Preparation and characterization of silver nanoparticles in natural polymers using laser ablation

In this paper we have done a comparative study on efficiency of natural polymers for stabilizing silver nanoparticles (Ag-NPs) prepared by laser ablation technique. The selected polymers are starch (St), gelatin (Gt) and chitosan (Ct). The fabrication process was carried out through ablation of a pure Ag plate by nanosecond Q-switched Nd?CYg pulsed laser (?? = 532?nm, 360?mJ/pulse). The stability of the samples was studied by measuring UV-visible absorption spectra of the samples one month after preparation. The result showed that the formation efficiency of NPs in St were highest and also the prepared NPs in St solution were more stable than other polymers during one month storage.     

Anti-proliferative effects of a small molecule inhibitor of CDK AT7519 on chronic myeloid leukemia (CML) cells through halting the transition of cells from G2/M phase of the cell cycle

Pathogenesis of chronic myeloid leukemia (CML) has mostly been studied with regard to the oncogenic role of BCR/ABL fusion; however, recent disclosures have declared that the challenges with the treatment of CML patients would not be resolved until the role of other aberrancies is ignored. Given the involvement of cyclin-dependent kinases (CDKs) in the pathogenesis of CML, the present study aimed to investigate the effects of a multi-CDK inhibitor AT7519 on BCR/ABL-harboring CML-derived K562 cells. Our results showed that AT7519 effectively reduced the survival of K562 and induced its anti-proliferative effect through the induction of G2/M arrest due to elevated p21 and p27. The resulting data also revealed that either direct or indirect suppression of c-Myc using specific c-Myc inhibitor 10058-F4 and selective PI3K inhibitor CAL-101 resulted in a superior cytotoxicity, suggesting that the activation of PI3K pathway could attenuate antileukemic effects of the inhibitor, at least partly, through a c-Mycdependent mechanism. To the best of our knowledge, to date, no study has addressed the effect of autophagy on CML cell response to AT7519, and, herein, we proposed for the first time that the suppression of autophagy boosted AT7519 cytotoxicity against K562. Overall, we suggested that selective CDK inhibitor AT7519 exerted antileukemic effect against CML cells and propose a novel therapeutic application for the inhibitor either as a single agent or in combination with c-Myc and/or PI3K inhibitors.     

Production of sustainable fibre-reinforced concrete incorporating waste chopped metallic film fibres and palm oil fuel ash

The consumption of waste materials is one of the essential concerns of waste management strategies in many parts of the world. With the advances in concrete technology, the utilisation of waste materials in the sustainable construction has developed increasingly widespread because of technological, economic and ecological advantages. This paper presents the workability and mechanical properties of concrete incorporating waste chopped metallic film (WCMF) fibres and palm oil fuel ash (POFA). Waste plastic results in waste discarding disaster and consequently causes significant harms to the environment. WCMF fibres were prepared by recycling metallic–plastic films used for food packaging. Six concrete mixes containing 0–1.25% WCMF fibres with a length of 20 mm were made of ordinary Portland cement (OPC). Further, six concrete mixes with the same fibre content were made, where 20% POFA substituted OPC. The combination of WCMF fibres and POFA decreased the workability of concrete mixes. The inclusion of WCMF fibres to OPC and POFA concrete mixes decreased the compressive strength. However, at the curing period of 91 days, the POFA-based mixes obtained higher compressive strength values than those of OPC-based mixtures. The positive interaction between WCMF fibres and POFA consequently enhanced the flexural and tensile strengths, impact resistance, thereby increasing energy absorption capacity and ductility of concrete composites. It revealed that WCMF fibres acted as a bridge arrester and improved the load-transfer capacity of the concrete specimens. The study showed that the utilisation of WCMF fibres in the production of sustainable concrete is a beneficial, affordable and feasible solution.     

Optimization and comparison of two different 3D culture methods to prepare cell aggregates as a bioink for organ printing

The ultimate goal of tissue engineering is to design and fabricate functional human tissues that are similar to natural cells and are capable of regeneration. Preparation of cell aggregates is one of the important steps in 3D tissue engineering technology, particularly in organ printing. Two simple methods, hanging drop (HD) and conical tube (CT) were utilized to prepare cell aggregates. The size and viability of the aggregates obtained at different initial cell densities and pre-culture duration were compared. The proliferative ability of the cell aggregates and their ability to spread in culture plates were also investigated. In both methods, the optimum average size of the aggregates was less than 500 μm. CT aggregates were smaller than HD aggregates. 5,000 cells per drop HD aggregates showed a marked ability to attach and spread on the culture surface. The proliferative ability reduced when the initial cell density was increased. Comparing these methods, we found that the HD method having better size controlling ability as well as enhanced ability to maintain higher rates of viability, spreading, and proliferation. In conclusion, smaller HD aggregates might be a suitable choice as building blocks for making bioink particles in bioprinting technique.     

Effects of Mentha longifolia L. essential oil on viability and cellular ultrastructure of Lactobacillus casei during ripening of probiotic Feta cheese

The effects of Mentha longifolia L. essential oil during ripening and storage probiotic Feta cheese were studied, in relation to viability and cellular ultrastructure of Lactobacillus casei. The addition of the essential oil in the concentrations from 0.0 to 0.03% was trialled: the 0.03% treatment resulted in the highest viability of L. casei and the lowest pH value compared with other treatments (P < 0.05). Electron microscopy showed that essential oil caused no harm to L. casei. This study demonstrated the favourable effects of M. longifolia on optimal maintenance of L. casei at the end of cheese storage period.     

Effect of R&D product and process expenditures on new product introductions

This study examines the relationship between the introduction of new products and R&D process and product expenditures of 15 industries. The objective is to determine the degree to which product and process R&D expenditures, uniquely or jointly, contribute to the development of new products. The findings suggest that concurrent R&D expenditures on products and processes lead to higher R&D output, as measured by new product announcements, than R&D expenditures on products or processes alone. As a by-product, the analysis clearly shows that the relationship between the number of new products introduced and product and process R&D expenditures can be represented by a function resembling the Cobb-Douglas production function