Solid state field-assisted silver ion exchange in porcelain stoneware: A new route toward antimicrobial tiles?

The development of tiles possessing antimicrobial activity is of great technological and scientific interest to improve the functionality of a very widely used article. Also the current SARS-CoV-2 pandemic is drawing the attention towards materials or compounds able to inactivate the virus, silver being among all the most promising one.In the present work, field-assisted ion exchange process was used to functionalize porcelain stoneware by introducing silver into the material surface using a solid silver electrode. The application of a small direct electric current (10 mA cm^?2) at 380 °C allowed to fasten silver diffusion. The penetration of silver into stoneware appears homogeneous and primarily involves an exchange between silver and sodium ions under the effect of the external electric current. Penetration depths approaching 120 μm can be obtained in only 5 min. Preliminary characterization revealed that the Ag-exchanged stoneware possesses a strong biocidal action against Staphylococcus aureus.     

High‐yield E‐band diplexer for fixed radio point‐to‐point equipment

The article describes practical guidelines for an E‐Band tuning‐less waveguide diplexer design (71–86 GHz) which requires looser fabrication tolerances and provides higher yield than traditional methods. Physical considerations concerning sensitivity to manufacturing inaccuracies are discussed and proven by designing and manufacturing two different diplexers on a set of typical specifications. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:508–512, 2014.     

GAS-PARTICLE PARTITIONING OF POLYCYCLIC AROMATIC HYDROCARBONS DURING THE SPRING AND SUMMER IN A SUBURBAN SITE NEAR MAJOR TRAFFIC ARTERIES

Concentrations of atmospheric polycyclic aromatic hydrocarbons were measured in a suburban site near major traffic arteries during the period April-August 2006. Total suspended particulate during the sampling period was 65.3 ± 33.9 μ g m^?3. Total PAH concentrations were 63.5 ± 20.1 ng m^?3 in the gaseous phase and 1.4 ± 0.3 ng m^?3 in the particulate phase. Observed concentrations were comparable with previously measured values reported in the literature for urban and suburban sites with a high anthropic influence. PAH concentration diagnostic ratios indicate that, during the spring and summer seasons, vehicular emission was the main source of atmospheric PAHs.

Gas/particle partitioning coefficients K _P were well correlated with both the sub-cooled liquid vapor pressures p _L ⁰ and the octanol-air partition coefficients K _OA . Measured K _P values were in a good agreement with K _P values predicted by applying a literature model, which takes into account both adsorption onto black carbon and absorption into the organic matter.     

PEEKWC microcapsules for selective oxidation of benzyl alcohols to aldehydes

In this study, we report on the preparation, characterization and use of new catalytic polymeric microcapsules for the selective oxidation of benzyl alcohols to benzaldehydes. The catalyst, ammonium molybdate tetrahydrate, was entrapped inside modified polyetheretherketone (PEEKWC) polymeric microcapsules during their preparation. Catalytic activity of the new PEEKWC microcapsules has been evaluated in the oxidation of substituted benzyl alcohols to benzaldehydes using hydrogen peroxide as oxidant.EDX analysis of the catalytic microcapsules showed a satisfactorily catalyst distribution on the shell and on the inner core. Proof of successful entrapment of catalyst inside polymeric matrix during the preparation was given by the different colorimetric reactions between the catalytic PEEKWC microcapsules and the oxidant (hydrogen peroxide).An interesting structure-reactivity behaviour, that may indeed be induced by the interaction between the polymeric membrane and the substrate, has been observed.PEEKWC catalytic microcapsules were stable under oxidation conditions and can be recycled without a loss of activity.     

Extracellular Vesicle-Derived microRNAs of Human Wharton’s Jelly Mesenchymal Stromal Cells May Activate Endogenous VEGF-A to Promote Angiogenesis

