COVID-19 vaccines reduce the risk of SARS-CoV-2 reinfection and hospitalization: Meta-analysis

The addictive protection against SARS-CoV-2 reinfection conferred by vaccination, as compared to natural immunity alone, remains to be quantified. We thus carried out a meta-analysis to summarize the existing evidence on the association between SARS-CoV-2 vaccination and the risk of reinfection and disease. We searched MedLine, Scopus and preprint repositories up to July 31, 2022, to retrieve cohort or case-control studies comparing the risk of SARS-CoV-2 reinfection or severe/critical COVID-19 among vaccinated vs. unvaccinated subjects, recovered from a primary episode. Data were combined using a generic inverse-variance approach. Eighteen studies, enrolling 18,132,192 individuals, were included. As compared to the unvaccinated, vaccinated subjects showed a significantly lower likelihood of reinfection (summary Odds Ratio-OR: 0.47; 95% CI: 0.42-0.54). Notably, the results did not change up to 12 months of follow-up, by number of vaccine doses, in studies that adjusted for potential confounders, adopting different reinfection definitions, and with different predominant strains. Once reinfected, vaccinated subjects were also significantly less likely to develop a severe disease (OR: 0.45; 95% CI: 0.38-0.54). Although further studies on the long-term persistence of protection, under the challenge of the new circulating variants, are clearly needed, the present meta-analysis provides solid evidence of a stronger protection of hybrid vs. natural immunity, which may persist during Omicron waves and up to 12 months

Prognostic role of circulating tumor cell trajectories in metastatic colorectal cancer

Abstract: Background: A large amount of evidence from clinical studies has demonstrated that circulating tumor cells are strong predictors of outcomes in many cancers. However, the clinical significance of CTC enumeration in metastatic colorectal cancer is still questioned. The aim of this study was to evaluate the clinical value of CTC dynamics in mCRC patients receiving first-line treatments. Materials and methods: Serial CTC data from 218 patients were used to identify CTC trajectory patterns during the course of treatment. CTCs were evaluated at baseline, at a first-time point check and at the radiological progression of the disease. CTC dynamics were correlated with clinical endpoints. Results: Using a cut-off of ≥1 CTC/7.5 mL, four prognostic trajectories were outlined. The best prognosis was obtained for patients with no evidence of CTCs at any timepoints, with a significant difference compared to all other groups. Lower PFS and OS were recognized in group 4 (CTCs always positive) at 7 and 16 months, respectively. Conclusions: We confirmed the clinical value of CTC positivity, even with only one cell detected. CTC trajectories are better prognostic indicators than CTC enumeration at baseline. The reported prognostic groups might help to improve risk stratification, providing potential biomarkers to monitor first-line treatments

The other side of COVID-19. A cross-sectional study on mental health in a sample of Italian nurses during the second wave

Introduction: The COVID-19 pandemic has led to a drastic increase in the workload of healthcare professionals, particularly nurses, with serious consequences for their psychological well-being. Our study aimed to identify demographic and work-related factors, as well as clinical predictors of post-traumatic stress disorder (PTSD) and generalized anxiety disorder (GAD), in nurses employed during the COVID-19 pandemic. Methods: We carried out a cross-sectional study between December 2020 and April 2021 on nurses employed during the COVID-19 second wave (October - December 2020). We evaluated PTSD and GAD using two validated questionnaires: i) the Impact of Event Scale – Revised (IES-R); and ii) General Anxiety Disorder –7 (GAD-7). Results: Overall, 400 nurses, whose mean age was 34.3 years (SD ± 11.7), were included in the study. Most were female (78.5%), unmarried (58.5%) and employed in the central (61.5%) regions of Italy. A total of 56.8% of all participants had clinical predictors of PTSD, recording a median IES-R score (IQR) of 37.0 (22.0, 51.0) (range 1-84; cut-off >33 for PTSD). Furthermore, 50% of respondents reported moderate-to-severe symptoms consistent with GAD, recording a median GAD-7 score (IQR) of 9.5 (6.0,14.0) (range 0-21; cut-off >10 for GAD). Multivariable analysis showed that moderate-to-severe GAD (aOR = 4.54, 95% CI: 2.93 - 7.05), being employed in the critical care area (aOR = 1.74, 95% CI: 1.01 - 3.00) and being female (aOR= 1.88, 95% CI: 1.09 - 3.22) were significantly associated with the presence of clinical predictors of PTSD. Discussion: The levels of PTSD symptoms and anxiety among nurses were high during the pandemic. PTSD and GAD represent a public health problem that should be addressed in the post-pandemic period. Healthcare organizations need to activate specific support and rehabilitation networks and programs for healthcare professionals employed during the COVID-19 pandemic

