Raman Scattering as a Selective Probe of Chiral Electronic Excitations in Bilayer Graphene

We report a symmetry resolved electronic Raman scattering (ERS) study of a bilayer graphene device under gate voltage. We show that the ERS continuum is dominated by interband chiral excitations of $A_{2}$ symmetry and displays a characteristic Pauli-blocking behavior similar to the monolayer case. Crucially, we show that non-chiral excitations make a vanishing contribution to the Raman cross-section due to destructive interference effects in the Raman amplitude matrix elements. This is in a marked contrast to optical absorption measurements and opens interesting venues for the use of Raman scattering as a selective probe of chiral degrees of freedom in topological matter and other 2D crystals

ZnO Nanostructured Thin Films via Supersonic Plasma Jet Deposition

Zinc Oxide nanostructured thin films were grown by a novel plasma assisted vapour deposition method, which aims to combine the versatility of deposition processes that are mediated by plasma with the capability to control particles diffusion and nucleation. For this purpose, the proposed approach spatially separates into two different vacuum chambers the creation of zinc oxide from a metalorganic precursor from the actual film growth, thanks to the extraction of a supersonic jet of plasma seeded by the precursor fragments. The characterization of the reactor in different plasma conditions has been carried out by means of optical emission spectroscopy (OES). ZnO films with different degrees of purity, thickness uniformity, as well as different morphologies can be obtained varying the deposition parameters. The samples profiles have been collected in order to evaluate deposition rates and films uniformity. The as-prepared as well as annealed thin films were characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to evaluate their chemical composition and purity. According to Raman analyses, the annealed samples are high-purity wurtzite-type crystalline zinc oxide films. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirm a surface morphology characterized by columnar structures

Toxic organic contaminants in airborne particles: levels, potential sources and risk assessment

In the last years, many studies have focused on risk assessment of exposure of workers to airborne particulate matter (PM). Several studies indicate a strong correlation between PM and adverse health outcomes, as a function of particle size. In the last years, the study of atmospheric particulate matter has focused more on particles less than 10 m or 2.5 m in diameter; however, recent studies identify in particles less than 0.1 m the main responsibility for negative cardiovascular effects. The present paper deals with the determination of 66 organic compounds belonging to six different classes of persistent organic pollutants (POPs) in the ultrafine, fine and coarse fractions of PM (PM < 0.1 m; 0.1 < PM < 2.5 mand 2.5 < PM < 10 m) collected in three outdoor workplaces and in an urban outdoor area. Data obtained were analyzed with principal component analysis (PCA), in order to underline possible correlation between sites and classes of pollutants and characteristic emission sources. Emission source studies are, in fact, a valuable tool for both identifying the type of emission source and estimating the strength of each contamination source, as useful indicator of environment healthiness. Moreover, both carcinogenic and non-carcinogenic risks were determined in order to estimate human health risk associated to study sites. Risk analysis was carried out evaluating the contribution of pollutant distribution in PM size fractions for all the sites. The results highlighted significant differences between the sites and specific sources of pollutants related to work activities were identified. In all the sites and for all the size fractions of PM both carcinogenic and non-carcinogenic risk values were below acceptable and safe levels of risks recommended by the regulatory agencies

Development of a repressible mycobacterial promoter system based on two transcriptional repressors

Tightly regulated gene expression systems represent invaluable tools for studying gene function and for the validation of drug targets in bacteria. While several regulated bacterial promoters have been characterized, few of them have been successfully used in mycobacteria. In this article we describe the development of a novel repressible promoter system effective in both fast- and slow-growing mycobacteria based on two chromosomally encoded repressors, dependent on tetracycline (TetR) and pristinamycin (Pip), respectively. This uniqueness results in high versatility and stringency. Using this method we were able to obtain an ftsZ conditional mutant in Mycobacterium smegmatis and a fadD32 conditional mutant in Mycobacterium tuberculosis, confirming their essentiality for bacterial growth in vitro. This repressible promoter system could also be exploited to regulate gene expression during M. tuberculosis intracellular growt

Development of a repressible mycobacterial promoter system based on two transcriptional repressors

Tightly regulated gene expression systems represent invaluable tools for studying gene function and for the validation of drug targets in bacteria. While several regulated bacterial promoters have been characterized, few of them have been successfully used in mycobacteria. In this article we describe the development of a novel repressible promoter system effective in both fast- and slow-growing mycobacteria based on two chromosomally encoded repressors, dependent on tetracycline (TetR) and pristinamycin (Pip), respectively. This uniqueness results in high versatility and stringency. Using this method we were able to obtain an ftsZ conditional mutant in Mycobacterium smegmatis and a fadD32 conditional mutant in Mycobacterium tuberculosis, confirming their essentiality for bacterial growth in vitro. This repressible promoter system could also be exploited to regulate gene expression during M. tuberculosis intracellular growth

