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Ascending aortic aneurysm (AAoA) is a silent disease with high mortality; however, the factors associated with a worse prognosis are not completely understood. The objective of this observational, longitudinal, single-center study was to identify the hemodynamic patterns and their influence on AAoA growth using computational fluid dynamics (CFD), focusing on the effects of geometrical variations on aortic hemodynamics. Personalized anatomic models were obtained from angiotomography scans of 30 patients in two different years (with intervals of one to three years between them), of which 16 (53%) showed aneurysm growth (defined as an increase in the ascending aorta volume by 5% or more). Numerically determined velocity and pressure fields were compared with the outcome of aneurysm growth. Through a statistical analysis, hemodynamic characteristics were found to be associated with aneurysm growth: average and maximum high pressure (superior to 100 Pa); average and maximum high wall shear stress (superior to 7 Pa) combined with high pressure (>100 Pa); and stress load over time (maximum pressure multiplied by the time interval between the exams). This study provides insights into a worse prognosis of this serious disease and may collaborate for the expansion of knowledge about mechanobiology in the progression of AAoA.

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Epigenetic changes, particularly histone compaction modifications, have emerged as critical regulators in the epigenetic pathway driving endothelial cell phenotype under constant exposure to laminar forces induced by blood flow. However, the underlying epigenetic mechanisms governing endothelial cell behavior in this context remain poorly understood. To address this knowledge gap, we conducted in vitro experiments using human umbilical vein endothelial cells subjected to various tensional forces simulating pathophysiological blood flow shear stress conditions, ranging from normotensive to hypertensive forces. Our study uncovers a noteworthy observation wherein endothelial cells exposed to high shear stress demonstrate a decrease in the epigenetic marks H3K4ac and H3K27ac, accompanied by significant alterations in the levels of HDAC (histone deacetylase) proteins. Moreover, we demonstrate a negative regulatory effect of increased shear stress on HOXA13 gene expression and a concomitant increase in the expression of the long noncoding RNA, HOTTIP, suggesting a direct association with the suppression of HOXA13. Collectively, these findings represent the first evidence of the role of histone-related epigenetic modifications in modulating chromatin compaction during mechanosignaling of endothelial cells in response to elevated shear stress forces. Additionally, our results highlight the importance of understanding the physiological role of HOXA13 in vascular biology and hypertensive patients, emphasizing the potential for developing small molecules to modulate its activity. These findings warrant further preclinical investigations and open new avenues for therapeutic interventions targeting epigenetic mechanisms in hypertensive conditions.

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Floating treatment islands (FTIs) offer effective solutions for stormwater management, providing flood attenuation and pollutant removal capabilities. However, there remains a knowledge gap concerning their performance, specifically in terms of pollutant removal and sediment deposition. To address this gap, the present study employs computational fluid dynamics (CFD) modeling to investigate the intricate interactions within FTI systems. Various FTI configurations are analyzed, considering mass removal through FTIs and sediment deposition, the first time where these two processes were considered together in a CFD environment. The findings demonstrate that FTIs have a significant influence on flow patterns and mass removal. Notably, FTIs enhance mass removal compared to the control case, with larger sediment particles exhibiting higher removal rates. The correlation between the short-circuit index and sedimentation in FTI ponds highlights the potential of FTIs as indicators of treatment efficiency. Furthermore, the study focuses on mass removal exclusively through the FTI root zones. The positioning of FTIs within the pond has a considerable impact, resulting in differences of up to 20% in mass removal. Moreover, the FTI configuration exerts a more pronounced influence on mass removal through FTIs than through sediment deposition alone. In cases where both processes occur simultaneously, the presence of FTIs lead to higher mass removal, primarily attributed to the FTIs themselves, particularly in the initial segment. Remarkably, certain FTI configurations enable mass removal exceeding 70% for large sediment particles, even with a pond length less than half of the original.

