Unrevealing the influence of reagent properties on disruption and digestibility of lignocellulosic biomass during alkaline pretreatment.

Beyond the conventional consideration of pretreatment severity (PS) responsible for biomass disruption, the influence of reagent properties on biomass (LCB) disruption is often overlooked. To investigate the LCB disruption as a function of reagent properties, reagents with distinct cations (NaOH and KOH) and significantly higher delignification potential were chosen. NaOH solution (3 % w/v) with a measured pH of 13.05 ± 0.01 is considered the reference, against which a KOH solution (pH = 13.05 ± 0.01) was prepared for LCB pretreatment under the same PS. Despite comparable lignin content, varying glucose yield of NaOH (68.76 %) and KOH (46.88 %) pretreated residues indicated the presence of heterogeneously disrupted substrate. Holocellulose extracted from raw poplar (ASC, control) and alkaline pretreated residues (C-NaOH and C-KOH) were analyzed using HPLC, XRD, SEM, TGA/DTG, XPS, and 13CP MAS NMR to investigate the pretreatment-induced structural modification. Results revealed that, despite the same pretreatment severity, better disruption in C-NaOH (higher accessible fibril surface and less-ordered region) leading to higher digestibility than C-KOH, likely due to the smaller ionic radius of Na+, facilitates better penetration into dense LCB matrix. This study elucidates the importance of considering the reagent properties during LCB pretreatment, eventually enhancing consciousness while selecting reagents for efficient LCB utilization.

Influence of Initial Severity of Depression on the Effectiveness of a Multimodal Therapy on Depressive Score, Heart Rate Variability, and Hemodynamic Parameters.

Depression is a major cause of disability among populations worldwide. Apart from primary symptoms, depressed patients often have a higher cardiovascular risk profile. Multimodal therapy concepts, including exercise, have emerged as promising approaches that not only improve depressive symptoms but also have a positive impact on cardiovascular risk profile. However, controversies have arisen concerning the influence of baseline severity on the effects of therapy concepts for this demographic. This study assessed whether pretreatment severity moderates psychological and physiological treatment outcomes of a multimodal therapy. A total of 16 patients diagnosed with mild depression (MD) and 14 patients diagnosed with severe depression (SD) took part in a 3-month outpatient multimodal treatment therapy. Before and after the treatment, depression score (Beck Depression Inventory (BDI)), peripheral systolic (pSBP) and diastolic (pDBP) blood pressure, central systolic (cSBP) and diastolic (cDBP) blood pressure, pulse wave velocity (PWV), heart rate (HR), and parasympathetic parameters of heart rate variability (RMSSD) were assessed. Significant time effects were detected for BDI (−20.0 ± 11.6, p > 0.001, η2 = 0.871), pSBP (−4.7 ± 6.8 mmHg, p < 0.001, η2 = 0.322), pDBP (−3.5 ± 6.9 mmHg, p = 0.01, η2 = 0.209), cSBP (−4.8 ± 6.5 mmHg, p < 0.001, η2 = 0.355), cDBP (−3.6 ± 6.8 mmHg, p = 0.008, η2 = 0.226), PWV (−0.13 ± 0.23 m/s, p = 0.008, η2 = 0.229), HR (4.3 ± 8.8 min−1, p = 0.015, η2 = 0.193), RMSSD (−12.2 ± 23.9 ms, p = 0.017, η2 = 0.251), and and SDNN (10.5 ± 17.8 ms, p = 0.005, η2 = 0.330). Significant time × group interaction could be revealed for BDI (p < 0.001, η2 = 0.543), with patients suffering from SD showing stronger reductions. Pretreatment severity of depression has an impact on the effectiveness of a multimodal therapy regarding psychological but not physiological outcomes.

Lignin fractionation to realize the comprehensive elucidation of structure-inhibition relationship of lignins in enzymatic hydrolysis.

