Three-component cascade carbopalladation/Heck cyclization/borylation: facile access to boryl-functionalized indenes.

A mild Pd-catalyzed three-component cascade cyclization functionalization of o-iodostyrenes, internal alkynes and boron reagents is presented. The transformation is driven by a controlled reaction sequence of intermolecular carbopalladation, intramolecular Heck-type cyclization, and a borylation process to give versatile boryl-functionalized indene skeletons in a selective fashion. Significantly, (Bpin)2, (Bneop)2 and CH2(Bpin)2 as boron sources are all tolerated. Additionally, the synthetic utility of this approach is demonstrated by gram-scale synthesis and synthetic transformations.

Tunning the hydrophobic performance and thermal stability of pectin film by acetic anhydride esterification.

Pectin, a polysaccharide found in plant cell walls, is characterized by a high abundance of hydroxyl groups and carboxylic acid groups, which results in a strong affinity for water and limits its suitability as a film material. This study aimed to modulate the esterification degree of PEC films by adjusting the concentration of acetic anhydride, and assess the impact of acetic anhydride esterification modification on the properties of the resultant PEC films. The results demonstrated successful grafting of acetic anhydride onto the galacturonic acid ring in the PEC molecule through the esterification process. The hydrophobicity, thermal stability, barrier properties, and mechanical properties of the esterified PEC films were investigated. Among the various concentrations tested, the E-PEC-0.25 film exhibited the highest contact angle of 103.46° and tensile strength of 33.44 MPa, showcasing optimal performance. The E-PEC-0.1 film achieved the highest esterification degree of 0.94 and elongation at a break of 21.11 %. It also exhibited the transparency of 11.66 and the lowest water vapor transmission rate of 0.56 g·mm/(m2·h·kpa). Additionally, TGA and DSC tests revealed enhanced thermal stability of the esterification-prepared films. These findings highlight the potential of acetic anhydride tuning as a promising strategy for optimizing pectin film production.

Temporal Dynamics of Fungal Communities in Alkali-Treated Round Bamboo Deterioration under Natural Weathering.

Microbes naturally inhabit bamboo-based materials in outdoor environments, sequentially contributing to their deterioration. Fungi play a significant role in deterioration, especially in environments with abundant water and favorable temperatures. Alkali treatment is often employed in the pretreatment of round bamboo to change its natural elastic and aesthetic behaviors. However, little research has investigated the structure and dynamics of fungal communities on alkali-treated round bamboo during natural deterioration. In this work, high-throughput sequencing and multiple characterization methods were used to disclose the fungal community succession and characteristic alterations of alkali-treated round bamboo in both roofed and unroofed habitats throughout a 13-week deterioration period. In total, 192 fungal amplicon sequence variants (ASVs) from six phyla were identified. The fungal community richness of roofed bamboo samples declined, whereas that of unroofed bamboo samples increased during deterioration. The phyla Ascomycota and Basidiomycota exhibited dominance during the entire deterioration process in two distinct environments, and the relative abundance of them combined was more than 99%. A distinct shift in fungal communities from Basidiomycota dominant in the early stage to Ascomycota dominant in the late stage was observed, which may be attributed to the increase of moisture and temperature during succession and the effect of alkali treatment. Among all environmental factors, temperature contributed most to the variation in the fungal community. The surface of round bamboo underwent continuous destruction from fungi and environmental factors. The total amount of cell wall components in bamboo epidermis in both roofed and unroofed conditions presented a descending trend. The content of hemicellulose declined sharply by 8.3% and 11.1% under roofed and unroofed environments after 9 weeks of deterioration. In addition, the contact angle was reduced throughout the deterioration process in both roofed and unroofed samples, which might be attributed to wax layer removal and lignin degradation. This study provides theoretical support for the protection of round bamboo under natural weathering.

Evaluating the mechanism of soybean meal protein for boosting the laccase-catalyzed of thymol onto lignosulfonate via restraining non-specific adsorption.

