The presence of GABA in gastropod mucus and its role in inducing larval settlement

Chemical substances that induce larval settlement have been the focus of many gastropod studies due to the importance of wild stock recruitment and production within aquaculture facilities. Gamma-aminobutyric acid (GABA), GABA analogs, and GABA-mimetics associated with certain crustose coralline algae (CCA), are known to induce larval settlement in commercial abalone (Haliotis) species, and other gastropods. Furthermore, mucus secreted from these gastropods has been shown to induce larval settlement, but the stimulatory components of mucus have not been thoroughly investigated. We now present data confirming that GABA is the settlement-inducing effector molecule contained within abalone mucus. To do this, we initially generated anti-GABA for use in immunoenzyme and immunofluorescent microscopy. Using these techniques GABA was identified in the nerves and epithelial cells of the foot, including mucus. Dried mucus samples subject to HPLC analysis revealed a mean concentration of 0.68 mM GABA after sample rehydration. The presence of GABA in these samples was confirmed by time-of-flight mass spectroscopy (TOF-MS). In addition, GABA was detected in the mucus of several abalone species and other gastropods by immunocytochemistry. Subsequent bioassays using both dry and fresh mucus strongly promoted induction of larval settlement.

Reverse microemulsion-mediated synthesis of SiO2-coated ZnO composite nanoparticles : multiple cores with tunable shell thickness

Monodispersed SiO₂-shell/ZnO-core composite nanospheres have been prepared in an oil-in-water microemulsion system. By using cyclohexane as the oil phase and Triton X-100 as the surfactant, composite nanospheres with high core loading levels and tunable shell thickness were obtained. Utilization of PVP capping agent on ZnO allowed the synthesis of composite nanospheres without forming any coreless SiO2 spheres or shell-less ZnO particles. The photoactivity of ZnO nanoparticles was greatly reduced by SiO2-coating, which enables their applications as durable, safe, and nonreactive UV blockers in plastics, coating, and other products.

Social/environmental reporting by Shell

This thesis uses textual analysis to examine how language use by global multinationals in social/environmental reports contributes to maintaining economically-based understandings of corporate responsibility. The findings suggest that such reporting does not just discharge accountability for social/environmental impacts; it also has implications for how these responsibilities are understood and accepted.

Fabrication and biofunctionalization of selenium-polypyrrole core-shell nanoparticles for targeting and imaging of cancer cells

Selenium-polypyrrole core-shell nanoparticles are fabricated by an in-situ polymerization process and functionalized with transferrin for targeting and imaging of human cervical cancer cells. The shell thickness and chemical composition of the as-synthesized particles can be manipulated by controlling the precursor concentration. The presence of the polymer layer can greatly increase the thermal stability of the selenium nanoparticles. The presence of transferrin molecules on the surface of the core-shell nanoparticles can significantly enhance their cellular uptake. The tranferrin-conjugated core-shell nanoparticles can be potentially used for the targeting and imaging of cancer cells.

A three-dimensional highly interconnected composite oxygen reduction reaction electrocatalyst prepared from a core-shell precursor

Getting intimate: A 3D interconnected Bi_0.5Sr _0.5FeO_3-ð (BSF)-Ag electrocatalyst is prepared from a BSF-AgNO₃ core-shell precursor in one step. The nanometer-sized Ag enhances the sintering process, enabling an optimum cathode microstructure and good cathode-to-electrolyte attachment upon firing at 850°C. A solid-oxide fuel cell based on this cathode shows a near 100% peak power density enhancement at 550°C.

Performance of columns packed with the new shell particles, Kinetex-C18

The performance of the new Kinetex-C₁₈ column was investigated. Packed with a new brand of porous shell particles, this column has an outstanding efficiency. Once corrected for the contribution of the instrument extra column volume, the minimum values of the reduced plate heights for a number of low molecular weight compounds (e.g., anthracene and naphtho[2,3-a]pyrene) were between 1.0 and 1.3, breaking the legendary record set 3 years ago by Halo-C₁₈ packed columns. The liquid-solid mass transfer of proteins (e.g., insulin and lyzozyme) is exceptionally fast on Kinetex-C₁₈ much faster than on the Halo-C₁₈ column. The different contributions of dispersion and mass transfer resistances to the column efficiency were determined and discussed. The possible reasons for this extremely high column efficiency are discussed.

One-dimensional polyelectrolyte/polymeric semiconductor core/shell structure : sulfonated poly(arylene ether ketone)/polyaniline nanofibers for organic field-effect transistors

A polyelectrolyte/polymeric semiconductor core/shell structure is developed for organic field-effect transistors (OFETs) based on sulfonated poly(arylene ether ketone)/polyaniline core/shell nanofibers via electrospinning and solution-phase selective polymerization. The polyelectrolyte does not work as a gate dielectric, but can provide an internal modulation from the nanointerface of the 1D core/shell nanostructure. The transistor devices display very high mobilities.

Au-doped polyacrylonitrile-polyaniline core-shell electrospun nanofibers having high field-effect mobilities

Au-doped polyacrylonitrile–polyaniline core–shell nanofibers are fabricated via electrospinning and subsequent gas-phase polymerization, providing a very high field-effect mobility of up to 11.6 cm² V⁻¹ s⁻¹. This method is also suitable for other conducting polymers and may eventually lead to a new and simplified fabrication of high-performance polymer organic field-effect transistors.