The adhesion of Plasmodium falciparum-infected erythrocytes (IRBCs) to human dermal microvascular endothelial cells (HDMECs) under flow conditions is regulated by a Src family kinase-and alkaline phosphatase (AP)-dependent mechanism. In this study, we showed that the target of the phosphatase activity is the ectodomain of CD36 at threonine-92 (Thr 92 ). Mouse fibroblasts (NIH 3T3 cells) transfected with wild-type CD36 or a mutant protein in which Thr 92 was substituted by Ala supported the rolling and adhesion of IRBCs. However, while the Src family kinase inhibitors PP1 and PP2 and the specific AP inhibitor levamisole significantly reduced IRBC adhesion to wild-type CD36 transfectants as with HDMECs, the inhibitors had no effect on IRBC adhesion to the mutant cells. Using a phosphospecific antibody directed at a 12-amino-acid peptide spanning Thr 92 , we demonstrated directly that CD36 was constitutively phosphorylated and could be dephosphorylated by exogenous AP. Endothelial CD36 was likewise constitutively phosphorylated. The phosphospecific antibody inhibited IRBC adhesion to HDMECs that could be reversed by preincubating the antibody with the phosphorylated but not the nonphosphorylated peptide. Pretreatment of HDMECs with AP abrogated the effect of PP1 on IRBC adhesion. Collectively, these results are consistent with a critical role for CD36 dephosphorylation through Src family kinase activation in regulating IRBC adhesion to vascular endothelium.The scavenger receptor CD36 expressed on erythroblasts, platelets, monocytes/macrophages, dendritic cells, microvascular endothelial cells, striated muscle cells, adipocytes, and mammary epithelial cells is increasingly recognized as a signaling molecule and/or coreceptor for diverse ligands that are implicated in the pathogenesis of major inflammatory diseases. Specifically, CD36 has been shown to elicit a proinflammatory response in microglial cells in the brain (3, 22) and macrophages in an atheroma (21) through its interaction with fibrillar -amyloid. In binding to CD36, -amyloid inhibits CD36-mediated clearance of oxidized lipoproteins and thus promotes accumulation of lipid peroxidases and accelerated atherogenesis (19). Evidence is also emerging that CD36 acts as a coreceptor for some but not all bacterial ligands for Toll-like receptor 2 activation (17). As a result, CD36-deficient mice were hypersusceptible to the gram-positive microbe Staphylococcus aureus.In Plasmodium falciparum malaria, CD36 has long been considered a major contributor to pathogenesis by acting as a vascular receptor for the adhesion of infected erythrocytes (IRBCs) (16). The deleterious effect of cytoadherence has been attributed to impairment of microcirculatory blood flow, with subsequent tissue hypoxia and organ dysfunction. There is strong clinical evidence to support this mechanical mechanism, such as the demonstration of lower-than-expected oxygen tension and reduced perfusion pressure in the cerebral circulation of patients with cerebral malaria (23,28). IRBC adhesion may a...
Icing has become a hot topic both in academia and in the industry given its implications in transport, wind turbines, photovoltaics, and telecommunications. Recently proposed de-icing solutions involving the propagation of acoustic waves (AWs) at suitable substrates may open the path for a sustainable alternative to standard de-icing or anti-icing procedures. Herein, the fundamental interactions are unraveled that contribute to the de-icing and/or hinder the icing on AW-activated substrates. The response toward icing of a reliable model system consisting of a piezoelectric plate activated by extended electrodes is characterized at a laboratory scale and in an icing wind tunnel under realistic conditions. Experiments show that surface modification with anti-icing functionalities provides a synergistic response when activated with AWs. A thoughtful analysis of the resonance frequency dependence on experimental variables such as temperature, ice formation, or wind velocity demonstrates the application of AW devices for real-time monitoring of icing processes.
Fabrication of tunable wetting surfaces is sought for the last years given its importance on energy, biomaterials and antimicrobials, water purification, microfluidics, and smart surfaces. Liquid management on surfaces mainly depends on the control at the micro‐ and nanoscale of both roughness and chemical composition. Herein, the combination of a soft‐template method and plasma‐enhanced chemical vapor deposition is presented for the synthesis of TiO2 nanofibers on porous substrates such as cellulose and stainless‐steel membranes. The protocol, carried out under mild conditions, produces 3D nanomembranes with superhydrophobicity and oleophilicity that are tested as microliter water/oil filters. Photoactivation of TiO2 by UV illumination provides a straightforward approach for wetting tunability that converts the surface into amphiphilic. A final chemical modification of the TiO2 nanofibers by embedding them in an elastomeric polymeric shell and by fluorine‐based grafting opens the path toward the formation of superomniphobic and self‐cleaning surfaces with long‐lasting lifetimes. Thus, a reliable procedure is demonstrated for the fabrication of TiO2 nanofibers, which allows the modification of porous supports and provides an innovative route for the development of 3D nanomembranes with under design wetting. This protocol is extendable to alternative metal oxides, metals, and core@shell nanoarchitectures with potential multifunctionalities.
The Radio Frequency Identification System, a wireless communication system, recently it is being applied to vehicular identification, the radio electric and geometry environment characteristics influence the Radio Channel, which one, have been analyzed extensively in different papers, but no one of them has analyzed the RFID technology applied to vehicular technology. The radio channel model is necessary for the effective design of transmitters and receivers, and to determining the positions of the tag and the reader. This motivates the analysis of the propagation environment for outdoor RFID systems. In order to know a feasible RFID application to the vehicular identification, a set of tests were implemented in laboratory and in the field, in order to obtain a channel model that predicts the average power level, a semi-stochastic model, where the average power level is given by the distance raised to some power that depends on the environment, and the field strength in an area around a transmitter, and take into account the structure and materials used at every location in the area. As a result from these tests, the RFID signal and the RFID channel behavior are the focus and discussion of this article.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.