The control of laccase-catalyzed efficiency often relies on the utilization of modifying enzyme molecules and shielding agents. However, their elevated costs or carcinogenicity led to the inability for large-scale application. To address this concern, we found that a low-cost protein from soybean meal can reduce lignin's ineffective adsorption onto enzymes for improving the efficiency of thymol grafting to lignosulfonate. The results demonstrated that by adding 0.5 mg/mL of additional soybean meal protein, the thymol reaction ratio of the modified lignosulfonate (L-0.5 S) significantly boosted from 18.1 % to 35.0 %, with the minimal inhibitory concentrations of the L-0.5 S against Aspergillus niger dramatically improved from 12.5 mg/mL to 3.1 mg/mL. Multiple characterization methods were employed to better understand the benefit of the modification under the addition of the soybean meal protein. The CO and R1-O group content increased from 20.5 % to 37.8 % and from 65.1 % to 75.5 %, respectively. The proposed potential reaction mechanism was further substantiated by the physicochemical properties. The incorporation of soybean meal effectively mitigated the non-specific adsorption of lignosulfonate, resulting in a reduction of the surface area of lignin from 235.0 to 139.2 m2/g. The utilization of soybean meal as a cost-effective and efficient shielding agent significantly enhanced the efficiency of subsequent enzyme catalysis. Consequently, the application of soybean meal in commercial enzyme catalysis holds considerable appeal and amplifies the relevance of this study in preservative industries.

Pd-Catalyzed Cascade Cyclization/Thiocarbonylation with Thioformates: Synthesis of Thioester-Functionalized Oxindoles.

A Pd-catalyzed thiocarbonylative cyclization of N-(o-iodoaryl)acrylamides with easily accessible thioformates has been developed. The reaction has a wide substrate scope with good yields and represents a powerful route to the synthesis of thioester-functionalized oxindoles. Both S-aryl and alkyl thioformates as the thioester sources were well tolerated. The active Pd-CO intermediate may play an important role in the transformation process.

Sequential In Situ-Formed Kukhtin-Ramirez Adduct and P(NMe2)3-Catalyzed O-Phosphination of α-Dicarbonyls with P(O)-H.

O-Phosphination of α-dicarbonyls via sequential in situ formation of a Kukhtin-Ramirez adduct and a P(NMe2)3-catalyzed process has been exploited for the synthesis of α-phosphoryloxy carbonyls. A range of P(O)-H derivatives, including diarylphosphine oxides, arylphosphinates, and phosphinates, are competent candidates to be introduced into the α-dicarbonyls in this transformation, and various α-phosphoryloxy carbonyls are obtained. This approach possesses advantages of mild conditions, simple operations, atom economy, high efficiency, and gram-scale synthesis, which make it promising in the synthesis toolbox.

Nonlinear strict distance and similarity measures for intuitionistic fuzzy sets with applications to pattern classification and medical diagnosis.

In this paper, we propose a new type of nonlinear strict distance and similarity measures for intuitionistic fuzzy sets (IFSs). Our proposed methods not only have good properties, but also improve the drawbacks proposed by Mahanta and Panda (Int J Intell Syst 36(2):615-627, 2021) in which, for example, their distance value of [Formula: see text] is always equal to the maximum value 1 for any intuitionistic fuzzy number [Formula: see text]. To resolve these problems in Mahanta and Panda (Int J Intell Syst 36(2):615-627, 2021), we establish a nonlinear parametric distance measure for IFSs and prove that it satisfies the axiomatic definition of strict intuitionistic fuzzy distances and preserves all advantages of distance measures. In particular, our proposed distance measure can effectively distinguish different IFSs with high hesitancy. Meanwhile, we obtain that the dual similarity measure and the induced entropy of our proposed distance measure satisfy the axiomatic definitions of strict intuitionistic fuzzy similarity measure and intuitionistic fuzzy entropy. Finally, we apply our proposed distance and similarity measures to pattern classification, decision making on the choice of a proper antivirus face mask for COVID-19, and medical diagnosis problems, to illustrate the effectiveness of the new methods.

Palladium-Catalyzed Allylation of P(O)H Compounds: Access to 2-Fluoroallylic Phosphorus Compounds.

