Bioprospecting Antimicrobials from Lactiplantibacillus plantarum: Key Factors Underlying Its Probiotic Action

Lactiplantibacillus plantarum (L. plantarum) is a well-studied and versatile species of lactobacilli. It is found in several niches, including human mucosal surfaces, and it is largely employed in the food industry and boasts a millenary tradition of safe use, sharing a long-lasting relationship with humans. L. plantarum is generally recognised as safe and exhibits a strong probiotic character, so that several strains are commercialised as health-promoting supplements and functional food products. For these reasons, L. plantarum represents a valuable model to gain insight into the nature and mechanisms of antimicrobials as key factors underlying the probiotic action of health-promoting microbes. Probiotic antimicrobials can inhibit the growth of pathogens in the gut ensuring the intestinal homeostasis and contributing to the host health. Furthermore, they may be attractive alternatives to conventional antibiotics, holding potential in several biomedical applications. The aim of this review is to investigate the most relevant papers published in the last ten years, bioprospecting the antimicrobial activity of characterised probiotic L. plantarum strains. Specifically, it focuses on the different chemical nature, the action spectra and the mechanisms underlying the bioactivity of their antibacterial and antiviral agents. Emerging trends in postbiotics, some in vivo applications of L. plantarum antimicrobials, including strengths and limitations of their therapeutic potential, are addressed and discussed.     

Comparison of Different Photocatalytic Systems for Acetonitrile Degradation in Gas–solid Regime

Photocatalytic degradation of acetonitrile was carried out in gas–solid regime by using two commercial TiO₂ samples (Merck and Degussa P25) irradiated in two continuous annular photoreactors. The inlet gas flow consisted of oxygen, nitrogen, acetonitrile and water vapours. The influence on the photodegradation rate of gas flow rate, acetonitrile, oxygen and water concentrations and photon flux was investigated. The degradation products of acetonitrile were carbon dioxide and hydrogen cyanide. The photocatalysts performance was not affected by the presence or absence of water vapour in the reacting mixture. The Langmuir–Hinshelwood model describes adequately the photoreactivity results and provides the values of kinetic and equilibrium adsorption constants. FT-IR spectroscopy was used to investigate the adsorption patterns and photo-oxidation intermediates of acetonitrile on fully hydrated surface of TiO₂ powders. Acetonitrile was adsorbed on Ti⁴⁺ surface ions and hydroxyl groups for both types of TiO₂. In the absence of UV light this interaction was completely reversible for Merck catalyst whereas for Degussa P25 part of adsorbed acetonitrile molecules reacted to form acetamide-like species.     

Mechanisms of moral disengagement in the exercise of moral agency.

This research examined the role of mechanisms of moral disengagement in the exercise of moral agency. Regulatory self-sanctions can be selectively disengaged from detrimental conduct by converting harmful acts to moral ones through linkage to worthy purposes, obscuring personal causal agency by diffusion and displacement of responsibility, misrepresenting or disregarding the injurious effects inflicted on others, and vilifying the recipients of maltreatment by blaming and dehumanizing them. The study examined the structure and impact of moral disengagement on detrimental conduct and the psychological processes through which it exerts its effects. Path analyses reveal that moral disengagement fosters detrimental conduct by reducing prosocialness and anticipatory self-censure and by promoting cognitive and affective reactions conducive to aggression. The structure of the paths of influence is very similar for interpersonal aggression and delinquent conduct. Although the various mechanisms of moral disengagement operate in concert, moral reconstruals of harmful conduct by linking it to worthy purposes and vilification of victims seem to contribute most heavily to engagement in detrimental activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Efficacy Beliefs as Determinants of Teachers' Job Satisfaction.

Self- and collective-efficacy beliefs were examined as main determinants of teachers' job satisfaction. In 103 Italian junior high schools, 2,688 teachers filled out self-reports to assess self-efficacy beliefs, their perceptions of the extent to which other school constituencies, namely, the principal, colleagues, staff, students, and families, were behaving in accordance with their obligations toward school well-functioning, their collective-efficacy beliefs, and their job satisfaction. Multilevel structural equation functioning, modeling analyses corroborated a conceptual model in which individual and collective-efficacy beliefs represent, respectively, the distal and proximal determinants of teachers' job satisfaction. The perceptions that teachers have of other constituencies' behavior largely mediated the links between self- and collective-efficacy beliefs. Collective-efficacy beliefs, in turn, partially mediated the influence that teachers' perceptions of other school constituencies' behavior exerts on their own job satisfaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Damage Accumulation in Glass Plates

This paper examines the glass cladding damage accumulation caused by wind loading. The primary focus is the effect of the non-Gaussian nature of wind pressure fluctuations. The damage is estimated using the Monte Carlo methodology and Brown’s integral formulation. The pressure time histories are generated by a numerical procedure based on the translation model, which is calibrated on experimental data. The stress field in the glass is calculated using the von Kármán plate model. A sensitivity analysis is performed estimating the damage statistical moments, up to the fourth order, and its probability density function. The obtained results demonstrate that the classical Gaussian assumption used to model wind pressure is unsafe. The accurate modeling of the non-Gaussian features produces a significant amplification of the damage mean value and higher variability of the damage distribution.     

Simulation of wind loading and response of geometrically non-linear structures with particular reference to large antennas

The study of the response of wind-loaded flexible structures generates several problems, related to the collection of significant experimental data and the modelling of the random wind velocity field, fluid-structure interaction and actual structural behaviour. This paper presents some results of recent research on these problems.

The first part of the paper tackles the modelling and simulation of wind velocity and presents the treatment of some direct measurements on the site of an important broadcasting antenna located on Monte Nerone (Appennine Mountains) on the Italia watershed, 1500 m above sea level.

The second part deals with the problem of determining structural response under wind loading. Because of the impracticability of operating in the frequency domain in the presence of non-linearities, simulation and direct step-by-step integration in the time domain have been chosen. Two specific examples are presented, both pertaining to guyed antennas, for which non-linearities have been shown to be significant. The effects of ice formations on the mast and / orthe stays have also been investigated.     

Two-dimensional photonic crystal resist membrane nanocavity embedding colloidal dot-in-a-rod nanocrystals

A novel technique for the fabrication of photonic crystal (PC) nanocavities coupled with colloidal nanocrystals is presented. A waveguiding resist membrane embedding highly emitting dot-in-a-rod nanocrystals was patterned through e-beam lithography and released through wet etching process. The proposed approach makes the PC structure independent of fabrication imperfections induced by etching steps. Micro-photoluminescence spectra revealed degenerated resonant modes (Q-factor approximately 700) whose fabrication-induced spectral splitting is comparable to the full width at half-maximum of the peaks. Active nanocavities tunable from visible to infrared spectral range on GaAs or Si substrates can be easily implemented by this technique.     

Optical control of energy-level structure of few electrons in AlGaAs/GaAs quantum dots

Optical control of the lateral quantum confinement and number of electrons confined in nanofabricated GaAs/AlGaAs quantum dots is achieved by illumination with a weak laser beam that is absorbed in the AlGaAs barrier. Precise tuning of energy-level structure and electron population is demonstrated by monitoring the low-lying transitions of the electrons from the lowest quantum-dot energy shells by resonant inelastic light scattering. These findings open the way to the manipulation of single electrons in these quantum dots without the need of external metallic gates.