Silica Gels
Mostrando 13-23 de 23 artigos, teses e dissertações.
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13. The Use of Silica Gels for the Cultivation of Halophilic Organisms: II. Quantitative Determinations
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14. New insights into allosteric mechanisms from trapping unstable protein conformations in silica gels
To understand why the classical two-state allosteric model of Monod, Wyman, and Changeux explains cooperative oxygen binding by hemoglobin but does not explain changes in oxygen affinity by allosteric inhibitors, we have investigated the kinetic properties of unstable conformations transiently trapped by encapsulation in silica gels. Conformational trapping
National Academy of Sciences.
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15. Silica gel medium to detect molds that produce aflatoxin.
A chemically defined nutrient solution containing tartaric acid was made solid by mixing it with an alkaline silicate solution. Production of aflatoxin by asperfilli growing on the silica gel medium coincided with the presence of a blue fluorescent area surrounding colonies, as observed under long-wave ultraviolet light. Presence of aflatoxin in the medium w
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16. Use of Silica Sol Step Gradients to Prepare Bundle Sheath and Mesophyll Chloroplasts from Panicum maximum1
The first method for the direct separation of mesophyll and bundle sheath chloroplasts from whole tissue homogenates of a C4 plant is described. Centrifugation of mixed chloroplast preparations from Panicum maximum through low viscosity silica sol gradients effectively separates large, starch-containing chloroplasts from smaller plastids. The large chloropla
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17. A Pneumatic Device for Rapid Loading of DNA Sequencing Gels
This work describes the design and construction of a device that facilitates the loading of DNA samples onto polyacrylamide gels for detection in the Perkin Elmer/Applied Biosystems (PE/ABI) 373 and 377 DNA sequencing instruments. The device is mounted onto the existing gel cassettes and makes the process of loading high-density gels less cumbersome while th
Cold Spring Harbor Laboratory Press.
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18. Fractionation and Analysis of Polypeptides of Euglena gracilis Chloroplasts 1
Intact Euglena gracilis chloroplasts, purified on gradients of silica sol, were lysed osmotically and fractionated by centrifugation on discontinuous gradients of sucrose into their soluble, envelope membrane, and thylakoid membrane components. The proteins of the different subchloroplast fractions, as well as those of whole chloroplasts, were analyzed by el
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19. Thin-layer chromatography of hippuric and m-methylhippuric acid in urine after mixed exposure to toluene and xylene.
The separation of hippuric and m-methylhippuric acid as toluene and m-xylene metabolites present in urine of people exposed simultaneously to toluene and xylene is described. Chloroform was used for hippuric and m-methylhippuric acid extraction. Satisfactory separation of these metabolites was obtained on TLC plates covered with silica gels and developed in
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20. Chromoplast-Specific Proteins in Capsicum annuum1
Chromoplasts are a common differentiation state of plastids in which the photosynthetic apparatus is absent and carotenoids accumulate to high levels. As a first step toward the isolation of chromoplast-specific genes, we have examined plastids of the bell pepper, Capsicum annuum L., for the presence of chromoplast-specific proteins. Intact chromoplasts were
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21. Ligand migration through the internal hydrophobic cavities in human neuroglobin
Neuroglobin (Ngb), a member of the globin superfamily, was found in the brain of vertebrates and is suggested to play a neuroprotective function under hypoxic conditions by scavenging nitrogen monoxide (NO) through a dioxygenase activity. In order for such a reaction to efficiently take place and to minimize the release of reactive intermediates in the cytos
National Academy of Sciences.
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22. The Myxococcus xanthus FprA protein causes increased flavin biosynthesis in Escherichia coli.
The fprA gene is immediately adjacent to the csgA gene (formerly known as spoC) of Myxococcus xanthus. Whereas the csgA gene has an essential role in cell interactions during the developmental cycle, the function of the fprA gene is unknown. Gene disruption was used to determine what affect a null mutation in this gene has on the phenotype of the cell. A csg
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23. Hemoglobin Syracuse (alpha2beta2-143(H21)His leads to Pro), a new high-affinity variant detected by special electrophoretic methods. Observations on the auto-oxidation of normal and variant hemoglobins.
Family members from four generations were found to have polycythemia and increased whole blood O2 affinity (P50; 11 mm Hg; normal, 27 mm Hg). No abnormal hemoglobin bands were seen after electrophoresis on starch gel at pH 8.6 or agar gel at pH 6.0. Analysis of the oxygenated hemolysate by isoelectric focusing on polyacrylamide gel revealed two closely space