An efficient palladium-catalyzed 2-fluoroallylation of P(O)H compounds with gem-difluorocyclopropanes is presented. The reaction provides a variety of 2-fluoroallylic phosphorus compounds in good yields with high Z selectivity through the sequential C-C bond activation, C-F bond cleavage, and C-P coupling process. Various H-phosphonates, H-phosphinates, and secondary phosphine oxides are all tolerated. In addition, the gram-scale synthesis and the late-stage modification of complex bioactive molecules show practical utilities of the transformation.

Palladium-Catalyzed Heck Cyclization with P(O)H Compounds to Construct Phosphinonyl-Azaindoline and -Azaoxindole Derivatives.

We report herein a concise method for the construction of phosphinonyl-azaindoline and -azaoxindole derivatives via a palladium-catalyzed cascade cyclization with P(O)H compounds. Various H-phosphonates, H-phosphinates, and aromatic secondary phosphine oxides are all tolerated under the reaction conditions. Furthermore, the phosphinonyl-azaindoline isomer families such as 7-, 5-, and 4-azaindolines could be synthesized in moderate to good yields.

Mechanistic insights into the cinnamaldehyde modification of lignin for sustainable anti-fungal reagent.

The limited anti-fungal activity of enzymatic hydrolysis lignin (EHL) has been a challenge in its direct application as a bamboo preservative. To address this issue, the cinnamaldehyde modification of EHL was carried out to introduce anti-fungal structures into the lignin matrix, effectively enhancing its anti-fungal activity. The results demonstrated that the minimal inhibitory concentrations of the modified lignin (EHL-DC) against Aspergillus niger significantly improved from 16 mg/mL to 1 mg/mL, with comparable enhancements in anti-fungal activity against other fungi. As a result of the modification, the EHL-DC is more prone to interact with fungal cell membranes, contributing to a roughened, shrunken hyphal surface and a decrease in mycelial biomass. Multiple characterization methods were employed to better grapple with the EHL-DC chemical changes. The nitrogen content increased from 2.3 % to 8.3 %, and alterations in elemental compositions further support the proposed reaction mechanism and its role in enhancing EHL's anti-fungal activity. This study offers novel insights into the high-value utilization of enzymatic hydrolysis lignin based on green chemistry principles.

Exploration of Optimal Reaction Conditions for Constructing Hydrophobic Polymers with Low Deformation to Facilitate the Dimensional Stability of Laminated Bamboo Lumber.

The environmental moisture changes would result in the deformation and cracking of laminated bamboo lumber (LBL) easily due to the unreleased internal stress, leading to poor durability. In this study, a hydrophobic cross-linking polymer with low deformation was successfully fabricated and introduced in the LBL by polymerization and esterification to improve its dimensional stability. In an aqueous solution, the 2-hydroxyethyl methacrylate (HEMA) and Maleic anhydride (MAh) were employed as the base compounds for synthesizing the copolymer of 2-hydroxyethyl methacrylate and maleic acid (PHM). The hydrophobicity and swelling performance of the PHM was adjusted by controlling the reaction temperatures. PHM-modified LBL's hydrophobicity as indicated by the contact angle, increased from 58.5° to 115.2°. The anti-swelling efficiency was also improved. Moreover, multiple characterizations were applied to clarify the structure of PHM and its bonding linkages in LBL. This study demonstrates an efficient avenue to facilitate the dimensional stability of LBL by PHM modification and sheds new light on the efficient utilization of LBL using a hydrophobic polymer with low deformation.

Succession of Fungal Community during Outdoor Deterioration of Round Bamboo.

