Nickel-Catalyzed Reductive [4 + 1] Sila-Cycloaddition of 1,3-Dienes with Dichlorosilanes.

Transition-metal-catalyzed sila-cycloaddition has been a promising tool for accessing silacarbocycle derivatives, but the approach has been limited to a selection of well-defined sila-synthons. Herein, we demonstrate the potential of chlorosilanes, which are industrial feedstock chemicals, for this type of reaction under reductive nickel catalysis. This work extends the scope of reductive coupling from carbocycle to silacarbocycle synthesis and from single C-Si bond formation to sila-cycloaddition reactions. The reaction proceeds under mild conditions and shows good substrate scope and functionality tolerance, and it offers new access to silacyclopent-3-enes and spiro silacarbocycles. The optical properties of several spiro dithienosiloles as well as structural variations of the products are demonstrated.

The Effect of Cooling Rates on Thermal, Crystallization, Mechanical and Barrier Properties of Rotational Molding Polyamide 11 as the Liner Material for High-Capacity High-Pressure Vessels.

The rapid development of hydrogen fuel cells has been paralleled by increased demand for lightweight type IV hydrogen storage vessels with high hydrogen storage density, which raises the performance requirements of internal plastic liners. An appropriate manufacturing process is important to improve the quality of polymer liners. In this paper, DSC, WAXD, a universal testing machine and a differential pressure gas permeameter were used to investigate the effect of the cooling rate of the rotational molding polyamide 11 on the thermal, crystallization, mechanical and barrier properties. The cooling rate is formulated according to the cooling rate that can be achieved in actual production. The results suggest that two PA11 liner materials initially exhibited two-dimensional (circular) growth under non-isothermal crystallization conditions and shifted to one-dimensional space growth due to spherulite collision and crowding during the secondary crystallization stage. The slower the cooling process, the greater the crystallinity of the specimen. The increase in crystallinity significantly improved the barrier properties of the two PA11 liner materials, and the gas permeability coefficient was 2-3-fold higher than at low crystallinity. Moreover, the tensile strength, the tensile modulus, the flexural strength, and the flexural modulus increased, and the elongation at break decreased as the crystallinity increased.

Improved Bayesian Optimization Framework for Inverse Thermal Conductivity Based on Transient Plane Source Method.

In order to reduce the errors caused by the idealization of the conventional analytical model in the transient planar source (TPS) method, a finite element model that more closely represents the actual heat transfer process was constructed. The average error of the established model was controlled at below 1%, which was a significantly better result than for the analytical model, which had an average error of about 5%. Based on probabilistic optimization and heuristic optimization algorithms, an optimization model of the inverse heat transfer problem with partial thermal conductivity differential equation constraints was constructed. A Bayesian optimization algorithm with an adaptive initial population (BOAAIP) was proposed by analyzing the influencing factors of the Bayesian optimization algorithm upon inversion. The improved Bayesian optimization algorithm is not affected by the range and individuals of the initial population, and thus has better adaptability and stability. To further verify its superiority, the Bayesian optimization algorithm was compared with the genetic algorithm. The results show that the inversion accuracy of the two algorithms is around 3% when the thermal conductivity of the material is below 100 Wm-1K-1, and the calculation speed of the improved Bayesian optimization algorithm is three to four times faster than that of the genetic algorithm.

Nickel-Catalyzed Cross-Electrophile 1,2-Silyl-Arylation of 1,3-Dienes with Chlorosilanes and Aryl Bromides.

Catalytic, three-component, cross-electrophile reactions have recently emerged as a promising tool for molecular diversification, but studies have focused mainly on the alkyl-carbonations of alkenes. Herein, the scope of this method has been extended to conjugated dienes and silicon chemistry through silylative difunctionalization of 1,3-dienes with chlorosilanes and aryl bromides. The reaction proceeds under mild conditions to afford 1,2-linear-silylated products, a selectivity that is different to those obtained from conventional methods via an intermediary of H(C)-η3 -π-allylmetal species. Preliminary mechanistic studies reveal that chlorosilane reacts with 1,3-diene first and then couples with aryl bromide.

Optimization of the Laminate Structure of a Composite Cylinder Based on the Combination of Response Surface Methodology (RSM) and Finite Element Analysis (FEA).

This study optimized the laminate structure of a composite cylinder under the constraint of minimum layup thickness. Based on the progressive damage theory, a finite element model of the cylinder was established, and the NOL ring tensile test was used to verify the accuracy of the damage theory. The winding angle, the number of layers, and the helical/hoop ratio (the stacking sequence) were selected as the optimization factors, and the burst pressure value was used to evaluate the quality of the laminate structure. Then the orthogonal experiments were designed by RSM. Combined with FEA, the function model of the burst pressure of the gas cylinder and each optimization factor was established to obtain the optimal layering scheme, satisfying the minimum burst pressure. In addition, finite element analysis was used to verify the optimal scheme, demonstrating that the error of the burst pressure predicted by the quadratic model established by the response surface design was not more than 5%. This study provides a faster and more efficient optimization method for the optimization design of composite gas cylinder layers.