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Meat is an important part of the food pyramid in Mexico, to such an extent that it is included in the basic food basket. In recent years, there has been great interest in the application of so-called emerging technologies, such as high-intensity ultrasound (HIU), to modify the characteristics of meat and meat products. The advantages of the HIU in meat such as pH, increased water-holding capacity, and antimicrobial activity are well documented and conclusive. However, in terms of meat tenderization, the results are confusing and contradictory, mainly when they focus on three HIU parameters: acoustic intensity, frequency, and application time. This study explores via a texturometer the effect of HIU-generated acoustic cavitation and ultrasonoporation in beef (m. Longissimus dorsi). Loin-steak was ultrasonicated with the following parameters: time tHIU = 30 min/each side; frequency fHIU = 37 kHz; acoustic intensity IHIU = ~6, 7, 16, 28, and 90 W/cm2. The results showed that acoustic cavitation has a chaotic effect on the loin-steak surface and thickness of the rib-eye due to Bjerknes force, generating shear stress waves, and acoustic radiation transmittance via the internal structure of the meat and the modification of the myofibrils, in addition to the collateral effect in which the collagen and pH generated ultrasonoporation. This means that HIU can be beneficial for the tenderization of meat.

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Preeclampsia, one of the main hypertensive disorders of pregnancy, is associated with circulating factors released by the ischemic placenta accompanied by systemic endothelial dysfunction. The etiology of preeclampsia remains poorly understood although it is associated with high maternal and fetal mortality and increased cardiovascular disease risk. Most cell model systems used for studying endothelial dysfunction have not taken into account hemodynamic physical factors such as shear-stress forces which may prevent extrapolation of cell data to in vivo settings. We overview the role of hemodynamic forces in modulating endothelial cell function and discuss strategies to reproduce this biological characteristic in vitro to improve our understanding of endothelial dysfunction associated with preeclampsia.

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Piezo1 channel is a sensor for shear-stress in the vasculature. Piezo1 activation induces vasodilation, and its deficiency contributes to vascular disorders, such as hypertension. In this study, we aimed to determine whether Piezo1 channel has a functional role in the dilation of pudendal arteries and corpus cavernosum (CC). For this, male Wistar rats were used, and the relaxation of the pudendal artery and CC was obtained using the Piezo1 activator, Yoda1, in the presence and absence of Dooku (Yoda1 antagonist), GsMTx4 (non-selective mechanosensory channel inhibitor) and L-NAME (nitric oxide synthase inhibitor). In the CC, Yoda1 was also tested in the presence of indomethacin (non-selective COX inhibitor) and tetraethylammonium (TEA, non-selective potassium channel inhibitor). The expression of Piezo1 was confirmed by Western blotting. Our data show that Piezo1 activation leads to the relaxation of the pudendal artery and CC as the chemical activator of Piezo1, Yoda1, relaxed the pudendal artery (47%) and CC (41%). This response was impaired by L-NAME and abolished by Dooku and GsMTx4 in the pudendal artery only. Indomethacin and TEA did not affect the relaxation induced by Yoda1 in the CC. Limited tools to explore this channel prevent further investigation of its underlying mechanisms of action. In conclusion, our data demonstrate that Piezo1 is expressed and induced the relaxation of the pudendal artery and CC. Further studies are necessary to determine its role in penile erection and if erectile dysfunction is associated with Piezo1 deficiency.

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Photodynamic therapy using Hypericin (Hy-PDT) is an alternative non-invasive treatment that enables selective tumor inhibition and angiogenesis derived from the differential recruitment of endothelial cells in the tumor microenvironment. Most PDT studies were performed on in vitro models without vascular biomechanical simulation. Our work strives to develop a microchip that generates a constant shear stress force to investigate the Hy-PDT efficiency on human umbilical vein endothelial cells (HUVECs). The microchip with a single straight microchannel was composed of the bottom layer (polystyrene), the middle layer (double-sided biocompatible adhesive tape), and the top layer (polyester film) and could produce shear stress in the range of 1.4 - 7.0 dyn cm-2. The quantification of vascular endothelial growth factor (VEGF), cell viability, and activities of caspases 3 and 7 were assayed to validate the microchip and Hy-PDT efficacy. After the endothelization, static and dynamic cell incubations with Hy were conducted in microchips. Compared to static systems, the shear stress displayed its effect on the increasing release of VEGF and promoted more cell damage and cell death via necrosis during Hy-PDT. In conclusion, the expressive shear stress-dependent manner during PDT treatments suggests that the microchip could be an essential approach in preclinical tests to evaluate the therapeutic outcome considering the endothelial shear stress microenvironment.

