Usefulness of the neuroandrologic profile study in patients with erectile dysfunction: review of a series of 180 cases

OBJECTIVES: To determine the usefulness of a complete neuroandrologic evaluation and SPACE (Single Potential Analysis Cavernous Electromyography) in the study of impotence. METHODS: We performed a clinical study, erection test with papaverine-phentolamine and neuroandrologic evaluation (bulbocavernous EMG, S2-S4 evoked potentials, evoked somatosensorial potentials, SPACE, D10-L2 skin sympathetic potentials, cystometrogram, and filling videocystography) in 180 patients consulting for impotence. RESULTS: We observed a relationship between the clinical diagnosis of impotence and the data from the neuroandrogenic study. The results of the study were classified as normal [in the clinical diagnosis of psychogenic impotence (100%), hormonal (80%) and vascular (60%)], abnormal [prevalent in the clinical diagnosis of structural impotence (87%)]. The erection test was mainly negative in all clinical diagnoses of impotence, except in psychogenic and vascular impotence (60% positive tests). CONCLUSIONS: The clinical data are useful in the diagnosis of impotence. The pharmacological erection test was not found to be very reliable. Complete neuroandrologic evaluation is indicated in non typified and mixed impotence, and can be performed in neurogenic impotence to identify the level of the lesion. Alone, SPACE does not appear to be useful as a screening test for neurologic lesions, but can be useful as a screening test for neuromuscular cavernous lesions. SPACE is indicated in structural, vascular and hormonal impotence. If SPACE is abnormal, the differential diagnosis between neurogenic and myogenic lesion can be made through a complete neuroandrologic evaluation.     

Experimental study on micro EDM-drilling of Ti6Al4V using helical electrode

There is a growing interest in the machining of micro-holes with high aspect-ratio in difficult-to-machine alloys for the aerospace industry. Processes based on electro discharge machining (EDM) and developed for the manufacture of both micro-electrode and micro-hole are actually used, but most of them involve micro-EDM machines. In this work, the influence of EDM parameters on material removal rate, electrode wear, machining time and micro-hole quality when machining Ti6Al4V is studied. Due to an inefficient removal of debris when increasing hole depth, a new strategy based on the use of helical-shaped electrodes has been proposed. The influence of helix angle and flute depth with respect to process performance has been addressed. Main results include 37% reduction in machining times (hole diameter 800 μm) when using electrode helix angle of 45° and flute-depth of 50 μm, and an additional 19% with flute-depth of 150 μm. Holes of 661 μm diameter and as much as 6.81 mm depth, which yields in aspect ratio of 10:1, have successfully been machined in Ti6Al4V.     

Comparison between laboratory and field leachability of MSWI bottom ash as a road material

The leaching properties of bottom ash from municipal solid waste incineration (MSWI) used as an aggregate substitute in unbound pavement layers are evaluated. The mechanical behaviour of bottom ash is acceptable for this application, but the potential environmental consequences constitute the most important limitation on the use of bottom ash as a road material. The environmental properties of bottom ash are assessed by means of the Dutch availability test NEN 7341 and the single-batch and two-stage batch European EN 12457 laboratory leaching tests. Furthermore, an experimental unbound pavement stretch is constructed to provide information on leaching behaviour under field conditions. In this high infiltration scenario, the results from predicted (based upon laboratory leaching tests) and measured releases (under field conditions) are compared, evidencing that predictions based on compliance leaching tests may be highly realistic. The depletion period of the extractable fraction of a number of elements in these field conditions is also quantified.     

A hybrid,auto-adaptive and rule-based multi-agent approach using evolutionary algorithms for improved searching

Selecting the most appropriate heuristic for solving a specific problem is not easy, for many reasons. This article focuses on one of these reasons: traditionally, the solution search process has operated in a given manner regardless of the specific problem being solved, and the process has been the same regardless of the size, complexity and domain of the problem. To cope with this situation, search processes should mould the search into areas of the search space that are meaningful for the problem. This article builds on previous work in the development of a multi-agent paradigm using techniques derived from knowledge discovery (data-mining techniques) on databases of so-far visited solutions. The aim is to improve the search mechanisms, increase computational efficiency and use rules to enrich the formulation of optimization problems, while reducing the search space and catering to realistic problems.     

Thermo-mechanical properties and microstructural considerations of MDI isocyanate-based bituminous foams

Stable bituminous foams have been obtained by using a 35/50 penetration grade bitumen and a reactive prepolymer (MDI-PPG) synthesized by the reaction of polymeric 4,4′-diphenylmethane diisocyanate (MDI) with a low molecular weight polypropylene glycol (PPG). In a first step, MDI-PPG and bitumen were allowed to react for up to 7 days. Foams were then obtained by adding an excess of water. The results obtained point out important changes in the material colloidal structure, as a consequence of the reactions between the –NCO groups and bitumen most polar fractions. Modification led to bituminous foams with low density and improved in-service properties (higher elasticity and resistance to deformation at high in-service temperatures, reduced thermal susceptibility and better flexibility at low temperatures), demonstrating their adequacy to be used in building applications. Properties were enhanced by subjecting the material to longer periods of curing prior to promote foaming.     

