studies of the Effect of Aromatic Amino Acids on Early Development of Chick Embryo (방향족 아미노산이 초기계배에 미치는 영향에 관한 세포생물학적 연구)

  • 최임순;주충노;최춘근;김재원
    • The Korean Journal of Zoology
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    • v.28 no.4
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    • pp.257-278
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    • 1985
  • The effect of aromatic amino acids such as phenylalaine, tryptophan and tyrosine on somitogenesis at the early stage of chick embryo has been investigated morphologically using light and electron microscopy. Micrographs of aromatic amino acid injected chick embryo showed that an incomplete somite segmentation occurred and some decremental effect on the nervous system were observed. Somites were poorly developed and their size were variable. Electron micrograph of somatic cells from aromatic amino acid injected chick embryo showed that chromatins were coagulated, some of mitochondria were damaged, and nucleus were transformed considerably in some cases. The protein and nucleic acid levels and some enzyme activities of 15-day chick embryo which received the injection of 1mg of aromatic amino acid in 0.05 ml of saline 24 hours after the incubation were analyzed. Protein, DNA and RNA levels of the test group were not lowered significantly but the activities of enzymes for basic metabolism, such as lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and glucose 6-phosphate dehydrogenase were considerably lowered as compared with those of control. From the present expeerimental results, it was tentatively suggested that the administration of amino acid might slow down the yolk granule degradation probably by feed back mechanism resulting in the disturbance of amino acid balance in the cell, which might give rise to impair normal metabolic pattern leading to abnormal somitogenesis to chick embryo at very early stage of development.

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Compression of The Trigeminal Ganglion Enhances Nociceptive Behavior Produced by Formalin in The Orofacial Area of Rats

  • Yang, Gwi-Y.;Park, Young-H.;Lee, Min-K.;Kim, Sung-K.;Ahn, Dong K.
    • International Journal of Oral Biology
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    • v.33 no.4
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    • pp.155-162
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    • 2008
  • The present study investigated inflammatory hypersensitivity following compression of the trigeminal ganglion in rats. Experiments were carried out on male Sprague-Dawley rats weighing 250-260 g. Under anesthesia, rats were mounted on a stereotaxic frame and injected with $8{\mu}L$ of 4% agar solution through a stainless steel injector to compress the trigeminal ganglion. In the control group, rats underwent a sham operation without agar injection. Injection sites were examined with a light micrograph after compression of the trigeminal ganglion. Air-puff thresholds (mechanical allodynia) were evaluated 3 days before surgery and 3, 7, 10, 14, 17, 21, 24, 30, and 40 days after surgery. Air-puff thresholds significantly decreased after compression of the trigeminal ganglion. Mechanical allodynia was established within 3 days and remained strong over 24 days, returning to preoperative levels approximately 40 days following compression. After subcutaneous injection of 5% formalin ($50{\mu}L$) in the compression of the trigeminal ganglion-treated rats, nociceptive scratching behavior was recorded for 9 successive 5-min internals. Injection of formalin into the vibrissa pad significantly increased the number of scratches and duration of noxious behavioral responses in sham-treated rats. Noxious behavioral responses induced by subcutaneous formalin administration were significantly potentiated in rats with trigeminal ganglion compression. These findings suggest that compression of the trigeminal ganglion enhanced formalin-induced infla-mmatory pain in the orofacial area.