• Title/Summary/Keyword: fiber cell

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A solar Cell Fiber using Semi-conductive Polymers (반도체형 고분자를 이용한 태양전지섬유)

  • Song, Jun-Hyung;Kim, Joo-Yong
    • Textile Coloration and Finishing
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    • v.20 no.1
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    • pp.44-47
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    • 2008
  • Organic semi-conductive materials have characteristics such as the advantages of easy formability, low-cost and diversity along with moderate semi-conductive properties. In this paper, we developed a flexible organic-inorganic hybrid solar cell fiber. First, we made a solar cell on the glass and attached the solar cell on the glass fiber similarly. In the latter case, thermal deposition method was employed in order to effectively apply ITO onto fiber surface. The amount of ITO was controlled by varying the temperature from 25, 150 to $300^{\circ}C$. Optimum result was obtained at $150^{\circ}C$ where maximize the deposition amount without significant decomposition of ITO. Despite of maximum open circuit voltage of 0.39V, the resulting current was quite unstable and weak, limiting realistic applications. It was, however, concluded that the flexible solar cell fiber developed showed a possibility of low-weight application from functional clothing for military to space suit mainly due to flexibility and thus wear ability.

Dietary Fiber Modulates Colon Cell Proliferation by Altering Luminal Concentrations of Short-Chain Fatty Acids

  • Kim, Dong-Yeon;Park, Mi-Young;Lee, Jung-Hee
    • Nutritional Sciences
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    • v.5 no.4
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    • pp.175-183
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    • 2002
  • To compare the effects of various types of dietary fiber on microbial production of short-chain fatty acids (SCFA) and on colon cell proliferation which is used as an intermediate biomarker for colon carcinogenesis, groups of 10 male Sprague-Dawley rats were fed one of four fiber-supplemented diets (6% cellulose, 6% pectin, 6% polydextrose, and a mixture of 3% cellulose and 3% polydextrose) for three weeks. As a control, a fiber-free diet was fed to a separate group of 10 rats. Cell proliferation was measured by in vivo incorporation of bromodeoxyuridine into DNA in the proximal and distal colon, respectively. Luminal concentrations of SCFA were measured by gas chromatography. Dietary fiber significantly influenced microbial production of SCFA in the colon; pectin supplementation produced the highest concentrations of luminal SCFA in both the proximal and distal colon (p<0.05). The degree of individual SCFA production was characterized by a relatively higher increase in butyrate production by the pectin-supplemented diet, and in propionate production by the polydextrose-supplemented diet, resulting in alterations of the molar ratios of acetate, propionate and butyrate. There were significant differences in colon cell proliferation among the diet groups; the pectin-supplemented diet produced a significantly higher effect on cell proliferation of distal colonic epithelial cells (p<0.05), and the polydextrose-supplemented diet produced an intermediate effect compared to the fiber-free or cellulose-supplemented diet. Increased cell proliferation was correlated to increased luminal concentrations of butyrate in the proximal colon and to increased luminal concentrations of propionate and butyrate in the distal colon (p<0.05). Therefore, these data suggest that dietary fiber may modulate colon cell proliferation by altering luminal SCFA concentrations, particularly butyrate and perhaps propionate. In addition, the present study is the first finding that has demonstrated a relative increase in colon cell proliferation due to supplementation with polydextrose, suggesting that the overuse of this artificially synthesized polysaccharide in food processing technology needs to be carefully evaluated from the public health point of view.

Influence of the Thickness and Doping Concentration in p- and n-Type Poly-Si Layers on the Efficiency of a Solar Cell Based on a Carbon Fiber

  • Yoon, Min-Seok;Shim, Young Bo;Han, Young-Geun
    • Journal of the Optical Society of Korea
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    • v.19 no.2
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    • pp.199-205
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    • 2015
  • We investigated the effects of the thickness and doping concentration in p- and n-type poly-Si layers on the performance of a solar cell based on a carbon fiber in order to improve the energy conversion efficiency of the cell. The short-circuit current density and open-circuit voltage of the carbon fiber-based solar cell were significantly influenced by the thickness and doping concentration in the p- and n-type poly-Si layers. The solar cell efficiency was successfully enhanced to ~10.5%.

