Using computer supported collaborative learning strategies for helping students acquire self-regulated problem-solving skills in mathematics

The main objective of this paper is to investigate the effectiveness of a proposed computer-based instructional method in Primary Education for self-regulated problem solving. The proposed instructional method is based on Sternberg’s model of problem solving within an authentic context. It consists of three main phases: observation, collaboration and semi-structured guidance. The ultimate learning objective is to augment the autonomous problem-solving skills of primary school children. In our study the Synergo tool was used, which is a synchronous computer supported collaborative learning tool, as well as the Moodle learning management system. The context which frames the method is authentic, very close to a students’ realistic learning situation. The findings of this study advocate that students can increase their problem-solving skills in a relatively short period of time. At the same time, they can improve their approach to the solution of a given mathematical problem, performing significant signs of autonomy.     

Polymeric Nanoparticles as a Self-Adjuvanting Peptide Vaccine Delivery System: The Role of Shape

Antigens incorporated in subunit vaccines are typically poorly immunogenic, so a strong immunostimulant (adjuvant) and/or delivery system is required to boost immunogenicity. In this work, the various functional polymer nanostructures, that is, rods, worms, spheres, and tadpoles are used to develop potent peptide antigen delivery systems. The antigen PADRE-J8 (PJ8), derived from Group A Streptococcus (GAS) M-protein, is either physically mixed or chemically conjugated to polymeric nanoparticles of different shapes. The physical mixture of polymeric nanoparticles and antigen is more effective in inducing antibody production than their chemical conjugates. Moreover, rod-shaped polymeric nanoparticles in physical mixture with PJ8 elicited higher and more opsonic antibody titers than powerful complete Freund's adjuvant (CFA)-adjuvanted antigen. Herein, for the first time it is demonstrated that a) the block copolymer, in nanoparticle form, can act as an immune adjuvant, b) nanoparticle shape plays a crucial role in their immunogenicity, and c) antigen conjugation is not required, nor is antigen encapsulation or absorption.     

The surrogate scaffold method for quantifying molecular release kinetics from drug delivery systems

The accurate determination of kinetics of therapeutic release from drug delivery vehicles is an essential step in the optimized design of such systems for biomedical and pharmaceutical applications. Most methods in current use for quantifying therapeutic release rates are developed to provide consistency, reproducibility, and ease of usage in a laboratory setting. These methods, however, do not necessarily mirror the release conditions when the drug delivery system comes into contact with the target tissue environment during application. As a result, the findings from these studies provide only comparative guidelines about the drug delivery rates and duration. Successful optimization of a drug delivery system requires complete, and accurate, knowledge about the release profile over an extended period of time to determine the initial release rate—including burst release if present, the rate of change of the release kinetics, and the maximum duration of delivery at a minimum therapeutic concentration level. We have developed an indirect method for the quantification of release kinetics suitable for nanoparticle-based drug delivery systems that utilizes a hydrogel scaffold as a tissue surrogate to better emulate therapeutic delivery into a target tissue environment. Details of the method and its application to the release of an angiogenic peptide from a nanoparticle emulsion are provided in this communication.     

Non-van der Waals 2D Materials for Electrochemical Energy Storage

The development of advanced electrode materials for the next generation of electrochemical energy storage (EES) solutions has attracted profound research attention as a key enabling technology toward decarbonization and electrification of transportation. Since the discovery of graphene's remarkable properties, 2D nanomaterials, derivatives, and heterostructures thereof, have emerged as some of the most promising electrode components in batteries and supercapacitors owing to their unique and tunable physical, chemical, and electronic properties, commonly not observed in their 3D counterparts. This review particularly focuses on recent advances in EES technologies related to 2D crystals originating from non-layered 3D solids (non-van der Waals; nvdW) and their hallmark features pertaining to this field of application. Emphasis is given to the methods and challenges in top-down and bottom-up strategies toward nvdW 2D sheets and their influence on the materials’ features, such as charge transport properties, functionalization, or adsorption dynamics. The exciting advances in nvdW 2D-based electrode materials of different compositions and mechanisms of operation in EES are discussed. Finally, the opportunities and challenges of nvdW 2D systems are highlighted not only in electrochemical energy storage but also in other applications, including spintronics, magnetism, and catalysis.