LOCALIZATION OF ACTIN IN THE LIVER FLUKE, FASCIOLA-HEPATICA

Adult and 3-week-old juvenile Fasciola hepatica were examined for the presence of the cytoskeletal protein actin. Techniques of direct fluorescence using fluorescein isothiocyanate (FITC)-phalloidin and of indirect immunofluorescence using a monoclonal anti-actin antibody (MAA) demonstrated actin in the testes, sub-tegumental and gut musculature, tegumental cell bodies and tegumental spines. In contrast, polyclonal anti-actin antibody (PAA) revealed immunostaining only in the vitellaria. Effective removal of the tegument with 1 % (w/v) sodium dodecyl sulphate (SDS) was confirmed by scanning electron microscopy (SEM), and this enabled immunoblotting of whole fluke and tegumental fractions with and without spines. Whole fluke fractions produced three bands corresponding to molecules exhibiting relative molecular weights of 43, 28 and 15 kDa, respectively, whereas the tegumental fraction with spines revealed a single band corresponding to 15 kDa in size. The fraction without spines displayed no bands. The present study localised actin in a number of different tissue types within the liver fluke. Using MAA, three forms of actin have been identified in the whole fluke and a single one in the tegumental spines.

Seedless synthesis of octahedral gold nanoparticles in condensed surfactant phase

We report a seedless synthetic method of gold octahedral nanoparticles in an aqueous phase. Eight facets with {111} crystalline structures of octahedral nanoparticles could be formed in an aqueous medium when the gold salt was reduced by ascorbic acid at room temperature in the presence of cetyltrimethylammonium bromide as a shape-inducing agent, and hydrogen peroxide as a reaction promoter. The growth kinetics and surface crystalline structures were characterized by UV–vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy.

Localisation of actin in the liver fluke, Fasciola hepatica

Adult and 3-week-old juvenile Fasciola hepatica were examined for the presence of the cytoskeletal protein actin. Techniques of direct fluorescence using fluorescein isothiocyanate (FITC)-phalloidin and of indirect immunofluorescence using a monoclonal anti-actin antibody (MAA) demonstrated actin in the testes, sub-tegumental and gut musculature, tegumental cell bodies and tegumental spines. In contrast, polyclonal anti-actin antibody (PAA) revealed immunostaining only in the vitellaria. Effective removal of the tegument with 1% (w/v) sodium dodecyl sulphate (SDS) was confirmed by scanning electron microscopy (SEM), and this enabled immunoblotting of whole fluke and tegumental fractions with and without spines. Whole fluke fractions produced three bands corresponding to molecules exhibiting relative molecular weights of 43, 28 and 15 kDa, respectively, whereas the tegumental fraction with spines revealed a single band corresponding to 15 kDa in size. The fraction without spines displayed no bands. The present study localised actin in a number of different tissue types within the liver fluke. Using MAA, three forms of actin have been identified in the whole fluke and a single one in the tegumental spines.

Synthesis of surfactant-free electrostatically stabilized gold nanoparticles by plasma-induced liquid chemistry

Plasma-induced non-equilibrium liquid chemistry is used to synthesize gold nanoparticles (AuNPs) without using any reducing or capping agents. The morphology and optical properties of the synthesized AuNPs are characterized by transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy. Plasma processing parameters affect the particle shape and size and the rate of the AuNP synthesis process. Particles of different shapes (e. g. spherical, triangular, hexagonal, pentagonal, etc) are synthesized in aqueous solutions. In particular, the size of the AuNPs can be tuned from 5 nm to several hundred nanometres by varying the initial gold precursor (HAuCl4) concentration from 2.5 mu M to 1 mM. In order to reveal details of the basic plasma-liquid interactions that lead to AuNP synthesis, we have measured the solution pH, conductivity and hydrogen peroxide (H2O2) concentration of the liquid after plasma processing, and conclude that H2O2 plays the role of the reducing agent which converts Au+3 ions to Au-0 atoms, leading to nucleation growth of the AuNPs.

Investigation of supported IrO2 as electrocatalyst for the oxygen evolution reaction in proton exchange membrane water electrolyser

Indium tin oxide (ITO) was used as a support for IrO2 catalyst in the oxygen evolution reaction. IrO2 nanoparticles were deposited in various loading on commercially available ITO nanoparticle, 17–28 nm in size using the Adam's fusion method. The prepared catalysts were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The BET surface area of the support (35 m2/g) was 3 times lower than the unsupported IrO2 (112.7 m2/g). The surface area and electronic conductivity of the catalysts were predominantly contributed by the IrO2. The supported catalysts were tested in a membrane electrode assembly (MEA) for electrolyser operation. The 90% IrO2-ITO gave similar performance (1.74 V@1 A/cm2) to that of the unsupported IrO2 (1.73 V@1 A/cm2) in the MEA polarisation test at 80 °C with Nafion 115 membrane which was attributed to a better dispersion of the active IrO2 on the electrochemically inactive ITO support, giving rise to smaller catalyst particle and thereby higher surface area. Large IrO2 particles on the support significantly reduced the electrode performance. A comparison of TiO2 and ITO as support material showed that, 60% IrO2 loading was able to cover the support surface and giving sufficient conductivity to the catalyst.

Exploring molecular recognition pathways within a family of gelators with different hydrogen bonding motifs

We report the synthesis of a family of gelators in which alkyl chains are connected to the amino groups of L-lysine methyl ester using a range of different hydrogen bonding linking groups (carbamate, amide, urea, thiourea and diacylhydrazine) using simple synthetic methodology based on isocyanate or acid chloride chemistry. The ability of these compounds to gelate organic solvents such as toluene or cyclohexane can be directly related to the ability of the linking group to form intermolecular hydrogen bonds. In general terms, the ability to structure solvents can be considered as: thiourea <carbamate <amide <urea similar to diacylhydrazine. This process has been confirmed by thermal measurements, scanning electron microscopy (SEM) and infrared and circular dichroism spectroscopies. By deprotecting the methyl ester group, we have demonstrated that a balance between hydrophobic and hydrophilic groups is essential-if the system has too much hydrophilicity (e. g., diacylhydrazine, urea) it will not form gels due to low solubility in the organic media. However, the less effective gelators based on amide and carbamate linkages are enhanced by converting the methyl ester to a carboxylic acid. Furthermore, subsequent mixing of the acid with a second component (diaminododecane) further enhances the ability to form networks, and, in the case of the amide, generates a two-component gel, which can immobilise a wide range of solvents of industrial interest including petrol and diesel (fuel oils), olive oil and sunflower oil (renewable food oils) and ethyl laurate, isopropyl myristate and isopropyl palmitate (oils used in pharmaceutical formulation). The gels are all thermoreversible, and may therefore be useful in controlled release/formulation applications.