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The Bayesian framework of CO2 flux inversions permits estimates of the retrieved flux uncertainties. Here, the reliability of these theoretical estimates is studied through a comparison against the misfits between the inverted fluxes and independent measurements of the CO2 Net Ecosystem Exchange (NEE) made by the eddy covariance technique at local (few hectares) scale. Regional inversions at 0.5° resolution are applied for the western European domain where ~ 50 eddy covariance sites are operated. These inversions are conducted for the period 2002–2007. They use a mesoscale atmospheric transport model, a prior estimate of the NEE from a terrestrial ecosystem model and rely on the variational assimilation of in situ continuous measurements of CO2 atmospheric mole fractions. Averaged over monthly periods and over the whole domain, the misfits are in good agreement with the theoretical uncertainties for prior and inverted NEE, and pass the chi-square test for the variance at the 30% and 5% significance levels respectively, despite the scale mismatch and the independence between the prior (respectively inverted) NEE and the flux measurements. The theoretical uncertainty reduction for the monthly NEE at the measurement sites is 53% while the inversion decreases the standard deviation of the misfits by 38%. These results build confidence in the NEE estimates at the European/monthly scales and in their theoretical uncertainty from the regional inverse modelling system. However, the uncertainties at the monthly (respectively annual) scale remain larger than the amplitude of the inter-annual variability of monthly (respectively annual) fluxes, so that this study does not engender confidence in the inter-annual variations. The uncertainties at the monthly scale are significantly smaller than the seasonal variations. The seasonal cycle of the inverted fluxes is thus reliable. In particular, the CO2 sink period over the European continent likely ends later than represented by the prior ecosystem model.

Background: Venous Access Devices (VADs) are the most used devices in COVID-19 patients. Objective: Identify VADs implanted, catheter related thrombosis (CRT), catheter-related bloodstream infection (CRBSI), and accidental remove of VADs in both COVID-19 positive and COVID-19 free patients. Successive analysis was conducted comparing COVID-19 positive patients with COVID-19 free with inverse probability propensity score weights using simple regression to account for these two confounders (peripheral tip as central/peripheral and hospitalization as no/yes). Methods: This multicenter, retrospective cohort study collected data from seven hospitals in Lombardy during the pandemic period from February 21st to May 31st 2020. Results: A total of 2206 VADs were evaluated, 1107 (50.2%) of which were inserted in COVID-19 patients. In COVID-19 cohort the first choice was Long Peripheral Cannula in 388 patients (35.1%) followed by Midline Catheter in 385 (34.8%). The number of “central tip” VADs inserted in COVID-free inpatients and COVID-19 positive were similar (307 vs 334). We recorded 42 (1.9%) CRT; 32 (79.2%) were observed in COVID-19 patients. A total of 19 CRBSI were diagnosed; 15 (78.95%) were observed in COVID-19. Accidental removals were the more represented complication with 123 cases, 85 (69.1%) of them were in COVID-19. COVID-19 significantly predicted occurrence of CRT (OR = 2.00(1.85–5.03); p Conclusions: CRT, CRBSI, and accidental removal are significantly more frequent in COVID-19 patients. Accidental removals are the principal complication, for this reason, the use of subcutaneously anchored securement is recommended for a shorter period than usual.

We investigated the temperature dependence of the amplified spontaneous emission (ASE) of the $\ensuremath{\beta}$ phase of poly(9,9-dioctylfluorene). We show that the ASE threshold increases with temperature of about 1 order of magnitude from $17\text{ }\ensuremath{\mu}\text{J}\text{ }{\text{cm}}^{\ensuremath{-}2}$ at 5 K to $206\text{ }\ensuremath{\mu}\text{J}\text{ }{\text{cm}}^{\ensuremath{-}2}$ at 300 K due to the thermal activation of uphill energy migration to nonradiative centers that reduces the population inversion for a given excitation density. The temperature increase also changes the luminescence line-shape switching on (around 100 K) the ASE from the C-C interunit stretch vibronic replica at the expense of the phenyl-ring quadrant stretch one.

We investigated the amplified spontaneous emission (ASE) properties of the β-phase of poly(9,9-dioctylfluorene) at T = 5 K. We observe ASE at about 478 nm with a threshold as low as 50 μJ cm−2. For excitation density higher than 350 μJ cm−2 a clear spectral rebroadening and a progressive ASE intensity saturation, ascribed to gain saturation, are observed. The gain saturation at 478 nm leads to ASE from the 470 nm vibronic band, with a threshold of about 3.0 mJ cm−2. We show that these effects are due to the break down, at high excitation density, of the four level amplifier scheme, typically applied to conjugated polymer films.