A Study on the Flame-Retardant Performance of Recycled Paper Building Materials Manufactured by 3D Printer

The increase in non-face-to-face lifestyles due to COVID-19 worldwide have shown an increase in delivery services. The number of parcels in 2020 was 3.373 billion, an increase of 20.9% from 2.788 billion in 2019. This phenomenon increased delivery box waste. Against this background, this study attempted to develop building materials from the recycling of delivery boxes. In this study, the self-developed WC (wet cellulose) 3D printer confirmed the standardization and uniform performance of the sample by filling the material supply cylinder with cellulose filaments and spraying the composite material through a 10 mm nozzle. The cellulose filament for a WC 3D printer is based on cellulose extracted from wastepaper, and a cellulose filament composite material is used by mixing additives. After manufacturing a specimen using the WC 3D printer, a reliability test for the flame-retardant performance of the material was conducted according to the ISO 11925-2 test method. As a result of the experiment, flame-retardant performance was confirmed at a 40 wt% or greater ceramic binder content. In addition, the WC 3D printer achieved accurate test results by producing specimens with uniform physical properties. In addition, we confirmed that 3D-printed WC can be used to develop customized building materials that can prevent fire spread.

No Change of Pneumocystis jirovecii Pneumonia after the COVID-19 Pandemic: Multicenter Time-Series Analyses.

Consolidated infection control measures imposed by the government and hospitals during COVID-19 pandemic resulted in a sharp decline of respiratory viruses. Based on the issue of whether Pneumocystis jirovecii could be transmitted by airborne and acquired from the environment, we assessed changes in P. jirovecii pneumonia (PCP) cases in a hospital setting before and after COVID-19. We retrospectively collected data of PCP-confirmed inpatients aged ≥18 years (N = 2922) in four university-affiliated hospitals between January 2015 and June 2021. The index and intervention dates were defined as the first time of P. jirovecii diagnosis and January 2020, respectively. We predicted PCP cases for post-COVID-19 and obtained the difference (residuals) between forecasted and observed cases using the autoregressive integrated moving average (ARIMA) and the Bayesian structural time-series (BSTS) models. Overall, the average of observed PCP cases per month in each year were 36.1 and 47.3 for pre- and post-COVID-19, respectively. The estimate for residuals in the ARIMA model was not significantly different in the total PCP-confirmed inpatients (7.4%, p = 0.765). The forecasted PCP cases by the BSTS model were not significantly different from the observed cases in the post-COVID-19 (-0.6%, 95% credible interval; -9.6~9.1%, p = 0.450). The unprecedented strict non-pharmacological interventions did not affect PCP cases.

Protection of Medical Staff during Tracheotomy: Lessons Learned from the COVID-19 Pandemic.

BACKGROUND: During the ongoing pandemic of COVID-19, tracheotomy under emergency situation is considered a high-risk procedure that causes probable expose to aerosolized secretion. SUMMARY: We reviewed our case and previous reports, and summarized a detailed protocol that is needed to protect medical staffs who perform tracheotomy under the COVID-19 pandemic, considering the patient's condition, experience of medical staff members, and available facilities and equipment. Key Messages: For efficient protection of medical staff who perform tracheotomy under the COVID-19 pandemic period, we suggest that the following needs to be considered: assessment of patient's condition (COVID-19 infection and the airway problem), route (safest route to the operating room), experienced surgical team, negative-pressure isolation facility and appliance (personal protective equipment) availability, and safe and appropriate post-tracheotomy care.

Emergent procedures for oropharyngeal bleeding during the COVID-19 pandemic: Protection of medical staff.

During an ongoing pandemic of COVID-19, controlling the oropharyngeal bleeding, such as post-tonsillectomy hemorrhage, with cauterization is considered a very vulnerable procedure for medical staff because of high probability of exposure to aerosolized secretion. The authors aimed to introduce an appropriate treatment protocol for oropharyngeal bleeding that provides first aid to patients while protecting medical staff at high-risk of infection such as COVID-19.