Tucker Balling (busport32)
Lignin is the second most abundant biobased material found on earth. It is produced mainly as a byproduct of pulp and paper industry and biorefineries. Despite its abundance, lignin valorization is not achieved on a large scale. Recently, there has been a growing demand for using the renewable and biodegradable raw materials in the commodity polymers. Potential use of lignin as a component in thermoplastic polymers is a promising approach for its value-added utilization. Given the vast applications of thermoplastic materials, there is lack of comprehensive review on lignin based thermoplastic polymers in literature. This review focuses on the utilization of lignin as functional and structural component of the thermoplastic polymers which requires structural modifications of lignin pertaining to the polymeric system. First, various lignin modifications were discussed in view of controlling the homogeneity, reactivity, processability and compatibility of lignin for successful thermoplastic copolymer synthesis and blend processing. Then, various copolymerization methodologies of lignin applicable for thermoplastic monomers are reviewed. Lastly, the lignin based thermoplastic blends are discussed which covers the lignin blends with various thermoplastic polymers and the chemical modifications required to improve its compatibility in polymer matrix. Some of the promising potential applications and future perspectives to achieve the goal of lignin-based commercial thermoplastics polymers are addressed.Systemic amyloidosis is a hereditary disorder that mostly arises as a result of specific point mutations to the wild type gene of lysozyme, forming mutant lysozyme variants leading to aggregation of the protein. The small monomeric protein Hen Egg White Lysozyme (HEWL) is a structural homolog of Human Lysozyme and is widely used as a model protein to investigate protein aggregation. In the present study, we have investigated the effect of 1-methylisatin, an indole derivative and glyoxal, a reactive dicarbonyl compound, on stress-induced aggregation of HEWL. Interaction of the compounds with HEWL induced changes in structure and surface hydrophobicity of the protein as evident from CD spectroscopy, tryptophan fluorescence and ANS binding studies. Additional experiments (Thioflavin T fluorescence, AFM imaging and DLS studies) demonstrate that stress induces amyloid-like fibrillation of HEWL, however, prior modification of the protein with glyoxal or 1-methylisatin significantly reduces its susceptibility to aggregation. High resolution mass spectrometric analysis indicated that 1-methylisatin primarily complexes with the protein in the form of a dimer. On the other hand, glyoxal-mediated modification of the protein induces formation of glycated adducts (carboxymethyllysine, hydroimidazolone). The results highlight possible clinical implications of the compounds in treatment of systemic amyloidosis and protein conformational disorder.Cultured murine macrophages (RAW 264.7) were used to investigate the effects of fracking sand dust (FSD) for its pro-inflammatory activity, in order to gain insight into the potential toxicity to workers associated with inhalation of FSD during hydraulic fracturing. While the role of respirable crystalline silica in the development of silicosis is well documented, nothing is known about the toxicity of inhaled FSD. The FSD (FSD 8) used in these studies was from an unconventional gas well drilling site. FSD 8was prepared as a 10 mg/ml stock solution in sterile PBS, vortexed for 15 s, and allowed to sit at room temperature for 30 min before applying the suspension to RAW 264.7cells. Compared to PBS controls, cellular viability was significantly decreased after a 24 h exposure to FSD. Intracellular reactive oxygen species (ROS) production and the production of IL-6, TNFα, and endothelin-1 (ET-1) were up-regulated as a result of the exposure, whereas the hydroxyl radical (.OH) was only detected in an acellular