Attitudes of university students towards mandatory COVID-19 vaccination policies. A cross-sectional survey in Rome, Italy

Mandatory vaccination (MV) against COVID-19 is a contentious topic. In this study, we used logistic regression models to identify attitudes among Sapienza University students towards MV for COVID-19. We considered three different scenarios: mandatory COVID-19 vaccination (MCV) for healthcare workers (HCWs) (Model 1), for all people aged ≥ 12 years (Model 2), and for admission to schools and universities (Model 3). We collected 5287 questionnaires over a six-month period and divided these into three groups (September-October 2021, November-December 2021, and January-February 2022). MCV for HCWs was the most strongly supported policy (69.8% in favour), followed by MCV for admission to schools and universities (58.3%), and MCV for the general population (54.6%). In a multivariable analysis, the models showed both similarities and differences. There was no association of socio-demographic characteristics with the outcomes, apart from being enrolled in non-healthcare courses, which negatively affected Models 2 and 3. A greater COVID-19 risk perception was generally associated with a more positive attitude towards MCV, although heterogeneously across models. Vaccination status was a predictor of being in favour of MCV for HCWs, whereas being surveyed in November-February 2022 favoured MCV for admission to schools and universities. Attitudes towards MCV were variable across policies; thus, to avoid unintended consequences, these aspects should be carefully considered by policymakers

Investigating the mechanism of action of DNA-loaded PEGylated lipid nanoparticles

PEGylated lipid nanoparticles (LNPs) are commonly used to deliver bioactive molecules, but the role of PEGylation in DNA-loaded LNP interactions at the cellular and subcellular levels remains poorly understood. In this study, we investigated the mechanism of action of DNA-loaded PEGylated LNPs using gene reporter technologies, dynamic light scattering (DLS), synchrotron small angle X-ray scattering (SAXS), and fluorescence confocal microscopy (FCS). We found that PEG has no significant impact on the size or nanostructure of DNA LNPs but reduces their zeta potential and interaction with anionic cell membranes. PEGylation increases the structural stability of LNPs and results in lower DNA unloading. FCS experiments revealed that PEGylated LNPs are internalized intact inside cells and largely shuttled to lysosomes, while unPEGylated LNPs undergo massive destabilization on the plasma membrane. These findings can inform the design, optimization, and validation of DNA-loaded LNPs for gene delivery and vaccine development

Genomic landscape and survival analysis of ctDNA “neo-RAS wild-type” patients with originally RAS mutant metastatic colorectal cancer

Background: The term “neo-RAS wild-type” refers to the switch to RAS wild-type disease in plasma circulating tumor DNA (ctDNA) from originally RAS mutant colorectal cancers. Consistently, the hypothesis to re-determine RAS mutational status in ctDNA at disease progression in RAS mutant mCRC opened to a new perspective for clinically-based selection of patients to be treated with EGFR inhibitors. Currently, the genomic landscape of “neo-RAS wild-type” is unknown. This is a prospective study aimed to investigate clinical and genomic features associated with RAS mutation clearance in a large cohort of RAS mutant mCRC patients who converted to RAS wild- type in liquid biopsy at failure of first-line treatments. Secondary aim was to investigate the long term prognostic significance of “true neo-RAS wild- type”. Patients and methods: 70 patients with stage IV RAS mutant colorectal cancer were prospectively enrolled. Plasma samples were collected at progression from first-line treatment. RAS/BRAF mutations in plasma were assessed by RT-PCR. In RAS/BRAF wild-type samples, ctDNA was used to generate libraries using a 17 genes panel whose alteration has clinical relevance. To investigate the prognostic significance of RAS mutation clearance, test curves for PFS and OS were represented by Kaplan-Meier estimator plot and Log-rank test. Results: The most commonly detected actionable mutations in “neo-RAS wild-type” were: PIK3CA (35.7%); RET (11.9%); IDH1 (9.5%); KIT (7%); EGFR (7%); MET (4.7%); ERBB2 (4.7%); FGFR3 (4.7%). Both OS and post-progression survival were longer in patients with “neo-RAS wild-type” compared to those who remained RAS mutant (p<0.001 for both). Conclusions: De-novo-targetable mutations occured in a large percentage of “neo-RAS wild-type”, being PIK3CA the most commonly detected. RAS mutation clearance in ctDNA is associated with long- term improvement of overall survival