Fruit wall anatomy of the genus Krigia (Asteraceae, Lactuceae) and their taxonomic implications (Krigia속의 과피의 해부학적 구조와 분류학적 의미)

  • Lee, Bok Won;Park, Ji Kuk;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
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    • v.34 no.4
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    • pp.321-333
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    • 2004
  • We researched fruit wall anatomical characters about the seven taxa of Krigia and the nearest one relative, Nothocalais cuspidata by making use of the fruit wall anatomy, and inferred systematical similarity. Among these characters, all species of the genus Krigia has identical characters in the shape of fruit and the number of rib, but showed specific differences in the shape of costa, the numbers of libriform fiber cell layers and fiber-sclereid cell layers in mesocarp, and development degree in these characters. Krigia biflora, K. cespitosa, K. occidentalis and K. wrightii have well developed libriform fiber cell, but K. dandelion, K. montana and K. virginica have undeveloped libriform fiber cell, and mostly consist of fiber-sclereid cell layers. According to the fruit wall anatomical characters, K. biflora which belonged to sect. Krigia in the previous classification system is more similar to sect. Cymbia than sect. Krigia.

Effect of Dietary Fiber and Fat on Tumor Incidence and Cell Proliferation of Colonic Mucosa in DMH-Treated Rats (Dimethylhydrazine으로 처리한 쥐에서 식이섬유소와 지방종류가 대장의 종양발생율과 세포증식에 미치는 영향)

  • 최주선
    • Journal of Nutrition and Health
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    • v.31 no.4
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    • pp.697-707
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    • 1998
  • This study was designed to observe the effect of dietary fiber and fat on colon tumor incidence and cell proliferation. Male Sqraue Dawley rats(n=225) at 7 weeks of age, were divided into 3 groups depending on the type of fat b(beef tallow, corn oil and DHA-rich fish oil) and each group was again divided into 3 groups depending on type of fiber(fiber-free, perctin and cellulose) . The experimental diet containing dietary fat at 15%(w/w) and fiber at 6%(w/w) levels was fed for 25 weeks. At the same time, each rats was intramuscularly injected with DMH two times a week for 6 weeks to geive total dose of 180mg/kg body weight. Cell proliferation was measured by in vivo incroporation of bromodeoxyuridine (BrdU) into DNA. Fish oil decreased the tumor incidence (9.67%) compared with beef talow (33.39%) and corn oil (21.21%). Tumor incidence was decreased in all groups that fed cellulose (11.67%) compared with those of fiber-free(21.74%) and pectic(19.70%). Most of tumors was distributed at the site of the distal colon. The rats fed both fish oil and cellulose significantly decreased th enumber of tumors and tumor incidence compared to other groups. Fish oil was more effective in preventing cell prolofieration by decreasing crypt length and labeling index(LI) compared with beef tallow(p<0.05). Cell proliferation in distal colon was more developed to the upper part of the crypt compared to proximal colon. Overall tumor incidence and cell proliferation were more affected by dietary fat. But the effect of dietary fiber was different depending on type of fat in the experimental diet. These results suggest that a DHA -rich fish oil may has more decisive effect in inhibiting the cell proliferation in colon.

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Solubilization of Plant Cell Walls by Extrusion (압출성형에 의한 식물세포벽의 수용화)

