Recent advances in flame retardant and mechanical properties of polylactic acid: A review.

The large-scale application of ecofriendly polymeric materials has become a key focus of scientific research with the trend toward sustainable development. Mechanical properties and fire safety are two critical considerations of biopolymers for large-scale applications. Polylactic acid (PLA) is a flammable, melt-drop carrying, and strong but brittle polymer. Hence, it is essential to achieve both flame retardancy and mechanical enhancement to improve safety and broaden its application. This study reviews the recent research on the flame retardant functionalization and mechanical reinforcement of PLA. It classifies PLA according to the type of the flame retardant strategy employed, such as surface-modified fibers, modified nano/micro fillers, small-molecule and macromolecular flame retardants, flame retardants with fibers or polymers, and chain extension or crosslinking with other flame retardants. The functionalization strategies and main parameters of the modified PLA systems are summarized and analyzed. This study summarizes the latest advances in the fields of flame retardancy and mechanical reinforcement of PLA.

Nutritional and Pharmaceutical Applications of Under-Explored Knottin Peptide-Rich Phytomedicines.

Phytomedicines reportedly rich in cystine knot peptides (Knottins) are found in several global diets, food/herbal supplements and functional foods. However, their knottin peptide content has largely been unexplored, notably for their emerging dual potentials at both the food and medicine space. The nutritional roles, biological targets and mechanism(s) of activity of these knotted peptides are largely unknown. Meanwhile, knottins have recently been unveiled as emerging peptide therapeutics and nutraceuticals of primary choice due to their broad spectrum of bioactivity, hyper stability, selective toxicity, impressive selectivity for biomolecular targets, and their bioengineering applications. In addition to their potential dietary benefits, some knottins have displayed desirable limited toxicity to human erythrocytes. In an effort to appraise what has been accomplished, unveil knowledge gaps and explore the future prospects of knottins, an elaborate review of the nutritional and pharmaceutical application of phytomedicines rich in knottins was carried out. Herein, we provide comprehensive data on common dietary and therapeutic knottins, the majority of which are poorly investigated in many food-grade phytomedicines used in different cultures and localities. Findings from this review should stimulate scientific interest to unveil novel dietary knottins and knottin-rich nutraceutical peptide drug candidates/leads with potential for future clinical application.

Toward a New Generation of Fire-Safe Energy Storage Devices: Recent Progress on Fire-Retardant Materials and Strategies for Energy Storage Devices.

Over the last few decades, tremendous progress has been achieved in the development of advanced materials for energy storage devices. These achievements have largely enabled the adoption and transition to key technologies such as mobile phones, electric vehicles, and internet of things. However, the recent surge in fire accidents and explosions emanating from energy storage devices have been closely associated with the highly flammable components that make up these devices which have often led to the loss of life and property. Therefore, replacing flammable materials with fire retardant materials has been recognized as the critical solution to the ever-growing fire problem in these devices. This review summarizes the progress achieved so far in the field of fire retardant materials for energy storage devices. Finally, a perspective on the current state of the art is provided, and a future outlook for these fire-retardant materials, strategies, and new characterization methods is discussed.

Relationship between greenhouse gas emission, energy consumption, and economic growth: evidence from some selected oil-producing African countries.

This paper investigates the relationship between greenhouse gas emissions, energy consumption, and output growth among African OPEC countries (Libya, Nigeria, Angola, Algeria, Equatorial Guinea, and Gabon) using the panel autoregressive distributed lag model (PARDL) estimated by means of mean group (MG) and pooled mean group (PMG) for the period 1970-2016. The paper estimated three panel models comprising the components of greenhouse gasses which includes nitrous oxide, carbon dioxide (CO2), and methane and examined their relationship with economic growth and energy consumption. The findings of the study showed evidence of a positive impact of economic growth on both CO2 and methane emissions in the long run. Its impact on nitrous oxide emissions although positive was found to be statistically insignificant. Energy consumption was also found to produce an insignificant positive impact on CO2, methane, and nitrous oxide emissions in the long run. In the short run, economic growth exerts a significant positive effect on methane emissions; however, its effect on CO2 and nitrous oxide emissions although positive was found to be statistically insignificant. Energy consumption produces an insignificant impact on all components of greenhouse gasses in the short run. In addition, our empirical results showed the presence of a non-linear relationship between methane emissions and economic growth, confirming the existence of the environmental Kuznets curve (EKC) only in the case of methane emissions model.