Bamboo's mechanical and aesthetic properties are significantly influenced by fungi. However, few studies have been conducted to investigate the structure and dynamics of fungal communities in bamboo during its natural deterioration. In this study, fungal community succession and characteristic variations of round bamboo in roofed and unroofed environments over a period of 13 weeks of deterioration were deciphered using high-throughput sequencing and multiple characterization methods. A total of 459 fungal Operational Taxonomic Units (OTUs) from eight phyla were identified. The fungal community's richness of roofed bamboo samples showed an increasing trend, whereas that of unroofed bamboo samples presented a declining trend during deterioration. Ascomycota and Basidiomycota were the dominant phyla throughout the deterioration process in two different environments: Basidiomycota was found to be an early colonizer of unroofed bamboo samples. Principal Coordinates Analysis (PCoA) analysis suggested that the deterioration time had a greater impact on fungal community variation compared to the exposure conditions. Redundancy analysis (RDA) further revealed that temperature was a major environmental factor that contributed to the variation in fungal communities. Additionally, the bamboo epidermis presented a descending total amount of cell wall components in both roofed and unroofed conditions. The correlation analysis between the fungal community and relative abundance of three major cell wall components elucidated that Cladosporium was negatively correlated with hemicellulose in roofed samples, whereas they presented a positive correlation with hemicellulose and a negative correlation with lignin in unroofed samples. Furthermore, the contact angle decreased during the deterioration process in the roofed as well as unroofed samples, which could arise from the degradation of lignin. Our findings provide novel insights into the fungal community succession on round bamboo during its natural deterioration and give useful information for round bamboo protection.

Highly regioselective and stereoselective cascade reductive cyclization of δ-ketoamide: practical access to oxa-bridged benzazepines.

A highly regioselective and stereoselective cascade reduction cyclization of δ-ketoamide is realized under LiAlH4-assisted conditions, providing an atom-economical and straightforward approach to access oxa-bridged benzazepines in moderate to good yields. This method overcomes the limitations of aldehydes or other precursors of primary alcohols and realizes the cascade reduction cyclization of secondary alcohol anions generated in situ from ketones. The reaction proceeds with broad substrate scope and good functional group compatibility.

Palladium-Catalyzed Cyclization Coupling with Cyclobutanone-Derived N-Tosylhydrazones: Synthesis of Benzofuran-3-Cyclobutylidenes and Spirocyclobutanes.

A palladium-catalyzed cyclization coupling of iodoarene-tethered alkynes with cyclobutanone-derived N-tosylhydrazones is reported, providing a convenient and efficient approach to benzofuran-3-cyclobutylidenes. On this basis, spirocyclobutanes can be generated smoothly in an efficient cascade manner by the addition of dienophiles. Good yields and scalability are demonstrated. Sequential intramolecular carbopalladation, palladium-carbene migratory insertion, δ-hydride elimination, and cycloaddition processes are involved.

Stabilizing and Enhancing Link Prediction through Deepened Graph Auto-Encoders.

Graph neural networks have been widely used for a variety of learning tasks. Link prediction is a relatively under-studied graph learning task, with current state-of-the-art models based on one- or two-layer shallow graph auto-encoder (GAE) architectures. In this paper, we overcome the limitation of current methods for link prediction of non-Euclidean network data, which can only use shallow GAEs and variational GAEs. Our proposed methods innovatively incorporate standard auto-encoders (AEs) into the architectures of GAEs to capitalize on the intimate coupling of node and edge information in complex network data. Empirically, extensive experiments on various datasets demonstrate the competitive performance of our proposed approach. Theoretically, we prove that our deep extensions can inclusively express multiple polynomial filters with different orders. The codes of this paper are available at https://github.com/xinxingwu-uk/DGAE.

Deep learning algorithm reveals probabilities of stage-specific time to conversion in individuals with neurodegenerative disease LATE.

Introduction: Limbic-predominant age-related TAR DNA-binding protein 43 (TDP-43) encephalopathy (LATE) is a recently defined neurodegenerative disease. Currently, there is no effective way to make a prognosis of time to stage-specific future conversions at an individual level. Methods: After using the Kaplan-Meier estimation and log-rank test to confirm the heterogeneity of LATE progression, we developed a deep learning-based approach to assess the stage-specific probabilities of time to LATE conversions for different subjects. Results: Our approach could accurately estimate the disease incidence and transition to next stages: the concordance index was at least 82% and the integrated Brier score was less than 0.14. Moreover, we identified the top 10 important predictors for each disease conversion scenario to help explain the estimation results, which were clinicopathologically meaningful and most were also statistically significant. Discussion: Our study has the potential to provide individualized assessment for future time courses of LATE conversions years before their actual occurrence.

Machine Learning Approach Predicts Probability of Time to Stage-Specific Conversion of Alzheimer's Disease.

