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Artifacts causing erroneous reported centerpoint thickness are common. Identifying clues that indicate suboptimal quality of optical coherence tomography (OCT) images are important to avoid erroneous interpretation of OCT data in clinical trials.

Carbon fiber reinforced epoxy is the most commonly used carbon fiber composite with superior performance. However, the growing demand of carbon fibers reinforced epoxy results in a huge consumption of...

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Poor psychiatric status and sleep quality were common among frontline healthcare workers (FHWs) during the outbreak of the 2019 novel coronavirus disease (COVID-19), but the change in these mental health outcomes overtime remained unknown. This study compared the psychiatric status and sleep quality of FHWs during and after the COVID-19 outbreak in China. FHWs who volunteered to work in Hubei province (the COVID-19 epicenter) were assessed at baseline during the COVID-19 outbreak and re-assessed when they returned to their place of origin (Liaoning province) after the COVID-19 outbreak. Participants’ psychiatric status and sleep quality were measured with the Symptom CheckList-90 (SCL-90) and the Pittsburgh Sleep Quality Index (PSQI), respectively. A total of 494 FHWs was assessed at baseline and 462 at follow-up assessments. The prevalence of poor psychiatric status was 10.5% at baseline and increased to 14.9% at the follow-up assessment (P = 0.04). The corresponding figures of poor sleep quality at baseline and follow-up assessment were 16.4% and 27.9%, respectively (P < 0.001). Multiple logistic regression analysis found that severe fatigue (p = 0.003, OR = 1.266, 95% CI = 1.081–1.483), poor sleep quality (p < 0.001, OR = 1.283, 95% CI = 1.171–1.405), and history of pre-existing psychiatric disorders (p < 0.001, OR = 5.085, 95% CI = 2.144–12.06) were independently associated with higher odds of poor psychiatric status among the FHWs. Poor psychiatric status and sleep quality were common among FHWs during the COVID-19 outbreak, and the prevalence increased following their volunteer experiences. This suggests a critical need for longer-term psychological support for this subpopulation.

Supported nickel catalyst (Ni-Cat) was used as a catalyst to improve the flame retardancy of intumescent flame-retardants (IFR) systems based on ammonium polyphosphate and pentaerythritol (PETOL) in polypropylene (PP) matrix. Limited oxygen index (LOI), UL-94 rating, and thermogravimetric analysis were used to characterize the flame retardancy and thermal stability of the PP systems, and field emission scanning electron microscopy (FE-SEM) and Fourier transformed infrared spectroscopy (FTIR) were used to analyze the microstructure and composition of the chars formed during measuring LOI value and after combustion at 8008C. The catalytic effect of NiCat was shown in an increase of LOI, a change in the char microstructure, and improvement of the thermal stability in the PP systems, which result from the synergistic effect of Ni-Cat and IFR. The results from FE-SEM and FTIR spectra of the char can explain how this synergistic effect happened.