A Comparative Study on the Flexural Behaviour of Rubberized and Hybrid Rubberized Reinforced Concrete Beams

This paper aims to investigate the flexural behaviour of the rubberized and hybrid rubberized reinforced concrete beams. A total of fourteen beams, 150×200 mm in cross-section with 1000 mm in length, were subject to a laboratory test over an effective span of 900 mm. The sand river aggregate was replaced by 10%, 12.5%, and 15% of crumb rubber (volume).   The hybrid structure contained two double layers: 1) rubberized reinforcement concrete at the top layer of the beam and 2) reinforcement concrete at the bottom layer of the concrete beam. The static responses by the flexural test of all the beams were evaluated in terms of their fresh properties, failure patterns, total energy, flexural strength, stiffness, and ultimate deflection, modulus of rupture, strain capacity, and ductility index. The results showed that there were improvements when the hybrid beams were used in most cases such as failure pattern, ultimate load, stiffness, modulus of rupture, and stress. The rubberized concrete beams showed improvements in the strain capacity as illustrated in strain gauges and stress-strain curves, toughness, ultimate deflection, and ductility index. The findings of the study revealed an improved performance with the use of the hybrid beams. This has resulted in the implementation of innovative civil engineering applications in the engineering sustainable structures

Untying a nanoscale knotted polymer structure to linear chains for efficient gene delivery in vitro and to the brain

The purpose of this study was to develop a platform transfection technology, for applications in the brain, which could transfect astrocytes without requiring cell specific functionalization and without the common cause of toxicity through high charge density. Here we show that a simple and scalable preparation technique can be used to produce a “knot” structured cationic polymer, where single growing chains can crosslink together via disulphide intramolecular crosslinks (internal cyclizations). This well-defined knot structure can thus “untie” under reducing conditions, showing a more favorable transfection profile for astrocytes compared to 25 kDa-PEI (48-fold), SuperFect® (39-fold) and Lipofectamine®2000 (18-fold) whilst maintaining neural cell viability at over 80% after four days of culture. The high transfection/lack of toxicity of this knot structured polymer in vitro, combined with its ability to mediate luciferase transgene expression in the adult rat brain, demonstrates its use as a platform transfection technology which should be investigated further for neurodegenerative disease therapies

A Fluorescently Labeled, Hyperbranched Polymer Synthesized from DE-ATRP for the Detection of DNA Hybridization

Journal articleThe early detection of oligonucleotide biomarkers of disease, such as microRNAs, has been established as a fundamental factor in cancer diagnosis. As the levels of these small molecules (microRNAs) in blood have recently been found to be significantly affected in cancer patients, they offer a means of early stage detection of cancer. Towards the goal of creating a novel method of DNA hybridization detection, we report the detection of specific sequences of small oligonucleotides in a model experiment carried out in serum. The results shown here display the versatility of the DE-ATRP method in synthesizing a specific polymer structure capable of changing its physical properties in the presence of double stranded DNA. The polymer was labeled and used to detect single-stranded DNA in serum successfully.peer-reviewe

Untying a nanoscale knotted polymer structure to linear chains for efficient gene delivery in vitro and to the brain

The purpose of this study was to develop a platform transfection technology, for applications in the brain, which could transfect astrocytes without requiring cell specific functionalization and without the common cause of toxicity through high charge density. Here we show that a simple and scalable preparation technique can be used to produce a "knot" structured cationic polymer, where single growing chains can crosslink together via disulphide intramolecular crosslinks (internal cyclizations). This well-defined knot structure can thus "untie" under reducing conditions, showing a more favorable transfection profile for astrocytes comp-red to 25 kDa-PEI (48-fold), SuperFect (R) (39-fold) and Lipofectamine (R) 2000 (18-fold) whilst maintaining neural cell viability at over 80% after four days of culture. The high transfection/lack of toxicity of this knot structured polymer in vitro, combined with its ability to mediate luciferase transgene expression in the adult rat brain, demonstrates its use as - platform transfection technology which should be investigated further for neurodegenerative disease therapies