BACKGROUND: The progression of Alzheimer's disease (AD) varies in different patients at different stages, which makes predicting the time of disease conversions challenging. OBJECTIVE: We established an algorithm by leveraging machine learning techniques to predict the probability of the conversion time to next stage for different subjects during a given period. METHODS: Firstly, we used Kaplan-Meier (KM) estimation to get the transition curves of different AD stages, and calculated Log-rank statistics to test whether the progression rate between different stages was identical. This quantitatively confirmed the progression rates known in the literature. Then, we developed an approach based on deep learning model, DeepSurv, to predict the probabilities of time-to-conversion. Finally, to help interpret the deep learning model in our approach, we identified important variables contributing the most to the DeepSurv prediction, whose significance were validated with the analysis of variance (ANOVA). RESULTS: Our machine learning approach predicted the time to conversion with a high accuracy. For each of the different stages, the concordance index (CI) of our approach was at least 86%, and the integrated Brier score (IBS) was less than 0.1. To facilitate interpretability of the prediction results, our approach identified the top 10 variables for each disease conversion scenario, which were clinicopathologically meaningful, and most of them were also statistically significant. CONCLUSION: Our study has the potential to provide individualized prediction for future time course of AD conversions years before their actual occurrence, thus facilitating personalized prevention and intervention strategies to slow down the progression of AD.

Simultaneously reinforcing and toughening of shape-memory epoxy resin with carboxylated lignosulfonate: Facile preparation and effect mechanism.

To improve the compatibility and reactivity of lignosulfonate (LS) with epoxy oligomers, the LS was firstly functionalized with anhydride via the carboxylation reaction. The carboxylated lignosulfonate (CLS) reinforced epoxy resin with excellent mechanical and shape memory performance was prepared facilely via distributing the CLS into the combined epoxy monomers of DGEBA and PEGDGE with the aid of water, rather than using the normal organic solvents. The incorporated CLS promoted the curing reaction of epoxy resin. A typical sea-island structure was formed in the cured sample at the CLS content of 5 phr, exhibiting the highest increases in tensile strength, modulus, elongation at break and toughness by 23.8 %, 18.2 %, 217 % and 113 %, respectively, relative to neat epoxy. Interestingly, the incorporation of CLS at a proper amount led to the simultaneous strengthening and toughing effects on cured epoxy resin, which could be attributed to the rigid structure of CLS covalently introduced in the epoxy resin network and the heterogeneous structure formed in the epoxy matrix. The rigid CLS component also restrained the movement of chain segments, consequently, the mechanical stability was enhanced and the fast shape recovery rate of epoxy resin network was slowed down to some extent.

Palladium-catalyzed Heck cyclization/carbonylation with formates: synthesis of azaindoline-3-acetates and furoazaindolines.

We report herein a palladium-catalyzed domino cyclization/carbonylation to access ester-functionalized azaindolines, applying formates as a convenient carbonyl source. All four azaindoline isomers were constructed, exhibiting good functional group compatibility. On this basis, modifying the starting tether on the aminopyridine led to furoazaindolines via an intramolecular reductive cyclization after the palladium-catalyzed process.

In Situ Construction of Thermotropic Shape Memory Polymer in Wood for Enhancing Its Dimensional Stability.

The extension of wood to a wider field has been restrained significantly due to its dimensional instability that arises from variation in moisture content, which in turn brings about the risk of cracking, warping or distortion. This work proposed a novel strategy to stabilize wood by means of the in situ construction of a thermotropic shape memory polymer (SMP) inside wood. The cross-linked copolymer network (PMP) with good shape memory behavior was first investigated based on the reaction of methyl methacrylate (MMA) and polyethylene glycol diacrylate (PEGDA) in a water/ethanol solution; then, the PMP was constructed inside wood via vacuum-pressure impregnation and in situ polymerization. The weight gain, volume increment and morphology observations clearly revealed that the PMP was mainly present in wood cell lumens, cell walls and pits. The presence of PMP significantly enhanced the dimensional stability of and reduced the cracks in wood. The desirable shape recovery abilities of PMP under heating-cooling cycles were considered to be the main reasons for wood dimensional stabilization, because it could counteract the internal stress or retard the shrinkage of cell walls once water was evaporated from the wood. This study provided a novel and reliable approach for wood modification.