Determination of the main bioaerosol components using chemical markers by liquid chromatography–tandem mass spectrometry

This work is part of an extensive research project aimed at the determination and characterization of bioaerosol with a multidisciplinary approach. In this context, one of the main objectives of the project has been the development of a comprehensive analytical method for the determination of different chemical biomarkers of the bioaerosol, by liquid chromatography coupled with tandem mass spectrometry. The following biomarkers have been considered, and correlated to specific components of bioaerosol as unambiguous indicators: • ergosterol fungal components • chlorophylls, phytosterols (stigmasterol and b-sitosterol), -tocoferol vegetable cells and algae • cholesterol animal cells, vegetable cells and algae. • dipicolinic acid bacterial spores • muramic and meso-2,6-diaminopimelic acid bacterial cells To verify the method, to find diagnostic ratios and to calculate the appropriate conversion factors, fungal spores, bacterial cells and spores, and algae of known species, commonly airborne, were analysed. The material was subjected to freezing and de-freezing cycles, followed by extraction, hydrolysis and purification of the biomarkers. The chromatographic separation of the bacterial biomarkers was achieved by using a polymeric column, based on Hydrophilic Liquid Interaction with the electrospray ionization mass spectrometric detection, whereas sterols and chlorophylls were separated by a reversed phase column, coupled to atmospheric pressure chemical ionization – tandem mass spectrometer. The optimized method was applied to environmental particulate matter sampled in an outdoor site. Bacterial and fungal content was compared to the results obtained from the classical direct viable counting method in the sampled particulate matte

Chip-Scalable, Room-Temperature, Zero-Bias, Graphene-Based Terahertz Detectors with Nanosecond Response Time.

The scalable synthesis and transfer of large-area graphene underpins the development of nanoscale photonic devices ideal for new applications in a variety of fields, ranging from biotechnology, to wearable sensors for healthcare and motion detection, to quantum transport, communications, and metrology. We report room-temperature zero-bias thermoelectric photodetectors, based on single- and polycrystal graphene grown by chemical vapor deposition (CVD), tunable over the whole terahertz range (0.1-10 THz) by selecting the resonance of an on-chip patterned nanoantenna. Efficient light detection with noise equivalent powers <1 nWHz-1/2 and response time ∼5 ns at room temperature are demonstrated. This combination of specifications is orders of magnitude better than any previous CVD graphene photoreceiver operating in the sub-THz and THz range. These state-of-the-art performances and the possibility of upscaling to multipixel architectures on complementary metal-oxide-semiconductor platforms are the starting points for the realization of cost-effective THz cameras in a frequency range still not covered by commercially available microbolometer arrays

Toxic organic contaminants in airborne particles responsible for negative health effects

Several studies in literature have highlighted associations between airborne particulate matter and several adverse health outcomes, as a function of particle size. Traditionally, PM studies have focused on particles less than 10 μm in diameter (PM10) or particles less than 2.5 μm in diameter (PM2.5), with each fraction characterized by a distinct source, and different composition and health effects. Since, diffusion in the alveolar region of smaller particles with an aerodynamic diameter less than 0.1 μm (i.e. 100 nm and therefore also defined as nanoparticles) becomes an effective mechanism and the probability of deposition increases. There is a great debate whether ultrafine fraction (PM0.1) is mainly responsible for negative cardiovascular effects caused by its high oxidative and mutagenic potential. In the present study, size-fractionated airborne particulate matter was collected from outdoor urban and working environments and analyzed for 105 organic contaminants of different classes: polycyclic aromatic hydrocarbons (PAH) and their derivatives (nitro-PAH and oxy-PAH); polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and Novel Brominated flame-retardants (N-BFRs) selected for their toxicity and persistence in the environment. The selected organic contaminants were subsequently divided into three different macro-groups based on chemical and physical properties (PAH/N-PAH/O-PAH; PCB and PBDE/N-BFR) and subjected to statistical analysis. The monitoring campaigns were carried out in four sites: an urban atmosphere (RM), a wastewater treatment plant (WWTP) where aerosol is generated during the different phases of the processes, an intensive livestock farming activity, characterized by sheds serving as a shelter for cows (COW) and an area where feed is stored (FEED). In each monitoring campaign PM was collected with a multistage low-pressure impactor able to sample 14 size intervals of PM on as many filters, subsequently joined to form three dimensional fractions (coarse, fine and ultrafine). The results obtained from the organic contaminant analyses and from the Principal Component Analysis (PCA) showed a correlation between sites and classes of pollutants, allowing the identification of characteristic emission sources of each monitored site. Emission source studies are in fact a valuable tool for both identifying the type of emission source characteristic of a specific place and estimating the strength of each contamination source in the same place of interest

