Stephenshauge9488

The aim of this work was to develop environmentally safe multi-purpose composite films based on maize starch (St), low weight chitosan (Chit), and Polyvinyl Alcohol (PVA). To this end the structural features and functional characteristics of the films were evaluated. The PVA content in the blends was varied in the range of 0-40 wt% (based on the total weight of the blend), the St/Chit ratio was fixed at 70/30 in weight. The results of the St/Chit/PVA composite films analysis by X-ray diffraction, FTIR spectroscopy, and SEM methods showed that the PVA concentration increase in the compositions resulted in phase separation between PVA and two other components of the blends, while the intermolecular interactions between St and Chit grew. The mechanical characteristics of the composite films improved with an increase in the PVA concentration. The UV-protective ability and biodegradation rate of St/Chit/PVA films decreased as the PVA content grew. The results of this systematic study enabled us to recommend the 10-20 wt% PVA additions to the St/Chit (70/30) matrix as an optimal supplement ensuring the formation of the films with advanced mechanical and functional characteristics without loss of biodegradability. V.Glycosylation is one of the most efficient biocompatible methodologies to enhance the water solubility of natural products, and therefore their bioavailability. The excellent regio- and stereoselectivity of nucleotide sugar-dependent glycosyltransferases enables single-step glycosylations at specific positions of a broad variety of acceptor molecules without the requirement of protection/deprotection steps. However, the need for stoichiometric quantities of high-cost substrates, UDP-sugars, is a limiting factor for its use at an industrial scale. To overcome this challenge, here we report tailor-made coimmobilization and colocalization procedures to assemble a bi-enzymatic cascade composed of a glycosyltransferase and a sucrose synthase for the regioselective 5-O-β-D-glycosylation of piceid with in situ cofactor regeneration. Coimmobilization and colocalization of enzymes was achieved by performing slow immobilization of both enzymes inside the porous support. The colocalization of both enzymes within the porous structure of a solid support promoted an increase in the overall stability of the bi-enzymatic system and improved 50-fold the efficiency of piceid glycosylation compared with the non-colocalized biocatalyst. Finally, piceid conversion to resveratrol 3,5-diglucoside was over 90% after 6 cycles using the optimal biocatalyst and was reused in up to 10 batch reaction cycles accumulating a TTN of 91.7 for the UDP recycling. V.To improve the properties of polylactic acid-grafted-bamboo fiber/polylactic acid (PLA-g-BF/PLA) composite, a compatible interface was constructed by adding nano-silica (nano-SiO2). The results showed that, with increased nano-SiO2 mass ratio, the composites' mechanical strength and water resistance were significantly improved. The composite with a 1.5% nano-SiO2 mass ratio exhibited the best mechanical properties and water resistance. Strain scanning results showed that the strain value at which the storage module (G') of the composite began to decrease was the largest with 1.5% nano-SiO2 and the G' and complex viscosity (η*) of the composite also reached the best state at this point. The interfacial compatibility between PLA-g-BF and PLA was also confirmed to be the best at this mass ratio. SEM and TEM analyses indicated that, when the mass ratio of nano-SiO2 was 1.5%, nanoparticles were uniformly dispersed in the composite and PLA-g-BF and PLA in a state of integration. The addition of nano-SiO2 was beneficial for the crystallization and nucleation of PLA, and composite crystallinity with 1.5% nano-SiO2 reached the maximum value. With increased interfacial compatibility and crystallinity of the composite, the thermal stability was also best when the mass ratio of nano-SiO2 was 1.5%. A new Schiff base of chitosan, namely Piperonal-chitosan (Pip-Cht), was synthesized for the first time, using a microwave irradiation method and characterized using spectroscopic techniques. The corrosion inhibition behavior of the new Schiff base was evaluated on carbon steel in 15% HCl medium via gravimetric and electrochemical techniques. This is the first work on the application of chemically functionalized chitosan as a corrosion inhibitor in the oil-well acidizing environment. The Pip-Cht inhibitor exhibited a high corrosion inhibition efficiency of 85.16% at a moderate dose of 600 mg L-1. Further, the addition of potassium iodide as a synergistic agent to the corrosive electrolyte produced a significant improvement in the inhibition efficiency to 91.15% at a low dosage of 10 mM of KI. At a higher temperature of 65 °C, the combination of both the inhibitor and KI yielded a high inhibition efficiency. The results of the gravimetric and electrochemical experiments were corroborated using AFM and SEM studies. The DFT calculations indicated that corrosion inhibition behavior of the Schiff base mainly occurs in the protonated form. V.The clustered regularly interspaced short palindromic repeats (CRISPR) system and the Cas9-derived proteins have been applied to genome editing in various organisms. Traditional Cas9 is typically used to knockout genes or specific DNA fragments based on the generation of double-stranded breaks, whereas nCas9 and dCas9 are fused with effectors to perform base pair transitions or epigenetic modification and regulation. However, this system has off-target effects and can cause genomic structure variations. Here, we comparatively analyzed Cas9 and BE3, an initial base editor based on the nCas9 fusion protein, in silkworms. Our results showed that base editing was superior to Cas9 in silkworm cultured cells. BE3 introduced accurate termination codons, whereas Cas9 did not. dBET6 Moreover, Cas9 induced chromosome translocation, chromosome fragment repetition, and chromosome fragment deletion, with the deletion frequency reaching up to 4.29%. BE3 was not able to induce these changes in our study. Furthermore, Cas9-derived proteins blocked ribosome advance and mRNA transcription for 9 days, with a 9.