Thermal nonlinear refraction in the dye-doped sol–gel xTiO2 · (100 − x)SiO2 system

The build-up time of the thermal lens effect induced by a Gaussian beam in the DO3-doped sol–gel system xTiO₂ · (100 − x)SiO₂ at different compositions, both in the liquid and gel phases has been measured in a Z-scan geometry. While the pure titania samples show a minimum of the thermal diffusivity, a maximum is found for x ≈ 30. The sol to gel transformation leads to an increase of the build-up times at all compositions.     

Advanced RNN Based NARMA Predictors

An analysis of nonlinear time series prediction schemes, realised though advanced Recurrent Neural Network (RNN) techniques is provided. Due to practical constraints in using common RNNs, such as the problem of vanishing gradient, some other ways to improve RNN based prediction are analysed. This is undertaken for a simple RNN through to the Pipelined Recurrent Neural Network (PRNN), which consists of a number of nested small-scale RNNs. A Nonlinear AutoRegressive Moving Average (NARMA) nonlinear model is introduced in the context of RNN architectures, and an posteriori mode of operation within that framework. Moreover, it is shown that the basic a priori PRNN structure exhibits certain a posteriori features. The PRNN based predictor, is shown to exhibit nesting, and to be able to represent block cascaded stochastic models, such as the Wiener–Hammerstein model. Simulations undertaken on a speech signal support the analysis.     

Catalytic decomposition of nitric oxide by perovskites

Catalytic decomposition of nitric oxide has been studied for nearly a century, using materials ranging from noble metals to alkaline earth metal oxides, without much success. Only since about last fifteen years some progress in finding promising materials has been made. Of the numerous catalyst systems studied, very few show tangible decomposition rates : copper substituted zeolites, silver-cobalt mixed oxides, some perovskites, and supported noble metals. Although at 773 K the rates of decomposition over zeolites are two to three orders higher than those over remaining systems, these materials have very low thermal stability, above 773 K. In this respect, perovskites have much higher potential, although so far no composition exhibiting practical decomposition rates has been found. Systematic study of the effect of composition on the performance should help to advance the complete understanding of this important reaction. In this paper a current state of art is outlined, and some latest preliminary results for new specially formulated perovskites are presented.     

Gel-Based Proteomic Identification of Suprabasin as a Potential New Candidate Biomarker in Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynaecologic cancer in postmenopausal women. We used 2D-DIGE and mass spectrometry to identify candidate biomarkers in endometrial cancer, analysing the serum protein contents of 10 patients versus 10 control subjects. Using gel-based proteomics, we identified 24 candidate biomarkers, considering only spots with a fold change in volume percentage ≥ 1.5 or intensity change ≤ 0.6, which were significantly different between cases and controls (p < 0.05). We used Western blotting analysis both in the serum and tissue of 43 patients for data validation. Among the identified proteins, we selected Suprabasin (SBSN), an oncogene previously associated with poor prognosis in different cancers. SBSN principal isoforms were subjected to Western blotting analysis in serum and surgery-excised tissue: both isoforms were downregulated in the tissue. However, in serum, isoform 1 was upregulated, while isoform 2 was downregulated. Data-mining on the TCGA and GTEx projects, using the GEPIA2.0 interface, indicated a diminished SBSN expression in the Uterine Corpus Endometrial Cancer (UCEC) database compared to normal tissue, confirming proteomic results. These results suggest that SBSN, specifically isoform 2, in tissue or serum, could be a potential novel biomarker in endometrial cancer.     

A shake table protocol for seismic assessment and qualification of acceleration-sensitive nonstructural elements

A shake table protocol for seismic assessment and qualification of acceleration-sensitive nonstructural elements (NEs) is developed. The paper critically reviews existing protocols and highlights their criticalities, pointing out the need for the development of novel assessment and qualification approaches and protocols. The protocol is developed in light of these criticalities, considering the most recent advances in the field and the specific expertise of the research team. The most significant and contributing parts of the developed protocol consist of the definition of novel required response spectra and the generation of signals for seismic performance evaluation tests. The reliability and robustness of the protocol are evidenced in the paper considering real-floor motions as a reference, also proving the superiority of the developed protocol with respect to the reference alternatives. The defined approach and procedures are generally applicable and easily extendable to different case studies, as the process is highly versatile and modifiable. The implementation of the developed approach and protocol in the literature and in practice will significantly enhance seismic assessment and qualification of acceleration-sensitive NEs. This will possibly have a strong impact on public safety and economy.     

