Virological surveillance of SARS-CoV-2 in an Italian northern area: Comparison of real time RT PCR cycle threshold (CT) values in three epidemic periods

Aim of the study was to investigate the differences in Ct values in nasopharingeal swabs collected in three SARS-CoV-2 epidemic periods: first one from February 23 to March 25 (14 days from lockdown started on March 11); the second one from March 26 to May 18 (14 days from the end of strict lockdown on May 4) and the third one from May 19 until June 15. Viral RNA was detected in nasopharyngeal swabs obtained both from inpatients and outpatients. COVID-19 infection was confirmed according to the Ct values for N1 and N2 genes ascertained by Real-Time RT-PCR assay as described by the CDC. We calculated the prevalence of nasopharyngeal swabs tested positive for SARS-CoV-2, the mean and median of the Cts and the percentage of samples equal or below the Ct value of 25 in the 3 periods considered. The average value of Ct increased, going from 24.80 in the first epidemic period to 26.64 in the second period to 28.50 in the third period (p <0.001). The percentage of samples with Ct lower than or equal to 25 also decreased sharply from 54.7% to 20.0%. These findings need to be integrated with epidemiological and clinical data. (www.actabiomedica.it)

Can sport and face masks get along?

The sports world has certainly been one of the most affected by the SARS-CoV-2 pandemic. In addition to the closure of clubs and gyms, the introduction of personal protective equipment and face masks has raised many doubts about the safety of their use during physical activity. This is due to the possible onset of symptoms related to the physical barrier standing in front of the airways, resulting in greater resistance to airways flow and a bigger respiratory work. The aim of this article was to analyze the data available so far in the literature to try to answer the question: Can sport and masks get along

Neutrons propagation in Lead: a feasibility study for experiments in the RSV TAPIRO fast research reactor

The increasing worldwide interest in Lead-cooled Fast Reactors (LFRs) substantiates the need to validate the analytical codes and methods used to support their design. For neutronic analyses, this is chiefly reflected in assessing the impact of nuclear data uncertainties on the integral and local parameters resulting from such analyses. Besides this driving interest, the aim of refining nuclear data moves continuous efforts for more accurate measurements, be them differential or integral, for which adequate facilities are required. A preliminary attempt at adjusting the ENDF/B-VIII.0 neutron data libraries for application to ALFRED – the demonstration reactor of future European LFRs – provided clear indications on the need to refine the cross-sections of Lead isotopes, and particularly of the elastic and inelastic ones at high energies. However, experiments dealing specifically with Lead's neutronics are not frequent in literature and even scarce in international databases establishing benchmark cases for the validation of neutronic codes or the adjustment of nuclear data libraries. Therefore, the availability at the ENEA's Casaccia research center of a fast source reactor – RSV TAPIRO – provides a unique opportunity to perform new integral experiments in support of fast reactors, including LFRs, owing to the well-characterized neutron spectrum of the thermal column, a spacious experimental slot within the biological shield of the reactor in the proximity of its external Copper reflector. Accordingly, a series of experiments – which could be recognized as benchmarks of international value – has been envisaged, dealing with the use of Lead in a reactor. The experiments concern the propagation of neutrons through blocks of materials representing relevant elements of a reactor core, and ranging from pure Lead to mixtures reproducing portions of the reflector and shield in LFRs. The paper is focused on the feasibility study of some of these experiments in which Lead and mixture blocks are inserted in the so-called thermal column of the RSV TAPIRO reactor and irradiated by the neutron flux emerging from the Copper reflector surrounding the reactor core. Despite the name of the experimental opening, the spectrum of the incident flux is relative hard, owing to the almost-pure fission spectrum in the core. The scope of the feasibility study includes the conceptual design of the blocks, moving from representative studies with target LFRs. An in-depth investigation was also performed concerning the required instrumentation: appropriate neutron detectors and threshold activation foils were selected aiming at characterizing the assembly's neutron flux intensity and energy spectrum, so that the measured reaction rates and spectral indexes could be used to assess the impact of nuclear data on these parameters, retrieving information for ad-hoc adjustments applied to LFRs

Passive air sampling: The use of the index of microbial air contamination

Background: Bioaerosol plays an important role in human life with potentially infectious, allergic and toxic effects. Active and passive methods can be used to assess microbial air contamination, but so far there is not a unanimous consensus regarding the indications about methods to be used and how to interpret the results. The passive method has been standardized by the Index of Microbial Air contamination (IMA). Classes of contamination and maximum acceptable levels of IMA have been proposed, related to different infection or contamination risks. The aim of this study was to provide information about the use of the passive sampling method, with reference to the IMA standard. Methods: We searched PubMed and Scopus for articles published until January 2020 reporting the citation of the article by Pasquarella et al. “The index of microbial air contamination. J Hosp Infect 2000". Only studies in English language where the IMA standard was applied were considered. Studies regarding healthcare settings were excluded. Results: 27 studies were analyzed; 12 were performed in Europe, 8 in Asia, 5 in Africa, 2 in America. Cultural heritage sites, educational buildings and food industries were the most common indoor monitored environments; in 8 studies outdoor air was monitored. Conclusions: This review has provided a picture of the application of standard IMA in different geographic areas and different environments at risk of airborne infection/contamination. The analysis of the results obtained, together with a wider collection of data, will provide a useful contribution towards the definition of reference limits for the various types of environments to implement targeted preventive measures