83 research outputs found

    GAS AND SOLID MIXING IN A THREE PARTITIONED FLUIDIZED BED

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    There are many gas-solid reaction systems which take place simultaneously in a single reactor, such as coal gasification. By splitting the reactions, high concentrated gases can be obtained without separation processes. Dual fluidized bed was proposed for this purpose. Similarly, simultaneous adsorption/desorption systems with dry sorbent for CO2 capture and the gasification reaction system with a char combustor and a gasifier separately were developed. For improving gas and solid mixing efficiencies of the dual fluidized beds, a hitherto unknown partitioned fluidized bed (PFB) is proposed. A basic concept of PFB is that lower parts between two separated fluidized beds are linked (opened), whereas upper parts are blocked by walls. Solid mixing occurs in lower parts with preventing gas mixing. The solid residence time becomes longer than that of dual fluidized bed and the high conversion of solid can be obtained. In this study, the gas and the solid mixing behaviors were investigated in three partitioned fluidized beds (left, center and right). The size of each fluidized bed is 7 cm (w) X 7 cm (d) X 30 cm (h) and partitioned above the 7 cm of distributor. Air and CO2-air mixture were used as fluidizing gas in each partitioned fluidized bed. For the gas mixing experiments, glass bead particles with 150 micron and density of 2.5g/cm3 were introduced. Outlet gas concentrations of each fluidized bed were analyzed by IR and then the gas exchanges between the reactors were calculated. For the solid mixing experiments, the polypropylene particles with 1000 micron and the density of 0.883 g/cm3 were continuously fed into the reactor. The gas mixing percentages were 0.4 ~ 16.0% of input gas amounts with varying gas velocities. The solid discharge rates in center and right side can be controlled by operating conditions

    Structural and histological characterization of oviductal magnum and lectin-binding patterns in Gallus domesticus

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    <p>Abstract</p> <p>Background</p> <p>Although chicken oviduct is a useful model and target tissue for reproductive biology and transgenesis, little is known because of the highly specific hormonal regulation and the lack of fundamental researches, including lectin-binding activities and glycobiology. Because lectin is attached to secreted glycoproteins, we hypothesized that lectin could be bound to secretory egg-white proteins, and played a crucial role in the generation of egg-white protein in the oviduct. Hence, the purpose of this study was to investigate the structural, histological and lectin-binding characteristics of the chicken oviductal magnum from juvenile and adult hens.</p> <p>Methods</p> <p>The oviductal magnums from juvenile and adult hens were prepared for ultrastructural analysis, qRT-PCR and immunostaining. Immunohistochemistry of anti-ovalbumin, anti-ESR1 and anti-PGR, and mRNA expression of egg-white genes and steroid hormone receptor genes were evaluated. Lectin histochemical staining was also conducted in juvenile and adult oviductal magnum tissues.</p> <p>Results</p> <p>The ultrastructural analysis showed that ciliated cells were rarely developed on luminal surface in juvenile magnum, but not tubular gland cells. In adult magnum, two types of epithelium and three types of tubular gland cells were observed. qRT-PCR analysis showed that egg-white genes were highly expressed in adult oviduct compared with the juvenile. However, mRNA expressions of <it>ESR1 </it>and <it>PGR </it>were considerably higher in juvenile oviduct than adult (<it>P </it>< 0.05). The immunohistochemical analysis showed that anti-ovalbumin antibody was detected in adult oviduct not in juvenile, unlikely anti-ESR1 and anti-PGR antibodies that were stained in both oviducts. In histological analysis, Toluidine blue was stained in juvenile and adult oviductal epithelia, and adult tubular glands located in the outer layer of oviductal magnum. In contrast, PAS was positive only in adult oviductal tubular gland. Lectins were selectively bound to oviductal epithelium, stroma, and tubular gland cells. Particularly, lectin-ConA and WGA were bound to electron-dense secretory granules in tubular gland.</p> <p>Conclusions</p> <p>The observation of ultrastructural analysis, mRNA expression, immunohistochemistry and lectin staining showed structural and physiological characterization of juvenile and adult oviductal magnum. Consequently, oviduct study could be helped to <it>in vitro </it>culture of chicken oviductal cells, to develop epithelial or tubular gland cell-specific markers, and to understand female reproductive biology and endocrinology.</p

