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BackgroundExtracellular vesicles (EVs) are regulators of cell-cell interactions and mediators of horizontal transfer of bioactive molecules between cells. EV-mediated cell-cell interactions play roles in physiological and pathophysiological processes, which maybe modulated by exposure to pathogens and cocaine use. However, the effect of pathogens and cocaine use on EV composition and function are not fully understood.ResultsHere, we used systems biology and multi-omics analysis to show that HIV infection (HIV +) and cocaine (COC) use (COC +) promote the release of semen-derived EVs (SEV) with dysregulated extracellular proteome (exProtein), miRNAome (exmiR), and exmiR networks. Integrating SEV proteome and miRNAome revealed a significant decrease in the enrichment of disease-associated, brain-enriched, and HIV-associated miR-128-3p (miR-128) in HIV + COC + SEV with a concomitant increase in miR-128 targets-PEAK1 and RND3/RhoE. Using two-dimensional-substrate single cell haptotaxis, we observed that in the presence of HIV + COC + SEV, contact guidance provided by the extracellular matrix (ECM, collagen type 1) network facilitated far-ranging haptotactic cues that guided monocytes over longer distances. Functionalizing SEV with a miR-128 mimic revealed that the strategic changes in monocyte haptotaxis are in large part the result of SEV-associated miR-128.ConclusionsWe propose that compositionally and functionally distinct HIV + COC + and HIV-COC- SEVs and their exmiR networks may provide cells relevant but divergent haptotactic guidance in the absence of chemotactic cues, under both physiological and pathophysiological conditions.

To implement standardized protective measures and to evaluate the safety and effectiveness of peripherally inserted central venous catheter (PICC) for severely and critically ill patients with COVID-19 in the isolation ward. PICC catheterization was performed to 9 patients who were diagnosed with COVID-19 and treated in the isolation ward. These patients were all given standardized protective measures during the PICC operation. The one-time success rate of catheterization was 100. 00%. There was no postoperative complications such as infection, bleeding, phlebitis, thrombosis, and no nosocomial infection occurred. The implementation of PICC catheterization in severely and critically ill patients in the isolation ward is safe and effective, and standardized protection in catheterization can effectively reduce the risk of cross-infection in hospital. (通过实施规范化防护措施, 评估经外周静脉置入中心静脉导管(PICC)在隔离病房收治的重型和危重型新型冠状病毒肺炎患者中应用的安全性和有效性。回顾隔离病房接受诊治的9例确诊/疑似患者的临床资料, 患者接受PICC置管术, 且术中实施规范化防护措施。9例患者均一次置管成功, 术后未发生感染、出血、静脉炎、血栓等并发症; 无一例置管患者和医务人员发生院内感染。隔离病房收治的重型和危重型新型冠状病毒肺炎患者中实施PICC置管安全、有效, 置管中规范化防护可以有效避免院内交叉感染的发生。)

Gas foil bearings have been utilized in high-speed rotational machinery due to their superiority of load capacity and stability, which are closely associated with the shearing flow induced by variable sections in multiwedge clearance. This study focuses on the evolution pattern of vortices in Taylor–Couette flow with three-lobe multiwedge clearance using large-eddy simulation. As the Taylor number (Ta) increases, the shearing flow transitions from separation flow to Taylor vortex flow, followed by secondary transitions leading to wavy vortex flow. Separation vortices occur around the joint between two lobes, significantly delaying the first transition. Subsequently, Taylor vortices emerge and interact with the separation vortices, resulting in a complex evolution pattern of vortex series with increasing Ta. The presence of separation vortices promotes the formation of angular periodicity in Taylor vortices, accelerating the occurrence of angular periodicity stall and enhancing energy exchange between adjacent Taylor vortices. Taylor vortices are prone to breaking and merging. Additionally, Taylor vortices disrupt the shear layer of separation vortices between the stall region and the mid-radius separation region, leading to the migration of the shear layer and the singularity toward the mid-radius. Consequently, separation vortices move toward the mid-radius and transform from a one main vortex structure to two main vortex structures. Furthermore, spectral analysis of turbulent kinetic energy (TKE) reveals an inverse energy cascade characteristic with a slope of −7/3 at high frequencies, attributed to the TKE transmission between Taylor vortices and separation vortices. Both types of vortices exhibit intermittent and periodic behavior. [ABSTRACT FROM AUTHOR]