Proteomic Analysis Identifies Molecular Players and Biological Processes Specific to SARS-CoV-2 Exposure in Endothelial Cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been responsible for the severe pandemic of acute respiratory disease, coronavirus disease 2019 (COVID-19), experienced in the 21st century. The clinical manifestations range from mild symptoms to abnormal blood coagulation and severe respiratory failure. In severe cases, COVID-19 manifests as a thromboinflammatory disease. Damage to the vascular compartment caused by SARS-CoV-2 has been linked to thrombosis, triggered by an enhanced immune response. The molecular mechanisms underlying endothelial activation have not been fully elucidated. We aimed to identify the proteins correlated to the molecular response of human umbilical vein endothelial cells (HUVECs) after exposure to SARS-CoV-2, which might help to unravel the molecular mechanisms of endothelium activation in COVID-19. In this direction, we exposed HUVECs to SARS-CoV-2 and analyzed the expression of specific cellular receptors, and changes in the proteome of HUVECs at different time points. We identified that HUVECs exhibit non-productive infection without cytopathic effects, in addition to the lack of expression of specific cell receptors known to be essential for SARS-CoV-2 entry into cells. We highlighted the enrichment of the protein SUMOylation pathway and the increase in SUMO2, which was confirmed by orthogonal assays. In conclusion, proteomic analysis revealed that the exposure to SARS-CoV-2 induced oxidative stress and changes in protein abundance and pathways enrichment that resembled endothelial dysfunction.     

Residual stress effect on the fracture toughness of lithium disilicate glass-ceramics

In glass-ceramics (GCs), on cooling from the crystallization temperature, internal residual stresses are generated due to the difference between the thermal expansion coefficient (TEC) of the crystal phase(s) and the residual glass. These stresses could degrade or promote their mechanical properties. In this work, we varied the magnitude of the residual stresses in lithium silicate GCs by designing their microstructures. The level of internal stresses was measured using (Synchrotron) X-ray diffraction. The effects of anisotropy of thermal expansion, crystal shape, and intensity of the residual stresses were analyzed and compared using theoretical models. We extended the Hsueh-Becher model to include the thermal expansion anisotropy of the orthorhombic lithium disilicate (LS2) crystals. We found that the average residual stresses within the LS2 crystals are compressive or null (−100 to ~0) and highly anisotropic. Most importantly, within the limits of this study, we found no evidence for the influence of (compressive or null) residual stresses on the fracture toughness of the studied GCs. Within the crystal size range from 1 to 5 μm, a highly crystallized volume fraction coupled to relatively large crystals (5 μm) of high elastic modulus improved the glass-ceramic fracture toughness. This result can guide the microstructural design of novel tough GCs.     

Dispersion of graphite flakes into boehmite sols for the preparation of bi-layer-graphene / alumina coatings on stainless steel for tribological applications

Carbon-alumina coatings on stainless steel were prepared by a sol-gel route. The dispersion of the commercial graphite flakes by an ultrasonic bath, an ultrasonic probe and a high-shear mixer, produce thinner flakes, few-layered-graphene and bi-layer-graphene (BLG), respectively. The coatings were examined by optical and electron microscopy, interferential rugosimetry, optical profilometry and Raman spectroscopy. The friction coefficient against a steel ball is decreased by a factor of 5–7 and the wear volume is reduced by a factor of 6–38 compared to a pure alumina coating. The best results correspond to the sample prepared using the high-shear mixer. Delamination of the graphite flakes into BLG during the friction test provides the system with debris suitable for tribofilm building up and lubrication but it is better to already have carbon dispersed as BLG in the coating before the test, notably because the carbon surface area available is much higher.     

An Adaptable Job Submission System Based on Moderate Price-Adjusting Policy in Market-Based Grids

A market-based computational grid is made up of large sets of heterogeneous and geographically distributed resources that are gathered into virtual organizations for executing consumer’s applications. One of the most important challenges in market-based grid systems is the management of grid users, which is called resource providers and consumers. The existing methods provide some alternative mechanisms for this problem, but they are not fully adequate. To address this problem, we propose an enhanced approach for adjusting price of grid resource using new effective parameters of microeconomic issue and also for prioritizing current jobs in the queue. This proposed approach is integrated with a cooperative method among local schedulers to accept jobs based on auction model. The results conclude that the inclusion of new parameters in price-adjusting affects the payment budget and job submission behavior of the schedulers. The evaluations of experimental results prove a remarkable performance of the proposed approach in diverse conditions and job workloads.     

Milk with different somatic cells counts and the physicochemical,microbiological characteristics and fatty acid profile of pasteurised milk cream: is there an association?