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This study involved evaluating the effects of rotational impeller speed agitation (N) and specific air flow rate (Фair) on bikaverin production and on the growth of Fusarium oxysporum employing 11 bench-scale bioreactor assays. The results showed that the maximum bikaverin production (close to 300 mg L-1) was achieved after 48 h of fermentation in rice medium (20 g L-1 milled rice in water) at 28 °C with a volumetric oxygen transfer coefficient (KLa) and shear stress values of approximately 20 h-1 and 17 N m-2, respectively. We reached this combination of parameters using an N of 340 rpm and Фair of 0.935 vvm. These KLa and shear stress values can be used as references when upscaling this process. Thus, this study was important to demonstrate how the main parameters in bioreactors affect bikaverin production and it presented important indications for upscaling this bioprocess.

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Cobalt-chromium (CoCr)-based alloys have emerged as an interesting biomaterial within biomedical field, mainly considering their biocompatibility, resistance to corrosion and absence of magnetism; however, its effect on cell metabolism is barely known and this prompted us better evaluating whether CoCr-enriched medium affects the metabolism of both osteoblast and endothelial cells, and also if there is a coupling between them. This is also considered here the already-known effect of Cobalt (Co) as a hypoxic element. Firstly, discs of CoCr [subjecting (W) or not (Wo) to dual acid-etched (DAE)] were incubated into FBS-free cell culture medium up to 24 h (37 °C). This CoCr-enriched medium was further used to treat shear-stressed endothelial cells cultures up to 72 h. Thereafter, the conditioned medium containing metabolites of shear-stressed endothelial cells in response to CoCr-enriched medium was further used to subject osteoblast's cultures, when the samples were properly harvested to allow the analysis of the molecular issues. Our data shows that CoCr-enriched medium contains 1.5 ng-2.0 ng/mL of Co, which was captured by endothelial cells and osteoblasts in about 30% in amount and it seems modulate their metabolic pathways: shear-stressed endothelial cells expressed higher profile of HIF1α, VEGF and nNOS genes, while their global profile of protein carbonylation was lower than the control cultures, suggesting lower oxidative stress commitment. Additionally, osteoblasts responding to metabolites of CoCr-challenged endothelial cells show dynamic expression of marker genes in osteogenic differentiation, with alkaline phosphatase (ALP), osteocalcin, and bone sialoprotein (BSP) genes being significantly increased. Additionally, tensional shear-stress forces decrease the stimulus for ColA1gene expression in osteoblasts responding to endothelial cells metabolites, as well as modifying the extracellular matrix remodeling related genes. Analyzing the activities of matrix metalloproteinases (MMPs), the data shows that shear-stressed endothelial cells metabolites increase the activities of both MMP9 and MMP2 in osteoblasts. Altogether, our data shows for the first time that shear-stressed endothelial metabolites responding to CoCr discs contribute to osteogenic phenotype in vitro, and this predicts an active crosstalk between angiogenesis and osteogenesis during osseointegration of CoCr alloy and bone healing, maybe guided by the Co-induced hypoxic condition.

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Although some studies have investigated the impact caused by chemicals used on water treatment (coagulants and oxidants) on cyanobacteria integrity, the isolated effect of shear stress during coagulation is still not fully understood. This study evaluated the impact of different velocity gradients, mixing times, and the addition of powdered activated carbon (PAC) on the integrity of Microcystis aeruginosa, Raphidiopsis raciborskii, and Dolichospermum circinale, known producers of toxin and taste and odor (T&O) compounds. No association was found between R. raciborskii cell lysis and velocity gradient, with or without PAC, demonstrating the high resilience of this taxon to shear stress. In contrast, an association was found for M. aeruginosa at the highest velocity gradient evaluated (1000 s-1) and for D. circinale above the lowest velocity gradient studied (600 s-1). After PAC addition, there was a reduction in the chances of finding M. aeruginosa intact cells above velocity gradient 800 s-1 at 45 s, while D. circinale show cell lysis in all the scenarios expect at 600 s-1 and 10 s of agitation. The additional impact of PAC on cell lysis may lead to more release of metabolites and shows the need to adjust the hydraulic conditions in the rapid mixing stage, especially when more "fragile" cyanobacteria are present. Neither cyanobacterial cell size nor morphology was shown to be relevant to shear stress sensitivity, indicating that cell wall composition might have been an important factor in controlling cell lysis.

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