ABSTRACT
Traditional pretreatment of lignocellulose is usually conducted under higher acidic and high temperature conditions, which leads to both the degradation of sugar and the condensation of lignin, hindering the subsequent conversion. An effective approach to fractionate lignocellulose into 93.9% of noncondensed lignin, 99.4% of cellulose, 17.8% of xylose, and 66.7% of xylooligosaccharides under mild conditions was developed using the formic acid solution at 80 °C for 100 min. The ß-O-4 bond content of lignin fractionated with formic acid (54.6 per 100 C9 units) was higher than dioxasolv lignin (48.4 per 100 C9 units), indicating that formic acid pretreatment well protected the ether bonds in lignin. Therefore, the hydrogenolysis of fractionated lignin contributed to 28.0% of aromatic monomer yield, which was comparable to dioxasolv lignin. As cellulose possesses a large amount of porosity because lignin was separated from lignocellulose, the hydrolysis of fractionated cellulose by molten salt hydrates gave a 96.4% of glucose yield.
Subject(s)
Cellulose , Lignin , Lignin/chemistry , Cellulose/chemistry , Xylose , Formates , Hydrolysis , BiomassABSTRACT
Objective: To explore the differences in event-related potentials (ERPs) of the subclinical types of major depressive disorders (MDD): melancholic (MEL), atypical (ATY), and anxious (ANX). Methods: Patients with MDD treated in the Clinical Department of Shanghai Mental Health Center between September 2017 and December 2020 were prospectively included. This study was approved by the Ethics Committee of the Shanghai Mental Health Center. They were evaluated using the Mini-International Neuropsychiatric Interview (MINI), 17-item Hamilton Depression Scale (HAMD-17), 30-item Self-rated Inventory of Depressive Symptomatology (IDS-30SR), 16-item Quick Inventory of Negative Symptom Scale (QIDS-16SR), and auditory and visual P300 ERPs. Results: Finally, 27, 14, and 20 patients with MEL, ATY, and ANX MDD were included in this study, respectively. There were no significant differences in demographic characteristics and HAMD-17, IDS-30SR, and QIDS-16SR total scores among the three groups (all P > 0.05). On the C3 lead, the latency for patients with MEL MDD was the longest, and the latency for patients with ATY MDD was the shortest (MEL vs. ATY vs. ANX: 373.89 ± 6.60 vs. 344.79 ± 9.78 vs. 359.33 ± 7.62, P = 0.039). On the Pz lead, the latency for patients with MEL MDD was the longest, and the latency for patients with ATY MDD was the shortest (MEL vs. ATY vs. ANX: 376.14 ± 6.51 vs. 347.21 ± 9.42 vs. 362.22 ± 8.63, P = 0.047). There were no differences in visual P300 ERPs among the three groups. Conclusion: There are significant differences in auditory C3 and Pz latency among MEL, ATY, and ANX MDD. These differences could help diagnose the subtype of MDD.
ABSTRACT
The traditional pretreatment leads to the recalcitration of C-C bonds during lignin fractionation, thus hindering their depolymerization into aromatic monomers. It is essential to develop an applicable approach to extract noncondensed lignin for its high-value applications. In this work, noncondensed lignins were extracted from poplar sawdust using recyclable p-toluenesulfonic acid for cleaving lignin-carbohydrate complex bonds effectively and ethanol as a stabilization reagent to inhibit lignin condensation. Lignin yield of 83.74% was recovered by 3 mol/L acid in ethanol at 85 °C for 5 h, and carbohydrates were well preserved (retaining 98.97% cellulose and 50.01% hemicelluloses). During lignin fractionation, the acid concentration and extraction time were the major drivers of condensation. Ethanol reacted with lignin at the α-position to prevent the formation of the condensed structure. The extracted lignin depolymerized over the Pd/C catalysts gave a yield of 50.35% of aromatic monomers, suggesting that the novel extraction process provided a promising way for noncondensed lignin production.