Gunnfigueroa1926

In this study, a series of chitosan derivatives bearing active halogenated aromatic imines were successfully synthesized via Schiff bases with the high degrees of substitution. Detailed structural characterization was carried out using Fourier transform infrared (FTIR) spectroscopy, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. Besides, the antifungal activity against three common plant pathogenic fungi, including Botrytis cinerea, Fusarium oxysporum f. sp. cucumerinum, and Fusarium oxysporum f. sp. niveum, was investigated using in vitro hyphal measurements. The results showed that double Schiff bases of chitosan derivatives exhibited enhanced antifungal activity compared with chitosan, especially at 1.0 mg/mL. The double Schiff bases of chitosan bearing halogeno-benzenes showed >95% inhibitory indices at 1.0 mg/mL against Botrytis cinereal since halogens had the stronger electron-withdrawing property. The higher degree of substitution was another positive effect to improve the antifungal activity. This study provides a practical strategy to synthesize new double Schiff bases of chitosan derivatives bearing halogeno-benzenes, which could be developed into stronger antifungal agents.In order to understand the effects of emulsion particle sizes on the properties of novel konjac glucomannan (KGM)-based emulsion films, four types of Pickering emulsions with different oil phase (10%, 30%, 50% and 70%, v/v) were prepared by the same stabilizers (2% BCNs/SPI colloidal particles dispersions) and added into the film-forming solutions to keep the same final oil content (0.2%, w/v) in all KGM-based emulsion films. The results showed that the average particle sizes of the prepared Pickering emulsion increased with the increase of the oil phase in emulsion system. The microstructure analyses indicated that the KGM-based emulsion films became smoother as the emulsion particle sizes increased. Moreover, the contact angle values of KGM-based emulsion films slightly increased with the increase of the emulsion particle sizes, while the thermal stability of KGM-based films was not significantly affected by the particle sizes. Furthermore, the KGM-based emulsion films formed mainly through the hydrogen bond interactions as analyzed by FTIR. In addition, with the increase of the emulsion particle sizes, physical and mechanical properties of KGM-based emulsion films were significantly affected. Taken together, these results suggested that the particle sizes of Pickering emulsions had remarkable effects on the properties of KGM-based emulsion films.Active composite films were developed by incorporating different concentration of dihydromyricetin (DMY) into konjac glucomannan (KGM)/gellan gum (GG) matrix. Physicochemical, mechanical, released behaviour, antioxidant and antimicrobial properties of composite films were investigated. The results from the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) indicated that DMY which well-dispersed in the KGM/GG matrix interacted with matrix through hydrogen bonds. The obtained films presented predominant thermostability, good water resistance property, excellent ultraviolet light barrier ability and sustained controlled release behaviour. In particular, the incorporation of DMY remarkably enhanced the antioxidant and antimicrobial activities of the films. Overall, the fabricated KGM/GG-DMY composite films have a promising application in the fields of food packaging.To reveal the structural characteristics and physicochemical properties of perennial ryegrass lignin, sequential alkali extractions or double ball-milling and enzymatic hydrolysis on the basis of ultrasonic and hydrothermal pretreatments were proposed in this study. Results revealed that sequential alkali extractions released 89.4% of original lignin from the ryegrass cell walls and 0.75-4.16% of associated carbohydrates as compared to the double ball-milling and enzymatic hydrolysis (96.0% and 18.39%). It was observed that the two types of lignin prepared were SGH-type and had different amounts of p-coumarates and ferulates, and primarily consisted of β-O-4' linkages combined with minor amounts of β-β' and β-5' linkages. Besides, alkali-soluble lignins exhibited relatively fewer β-O-4' linkages, higher S/G ratios and H-type units, and abundant phenolic OH groups as compared to the double enzymatic lignin. Overall, the deeper investigation of the lignin structure of ryegrass will provide useful information for the efficient utilization of lignin macromolecules in biorefineries.Friendships constitute important relationships, and often function to reduce stress, but have been under-studied. In mother-child dyads, infants coordinate their stress response with their caregivers without experiencing the stressor themselves. The current study used a modified version of the Trier Social Stress Test to examine whether i) friends are physiologically attuned (i.e., cortisol and progesterone); ii) attunement differs as a function of social acceptance or rejection external to the dyad; and, iii) friends can 'catch' a stress response only through non-verbal cues. TH1760 Friends showed both cortisol and progesterone attunement at the beginning of the study. Friends showed cortisol attunement across time and conditions. Friends' progesterone levels were significantly, but negatively associated across time and conditions. They did not, however, show a stress contagion as a result of one friend experiencing stress. These findings suggest that cortisol and progesterone play different roles in the attunement of stress and subsequent affiliation.Economic decisions are characterized by their uncertainty and the lack of explicit feedback that indicates the correctness of decisions at the time they are made. Nevertheless, very little is known about the neural mechanisms involved in this process. Our study sought to identify the neurophysiological correlates of purchase decision-making in situations where the optimal purchase time is not known. EEG was recorded in 24 healthy subjects while they were performing a new experimental paradigm that simulates real economic decisions. At the time of price presentation, we found an increase in the P3 Event-Related Potential and induced theta and alpha oscillatory activity when participants chose to buy compared to when they decided to wait for a better price. These results reflect the engagement of attention and executive function in purchase decision-making and might help in the understanding of brain mechanisms underlying economic decisions in uncertain scenarios.