Is the Mott transition relevant to f-electron metals ?

We study how a finite hybridization between a narrow correlated band and a wide conduction band affects the Mott transition. At zero temperature, the hybridization is found to be a relevant perturbation, so that the Mott transition is suppressed by Kondo screening. In contrast, a first-order transition remains at finite temperature, separating a local moment phase and a Kondo- screened phase. The first-order transition line terminates in two critical endpoints. Implications for experiments on f-electron materials such as the Cerium alloy Ce$_{0.8}$La$_{0.1}$Th$_{0.1}$ are discussed.Comment: 5 pages, 3 figure

Development and application of an electrochemical plate coupled with immunomagnetic beads (ELIME) array for salmonella enterica detection in meat samples

Salmonella is one of the main organisms causing outbreaks of foodborne illness, and meat is one of the major vehicles of salmonellosis throughout the world. A novel analytical immunosensor array, based on a 96-well electrochemical plate coupled with immunomagnetic beads (ELIME array), is proposed for the detection of Salmonella in meat samples. After an optimization study, using Salmonella enterica serotype Enteritidis as reference antigen, the ability of the method to interact with a large number of Salmonella serovars commonly present in food was evaluated. The assay was then used to analyze samples of pork, chicken, beef, and turkey experimentally inoculated with Salmonella as well as real samples. The results were compared with those from the International Standard of Organization (ISO) culture method. The comparison showed that the ELIME array is able to detect a low number of Salmonella cells (1-10 CFU per 25 g) after only 6 h of incubation in a pre-enrichment broth. The investigation revealed a very good agreement between culture and ELIME array methods for meat samples, reducing the time for performing the analysis and obtaining the results quickly

SYBR Green Real-Time PCR for Salmonella detection in meat products

The objective of this study was to develop a SYBR Green Real-Time PCR method for detecting salmonellae in meat samples. The study was conducted both on S. Typhimurium experimentally and naturally contaminated meat samples analyzed in parallel with the standard cultural method (ISO 6579/2001). After the pre-enrichment phase, a boiling DNA extraction procedure combined wity SYBR-Green I Real Time PCR, using primers Styinva-JHO-2, was developed

Mott transitions with partially filled correlated orbitals

We investigate the metal-insulator Mott transition in a generalized version of the periodic Anderson model, in which a band of itinerant non-interacting electrons is hybridrized with a narrow and strongly correlated band. Using the dynamical mean-field theory, we show that the precondition for the Mott transition is that the total filling of the two bands takes an odd integer value. Unlike the conventional portrait of the Mott transition, this condition corresponds to a non-integer filling of the correlated band. For an integer constant occupation of the correlated orbitals the system remains a correlated metal at arbitrary large interaction strength. We picture the transition at a non-integer filling of the correlated orbital as the Mott localization of the singlet states between itinerant and strongly interacting electrons, having occupation of one per lattice site. We show that the Mott transition is of the first order and we characterize the nature of the resulting insulating state with respect to relevant physical parameters, such as the charge-transfer energy

Salmonella enterica Control in Stick Carrots Through Incorporation of Coriander Seeds Essential Oil in Sustainable Washing Treatments

Chemical disinfectants represent one of the commonly used practice in minimally processed vegetables food-chain. However, the scarce safety and sustainability of these agents force food industry to move toward more sustainable “green washing solutions.” Among the latter, while the application of plant derivates for the control of several pathogens is already well-known, the potential anti-Salmonella activity of Coriandrum sativum seeds derivates is still unexplored and was therefore investigated in this study. In detail, Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) of different coriander seed derivates (i.e., essential oil, hydrosol, and ethanolic extract) were determined by broth dilution against six Salmonella enterica strains isolated from fresh and minimally processed fruits and vegetables. Only the essential oil (EO) was effective in vitro with strain-dependent results. In addition, when mixed in co-culture, the strains were more sensitive to the essential oil treatment. Chemical investigations allowed to define (s)-(+)-linalool as major compound in the essential oil, and to underline interesting phenolic content with correlated antioxidant capacity. A cocktail of three strains of different serovars was selected and employed for a preliminary in situ trial on stick carrots. The obtained results allowed to establish that the application of coriander seed EO at concentrations of 5 μL mL−1 was able to reduce and contain the growth of the Salmonella cocktail up to 24 h at 10°C. Good sensory evaluation results were obtained by applying this EO concentration as washing treatment, especially in terms of color parameter. Further studies should be undertaken to emphasize the upstream activity, improving the formulation or exploiting a combined effect with other sanitizers or treatments (e.g., physical treatments). The present study contributes to the knowledge on coriander derivates activity against Salmonella spp. and on the potential application as sustainable washing treatment in removing this pathogen from fresh cut carrots

Orbitally resolved lifetimes in Ba(Fe0.92Co0.08)2As2 measured by ARPES

Despite many ARPES investigations of iron pnictides, the structure of the electron pockets is still poorly understood. By combining ARPES measurements in different experimental configurations, we clearly resolve their elliptic shape. Comparison with band calculation identify a deep electron band with the dxy orbital and a shallow electron band along the perpendicular ellipse axis with the dxz/dyz orbitals. We find that, for both electron and hole bands, the lifetimes associated with dxy are longer than for dxz/dyz. This suggests that the two types of orbitals play different roles in the electronic properties and that their relative weight is a key parameter to determine the ground state

Optical conductivity signatures of open Dirac nodal lines

We investigate the optical conductivity and far-infrared magneto-optical response of BaNiS$_2$, a simple square-lattice semimetal characterized by Dirac nodal lines that disperse exclusively along the out-of-plane direction. With the magnetic field aligned along the nodal line the in-plane Landau level spectra show a nearly $\sqrt{B}$ behavior, the hallmark of a conical-band dispersion with a small spin-orbit coupling gap. The optical conductivity exhibits an unusual temperature-independent isosbestic line, ending at a Van Hove singularity. First-principles calculations unambiguously assign the isosbestic line to transitions across Dirac nodal states. Our work suggests a universal topology of the electronic structure of Dirac nodal lines

Nine-year nationwide environmental surveillance of hepatitis E virus in urban wastewaters in Italy (2011–2019)

Hepatitis E virus (HEV) is an emerging causative agent of acute hepatitis worldwide. To provide insights into the epidemiology of HEV in Italy, a large-scale investigation was conducted into urban sewage over nine years (2011–2019), collecting 1374 sewage samples from 48 wastewater treatment plants located in all the 20 regions of Italy. Broadly reactive primers targeting the ORF1 and ORF2 regions were used for the detection and typing of HEV, followed by Sanger and next generation sequencing (NGS). Real-time RT-qPCR was also used to attempt quantification of positive samples. HEV RNA detection occurred in 74 urban sewage samples (5.4%), with a statistically significant higher frequency (7.1%) in central Italy. Fifty-six samples were characterized as G3 strains and 18 as G1. While the detection of G3 strains occurred in all the surveillance period, G1 strains were mainly detected in 2011–2012, and never in 2017–2019. Typing was achieved in 2 samples (3f subtype). Viral concentrations in quantifiable samples ranged from 1.2 × 103 g.c./L to 2.8 × 104 g.c./L. Our results suggest the considerable circulation of the virus in the Italian population, despite a relatively small number of notified cases, a higher occurrence in central Italy, and a noteworthy predominance of G3 strains