Thermal transitions and heat‐sealing of glycerol‐plasticized whey protein films

Transparent, flexible whey protein‐based edible films plasticized with glycerol were produced by wet (solution‐casting) and dry (twin‐screw extrusion followed by compression‐molding) processes. The relationship between the thermal transitions and the heat‐sealability of the whey protein‐based edible films was investigated. Differential Scanning Calorimetry showed the existence of endothermic peaks with an onset transition temperature of 156.3 ± 1.4°C for both the solution‐cast and extruded films. Films were heat‐sealed using an impulse heat‐sealer at an effective jaw pressure of 293.31 kPa, a voltage of 15 V and a cooling time of 4 s. Various impulse times, ranging from 1.5 to 2.5 s, were used to heat‐seal the films. A thermocouple was used to measure the heat‐sealing temperatures at each impulse time. Heat‐sealing temperatures ranged between 126.1 ± 9.0 and 204.0 ± 5.4°C for the shortest and longest impulse times, respectively. Seal strengths were determined using an Instron Universal Testing Machine. Film thickness appeared to have an effect on seal strength; higher strengths were achieved for thinner films, which, in this case, were the solution‐cast films. Thicker (extruded) films required a longer minimum impulse time to achieve a heat‐seal. The highest seal strength (433.07 ± 39.37 N/m) was obtained with solution cast films (thickness of 0.13 ± 0.01 mm) sealed with an impulse time of 2 s (164.6 ± 5.1°C). Impulse times above 2.5 s (204.0 ± 5.4°C) resulted in degradation of both solution‐cast and extruded films. Copyright © 2009 John Wiley & Sons, Ltd.     

Procedural uncertainties of Proctor compaction tests applied on MSWI bottom ash

MSWI bottom ash is a well-graded highly compactable material that can be used as a road material in unbound pavements. Achieving the compactness assumed in the design of the pavement is of primary concern to ensure long term structural stability. Regulations on road construction in a number of EU countries rely on standard tests originally developed for natural aggregates, which may not be appropriate to accurately assess MSWI bottom ash. This study is intended to assist in consistently assessing MSWI bottom ash compaction by means of the Proctor method. This test is routinely applied to address unbound road materials and suggests two methods. Compaction parameters show a marked procedural dependency due to the particle morphology and weak particle strength of ash. Re-compacting a single batch sample to determine Proctor curves is a common practise that turns out to overvalue optimum moisture contents and maximum dry densities. This could result in wet-side compactions not meeting stiffness requirements. Inaccurate moisture content measurements during testing may also induce erroneous determinations of compaction parameters. The role of a number of physical properties of MSWI bottom ash in compaction is also investigated.     

Spatial scanning spectroelectrochemistry. Study of the electrodeposition of Pd nanoparticles at the liquid/liquid interface

Spatial scanning spectroelectrochemistry is a new analytical technique that provides spectral information at different distances from an electrified liquid/liquid interface where an electrochemical process takes place. As a proof of concept, we have studied two different electrochemical processes at the electrified liquid/liquid interface: (1) Ru(bpy)(3)(2+) transfer through the water/1,2-dichloroethane interface and (2) electrodeposition of Pd nanoparticles at the water/1,2-dichloroethane interface. The instrumental setup developed consists of a movable slit for the light beam to sample at well-defined positions on both sides of the interface, providing important information about the chemical process occurring. If the slit is scanned at different distances from the interface during an electrochemical experiment, a complete picture of the reactions and equilibria in the diffusion layer can be obtained. For example, in the case of the Ru(bpy)(3)(2+), the experiments show clearly how the complex is transferred from one phase to the other. In the case of electrosynthesis of Pd nanoparticles, it is demonstrated that nanoparticles are not only deposited at the interface but diffuse to the aqueous bulk solution. These in situ observations were confirmed by ex situ experiments using transmission electron microscopy.     

Using solution thermodynamics to describe the dispersion of rod-like solutes: application to dispersions of carbon nanotubes in organic solvents

We report a simple model describing the solubility of rods in solvents, expressing the final result explicitly in terms of the surface entropy and the enthalpy of mixing. This model can be combined with any expression for the mixing enthalpy depending on the requirements. For example, in one instance it predicts the dispersed concentration of rods to decrease exponentially with the Flory-Huggins parameter of the dispersion. Using a different enthalpy function, it predicts a Gaussian peak when concentration is plotted versus solvent surface energy. The model also suggests specific solvent-rod interactions to be important and shows the dispersed concentration to be very sensitive to ordering at the solvent-rod interface. We have used this model to describe experimental results for the concentration of dispersed nanotubes in various solvents. Qualitative agreement with these predictions is observed experimentally. However, we suggest that the fact that quantitative agreement is not found may be explained by solvent ordering at the nanotube surface.