A better understanding of the relationship between lignin structures and their inhibitory effects in enzymatic saccharification would facilitate the development of lignocellulose biorefinery process. However, the heterogeneity of lignins challenges the elucidation of lignin structure-inhibition correlation. In this study, two types of lignin fractions including ethanol soluble lignins and ethanol insoluble lignins were respectively isolated from the poplars pretreated with various severities. The impacts of pretreatment severities on the structural changes of lignin fractions were studied from the perspective of inter-units linkages, condensed aromatic substructure, and hydroxyl groups. Furthermore, it was observed that lignin addition strongly inhibited the enzymatic saccharification of pure cellulose by 13.3 âˆ¼ 56.3%. Lignin inhibition extents were increased with the elevated pretreatment severity. The relationships between the lignin structural features and lignin inhibition were analyzed, which revealed that the contents of condensed aromatic units and phenolic hydroxyl were crucial factors determining the lignin inhibition.

Predictors and Moderators of Clinical Outcomes in Adolescents with Severe Mental Disorders After an Assertive Community Treatment.

Previous studies have shown that stressful life events (SLEs), gender, social functioning and pretreatment severity are some of the predictors and/or moderators of treatment outcome in psychiatric care. The current study explored the effect of these predictors and moderators on the treatment outcome related to assertive community treatment (ACT) proposed to young people with severe mental disorders. 98 patients were assessed for externalizing and emotional difficulties, at admission and then at discharge of an ACT. Analyses revealed significant improvements in terms of symptomatology. In particular, regression analyses showed that pretreatment severity is a significant predictor of the outcome on emotional symptoms and is moderated by SLE on the outcome on externalizing symptoms. Furthermore, higher social functioning proved to predict better outcome on externalizing symptoms. Our results further evidence that these factors can explain inter-individual differences in outcome related to ACT. The theoretical and clinical implications of these results are discussed.

Effect of dilute acid pretreatment severity on the bioconversion efficiency of Phalaris aquatica L. lignocellulosic biomass into fermentable sugars.

The effect of dilute acid pretreatment severity on the bioconversion efficiency of Phalaris aquatica lignocellulosic biomass into fermentable sugar monomers was studied. The pretreatment conditions were expressed in a combined severity factor (CSF), ranged from 0.13 to 1.16. The concentration of xylose and total monomeric sugars released from hemicellulose increased with pretreatment as the CSF increased. Dilute acid pretreatment resulted in about 1.7-fold increase in glucose release relative to the untreated biomass, while CSF was positively correlated with glucose recovery. A maximum glucose yield of 85.05% was observed at high severity values (i.e. CSF 1.16) after 72 h. The total amount of sugars released (i.e. xylose and glucose) was increased with pretreatment severity and a maximum conversion efficiency of 76.1% of structural carbohydrates was obtained at a CSF=1. Our data indicated that Phalaris aquatica L. is an alternative bioethanol feedstock and that hemicellulose removal promotes glucose yield.

Influence of steam pretreatment severity on post-treatments used to enhance the enzymatic hydrolysis of pretreated softwoods at low enzyme loadings.

It is recognized that some form of post-treatment will usually be required if reasonable hydrolysis yields (>60%) of steam pretreated softwood are to be achieved when using low enzyme loadings (5 FPU/g cellulose). In the work reported here we modified/removed lignin from steam pretreated softwood while investigating the influence that the severity of pretreatment might have on the effectiveness of subsequent post-treatments. Although treatment at a lower severity could provide better overall hemicellulose recovery, post-treatment was not as effective on the cellulosic component. Pretreatment at medium severity resulted in the best compromise, providing reasonable recovery of the water soluble hemicellulose sugars and the use of post-treatment conditions that significantly increased the enzymatic hydrolysis of the water insoluble cellulosic component. Post-treatment with alkaline hydrogen peroxide or neutral sulfonation resulted in 62% cellulose hydrolysis at an enzyme loading of 5 FPU/g cellulose, which was four times greater than was obtained when the cellulosic fraction was not post-treated. When the enzyme loading was increased to 15 FPU/g cellulose, the post-treated cellulosic fraction was almost completely hydrolyzed to glucose. Despite the higher lignin content (44%) of the sulfonated substrate, similar hydrolysis yields to those achieved after alkaline peroxide post-treatment (14% lignin content) indicated that, in addition to lignin removal, lignin modification also plays an important role in influencing the effectiveness of hydrolysis when low enzyme loadings are used.