All-carbon THz components based on laser-treated diamond

We report on fs laser structuring and graphitization of diamond and experimental characterization of its THz response. A full characterization of graphitized, conductive layer generated by laser irradiation is carried out by performing scanning-electron microscopy, Raman spectroscopy and electrical measurements. The transmittance of the laser textured diamond samples, both with the graphitic overlayer and after selective oxidizing etching, is analyzed in the (0.25 ÷ 6.0) THz spectral range. A significant selective absorption of the graphitized overlayer towards polarized THz radiation is demonstrated, which is associated to the formation of graphitic laser induced periodic surface structures. This anisotropy allows conceiving compact passive metasurfaces based on conductive/dielectric patterns on the diamond plate surface for the development of robust, lightweight and broadband THz optical components

Prevalence and death rate of COVID-19 in systemic autoimmune diseases in the first three pandemic waves. Relationship to disease subgroups and ongoing therapies

Objective: Autoimmune systemic diseases (ASD) represent a predisposing condition to COVID-19. Our prospective, observational multicenter telephone survey study aimed to investigate the prevalence, prognostic factors, and outcomes of COVID-19 in Italian ASD patients. Method: The study included 3,918 ASD pts (815 M, 3103 F; mean age 59±12SD years) consecutively recruited between March 2020 and May 2021 at the 36 referral centers of COVID-19 & ASD Italian Study Group. The possible development of COVID-19 was recorded by means of a telephone survey using a standardized symptom assessment questionnaire. Results: ASD patients showed a significantly higher prevalence of COVID-19 (8.37% vs 6.49%; p<0.0001) but a death rate statistically comparable to the Italian general population (3.65% vs 2.95%). Among the 328 ASD patients developing COVID-19, 17% needed hospitalization, while mild-moderate manifestations were observed in 83% of cases. Moreover, 12/57 hospitalized patients died due to severe interstitial pneumonia and/or cardiovascular events; systemic sclerosis (SSc) patients showed a significantly higher COVID-19-related death rate compared to the general population (6.29% vs 2.95%; p=0.018). Major adverse prognostic factors to develop COVID-19 were: older age, male gender, SSc, pre-existing ASD-related interstitial lung involvement, and long-term steroid treatment. Of note, patients treated with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) showed a significantly lower prevalence of COVID-19 compared to those without (3.58% vs 46.99%; p=0.000), as well as the SSc patients treated with low dose aspirin (with 5.57% vs without 27.84%; p=0.000). Conclusion: During the first three pandemic waves, ASD patients showed a death rate comparable to the general population despite the significantly higher prevalence of COVID-19. A significantly increased COVID-19-related mortality was recorded in only SSc patients' subgroup, possibly favored by preexisting lung fibrosis. Moreover, ongoing long-term treatment with csDMARDs in ASD might usefully contribute to the generally positive outcomes of this frail patients' population