New autopsy technique in COVID-19 positive dead bodies: opening the thoracic cavity with an outlook to reduce aerosol spread.

AIMS: After the advent of the COVID-19 pandemic, most countries have modified some of their health-related regulations. However, this has not been in the case of the postmortem of deceased because it has a legal aspect. Thus, the healthcare providers knowingly or unknowingly faced the threat of COVID-19 exposure from those dead bodies. To introduce an autopsy technique that reduces the droplet spreads, especially in those mortuaries where the biosafety mechanism is not highly equipped. METHODS: The validity of the new incision was achieved through the calculation of the Scale Content Validity Index (SCVI) taking inputs from 17 forensic specialists. The subjects for the new technique were selected from the patients who were RTPCR positive for COVID-19 or clinically or radiologically showing features of COVID-19. RESULTS: The dissection procedure was finalised by achieving the SCVI at 0.92. The chest cavity was approached through the abdominal cavity by opening the diaphragm and dissecting out the contents of the chest using a long blade knife. CONCLUSIONS: The advantage of this approach is that the autopsy surgeon and pathologists do not have to open the chest cavity by dissecting the Sternum, and hence the chance of droplet infection becomes almost nil. This technique is complete, simple, less time-consuming and conducive for sample collection, and even reduces the possibility of body fluid seepage following a postmortem examination.

Tandem solar cells made from amorphous silicon and polymer bulk heterojunction sub-cells.

A tandem solar cell based on a combination of an amorphous silicon (a-Si) and polymer solar cell (PSC) is demonstrated. As these tandem devices can be readily fabricated by low-cost methods, they require only a minor increase in the total manufacturing cost. Therefore, a combination of a-Si and PSC provides a compelling solution to reduce the cost of electricity produced by photovoltaics.

Mechanism of polymer drag reduction using a low-dimensional model.

Using a retarded-motion expansion to describe the polymer stress, we derive a low-dimensional model to understand the effects of polymer elasticity on the self-sustaining process that maintains the coherent wavy streamwise vortical structures underlying wall-bounded turbulence. Our analysis shows that at small Weissenberg numbers, Wi, elasticity enhances the coherent structures. At higher Wi, however, polymer stresses suppress the streamwise vortices (rolls) by calming down the instability of the streaks that regenerates the rolls. We show that this behavior can be attributed to the nonmonotonic dependence of the biaxial extensional viscosity on Wi, and identify it as the key rheological property controlling drag reduction.