21 research outputs found
Background and comparison of water-quality, streambed-sediment, and biological characteristics of streams in the Viburnum Trend and the exploration study areas, southern Missouri, 1995 and 2001 /
Shipping list no.: 2004-0239-P.Includes bibliographical references (p. 17-18).Mode of access: Internet
Defining potentially conserved RNA regulons of homologous zinc-finger RNA-binding proteins.
Glucose inhibition of gluconeogenic growth suppressor 2 protein (Gis2p) and zinc-finger protein 9 (ZNF9) are conserved yeast and human zinc-finger proteins. The function of yeast Gis2p is unknown, but human ZNF9 has been reported to bind nucleic acids, and mutations in the ZNF9 gene cause the neuromuscular disease myotonic dystrophy type 2. To explore the impact of these proteins on RNA regulation, we undertook a systematic analysis of the RNA targets and of the global implications for gene expression
Electrochemical impedance spectroscopy fingerprints the ion selectivity of microgel functionalized ion-exchange membranes
Surface modification methods are applied to alter interfacial phenomena and improve ion transport through membranes. In this work we present a novel method for tailoring the surface of cation-exchange membranes based on the deposition of thin microgel monolayers. The charge of such layers exerts a strong influence on the monovalent-ion-selectivity, and this is reflected in the electrochemical impedance responses. Membranes coated with uncharged microgels show similar behavior to that of unmodified ones, with impedance spectra dominated by low-frequency diffusional arcs. However, membranes modified with positively charged microgels exhibit an increased resistance due to the hindered transport of cations through the modification. An additional high-frequency capacitive arc is obtained with the monovalent-ion-selective membranes, which is attributed to concentration polarization effects at the membrane/modification interface. The characteristic frequency of this arc decreases with the valency of the ion, thus proving that multivalent ions pass through the modification layer at rates much slower than monovalent ones. Accordingly, electrochemical impedance spectroscopy has been used to feature monovalent-ion-selective properties of layered membranes. Keywords: Microgels, Monovalent-ion-selectivity, Impedance spectroscopy, Electrodialysis, Ion-exchange membrane
Unraveling the effect of charge distribution in a polyelectrolyte multilayer nanofiltration membrane on its ion transport properties
Water quality, hydrology, and invertebrate communities of three remnant wetlands in Missouri, 1995-97 /
Shipping list no.: 99-0097-P.Includes bibliographical references (p. 54-56).Mode of access: Internet
Microbiological and chemical quality of ground water used as a source of public supply in southern Missouri : Phase II, April-July, 1998 /
Shipping list no.: 2001-0100-P.Includes bibliographical references (p. 28-30).Mode of access: Internet
Periphyton communities in streams of the Ozarks plateaus and their relations to selected environmental factors /
Shipping list no.: 2003-0185-P."National Water-Quality Assessment Program."Includes bibliographical references (p. 63-65).Mode of access: Internet