  • 황재관;김종태;홍석인;김철진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.2
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    • pp.358-370
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    • 1994
  • Plant cell walls consist of a variety of chemical constituents such as cellulose, humicelluloses, pertins, lignin, glycoproteins, etc. These components are strongly linked through hydrogen , covalent, ionic and hydrophobic bondings, which thus confers the self-protection capability on plants. Some processing by-products (hulls, brans, pomaces) of cereal, fruits and vegetables are very limited in further utilization due to their compact structural rigidity. In view of the fact that the plant cell walls are essentially composed of dietary fiber components , solubilization of the strong intermolecular linkage s can contribute to increasing the soluble dietary fiber content and thus diversifying the functional and physiological role of plant cell walls as dietary fiber sources. This article reviews the chemical constituents of cereals, fruits & vegetables and brown seaweeds with reference to their intermoleuclar linkages. An particular emphasis will be placed on the solubilizing phenomena of rigid plant cell walls by extrusion and the resulting change of functional properties. It is suggested that underutilized food resources, typically exemplified by various food processing by-products and surplus seaweeds, can be successfully modified toward improved functional performance by extrusion.

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Cell-laden Gelatin Fiber Contained Calcium Phosphate Biomaterials as a Stem Cell Delivery Vehicle for Bone Repair (세포 함유 젤라틴 파이버 응용을 통한 골 재생 유도용 인산칼슘 생체재료 세포 탑재 연구)

  • Kim, Seon-Hwa;Hwang, Changmo;Park, Sang-Hyug
    • Journal of Biomedical Engineering Research
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    • v.43 no.1
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    • pp.61-70
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    • 2022
  • Natural and synthetic forms of calcium phosphate cement (CPC) have been widely used in bone repair and augmentation. The major challenge of injectable CPC is to deliver the cells without cell death in order to regenerate new bone. The study objective was to investigate for the potential of stem cell-laden gelatin fibers containing injectable, nanocrystalline CPC to function as a delivery system. Gelatin noddle fiber method was developed to delivered cells into nCPC. Experimental groups were prepared by mixing cells with nCPC, mixing cell-laden gelatin fibers with nCPC and mixing cell-laden gelatin fibers containing BMP-2 with nCPC. Media diffusion test was conducted after dissolving the gelatin fibers. SEM examined the generated channels and delivered cell morphology. Fibers mixed with nCPC showed physical setting and hardening within 20 min after injection and showed good shape maintenances. The gelatin fibers mixed nCPC group had several vacant channels generated from the dissolved gelatin. Particularly, proliferation and attachment of the cells were observed inside of the channels. While live cells were not observed in the cell mixed nCPC group, cells delivered with the gelatin fibers into the nCPC showed good viability and increased DNA content with culture. Cell-laden gelatin fiber was a novel method for cell delivery into nCPC without cell damages. Results also indicated the osteogenic differentiation of gelatin fiber delivered cells. We suggest that the cell-laden gelatin fibers mixed with nCPC can be used as an injectable cell delivery vehicle and the addition of BMP-2 to enhances osteogenesis.

Ultraviolet Microscopic Study on Lignin Distribution in the Fiber Cell Wall of BCTMP

  • Yoon, Seung-Lak;Yasuo Kojina
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.1
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    • pp.61-66
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    • 2004
  • Bleached chemithermomechanical pulp (BCTMP) was produced from CTMP of Betula maximowicziana Regel by two staged ozone-hydrogen peroxide bleaching in order to improve the optical properties of high yield pulp. This pulp was used for the evaluation of optical properties improvement, chemical characteristics of lignin in fiber and the relationship between lignin and optical properties in fiber cell wall. Hydrogen peroxide treatment improved the brightness, but the post color number (PC No.). There was little improvement on optical properties by ozone treatment, but this could be improved more by using two staged ozone-hydrogen peroxide bleaching. The hydrogen peroxide treatment did not make any change on chemical characteristics of lignin in cell wall, but by ozone treatment, it was found that the non-aromatic conjugated structure was existed in the surface of cell wall, but this could be removed by hydrogen peroxide treatment in two staged ozone-hydrogen peroxide treatment. Therefore, the optical properties was significantly improved, due to the removal of non-aromatic conjugated structure.

