Search results for " tension"
showing 10 items of 270 documents
Coexistence of active Brownian disks: van der Waals theory and analytical results
2020
At thermal equilibrium, intensive quantities like temperature and pressure have to be uniform throughout the system, restricting inhomogeneous systems composed of different phases. The paradigmatic example is the coexistence of vapor and liquid, a state that can also be observed for active Brownian particles steadily driven away from equilibrium. Recently, a strategy has been proposed that allows to predict phase equilibria of active particles [Solon et al., Phys. Rev. E 97, 020602(R) (2018)2470-004510.1103/PhysRevE.97.020602]. Here we elaborate on this strategy and formulate it in the framework of a van der Waals theory for active disks. For a given equation of state, we derive the effecti…
The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral s…
2012
Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to suc…
From the oxygen to the organ protection: Erythropoietin as protagonist in internal medicine
2006
Erythropoietin (EPO), already known as the stimulating hormone for erythropoiesis, has shown different and interesting pleiotropic actions. It does not only affect erythroid cells, but also myeloid cells, lymphocytes and megakaryocytes. This hormone can also enhance phagocytic function of the polymorphonuclear cells and reduce the activation of macrophages, thus modulating the inflammatory process.Moreover, hematopoietic and endothelial cells probably have the same cellular origin, and the discovery of erythropoietin receptors (EPO-R) also on mesangial and myocardial cells, smooth muscle fibrocells and neurons has prompted the study of the non-erythropoietic functions of this hormone.The in…
Thermodynamical aspects regarding the formation of self-assembly decylpolyglucoside structures
2005
In this study, we used a generalized form of a recently reported parametrization based on the differential geometry and the thermodynamics of dispersed systems to ascertain the capability of decylpolyglucoside alone or in association with cholesterol to form vesicle structures (niosomes). The theoretical calculation of the energy balance involved in the vesicles formation was carried out using values of the critical concentration of formation (ccf), surface tension and the molar surface area of the non-ionic surfactant. Furthermore, in order to confirm the theoretical results found in this work, we prepared and characterized vesicles made with decylpolyglucoside and cholesterol. The vesicle…
Crystallization of hard spheres revisited. II. Thermodynamic modeling, nucleation work, and the surface of tension
2018
Combining three numerical methods (forward flux sampling, seeding of droplets, and finite-size droplets), we probe the crystallization of hard spheres over the full range from close to coexistence to the spinodal regime. We show that all three methods allow us to sample different regimes and agree perfectly in the ranges where they overlap. By combining the nucleation work calculated from forward flux sampling of small droplets and the nucleation theorem, we show how to compute the nucleation work spanning three orders of magnitude. Using a variation of the nucleation theorem, we show how to extract the pressure difference between the solid droplet and ambient liquid. Moreover, combining th…
Emulsion-based systems for fabrication of electrospun nanofibers: food, pharmaceutical and biomedical applications
2017
International audience; Electrospinning is considered a promising technology for fabricating ultrafine fibers via the application of electrostatic repulsive forces. Electrospun nanofibers produced via emulsion electrospinning are widely used as delivery systems to encapsulate bioactive compounds and drugs in food and pharmaceuticals, respectively. Emulsion electrospinning has also gained significant interest for the production of vehicles for sustained and controlled release. There are several parameters affecting the properties of fabricated fibers including the type of emulsion, emulsion composition, electric field strength, conductivity of solution, surface tension, electrode configurati…
Influence of oxygen tension on the anti-inflammatory and chondroprotective effects of heme oxygenase-1 in healthy and osteoarthritic human chondrocyt…
2012
s / Osteoarthritis and Cartilage 20 (2012) S54–S296 S136 their isolation. The absence of cross-reaction with the IIA isoform was established by ELISA andWB. In addition, the Saos-2 cell linewas chosen to test a possible labelling of other fibrillar procollagens, mainly type I, V and XI. In fact, this cell line is described to synthesize the (a1)I, (a2)I, (a1)V, (a2)V, (a1)XI and (a2)XI, but no (a3)XI chains. No signal was detected on WB of cellular extracts or conditioned media with anti-pNIIB52, whereas antibodies to the collagen I, V and XI triple-helical parts revealed indeed the presence of proforms of these collagens. Conclusions: Anti-pNIIB52 antibodies allow a very sensitive and spec…
Pseudo-Planar Organic Heterojunctions by Sequential Printing of Quasi-Miscible Inks
2021
This work deals with the interfacial mixing mechanism of picoliter (pL)-scale droplets produced by sequential inkjet printing of organic-based inks onto ITO/PET surfaces at a moderately high Weber number (~101). Differently from solution dispensing processes at a high Bond number such as spin coating, the deposition by inkjet printing is strictly controlled by droplet velocity, ink viscosity, and surface tension. In particular, this study considers the interfacial mixing of droplets containing the most investigated donor/acceptor couple for organic solar cells, i.e., poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM), showing how low-viscosity and low-surfac…
Theory of mercury intrusion in a distribution of unconnected wedge-shaped slits
2004
Effective mercury intrusion in a wedge-shaped slit is gradual, the intruded depth increasing with applied pressure. The Washburn equation must be modified accordingly. It relates the distance, e, separating the three-phase contact lines on the wedge faces to the hydrostatic pressure, P, wedge half-opening angle alpha, mercury surface tension gamma, and contact angle theta: e=(-2gamma/P)cos(theta-alpha) if theta-alpha>pi2. The equations relating the volume of mercury in a single slit to hydrostatic pressure are established. The total volume of mercury V(Hg)(tot)(E(0),e) intruded in a set of unconnected isomorphous slits (same alpha value) with opening width, E, distributed over interval [E(0…
Solubilization by polysoaps
1994
The aqueous solubilization power of several series of micellar homopolymers and copolymers (''polysoaps'') is investigated. Using five insoluble or poorly water-soluble dyes, comparisons of the capacities are made with respect to the influence of structural variables such as the polymer backbone, the polymer geometry, the comonomer content, and the charge of the hydrophilic group. Some guidelines for polysoap structures suited for efficient solubilization are established. Noteworthy is that the solubilization capacities of the polysoaps are neither linked to the ability to reduce the surface tension of water, nor to the polarity of the solubilization sites deduced from spectroscopic probes.