Effect of interchain separation on the photoinduced absorption spectra of polycarbazolyldiacetylenes

The photoinduced absorption spectra of a novel polycarbazolyldiacetylene with long aliphatic chains on the carbazolyl side groups are measured and compared with those of the unsubstituted polyDCHD. The two polymers in the blue form exhibit very similar electronic absorption spectra and Raman frequencies. This fact indicates that the conjugation length of the polydiacetylene backbone is not too affected by the long substituents. In contrast, the near steady-state photoinduced absorption spectra show that different photogeneration mechanisms are involved in the two polymers. This result can be ascribed to the role played by the interchain distance in the dynamics of the relaxation processes in polydiacetylenes

Choosing between Homologous or Heterologous COVID-19 Vaccination Regimens: A Cross-Sectional Study among the General Population in Italy

A shortage of COVID-19 vaccines and reports of side-effects led several countries to recommend a heterologous regimen for second vaccine doses. This study aimed to describe the reasons behind individuals’ choices of a homologous or a heterologous second vaccination. This cross-sectional study enrolled individuals under 60 who had received a first dose of Vaxzevria and could choose between a homologous or heterologous regimen for their second dose. Quantitative (socio-demographic, clinical characteristics) and qualitative data were collected and analysed through a generalized linear model and thematic analysis, respectively. Of the 1437 individuals included in the analysis, the majority (76.1%) chose a heterologous second dose of the COVID-19 vaccination. More females chose a heterologous vaccination regimen (p = 0.003). Younger individuals also tended to choose heterologous vaccination (p < 0.001). The main motivation in favour of heterologous vaccination was to follow the Italian Ministry of Health recommendations (n = 118; 53.9%). This study showed that most individuals, mainly younger people and females, chose a heterologous dose of COVID-19 vaccination after their first viral vector vaccine. Heterologous vaccinations could be an effective public health measure to control the pandemic as they are a safe and efficient alternative to homologous regimens

Long-lived photoexcited states in polydiacetylenes with different molecular and supramolecular organization

With the aim of determining the importance of the molecular and supramolecular organization on the excited states of polydiacetylenes, we have studied the photoinduced absorption spectra of the red form of poly[1,6-bis(3,6-didodecyl-N-carbazolyl)-2,4-hexadiyne] (polyDCHD-S) and the results compared with those of the blue form of the same polymer. An interpretation of the data is given in terms of both the conjugation length and the interbackbone separation also in relation to the photoinduced absorption spectra of both blue and red forms of poly[1,6-bis(N-carbazolyl)-2,4-hexadiyne] (polyDCHD), which does not carry the alkyl substituents on the carbazolyl side groups. Information on the above properties is derived from the analysis of the absorption and Raman spectra of this class of polydiacetylenes

Fitting Early Phases of the COVID-19 Outbreak: A Comparison of the Performances of Used Models

The COVID-19 outbreak involved a spread of prediction efforts, especially in the early pandemic phase. A better understanding of the epidemiological implications of the different models seems crucial for tailoring prevention policies. This study aims to explore the concordance and discrepancies in outbreak prediction produced by models implemented and used in the first wave of the epidemic. To evaluate the performance of the model, an analysis was carried out on Italian pandemic data from February 24, 2020. The epidemic models were fitted to data collected at 20, 30, 40, 50, 60, 70, 80, 90, and 98 days (the entire time series). At each time step, we made predictions until May 31, 2020. The Mean Absolute Error (MAE) and the Mean Absolute Percentage Error (MAPE) were calculated. The GAM model is the most suitable parameterization for predicting the number of new cases; exponential or Poisson models help predict the cumulative number of cases. When the goal is to predict the epidemic peak, GAM, ARIMA, or Bayesian models are preferable. However, the prediction of the pandemic peak could be made carefully during the early stages of the epidemic because the forecast is affected by high uncertainty and may very likely produce the wrong results