    A Study of Solids and Gas Mixing in a Partitioned Fluidized Bed

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    A partitioned fluidized bed gasifier has been developed for improving coal gasification performance. The basic concept is to divide a fluidized bed into two parts, a gasifier and a combustor, by a partition. Char is burnt in the combustor and generated heat is supplied to the gasifier by solid mixing. Therefore, solid mixing should be maximized whereas gas mixing between syngas and the combusted gas should be minimized. In this study, gas and solid mixing behaviors were verified in cold model acrylic beds. For monitoring solid mixing behavior, transient temperature trends in the beds were analyzed. A heat source and a heat sink were installed in each bed. Dozens of thermocouples were used to monitor temperature distribution

    SERPINE2 Polymorphisms and Chronic Obstructive Pulmonary Disease

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    A number of genome-wide linkage analyses have identified the 2q33.3-2q37.2 region as most likely to contain the genes that contribute to the susceptibility to chronic obstructive pulmonary disease (COPD). It was hypothesized that the SERPINE2 gene, which is one of the genes located at the 2q33.3-2q37.2 region, may act as a low-penetrance susceptibility gene for COPD. To test this hypothesis, the association of four SERPINE2 single nucleotide polymorphisms (SNPs; rs16865421A>G, rs7583463A>C, rs729631C>G, and rs6734100C>G) with the risk of COPD was investigated in a case-control study of 311 COPD patients and 386 controls. The SNP rs16865421 was associated with a significantly decreased risk of COPD in a dominant model for the polymorphic allele (adjusted odds ratio [OR]=0.66, 95% confidence interval [CI]=0.45-0.97, P=0.03). In haplotype analysis, the GACC haplotype carrying the polymorphic allele at the rs16865421 was associated with a significantly decreased risk of COPD when compared to the AACC haplotype (adjusted OR=0.58, 95% CI=0.38-0.89, P=0.01), and this effect was evident in younger individuals (adjusted OR=0.30, 95% CI=0.14-0.64, P=0.002). This study suggests that the SERPINE2 gene contributes to the susceptibility to COPD

    Telomerase Activity and the Risk of Lung Cancer

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    Telomerase play a key role in the maintenance of telomere length and chromosome integrity. We have evaluated the association between telomerase activity and the risk of lung cancer in peripheral blood. Telomerase activity in peripheral blood mononuclear cells was measured by a PCR-designed telomeric repeat amplification protocol in 63 lung cancer patients and 190 healthy controls that were matched for age, gender, and smoking status. Telomerase activity was significantly lower in the lung cancer patients than in controls (mean ± standard deviation; 1.32 ± 1.65 vs 2.60 ± 3.09, P < 1 × 10-4). When telomerase activity was categorized into quartiles based on telomerase activity in the controls, the risk of lung cancer increased as telomerase activity reduced (Ptrend = 1 × 10-4). Moreover, when the subjects were categorized based on the median value of telomerase activity, subjects with low telomerase activity were at a significantly increased risk of lung cancer compared to subjects with high telomerase activity (adjusted odds ratio = 3.05, 95% confidence interval = 1.60-5.82, P = 7 × 10-4). These findings suggest that telomerase activity may affect telomere maintenance, thereby contributing to susceptibility to lung cancer

    A Proposed Manual for the Efficient Management of Kiwifruit Bacterial Canker in Korea

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    Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker, is currently causing severe economic losses to kiwifruit production worldwide. The pathogen has affected green-fleshed kiwifruit cutlivars and yellow-fleshed kiwifruit cultivars since 1988 and 2006 in Korea, respectively. In recent years, the biovar 3 strains of P. syringae pv. actinidiae were introduced through imported contaminated pollens and have rapidly spread to neighboring kiwiruit orchards by secondary infection, leading to outbreaks of bacterial canker and tremendous damages on yellow- and red-fleshed kiwifruit cultivars. In this review, we summarize the various management practices of bacterial canker of kiwifruit such as disease escaping, cultural practices, blocking of dissemination, early diagnosis, eradication of inoculum sources, chemical control, and trunk injection on the basis of our research works and field experiences and important research products conducted during the last three decades in the world. Finally, we propose a manual for the efficient management of the disease that can be practically utilized at the farmers’ orchards in order to keep kiwifruit vines healthy in the future

    A Proposed Manual for the Efficient Management of Kiwifruit Bacterial Canker in Korea

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