In this study, raw cow milk containing somatic cells counts (SCC) at mean levels of 39 000 cells mL^?1 (low), 349 000 cells mL^?1 (intermediate) and 1 297 000 cells mL^?1 (high) was used for the production of pasteurised cream. Physicochemical (pH, fat and fatty acid profile) and microbiological analyses (mesophilic and psychrotrophs) were performed in the obtained creams during 30 days of refrigerated storage at 5 °C ± 2. No interactions (P > 0.05) were found between SCC, storage time and the physicochemical and microbiological variables studied. Fatty acid profile was similar among the SCC creams, except for oleic acid (C18:1), which decreased (P < 0.05) in intermediate and high SCC creams. Considering the technological aspect, our findings suggest that milk cream manufacture can be an interesting option for the use of high SCC milk.     

Chia seeds to develop new biodegradable polymers for food packaging: Properties and biodegradability

Chia seeds are a promising raw material for the development of biodegradable and edible polymers due to their composition and properties. This study aimed to evaluate the effects of drying process of chia mucilage (oven and freeze-drying) and the incorporation of chia oil in films for food packaging. The films were formed by casting using chia mucilage and glycerol. The polymers developed were evaluated by physicochemical properties, microstructure, thermal properties, and biodegradation. The drying process of mucilage and oil incorporation in films affected mainly mechanical and color properties. Freeze-dried mucilage resulted in superior mechanical performance. Differences were caused by the effect of drying process in the molecular structure of chia mucilage and the incorporation of oil among the polymer chains. Chia mucilage films were completely soluble in water and biodegraded in a short time in soil. These films are promising biodegradable polymers for the development of eco-friendly food packaging and edible sachets for small pre-measured portions, preventing environment pollution and facilitating product consumption.     

Thermohydrodynamic Behavior of Misaligned Plain Journal Bearings: Theoretical and Experimental Approaches

Hydrodynamic journal bearings are essential components for supporting and guiding the rotating shafts of high-speed machinery. Manufacturing defects in assembly or thermal distortions may introduce problems during running, such as misalignment. The destructive effects of this kind of running problem have justified the development of a numerical model to predict the bearing operating characteristics under steady-state conditions. The present work presents in detail the three-dimensional thermohydrodynamic approach adopted in this study in order to consider the thermal field variations. This model also includes lubricant film rupture and reformation phenomena by conserving the mass flow rate. In addition, an experimental validation is made by comparison with measurements carried out on our test device for various operating conditions and misalignment torques. The influence of misalignment direction is also investigated by considering numerical and experimental approaches used in the study of bearing behavior variations.     

Development and characterization of composite chitosan/active carbon hydrogels for a medical application

Composite chitosan/active carbon (AC) hydrogels were elaborated by a novel route, consisting in exposing the chitosan solution to ammonia vapors. This vapor‐induced gelation method was compared with the conventional elaboration process, a direct immersion of the chitosan solution in liquid ammonia. The hydrogels were characterized to evaluate their potential application as wound‐dressings, mostly regarding their morphology, mechanical properties, swelling behavior, and sorption capacities for malodorous compounds emitted from wounds as diethylamine (DEA). The influence of elaboration route, chitosan concentration, and AC incorporation was studied. The results show that freeze‐dried hydrogels have a porous asymmetric structure dependent on the chitosan concentration and which promotes exudates drainage. The nanostructure of the parent hydrogel is semi‐crystalline and slightly dependent on the gelation conditions. It confers on hydrogel an acceptable mechanical behavior (compressive modulus up to 1.08·10⁵ Pa). Hydrogels including AC display enhanced sorption kinetics for DEA, with sorption capacities up to 49 mg g^?1. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of conductive adhesives based on epoxy resin and polyaniline.DBSA using the in situ polymerization and physical mixing procedures

Electrically conductive adhesives based on epoxy-anhydride system containing polyaniline (PAni) doped with dodecylbenzenesulfonic acid (DBSA) have been successfully developed and characterized. The blends were prepared by physical mixing and by in situ polymerization of aniline within epoxy matrix. The in situ polymerization procedure contributes for the formation of a conducting pathway with lower amount of PAni.DBSA. A conductivity as low as 10^?3 S cm^?1 with 12 wt% of PAni and excellent adhesion properties were achieved with these systems. The microstructure of the conductive adhesives was studied by means of scanning electron microscopy (SEM). In the case of blends prepared by in situ polymerization, PAni.DBSA is dispersed within the epoxy matrix in the form of microtubules. Dielectrical properties as a function of frequency and temperature have also indicated a great interaction between polyaniline and epoxy matrix by in situ polymerization procedure.     

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