A complete diagnostic autopsy is the gold-standard to gain insight into Coronavirus disease 2019 (COVID-19) pathogenesis. To delineate the in situ immune responses to SARS-CoV-2 viral infection, here we perform comprehensive high-dimensional transcriptional and spatial immune profiling in 22 COVID-19 decedents from Wuhan, China. We find TIM-3-mediated and PD-1-mediated immunosuppression as a hallmark of severe COVID-19, particularly in men, with PD-1⁺ cells being proximal rather than distal to TIM-3⁺ cells. Concurrently, lymphocytes are distal, while activated myeloid cells are proximal, to SARS-CoV-2 viral antigens, consistent with prevalent SARS-CoV-2 infection of myeloid cells in multiple organs. Finally, viral load positively correlates with specific immunosuppression and dendritic cell markers. In summary, our data show that SARS-CoV-2 viral infection induces lymphocyte suppression yet myeloid activation in severe COVID-19, so these two cell types likely have distinct functions in severe COVID-19 disease progression, and should be targeted differently for therapy.

A transient-state numerical simulation is conducted to investigate the cavitation flow in the ball valve of a common rail (CR) injector. The computational fluid dynamics (CFD) software, employing the RANS turbulence model, is employed for this purpose. The study aims to analyze the characteristics and underlying causes of the uneven distribution of cavitation in the ball valve. The results reveal a significant occurrence of cavitation, exhibiting an uneven distribution along the walls of both the ball and the valve seat. Notably, the initiation position of the intense cavitation region on the wall of the ball is observed to lag behind that on the wall of the valve seat. The intense cavitation region on the wall of the ball is found to reside behind the sealing surface of the ball valve. The intense cavitation region on the wall of the ball is located behind the sealing surface of the ball valve. This region experiences flow separation caused by main flow detour, resulting in the formation of vortices that entrapped the cavitation cloud, thus fostering the development of intense cavitation. Conversely, the intense cavitation region on the wall of the valve seat originates from the entrance of the ball valve. This can be attributed to the sudden change in geometry at the entrance, leading to a significant pressure drop and inducing cavitation based on geometric factors. Furthermore, the stagnation effect caused by the ball exacerbates the discrepancy in the distribution of the intense cavitation region between the ball and the valve seat.