A comparative study of the effects of graphite, wollastonite, and titanium dioxide fillers on the properties of starch-based biodegradable plastic film.

This research paper aims to explore the effect of graphite, wollastonite, and titanium dioxide as reinforcing fillers on starch-based biodegradable plastic (SBP) films. GF-SBP (graphite filler containing SBP), WF-SBP (wollastonite containing SBP), and TF-SBP (titanium dioxide containing SBP) films were developed and analyzed for various properties such as thickness, density, tensile strength, elongation break, morphology, thermal stability, solubility, moisture content, moisture absorbance, biodegradability, and antibacterial activity. The results reveal that WF-SBP films had the highest tensile strength of 5.43 MPa and greatest elongation break value of 22% as compared to other films. Thermogravimetric analysis showed that SBP films with and without filler degraded slowly between 150 and 600°C. The highest thermal stability was recorded for TF-SBP films which showed stability (11% mass loss) up to 150°C. The biodegradability test conducted using soil burial method suggested that TF-SBP film degraded within 90 days, GF-SBP films degraded completely in 120 days, and WF-SBP films took more than 120 days to degrade. The synthesized SBP films were analyzed for their antibacterial potential against gram-positive and gram-negative bacteria, and results showed that WF-SBP film exhibited the best antibacterial activity by producing a large zone of inhibition against Escherichia coli.

Spontaneous pneumomediastinum and subcutaneous emphysema in patients with COVID-19.

BACKGROUND: Coronavirus disease 2019 is an infectious disease caused by severe acute respiratory syndrome virus coronavirus 2 (SARS-COV-2). Many aspects of its pathology and pathogenesis are not well understood. MATERIAL AND METHODS: We describe a series of spontaneous air leak cases we found in our coronavirus disease 2019 (COVID-19) positive 1086-patient cohort. RESULTS: Two out of six patients eventually required mechanical ventilation and succumbed to COVID-19. We presume that acute lung injury leading to SARS-CoV-2 with associated acute respiratory distress syndrome predisposes patients to this complication. CONCLUSION: This series is presented to highlight the emerging association of COVID-19 with spontaneous air leaks leading to pneumomediastinum, pneumothorax, and subsequent subcutaneous emphysema even in patients who have never received invasive mechanical ventilation and this may be more likely with the institution of high flow nasal cannula.