Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering

Injection of cell‐laden scaffolds in the form of mesoscopic particles directly to the site of treatment is one of the most promising approaches to tissue regeneration. Here, a novel and highly efficient method is presented for preparation of porous microbeads of tailorable dimensions (in the range ≈300–1500 mm) and with a uniform and fully interconnected internal porous texture. The method starts with generation of a monodisperse oil‐in‐water emulsion inside a flow‐focusing microfluidic device. This emulsion is later broken‐up, with the use of electric field, into mesoscopic double droplets, that in turn serve as a template for the porous microbeads. By tuning the amplitude and frequency of the electric pulses, the template droplets and the resulting porous bead scaffolds are precisely produced. Furthermore, a model of pulsed electrodripping is proposed that predicts the size of the template droplets as a function of the applied voltage. To prove the potential of the porous microbeads as cell carries, they are tested with human mesenchymal stem cells and hepatic cells, with their viability and degree of microbead colonization being monitored. Finally, the presented porous microbeads are benchmarked against conventional microparticles with nonhomogenous internal texture, revealing their superior performance.     

New calcium‐free Na2O–Al2O3–P2O5 bioactive glasses with potential applications in bone tissue engineering

Sodium aluminophosphate glasses were evaluated for their bone repair ability. The glasses belonging to the system 45Na₂O–xAl₂O₃‐(55‐x)P₂O₅, with x = (3, 5, 7, 10 mol%) were prepared by a melt‐quenching method. We assessed the effect of Al₂O₃ content on the properties of Na₂O–Al₂O₃–P₂O₅ (NAP) glasses, which were characterized by density measurements, DSC analyses, solubility, bioactivity in simulated body fluid and cytocompatibility with MG‐63 cells. To the best of our knowledge, this is the first investigation of calcium‐free Na₂O–Al₂O₃–P₂O₅ system glasses as bioactive materials for bone tissue engineering.     

Real-Time FPGA Implementation of Parallel Connected Component Labelling for a 4K Video Stream

Journal of Signal Processing Systems - In this paper, a hardware implementation in reconfigurable logic of a single-pass connected component labelling (CCL) and connected component analysis (CCA)...     

Workflow management system with smart procedures

Supervision of repair and diagnostic works aimed at improving the safety of maintenance crews is one of the key objectives of the distributed INRED system. Working in a real industrial environment, the INRED system includes, among others, the so-called INRED-Workflow, which provides an infrastructure for process automation. Participants of the service processes, managed by the INRED-Workflow, are controlled at each stage of the performed service procedures, both by the system and other process participants, such as quality managers and technologists. All data collected from the service processes is stored in the System Knowledge Repository (SKR) for further processing by using advanced algorithms, and the so-called Smart Procedures merge services supplied by other INRED system modules. The applicability of workflow management systems in conjunction with image recognition and machine learning methods has not yet been thoroughly explored. The presented paper shows the innovative usage of such systems in the supervision of the repair and diagnostic works.

     

VFO Path following Control with Guarantees of Positionally Constrained Transients for Unicycle-Like Robots with Constrained Control Input

The Vector-Field-Orientation (VFO) method is a control design concept which was originally introduced for the unicycle kinematics to solve two classical control tasks corresponding to the trajectory tracking and set-point control problems. A unified solution to both the tasks was possible by appropriate definitions of the so-called convergence vector field. So far, there has not been a version of the VFO control law for the third classical control task concerning the path following problem, which is particularly meaningful in the context of practical applications. The paper fills this gap by presenting a novel VFO path following controller devised for robots of unicycle-like kinematics with the amplitude-limited control input. Opposite to most path following controllers proposed in the literature, the new control law utilizes the recently introduced level curve approach which does not employ any parametrization of a reference path. In this way, the proposed solution is free of main limitations resulting from the need of unique determination of the shortest distance from a robot to the path. In contrast to other solutions, a formal analysis of the closed-loop dynamics presented in this paper provides sufficient conditions which guarantee constrained transients of robot motion with the position confined to a prescribed subset around a reference path. Theoretical results have been validated by numerical examples and experimentally verified with utilization of a laboratory-scale differentially driven robot.     

The impact of ICT on labor productivity in the EU

The paper is concerned with investigating relationships between labor productivity and information and communication technology (ICT) components such as the use of enterprise resource planning (ERP), e-commerce and customer relationship management (CRM) software, and the number of ICT specialists at the country level. The proposed approach uses a neoclassical framework of growth accounting and a translog production function to examine the impact of ICT components on labor productivity in the transition and developed economies of the European Union (EU). Our findings show the positive and significant influence of selected ICT components on labor productivity in EU countries. Moreover, the results indicate that the impact of ERP, e-commerce and CRM software on labor productivity is greater in transition economies than in developed economies of the EU.     

Effects of Forming Pressure on Physicochemical Properties of YBCO Ceramics

This article details the solid-state synthesis of high-temperature superconducting YBa₂Cu₃O_7?x. Tests were carried out on samples formed at different pressures (200, 400, 600 and 800 MPa) before being annealed under pure oxygen. The X-ray diffraction method showed that, regardless of the forming pressure, the samples contain about 97 wt.% of Y-123 phase. SEM images showed a polycrystalline structure of samples of similar grain size and number of pores (intergranular spaces). The values of critical temperatures (T_c0), determined from magnetoresistance measurements, are about 91.5 K for all samples, and the T_c0 temperatures do not depend on sample-forming pressure. Magnetoresistance measurements have shown that samples formed with higher pressures exhibit smaller changes in T_c0 and superconducting transition width ΔT due to the influence of the H_DC magnetic field, than the samples formed with lower pressures. Values of specific resistance determined by the use of van der Pauw method at 300 K is about 2 mΩcm for all samples. The critical temperatures (T cintra) of grains and critical current densities at 77 K were determined from AC magnetic susceptibility measurements, and they are about 91.6 K and 400 A cm^?2, respectively.     

Modal context restriction for multiagent BDI logics

Artificial Intelligence Review - We present and discuss a novel language restriction for modal logics for multiagent systems, called modal context restriction, that reduces the complexity of the...