Despite low levels of vascular endothelial growth factor (VEGF)-A, the secretome of human Wharton’s jelly (WJ) mesenchymal stromal cells (MSCs) effectively promoted proangiogenic responses in vitro, which were impaired upon the depletion of small (~140 nm) extracellular vesicles (EVs). The isolated EVs shared the low VEGF-A profile of the secretome and expressed five microRNAs, which were upregulated compared to fetal dermal MSC-derived EVs. These upregulated microRNAs exclusively targeted the VEGF-A gene within 54 Gene Ontology (GO) biological processes, 18 of which are associated with angiogenesis. Moreover, 15 microRNAs of WJ-MSC-derived EVs were highly expressed (Ct value ≤ 26) and exclusively targeted the thrombospondin 1 (THBS1) gene within 75 GO biological processes, 30 of which are associated with the regulation of tissue repair. The relationship between predicted microRNA target genes and WJ-MSC-derived EVs was shown by treating human umbilical-vein endothelial cells (HUVECs) with appropriate doses of EVs. The exposure of HUVECs to EVs for 72 h significantly enhanced the release of VEGF-A and THBS1 protein expression compared to untreated control cells. Finally, WJ-MSC-derived EVs stimulated in vitro tube formation along with the migration and proliferation of HUVECs. Our findings can contribute to a better understanding of the molecular mechanisms underlying the proangiogenic responses induced by human umbilical cord-derived MSCs, suggesting a key regulatory role for microRNAs delivered by EVs.     

Carcinoma cell lines resistant for growth inhibition and apoptosis to retinoic acid are responsive to 4-hydroxy-phenyl-retinamide: correlation with tissue transglutaminase

Retinoic acid (RA)-resistant cell lines are highly malignant. To inhibit the growth of the RA-resistant cells we used 4-HPR, a synthetic retinoid, which may act through alternative signal transduction pathways. 4-HPR induced cell growth inhibition and apoptosis in all RA-sensitive as well as -resistant cells, demonstrating a wider spectrum of potency over RA. 4-HPR induced tissue TGase activity. A tight correlation between the induction of tissue TGase, the inhibition of cell growth, and apoptosis was evident in all eight RA-sensitive cell lines. However, basal TGase differed in the different cells, suggesting inducibility rather than basal levels as the relevant parameter. In sharp contrast to the RA-sensitive cells, RA-resistant cells showed sporadic response to 4-HPR for tissue TGase. The wider spectrum of activity of 4-HPR in inhibiting cell growth and inducing apoptosis makes it a good candidate for the treatment of RA-resistant cancer cells.     

Dependability modeling and evaluation of multiple-phased systems using DEEM

Multiple-Phased Systems (MPS), i.e., systems whose operational life can be partitioned in a set of disjoint periods, called "phases", include several classes of systems such as Phased Mission Systems and Scheduled Maintenance Systems. Because of their deployment in critical applications, the dependability modeling and analysis of Multiple-Phased Systems is a task of primary relevance. The phased behavior makes the analysis of Multiple-Phased Systems extremely complex. This paper describes the modeling methodology and the solution procedure implemented in DEEM, a dependability modeling and evaluation tool specifically tailored for Multiple Phased Systems. It also describes its use for the solution of representative MPS problems. DEEM relies upon Deterministic and Stochastic Petri Nets as the modeling formalism, and on Markov Regenerative Processes for the model solution. When compared to existing general-purpose tools based on similar formalisms, DEEM offers advantages on both the modeling side (sub-models neatly model the phase-dependent behaviors of MPS), and on the evaluation side (a specialized algorithm allows a considerable reduction of the solution cost and time). Thus, DEEM is able to deal with all the scenarios of MPS which have been analytically treated in the literature, at a cost which is comparable with that of the cheapest ones, completely solving the issues posed by the phased-behavior of MPS.     

A tour of secure software engineering solutions for connected vehicles

The growing number of vehicles daily moving on roads increases the need of protecting the safety and security of passengers, pedestrians, and vehicles themselves. This need is intensified when considering the pervasive introduction of Information and Communication Technologies (ICT) systems into modern vehicles, because this makes such vehicles potentially vulnerable from the point of view of security. The convergence of safety and security requirements is one of the main outstanding research challenges in software-intensive systems. This work reviews existing methodologies and solutions addressing security issues in the automotive domain with a focus on the integration between safety and security aspects. In particular, we identify the main security issues with vehicular communication technologies and existing gaps between state-of-the-art methodologies and their implementation in the real world. Starting from a literature survey and referring to widely accepted standards of the domain, such as AUTOSAR and ISO 26262, we discuss research challenges and set baselines for a holistic secure-by-design approach targeting safety and security aspects all along the different phases of the development process of automotive software.     

Configuring a VR simulator for the evaluation of advanced human–machine interfaces for hydraulic excavators

Virtual Reality - This study is aimed at evaluating the impact of different technical solutions of a virtual reality simulator to support the assessment of advanced human–machine interfaces...