Reduction of Protein Networks Models by Passivity Preserving Projection

Reduction of complex protein networks models is of great importance.The accuracy of a passivity preserving algorithm (PRIMA) for model order reduction (MOR) is here tested on protein networks,introducing innovative variations of the standard PRIMA method to fit the problem at hand.The reduction method does not require to solve the complete system,resulting in a promising tool for studying very large-scale models for which the full solution cannot be computed.The mathematical structure of the considered kinetic equations is preserved.Keeping constant the reduction factor,the approximation error is lower for larger systems.     

Enrofloxacin inclusion complexes with cyclodextrins

Inclusion complexes using α-, β-, γ-, and hydroxypropyl-β-CD (HP-β-CD) were produced with the antibiotic enrofloxacin, with the aim of increasing its solubility by complexation. Phase solubility diagrams were obtained, to confirm the formation of inclusion complexes, and to determine the solubility enhancement and stability constant of each complex. Enrofloxacin inclusion in β-CD showed the highest value of the complex stability constant (35.56?mmol?L^?1), but the greatest increase in solubility was obtained using HP-β-CD reaching a 1258% increase over enrofloxacin solubility in the absence of CD. The order of highest enrofloxacin solubility achieved was: HP-β-CD?>?α-CD?>?γ-CD?>?β-CD. In addition, formation of complexes was confirmed by differential scanning calorimetry and thermogravimetry, applied to the complexes obtained by the kneading technique. The influence of citric acid, alone or as an adjunct of β-CD, on the solubility of enrofloxacin was also determined. A solution of 15?mmol?L^?1 citric acid dissolved 10?g?L^?1 of enrofloxacin, but a gradual increase in β-CD concentration in the presence of citric acid did not increase the degree of solubilization of enrofloxacin.     

Analysis of gear rattle by means of a wavelet-based signal processing procedure

In the paper a wavelet-based signals processing technique for the experimental detection of the gear rattle produced by the teeth impacts in lightly loaded gears is proposed. The Discrete Wavelet Transform is used to decompose the signal of the angular relative motion of an helical gear pair, and the wavelet decomposition details are adopted to analyze the dynamic behavior under rattle condition. In particular the procedure permits to evaluate the quality of the impacts between the teeth, discriminating between the two different sides of teeth contacts when there is a double-sided rattle condition. This technique enables, moreover, to define new indices for metrics of gear rattle especially useful in order to conduct comparisons for different operative conditions. Some examples of application of the proposed technique are reported in the paper adopting experimental signals acquired by two high resolution incremental encoders on a specific gear pair test rig. The experimental investigations regard comparative analyses with respect to the speed fluctuations amplitude, the rattle frequency and the lubrication regime.     

Structure and Morphology of SBA-15 Thin Films on Different Substrates

Well-ordered hexagonal mesoporous silica thin films, SBA-15 type, were synthesized with Pluronic P123 and tetraethyl orthosilicate in a diluted ethanol-hydrochloric acid solution. Films deposited on a broad range of distinct substrates by a sol-gel dip-coating method resulted in transparent and adherent samples. Transmission electron microscopy images revealed, predominantly, well-ordered regions of hexagonal arrays of cylindrical mesopores parallel to the substrate. X-ray reflectivity showed similar lattice parameters for all analyzed films, with a (h00) preferred orientation. The films presented diverse shrinkage susceptibilities, which were tested after different polymer removal procedures. Calcined films have 342 m²/g surface area, 0.130 cm³/g pore volume, and 6.8 nm pore diameter. The wetting characteristics of the substrates in water and alcoholic solutions were evaluated. The films showed different structural properties, mostly related to the mean surface roughness of the substrates and to the drying process.     

Taming nonlocality in theories with Planck-scale deformed Lorentz symmetry

We report a general analysis of worldlines for theories with deformed relativistic symmetries and momentum dependence of the speed of photons. Our formalization is faithful to Einstein's program, with spacetime points viewed as an abstraction of physical events. The emerging picture imposes the renunciation of the idealization of absolutely coincident events, but is free from some pathologies which had been previously conjectured.     

Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry

A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal? device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL(-1) (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL(-1). The detection limits were 0.5 ng mL(-1) (MET), 1 ng mL(-1) (MPH) and 2 ng mL(-1) (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal? device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.     

Quasitilted algebras admit a preprojective component

Quasitilted algebras are generalizations of tilted algebras. As a main result we show here that the Auslander-Reiten quiver of such an algebra has a preprojective component