Flexible and efficient profiling with aspect‐oriented programming

Many profilers for virtual execution environments, such as the Java virtual machine (JVM), are implemented with low‐level bytecode instrumentation techniques, which is tedious, error‐prone, and complicates maintenance and extension of the tools. In order to reduce the development time and cost, we promote building profilers for the JVM using high‐level aspect‐oriented programming (AOP). We show that the use of aspects yields concise profilers that are easy to develop, extend, and maintain, because low‐level instrumentation details are hidden from the tool developer. In order to build efficient profilers, we introduce inter‐advice communication, an extension to common AOP languages that enables efficient data passing between advices that are woven into the same method using local variables. We illustrate our approach with two case studies. First, we show that an existing, instrumentation‐based tool for listener latency profiling can be easily recast as an aspect. Second, we present an aspect for comprehensive calling context profiling. In order to reduce profiling overhead, our aspect parallelizes application execution and profile creation, resulting in a speedup of 110% on a machine with more than two cores, compared with a primitive, non‐parallel approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Silane-Mediated Expansion of Domains in Si-Doped κ-Ga2O3 Epitaxy and its Impact on the In-Plane Electronic Conduction

Unintentionally doped (001)-oriented orthorhombic κ-Ga₂O₃ epitaxial films on c-plane sapphire substrates are characterized by the presence of ≈ 10 nm wide columnar rotational domains that can severely inhibit in-plane electronic conduction. Comparing the in- and out-of-plane resistance on well-defined sample geometries, it is experimentally proved that the in-plane resistivity is at least ten times higher than the out-of-plane one. The introduction of silane during metal-organic vapor phase epitaxial growth not only allows for n-type Si extrinsic doping, but also results in the increase of more than one order of magnitude in the domain size (up to ≈ 300 nm) and mobility (highest µ ≈ 10 cm²V⁻¹s⁻¹, with corresponding lowest ρ ≈ 0.2 Ωcm). To qualitatively compare the mean domain dimension in κ-Ga₂O₃ epitaxial films, non-destructive experimental procedures are provided based on X-ray diffraction and Raman spectroscopy. The results of this study pave the way to significantly improved in-plane conduction in κ-Ga₂O₃ and its possible breakthrough in new generation electronics. The set of cross-linked experimental techniques and corresponding interpretation here proposed can apply to a wide range of material systems that suffer/benefit from domain-related functional properties.     

Terpyridine Glycoconjugates and Their Metal Complexes: Antiproliferative Activity and Proteasome Inhibition

Metal terpyridine complexes have gained substantial interest in many application fields, such as catalysis and supramolecular chemistry. In recent years, the biological activity of terpyridine and its metal complexes has aroused considerable regard. On this basis, we synthesised new terpyridine derivatives of trehalose and glucose to improve the water solubility of terpyridine ligands and target them in cancer cells through glucose transporters. Glucose derivative and its copper(II) and iron(II) complexes showed antiproliferative activity. Interestingly, trehalose residue reduced the cytotoxicity of terpyridine. Moreover, we tested the ability of parent terpyridine ligands and their copper complexes to inhibit proteasome activity as an antineoplastic mechanism.     

“A Study in Yellow”: Investigations in the Stereoselectivity of Ene-Reductases

Ene-reductases from the Old Yellow Enzyme (OYE) superfamily are a well-known and efficient biocatalytic alternative for the asymmetric reduction of C=C bonds. Considering the broad variety of substituents that can be tolerated, and the excellent stereoselectivities achieved, it is apparent why these enzymes are so appealing for preparative and industrial applications. Different classes of C=C bonds activated by at least one electron-withdrawing group have been shown to be accepted by these versatile biocatalysts in the last decades, affording a vast range of chiral intermediates employed in the synthesis of pharmaceuticals, agrochemicals, flavours, fragrances and fine chemicals. In order to access both enantiomers of reduced products, stereodivergent pairs of OYEs are desirable, but their natural occurrence is limited. The detailed knowledge of the stereochemical course of the reaction can uncover alternative strategies to orient the selectivity via mutagenesis, evolution, and substrate engineering. An overview of the ongoing studies on OYE-mediated bioreductions will be provided, with particular focus on stereochemical investigations by deuterium labelling.     

Special issue on machine learning for security and privacy: advancing the state-of-the-art applications

Neural Computing and Applications -