Destruction of Helminth (Ascaris suum) Eggs by Ozone

Based on the properties of ozone as a strong germicidal agent, the inactivation kinetics or disintegration of Ascaris suum eggs in water were studied. Ozone was applied in synthetic samples, the concentration of dissolved ozone in the liquid phase was typically between 3.5 to 4.7mg/L, pH 5, 9. The value of 90% inactivation (t₉₀) obtained was at 1 h, the remaining 10% being inactivated in 2 h. A linear correlation between the logarithm of bacterial or yeast concentration (N) and contact time was found, being the linear significant correlation coefficient (r of 0.95). That 2-log inactivation occurred at a CT value near 4.7mg/min/L. The best reduction percentage was of 99.00 in 120min. It therefore could be demonstrated that ozone indeed induces effects on the helminth eggs.     

Development of Polyamine-Substituted Triphenylamine Ligands with High Affinity and Selectivity for G-Quadruplex DNA

Currently, significant efforts are devoted to designing small molecules able to bind selectively to guanine quadruplexes (G4s). These noncanonical DNA structures are implicated in various important biological processes and have been identified as potential targets for drug development. Previously, a series of triphenylamine (TPA)-based compounds, including macrocyclic polyamines, that displayed high affinity towards G4 DNA were reported. Following this initial work, herein a series of second-generation compounds, in which the central TPA has been functionalised with flexible and adaptive linear polyamines, are presented with the aim of maximising the selectivity towards G4 DNA. The acid–base properties of the new derivatives have been studied by means of potentiometric titrations, UV/Vis and fluorescence emission spectroscopy. The interaction with G4s and duplex DNA has been explored by using FRET melting assays, fluorescence spectroscopy and circular dichroism. Compared with previous TPA derivatives with macrocyclic substituents, the new ligands reported herein retain the G4 affinity, but display two orders of magnitude higher selectivity for G4 versus duplex DNA; this is most likely due to the ability of the linear substituents to embrace the G4 structure.     

Microstructure and wear studies of laser clad Al-Si/SiC(p) composite coatings

Coatings of a composite material consisting of an Al-Si matrix reinforced with SiC particles were produced by laser cladding on UNS A03560 cast Al-alloy substrates from mixtures of powders of Al-12 wt.% Si alloy and SiC. The influence of the processing parameters on the microstructure and abrasive wear resistance of the coatings was studied. For an interaction time of 0.08 s and a power density of 330 MW/m², corresponding to a specific energy of 26 MJ/m², the interaction between SiC and liquid Al is limited and the reinforcement particles remain essentially undissolved. The coating's microstructure is formed of SiC particles dispersed in a matrix consisting of primary α-Al dendrites and interdendritic α-Al + Si eutectic. For interaction times of 0.3 and 0.45 s and a power density of 193 MW/m², corresponding to specific energies of 58 and 87 MJ/m², SiC reacts with molten Al and partially dissolves. The resulting microstructure consists of undissolved SiC particles, found mainly at the bottom of the clad tracks, where the maximum temperature reached during processing is lower, and Al₄SiC₄ and Si particles dispersed in a matrix of α-Al + Si eutectic. The coatings prepared with higher specific energy (58 MJ/m²) present a hardness of 250 V and an abrasive wear rate in three-body abrasion tests with SiC as abrasive of 1.7 × 10^− 4 mm³/m, while those produced with 26 MJ/m² present a hardness of 120 V and a wear rate of 0.43 × 10^− 4 mm³/m. These results show that Al₄SiC₄ and Si increase the hardness of the material by dispersion hardening but do not contribute to its abrasive wear resistance, because they are softer than the abrasive particles, and confirm that the parameters used to prepare Al-Si-SiC composite coatings by laser cladding must be selected so that only minimal reactions occur between SiC and molten Al.     

Delayed hospitalization of the patient with acute stroke

INTRODUCTION AND OBJECTIVE: We analyze the main factors influencing the time delay between onset and admission to the hospital in acute stroke. PATIENTS AND METHODS: Consecutive series of 1,344 patients with acute stroke or transient ischemic attack admitted at two reference hospitals of Valencia and included at the same stroke register. Factors assessed were age, sex, vascular risk factors, stroke onset and arrival at hospital, stroke severity and stroke subtype. RESULTS: In 30% of patients the stroke onset time was unknown. 70.7% of patients with acute stroke, and known onset, arrived to the hospital in the first six hours. The median time from onset to admission was: TIA, 2 hours; cerebral infarct, 3 hours (lacunar infarcts 5 hours, non-lacunar infarcts 2 hours) and intracerebral hemorrhage, 2 hours. Patients with severe stroke arrive earlier at the hospital (p < 0.001). Neither sex, age, nor vascular risk factors influence the delay time. CONCLUSIONS: The arrival time varies with stroke subtype: patients with intracerebral hemorrhage or TIA arrive earlier than those with cerebral infarct, and non-lacunar infarcts earlier than lacunar ones. Furthermore, patients with severe stroke are admitted sooner at the hospital.     

Alizarin Complexone on Nanocrystalline TiO2: A Heterogeneous Approach to Anion Sensing

A novel, heterogeneous approach to “naked‐eye” colorimetric and spectrophotometric anion sensing is demonstrated, employing the molecular receptor alizarin complexone adsorbed onto a nanocrystalline, mesoporous TiO₂ film. pH buffer action intrinsic to the TiO₂ film allows dip sensing in aqueous solutions. This heterogeneous sensing system exhibits a high selectivity to F^– and CN^– anions, high sensitivity, a rapid response time, and excellent reusability.     

Electrochemical studies of laser-treated Co-Cr-Mo alloy in a simulated physiological solution

The aims of this work were to study the crevice corrosion resistance of laser-treated Co-Cr-Mo alloy by electrochemical techniques and to characterize the electronic properties of the passivating films. Open-circuit experiments and cyclic polarizations with crevice-free samples have been carried out as well as electrochemical impedance spectra using Bode-Nyquist and Mott-Schottky techniques. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis have been used in order to evaluate surface modifications. It has been observed that laser-treated Co-Cr-Mo alloy shows good corrosion resistance in spite of some degradation at the dendrites formed during treatment. By XPS it was found that at 6–9 nm depth there exists an enrichment in oxygen and a decrease of Cr which could have a slight effect on the corrosion resistance and it was seen that the film is mostly formed by Cr₂O₃. Mott-Schottky plots show that a possible transition from n-type to p-type semiconductivity may have occurred.     

Wideband sounding of 11.66 GHz trans-horizon channel

A high speed, wideband channel probe is briefly described. The use of the probe on an experimental 158 km link across the English Channel is reported. Preliminary results depicting the time-variant and frequency-selective characteristics of the link are presented     

Whole-Body Balance Control of a Humanoid Robot in Real Time Based on ZMP Stability Regions Approach

Abstract

One of the most important and complex tasks for a humanoid robot is to avoid overturning during a bipedal gait. This work aims at setting the base for designing a general balance controller to be used with any humanoid robot. In addition, it is based on a strong simplification of humanoid model which attempts to be used in real-time applications. In particular, several “stability zones” are defined as function of the criticalness of balance. The results are presented in simulation and experimentally, using the humanoid platforms HOAP-3 and TEO.