Addressing the magnetic properties of sub-monolayers of single-molecule magnets by X-ray magnetic circular dichroism

We report on a comparative study of electronic and magnetic properties of Mn6 single-molecule magnets (SMMs) grafted on gold surface. Two derivatives with spin-ground states S ¼ 4 andhave been functionalized with 3-tp-CO2 (3-thiophene carboxylate, tpc) ligands and characterized thick films (TFs) as well as sub-monolayers (sMLs) by synchrotron based techniques. X-ray absorption spectroscopy at the Mn L2,3 edges shows the modification of the spectral lineshape in the sMLs respect to the TFs suggesting that the local symmetry at the Mn sites changes once the molecules deposited on gold surface. In spite of this, the expected MnIII oxidation state is preserved. X-ray magnetic circular dichroism (XMCD) spectra show that the total magnetic moment is only spin part because of the quenched orbital moment. Moreover, variable temperature and variable XMCD spectra reveal an effective decrease of the Mn spin moment for both derivatives

Tuning the electronic response of metallic graphene by potassium doping

: Electron doping of graphene has been extensively studied on graphene-supported surfaces, where the metallicity is influenced by the substrate. Herewith we propose potassium adsorption on free-standing nanoporous graphene, thus eluding any effect due to the substrate. We monitor the electron migration in the π* downward-shifted conduction band. In this rigid band shift, we correlate the spectral density of the π* state in the upper Dirac cone with the associated plasmon, blue-shifted with increasing K dose, as deduced by electron energy loss spectroscopy. These results are confirmed by the Dirac plasmon activated by the C 1s emitted electrons, thanks to spatially resolved photoemission. This crosscheck constitutes a reference on the correlation between the electronic π* states in the conduction band and the Dirac plasmon evolution upon in situ electron doping of fully free-standing graphene

Lateral Fusion of Chemical Vapor Deposited N = 5 Armchair Graphene Nanoribbons

Bottom-up synthesis of low-bandgap graphene nanoribbons with various widths is of great importance for their applications in electronic and optoelectronic devices. Here we demonstrate a synthesis of N = 5 armchair graphene nanoribbons (5-AGNRs) and their lateral fusion into wider AGNRs, by a chemical vapor deposition method. The efficient formation of 10- and 15-AGNRs is revealed by a combination of different spectroscopic methods, including Raman and UV-vis-near-infrared spectroscopy as well as by scanning tunneling microscopy. The degree of fusion and thus the optical and electronic properties of the resulting GNRs can be controlled by the annealing temperature, providing GNR films with optical absorptions up to 2250 nm

Antiferromagnetic coupling of TbPc2 molecules to ultrathin Ni and Co films

The magnetic and electronic properties of single-molecule magnets are studied by X-ray absorption spectroscopy and X-ray magnetic circular dichroism. We study the magnetic coupling of ultrathin Co and Ni films that are epitaxially grown onto a Cu(100) substrate, to an in situ deposited submonolayer of TbPc2 molecules. Because of the element specificity of the X-ray absorption spectroscopy we are able to individually determine the field dependence of the magnetization of the Tb ions and the Ni or Co film. On both substrates the TbPc2 moleculescouple antiferromagnetically to the ferromagnetic films, which is possibly due to a superexchange interaction via the phthalocyanine ligand that contacts the magnetic surface