Two-year clinical evaluation of preventive resin restorations

Structural and morphologic changes in peripheral blood neutrophilic leukocytes were examined with the aim to diagnose and predict the clinical course of acute pyoinflammatory maxillofacial diseases. Classification of structural and morphologic signs of neutrophilic leukocyte activation levels during odontogenic pyoinflammatory diseases were studied using optic and electron microscopy. There degrees of neutrophilic leukocyte activation were distinguished: inactive, moderately active, and hyperactive. Inactive cells occurred in normal subjects and patients with mild forms of the disease, moderately active ones in patients with mild and medium-severe condition, hyperactive ones in those with medium-severe and grave disease. Increased count of hyperactive neutrophilic leukocytes in the peripheral blood was a sign predicting a grave clinical course of the disease with complications.     

EXPERIMENTAL INVESTIGATION ON THE EFFECTS OF COLD EXPANSION OF FASTENER HOLES

A series of experimental investigations concerning the residual stress fields at cold-expanded fastener holes and of the behavior of fatigue cracks at such holes has been conducted. These studies have included measurement of the initial, cold-work-induced residual stress fields at both uncracked and cracked holes and the performance of both constant amplitude and spectrum fatigue crack growth tests.     

In vivo efficacy of antimicrobial-coated fabric from prosthetic heart valve sewing rings

Escherichia coli tRNA(Val) with pyrimidine substitutions for the universally conserved 3'-terminal adenine can be readily aminoacylated. It cannot, however, transfer valine into polypeptides. Conversely, despite being a poor substrate for valyl-tRNA synthetase, tRNA(Val) with a 3'-terminal guanine is active in in vitro polypeptide synthesis. To better understand the function of the 3'-CCA sequence of tRNA in protein synthesis, the effects of systematically varying all three bases on formation of the Val-tRNA(Val):EF-Tu:GTP ternary complex were investigated. Substitutions at C74 and C75 have no significant effect, but replacing A76 with pyrimidines decreases the affinity of valyl-tRNA(Val) for EF-Tu:GTP, thus explaining the inability of these tRNA(Val) variants to function in polypeptide synthesis. Valyl-tRNA(Val) terminating in 3'-guanine is readily recognized by EF-TU:GTP. Dissociation constants of the EF-Tu:GTP ternary complexes with valine tRNAs having nucleotide substitutions at the 3' end increase in the order adenine < guanine < uracil; EF-Tu has very little affinity for tRNA terminating in 3' cytosine. Similar observations were made in studies of the interaction of 3' end mutants of E. coli tRNA(Ala) and tRNA(Phe) with EF-Tu:GTP. These results indicate that EF-Tu:GTP preferentially recognizes purines and discriminates against pyrimidines, especially cytosine, at the 3' end of aminoacyl-tRNAs.     

Characterisation of Ce0.8Gd0.2O1.9/3Y-TZP composite electrolytes—effects of weight % 3Y-TZP particles

Solid oxide fuel cell electrolytes are currently manufactured from zirconia. This is due to its high ionic conductivity and mechanical strength. However, a disadvantage of zirconia is the high temperatures required for efficient operation, greater than 900°C for cells not utilising thin supported electrolytes. A study to characterise the properties of an alternative composite solid electrolyte, based on a gadolinia doped ceria matrix surrounding yttria stabilised tetragonal zirconia particles is presented. Composite samples produced using 1, 2, 5, 10 and 20 wt% zirconia particles were characterised using a range of different experimental techniques including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, mechanical testing and impedance spectroscopy. Results showed a lowering in flexure strength of the experimental composite samples with the addition of particles. It is considered that the particles acted as regions where cracks could initiate.     

Dielectronic recombination for He-like Br ions channeled along the 110 direction in Ni

Dielectronic recombination for He-like ⁷⁹Br has been measured for channeling along a 110 axis in Ni. The KLL resonance has a FWHM of 14% of the beam energy and an area corresponding to a density of about 6 electrons per atom.     

The work of fracture of epoxy resins

The work of fracture has been measured for some epoxy resins at liquid helium temperature, and when possible, at room temperature.     

Extrusion of self-reinforced thermoplastic composites illustrated by high density polyethylene

A method is described for solid state coextrusion of self-reinforced and transparent composites for high density polyethylene composed of core and sheath components. The high density polyethylenes are coextruded below their melting points. The cocylindrical composites have a high tensile modulus and strength, a high orientation for both core and sheath components and possess considerable resistance to core/sheath separation. This resistance to pull-out is due to compressive and radial stresses developed during the composite coextrusion and not to bonding by epitaxial crystallization.