Colony Stimulating Factor-1 Receptor is a central component of the foreign body response to biomaterial implants in rodents and non-human primates

Host recognition and immune-mediated foreign body response (FBR) to biomaterials can compromise the performance of implanted medical devices. To identify key cell and cytokine targets, here we perform in-depth systems analysis of innate and adaptive immune system responses to implanted biomaterials in rodents and non-human primates. While macrophages are indispensable to the fibrotic cascade, surprisingly neutrophils and complement are not. Macrophages, via CXCL13, lead to downstream B cell recruitment, which further potentiated fibrosis, as confirmed by B cell knock out and CXCL13 neutralization. Interestingly, Colony Stimulating Factor-1 Receptor (CSF1R) is significantly increased following implantation of multiple biomaterial classes: ceramic, polymer, and hydrogel. Its inhibition, like macrophage depletion, leads to complete loss of fibrosis, but spares other macrophage functions such as wound healing, ROS production, and phagocytosis. Our results indicate targeting CSF1R may allow for a more selective method of fibrosis inhibition, and improve biomaterial biocompatibility without the need for broad immunosuppression

An empirical investigation of factors affecting e-collaboration diffusion in SMEs

Organizations today operate in a complex, unpredictable, competitive and global business environment. Organizations have responded to these challenges by implementing collaborative supply chain management (SCM) which allows their organizations to gain competitive advantages. E-collaboration implementation is one of the key technologies to facilitate the success of SCM, which allows the integration of business processes and the sharing of information among supply chain members. E-collaboration has been implemented with considerable success in the supply chain by organizations such as Infineon and Wal-Mart. However, these large organizations have more financial and technical resources compared to Small and Medium Enterprises (SMEs). Little research on the implementation of e-collaboration has focused on the perspective of SMEs. Furthermore, most studies on e-collaboration implementation have traditionally examined the adoption stage of e-collaboration tools instead of a multi-stage diffusion process of technology. The main objective of this study is to understand the factors that influence the diffusion of e-collaboration in SCM among the SMEs. This study proposes a research model to examine a stage-based e-collaboration diffusion process in SMEs. An integration technology adoption model based on Technological-Organizational-Environmental (TOE) framework, Interorganizational Relationships (IOR), and Unified Theory of Acceptance and Use of Technology (UTAUT) is proposed and empirically validated

Optically driven oscillations of ellipsoidal particles. Part II: Ray-optics calculations

We report numerical calculations on the mechanical effects of light on micrometer-sized dielectric ellipsoids immersed in water. We used a simple two-dimensional ray-optics model to compute the radiation pressure forces and torques exerted on the object as a function of position and orientation within the laser beam. Integration of the equations of motion, written in the Stokes limit, yields the particle dynamics that we investigated for different aspect ratios k. Whether the beam is collimated or focused, the results show that above a critical aspect ratio kC, the ellipsoids cannot be stably trapped on the beam axis; the particle never comes to rest and rather oscillates permanently in a back-and-forth motion involving both translationand rotation in the vicinity of the beam. Such oscillations are a direct evidence of the non-conservative character of optical forces. Conversely, stable trapping can be achieved for k < kC with the particle standing idle in a vertical position. These predictions are in very good qualitative agreement with experimental observations. The physical origin of the instability may be understood from the force and torque fields whose structures greatly depend on the ellipsoid aspect ratio and beam diameter. The oscillations arise from a non-linear coupling of the forces and torques and the torque amplitude was identified as the bifurcation control parameter. Interestingly, simulations predict that sustained oscillations can be suppressed throughthe use of two coaxial counterpropagating beams, which may be of interest whenever a static equilibrium is required as in basic force and torque measurements or technological applications.Méthodes avancées pour la caractérisation optique de systèmes particulaires complexesEuropean ITN COMPLOID