Evaluation of chitosan salt properties in the production of AgNPs materials with antibacterial activity

In this study, water-soluble chitosan salts (chitosan amine sulfopropyl salts) were prepared from chitosan samples with different molecular weights and deacetylation degrees. These soluble-in-water polymer salts allowed us to produce, in an eco-friendly and facile method, silver nanoparticles (AgNPs) with better control on size and polydispersity, even at large silver concentrations than their corresponding chitosan sample. Chitosan salt-based materials (films and scaffolds) were analyzed in terms of antibacterial properties against Staphylococcus aureus ATCC23915 or Pseudomonas aeruginosa ATCC 27853. 3D scaffolds enhanced the effect of the chitosan-AgNPs combination compared to the equivalent films

SARS-CoV-2 Infection in San Patrignano, the Largest European Drug Rehabilitation Community

Background: Studies on SARS-CoV-2 conducted in confined settings for prolonged times allow researchers to assess how the coronavirus spreads. San Patrignano (SP), Italy, is the largest European drug rehabilitation facility. Methods: Between 15 October and 31 December 2020, all SP residents were tested for SARS-CoV-2. We analyzed the relationships between individual characteristics and being SARS-CoV-2-positive. Three selected predictive models were used to calculate the number of expected hospitalizations. For each model, we summed the estimated individual risks to obtain the expected number of hospitalizations in our sample, and we tested whether the observed and expected numbers differed. Results: Of 807 residents, 529 (65.6%) were SARS-CoV-2-positive. Of these 323 (61.1%) were symptomatic. A strong relationship was found between being positive and living connections (p-value < 0.001). No statistically significant relationship was found with age, sex, smoking history, or comorbidities. Although 9 to 17 hospitalizations were expected, no hospitalizations were observed (p-value < 0.001). No one died of COVID-19. Conclusions: The peculiar characteristics of SP residents or the SP environment might at least partially explain the null hospitalization rates. Despite the extreme uniqueness of our population and despite the protected environment and all precautions that were taken, the fact that the virus was able to circulate and infect a large portion of the population highlights the fundamental role of social interactions in the spread of the disease

Total list of the sessile taxa found, in systematic order by major taxa.

<p>Within major taxa, species or species groups are ordered alphabetically. Species are named according to the World Register of Marine Species (<a href="http://www.marinespecies.org/" target="_blank">www.marinespecies.org/</a>).</p

Change in reef community at Portofino, in the vicinity of sampling site J: a) <i>Sargassum vulgare</i> and <i>Dictyopteris polypodioides</i> canopy in 1981; b) <i>Sarpa salpa</i> grazing in a turf-dominated environment in 2009.

<p>Change in reef community at Portofino, in the vicinity of sampling site J: a) <i>Sargassum vulgare</i> and <i>Dictyopteris polypodioides</i> canopy in 1981; b) <i>Sarpa salpa</i> grazing in a turf-dominated environment in 2009.</p

Results of PERMANOVA analyses on individual taxa and three-dimensional categories.

<p>Bold numbers indicate significant results.</p

Cover of three dimensional categories for each sites in 1993 (white) and 2008 (grey).

<p><b>a</b>): high; <b>b</b>) medium-high; <b>c</b>) medium; <b>d</b>) medium-low; <b>e</b>) low. Note that scales on Y axis are different. The vertical dotted line separates the sampling sites within the MPA (black characters) from those outside (grey characters).</p