Prognosis and Interplay of Cognitive Impairment and Sarcopenia in Older Adults Discharged from Acute Care Hospitals

Sarcopenia and cognitive impairment are associated with an increased risk of negative outcomes, but their prognostic interplay has not been investigated so far. We aimed to investigate the prognostic interaction of sarcopenia and cognitive impairment concerning 12-month mortality among older patients discharged from acute care wards in Italy. Our series consisted of 624 patients (age = 80.1 ± 7.0 years, 56.1% women) enrolled in a prospective observational study. Sarcopenia was defined following the European Working Group on Sarcopenia in Older People (EWGSOP) criteria. Cognitive impairment was defined as age- and education-adjusted Mini-Mental State Examination (MMSE) score &lt; 24 or recorded diagnosis of dementia. The study outcome was all-cause mortality during 12-month follow-up. The combination of sarcopenia and cognitive ability was tested against participants with intact cognitive ability and without sarcopenia. Overall, 159 patients (25.5%) were identified as having sarcopenia, and 323 (51.8%) were cognitively impaired. During the follow-up, 79 patients (12.7%) died. After adjusting for potential confounders, the combination of sarcopenia and cognitive impairment has been found associated with increased mortality (HR = 2.12, 95% CI = 1.05-4.13). Such association was also confirmed after excluding patients with dementia (HR = 2.13, 95% CI = 1.06-4.17), underweight (HR = 2.18, 95% CI = 1.03-3.91), high comorbidity burden (HR = 2.63, 95% CI = 1.09-6.32), and severe disability (HR = 2.88, 95% CI = 1.10-5.73). The co-occurrence of sarcopenia and cognitive impairment may predict 1-year mortality in older patients discharged from acute care hospitals

Cervical cancer elimination in Italy: Current scenario and future endeavors for a value based prevention

BackgroundCervical Cancer (CC) is a vaccine-preventable disease, and it is treatable if diagnosed early and managed properly. However, it is the fourth most common cancer in women worldwide with about 604,127 cases and 341,831 deaths in 2020. In Italy, it represents the fifth most common cancer in women under 50 years of age with about 2,400 new cases in 2020. The CC elimination is today a global public health goal published by the World Health Organization (WHO) in 2020 and a commitment of the European Union that has included it in Europe's Beating Cancer Plan. Therefore, urgent action is needed, at international and national level, to implement value-based interventions regarding vaccination, screening and timely management of the disease. Our study aims to describe the state of the art of Human Papilloma Virus (HPV) prevention in Italy and to get a consensus on indicators for monitoring the progress toward CC elimination at national level. MethodsThe study envisaged the following activities: research and synthesis of the evidence on strategies and actions for CC elimination at regional Italian level; identification of indicators to monitor such strategies/actions; organization of a multi-stakeholder consensus to reach the agreement on main indicators to be used in Italy. ResultsAs for HPV vaccination coverage, the last Italian available data (December 31st, 2020) showed that it was way below the target (95%) with full cycle vaccination coverage ranging from 6 to 61.7% in female adolescents and from 5.4 to 55.4% in male adolescents (2008 birth cohorts). The coverage rate of CC screening is variable with a range of 61.7-89.6%. Furthermore, coverage rates due to organized screening programs (excluding out-of-pocket screening) shows a range from 20.7 to 71.8%. The mapping of the Italian Regions highlighted an important regional heterogeneity in respect to organizational/operational issue of HPV vaccination and CC screening. Indicators for monitoring CC elimination strategies have been drawn from the Australian experience and distinguished by disease outcomes, vaccination coverage, screening participation and treatment uptake. The highest consensus was reached for the following indicators: CC incidence; detection of high-grade cervical disease; CC mortality; full cycle vaccination coverage; screening participation; high-grade cervical disease treatment rates; CC treatment rates. ConclusionsThe assessment of the current status of CC elimination as overarching goal beyond the achievement of vaccine, screening and treatment targets represents the first step for the identification of interventions to be implemented to accelerate the path toward CC elimination. Based on this and following the WHO call, a value-based approach is proposed to untangle the full benefit of HPV-related cancers elimination strategies and identify priority and best practices