Calcium Channel Blockers Suppress the Responses of Rat Dorsal Horn Cell to Nociceptive Input (쥐 척수후각세포의 유해자극 반응에 대한 칼슘이온통로 차단제의 억제작용)

  • Kang, Sok-Han;Kim, Kee-Soon;Shin, Hong-Kee
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.6
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    • pp.625-637
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    • 1997
  • Calcium ions are implicated in a variety of physiological functions, including enzyme activity, membrane excitability, neurotransmitter release, and synaptic transmission, etc. Calcium antagonists have been known to be effective for the treatment of exertional angina and essential hypertension. Selective and nonselective voltage-dependent calcium channel blockers also have inhibitory action on the acute and tonic pain behaviors resulting from thermal stimulation, subcutaneous formalin injection and nerve injury. This study was undertaken to investigate the effects of iontophoretically applied $Ca^{++}$ and its antagonists on the responses of WDR (wide dynamic range) cells to sensory inputs. The responses of WDR cells to graded electrical stimulation of the afferent nerve and also to thermal stimulation of the receptive field were recorded before and after iontophoretical application of $Ca^{++}$, EGTA, $Mn^{++}$, verapamil, ${\omega}-conotoxin$ GVIA, ${\omega}-conotoxin$ MVIIC and ${\omega}-agatoxin$ IVA. Also studied were the effects of a few calcium antagonists on the C-fiber responses of WDR cells sensitized by subcutaneous injection of mustard oil (10%). Calcium ions and calcium channel antagonists ($Mn^{++}$, verapamil, ${\omega}-conotoxin$ GVIA & ${\omega}-agatoxin$ IVA) current-dependently suppressed the C-fiber responses of WDR cells without any significant effects on the A-fiber responses. But ${\omega}-conotoxin$ MVIIC did not have any inhibitory actions on the responses of WDR cell to A-fiber, C-fiber and thermal stimulation. Iontophoretically applied EGTA augmented the WDR cell responses to C-fiber and thermal stimulations while spinal application of EGTA for about $20{\sim}30\;min$ strongly inhibited the C-fiber responses. The augmenting and the inhibitory actions of EGTA were blocked by calcium ions. The WDR cell responses to thermal stimulation of the receptive field were reduced by iontophoretical application of $Ca^{++}$, verapamil, ${\omega}-agatoxin$ IVA, and ${\omega}-conotoxin$ GVIA but not by ${\omega}-conotoxin$ MVIIC. The responses of WDR cells to C-fiber stimulation were augmented after subcutaneous injection of mustard oil (10%, 0.15 ml) into the receptive field and these sensitized C-fiber responses were strongly suppressed by iontophoretically applied $Ca^{++}$, verapamil, ${\omega}-conotoxin$ GVIA and ${\omega}-agatoxin$ IVA. These experimental findings suggest that in the rat spinal cord, L-, N-, and P-type, but not Q-type, voltage-sensitive calcium channels are implicated in the calcium antagonist-induced inhibition of the normal and the sensitized responses of WDR cells to C-fiber and thermal stimulation, and that the suppressive effect of calcium and augmenting action of EGTA on WDR cell responses are due to changes in excitability of the cell.

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Development of Load Cell Using Fiber Brags Grating Sensors and Differential Method for Structural Health Monitoring (구조 건전성 모니터링을 위한 광섬유 브래그 격자 센서와 차동법을 적용한 로드셀 개발)

  • Kim, Dae-Hyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.4
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    • pp.299-307
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    • 2009
  • Emerging fiber optic sensor technologies have shown great potential to overcome the difficulties associated with conventional sensors. Fiber optic sensors are immune to EM noise and electric shock and thus can be used in explosion-prone areas. Several kinds of fiber optic sensors have been developed over the last two decades to take advantage of these merits. There have also been many field applications of fiber optic sensors for structural health monitoring as NDT/HDE. However, very few sensors, particularly a load cell have been successfully commercialized. This Paper Presents a load cell using fiber Bra99 gra1ing (FBG) sensors. The shape of the load cell is a link type, and three FBG sensors are used for measuring strains at three different points. Especially, these strains are processed with a differential method in order to exclude common mode noise such as temperature. Moreover, the sensitivity, the linearity and the resolution of the load cell were successfully verified from the experiment of tension test.