In the shark rectal gland (SRG), apical Cl[superscript]- secretion through CFTR channels is tightly coupled to a basolateral K[superscript]+ conductance. The identity of this K[superscript]+ conductive pathway is unknown. Studies were performed in the isolated perfused SRG with 16 K[superscript]+ channel inhibitors at their IC50 and with acidic perfusate. During maximal chloride secretion stimulated by forskolin and IBMX, secretion was inhibited >90% by barium chloride, a non-selective inhibitor of K[superscript]+ channels. Specific inhibitors of calcium sensitive, voltage sensitive, ATP sensitive, and inward rectifying K[superscript]+ channels had no effect on chloride secretion. The inhibitors quinidine, quinine, bupivicaine, anandamide, and low perfusate pH (6.0) abruptly and reversibly inhibited secretion by >90%, consistent with the presence of the Two-Pore-Domain (4TM 2P/KCNK/K2P) family of K+ channels. Degenerate primers were designed to regions of high amino acid homology in known mammal and teleost 4TM 2P K[superscript]+ channel subtypes: TWIK, THIK, TASK, TREK, and TRAAK. PCR with cDNA from several shark tissues identified a putative TASK-1 fragment (394 bp) in shark rectal gland, brain, gill, and kidney. 5and 3 RACE PCR was used to obtain the entire 3 sequence and partial 5 sequence of the shark gene. Genome walking was then used to obtain the remaining 5sequence, including 335 bp of untranslated region sequence upstream of the start codon. The full length clone (1282bp) had an open reading frame encoding a protein of 375 amino acids. This isoform was 80% identical at the amino acid level to the human TASK-1 protein (394 amino acids). Major structural features of the human protein were conserved in the shark ortholog, including the four transmembrane segments (M1-M4), the 2P domains (P1 and P2), short NH2- and long COOH-termini, and an extended extracellular loop between M1 and P1. Shark and human TASK-1 full-length clones were expressed in Xenopus oocytes and studied with two electrode voltage clamp (TEVC) techniques. Both the shark and human TASK-1 channel showed identical current voltage relationships (outward rectifying) with a reversal potential near -90 mV compared to water injected controls. The responses to the inhibitor quinine, and the TASK-1 inhibitor bupivacaine, were identical in shark and human TASK-1. However, shark TASK-1 differed from the human ortholog in two critical responses: response to pH and the metal zinc. The pKa for shark TASK-1 was 7.75 vs. 7.37 for human TASK-1, values that are exceedingly close to the arterial pH for each species, suggesting that TASK-1 channels are regulated closely by the ambient pH. An antibody specific to shark TASK-1 was generated and expression of TASK-1 protein in the rectal gland was confirmed by confocal immuno-fluorescent microscopy which revealed localization to the basolateral membrane, with some apical staining. Shark rectal gland TASK-1 appears to be the major K[superscript]+ channel coupled to secretion in the SRG, is the oldest 4TM 2P family member identified to date, and is the first TASK-1 channel identified to play an essential role in chloride secreting epithelia.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 108-119).

Thesis (M.S.)--University of Toledo, 2009. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Science." Title from title page of PDF document. Bibliography: p. 39-48.

Thesis (Ph. D.)--University of Nevada, Reno, 1999. / Includes bibliographical references. Online version available on the World Wide Web.

Thesis (Ph.D.)--Ohio University, November, 2009. / Release of full electronic text on OhioLINK has been delayed until December 1, 2014. Title from PDF t.p. Includes bibliographical references.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1981. / Includes bibliographical references (p. 63-65).

No description available.

The design, synthesis and characterization of novel conjugated polymers are described. Using a coupling reaction recently developed within our labs, polymers were constructed through triazene linkages generated by joining N-heterocyclic carbenes (NHCs) with organic azides. This triazene reaction produced polymer of sufficiently high molecular weight as to be spin-coated and rendered conductive upon doping with iodine. The reaction also has potential for executing post-polymerization modifications. This was evidenced through rapid functionalization of poly(4-methylazido-styrene) via triazene formation using a commercially available N-heterocyclic carbene (NHC). A formal anion metathesis of benzobis(imidazolium)s was used to transform neutral block copolymers into block ionomers. Further investigation of the block ionomers revealed their solvent mediated self assembly. The gradual change of organic to aqueous media caused the adoption of a three-dimensional micelle conformation as determined by transmission electron microscopy and dynamic light scattering. Through the exploitation of carbene-carbon disulfide adducts, new chain transfer agents were generated. After 2-dithiocarboxylate-imidazolium adduct formation, alkylation was performed with benzyl bromide. The resulting charged chain transfer agent was tested for its ability to moderate radical addition fragmentation (RAFT) polymerizations of styrene. A considerable increase in transfer kinetics as compared to that of commonly used RAFT agents was observed whilst retaining low polydispersity and molecular weight control. The rate enhancement is presumably due to the electron withdrawing imidazolium activating the thionyl towards the nucleophilic radical while retaining effective fragmentation. Ion coordinating macrocycles were affixed to a poly(methacrylate) scaffold for employment as electrolyte extractants. Polymer bound calix[4]pyrrole was found to complex fluoride and chloride with sufficient strength as to extract tetrabutylammonium salts from water. Enhanced extraction abilities were observed when calix[4]pyrrole was used in conjunction with benzo-15-crown-5. Methacrylate polymers containing both macrocycles affected the removal of aqueous potassium fluoride from a biphasic water/dichloromethane mixture. To provide evidence for the presence of potassium fluoride within the dichloromethane layer, ¹⁹F NMR and flame emission spectroscopy were used. / text

A self-contained self-rescue unit is a device that is used in the mining industry in case of fires or release of toxic gases that depletes or contaminates breathable oxygen in the surrounding atmosphere. These units are the first line of defense by providing oxygen in a closed breathing cycle, allowing personnel to get themselves to safety. The goal of this project was to design a unit that is more comfortable to carry during the daily operations in and outside the mines. A unit that is easier to done and less likely to damage the users and/or surrounding mining equipment. It is developed in close collaboration with Atlas Copco, as the main sponsor, as well as Dräger and personnel working at Zink Gruvan Mining.  The result is a unit with an operational time of twenty minutes and a reduced size and weight. It’s position can be adjusted to be worn around the waist or the chest, depending on the tasks the user performs, as well as simplifying the donning procedure.

Existing tunable diode laser absorption spectroscopy (TDLAS) sensors for potassium (K) and for water vapor (H2O) and temperature were combined to enable simultaneous measurements in combustion and gasification processes. In-situ real-time detection of the above mentioned combustion parameters will improve the understanding of ash-formation during thermochemical conversion of biomass. Simultaneous measurements facilitate the experimental procedure and decrease the methodological uncertainty introduced by the heterogeneous nature of the pellets. The K sensor is based on direct absorption spectroscopy (DAS), whereas the H2O system employs wavelength modulation spectroscopy (WMS) together with two-line thermometry for temperature assessment. Two methods for combining the laser beams were evaluated, the first involving dichroic elements, the second using available fiber optic combiners. The latter method was considered advantageous. An existing LabVIEW program was modified to allow for simultaneous signal generation and data acquisition for both sensors. The sensors were then tested separately in a low pressure K cell and in ambient air. The combined sensor was applied to simultaneous measurements above various pelletized biofuels during combustion in a single pellet reactor (SPR). Significant difference in absolute concentration and time histories were observed between fuels, in particular for K and temperature. Significant K concentrations were only observed during the devolatilization phase. The combined sensor will be useful in fundamental combustion research.