Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19 A Living Systematic Review of Multiple Streams of Evidence

Background: Mechanical ventilation is used to treat respiratory failure in coronavirus disease 2019 (COVID-19). Purpose: To review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19. (PROSPERO registration: CRD42020178187) Data Sources: 21 standard, World Health Organization–specific and COVID-19–specific databases, without language restrictions, until 1 May 2020. Study Selection: Studies of any design and language comparing different oxygenation approaches in patients with coronavirus infections, including severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), or with hypoxemic respiratory failure. Animal, mechanistic, laboratory, and preclinical evidence was gathered regarding aerosol dispersion of coronavirus. Studies evaluating risk for virus transmission to health care workers from aerosol-generating procedures (AGPs) were included. Data Extraction: Independent and duplicate screening, data abstraction, and risk of bias assessment (GRADE for certainty of evidence and AMSTAR 2 for included systematic reviews). Data Synthesis: 123 studies were eligible (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs. Limitation: Direct studies in COVID-19 are limited and poorly reported. Conclusion: Indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to health care workers

Wear protection of deep drawing tools by systematic optimization of highly stressed surfaces

The automotive sector is one of the largest energy consumers in Germany. Requests from politics and industry to significantly reduce emissions require new developments during utilization as well as during production phase. In line with the framework concept "InnoCaT", where more than 60 companies and research facilities from Germany take part, possibilities for producing companies are developed and analyzed to reduce the resource and energy consumption and by this reducing costs along the entire process chain of car body manufacturing. One approach to design car bodies lighter and more efficiently is to use aluminium and high strength steels. By this means weight and sheet thickness are reduced. However higher strengths of the steels and the adhesion affinity of aluminium significantly increase the requirements regarding the used tool steel. Thus grooves or galling appear more frequent at highly stressed surfaces. To assure high lifetimes and by this increase especially the resource efficiency concerning use of material and setting-up times within the press plant, a local optimization at the highly stressed surfaces is necessary. For this a FEM/BEM-tool for a time efficient and exact calculation of the occurring tool loads for complex die profiles is developed. Based on this development of load calculation a shape-optimization is performed at the corresponding areas. After the geometric optimization of the tool a local laser surface treatment for further wear protection is carried out using laser cladding or laser alloying/ -dispersing. By combining the technologies a highly wear resistant surface is achievable, which increases the tool's lifetime as well as the reproducibility within production