Dynamic Kinetic Cross-Electrophile Arylation of Benzyl Alcohols by Nickel Catalysis.

Catalytic transformation of alcohols via metal-catalyzed cross-coupling reactions is very important, but it typically relies on a multistep procedure. We here report a dynamic kinetic cross-coupling approach for the direct functionalization of alcohols. The feasibility of this strategy is demonstrated by a nickel-catalyzed cross-electrophile arylation reaction of benzyl alcohols with (hetero)aryl electrophiles. The reaction proceeds with a broad substrate scope of both coupling partners. The electron-rich, electron-poor, and ortho-/meta-/para-substituted (hetero)aryl electrophiles (e.g., Ar-OTf, Ar-I, Ar-Br, and inert Ar-Cl) all coupled well. Most of the functionalities, including aldehyde, ketone, amide, ester, nitrile, sulfone, furan, thiophene, benzothiophene, pyridine, quinolone, Ar-SiMe3, Ar-Bpin, and Ar-SnBu3, were tolerated. The dynamic nature of this method enables the direct arylation of benzylic alcohol in the presence of various nucleophilic groups, including nonactivated primary/secondary/tertiary alcohols, phenols, and free indoles. It thus offers a robust alternative to existing methods for the precise construction of diarylmethanes. The synthetic utility of the method was demonstrated by a concise synthesis of biologically active molecules and by its application to peptide modification and conjugation. Preliminary mechanistic studies revealed that the reaction of in situ formed benzyl oxalates with nickel, possibly via a radical process, is an initial step in the reaction with aryl electrophiles.

Regiocontrolled Reductive Vinylation of Aliphatic 1,3-Dienes with Vinyl Triflates by Nickel Catalysis.

The regiocontrolled functionalization of 1,3-dienes has become a powerful tool for divergent synthesis, yet it remains a long-standing challenge for aliphatic substrates. Herein, we report a reductive approach for a branch-selective 1,2-hydrovinylation of aliphatic 1,3-dienes with R-X electrophiles, which represents a new selectivity pattern for diene functionalization. Simple butadiene, aromatic 1,3-dienes, and highly conjugated polyene were also tolerated. The combination of Ni(0) and the phosphine-nitrile ligand generally resulted in >20:1 regioselectivity with the retention of the geometry of the C3-C4 double bonds. This reaction proceeds with a broad substrate scope, and it allows for the conjugation of two biologically active units to form more complex polyene molecules, such as tetraene and pentaene as well as heptaene.

Cross-Electrophile C(sp2 )-Si Coupling of Vinyl Chlorosilanes.

The cross-electrophile coupling has become a powerful tool for C-C bond formation, but its potential for forging the C-Si bond remains unexplored. Here we report a cross-electrophile Csp2 -Si coupling reaction of vinyl/aryl electrophiles with vinyl chlorosilanes. This new protocol offers an approach for facile and precise synthesis of organosilanes with high molecular diversity and complexity from readily available materials. The reaction proceeds under mild and non-basic conditions, demonstrating a high step economy, broad substrate scope, wide functionality tolerance, and easy scalability. The synthetic utility of the method is shown by its efficient accessing of silicon bioisosteres, the design of new BCB-monomers, and studies on the Hiyama cross-coupling of vinylsilane products.

Highly Enantioselective Cross-Electrophile Aryl-Alkenylation of Unactivated Alkenes.

Enantioselective cross-electrophile reactions remain a challenging subject in metal catalysis, and with respect to data, studies have mainly focused on stereoconvergent reactions of racemic alkyl electrophiles. Here, we report an enantioselective cross-electrophile aryl-alkenylation reaction of unactivated alkenes. This method provides access to a number of biologically important chiral molecules such as dihydrobenzofurans, indolines, and indanes. The incorporated alkenyl group is suitable for further reactions that can lead to an increase in molecular diversity and complexity. The reaction proceeds under mild conditions at room temperature, and an easily accessible chiral pyrox ligand is used to afford products with high enantioselectivity. The synthetic utility of this method is demonstrated by enabling the modification of complex molecules such as peptides, indometacin, and steroids.

Anti-Obesity Activity of Sanghuangporus vaninii by Inhibiting Inflammation in Mice Fed a High-Fat Diet.

Obesity is an unhealthy condition associated with various diseases characterized by excess fat accumulation. However, in China, the prevalence of obesity is 14.1%, and it remains challenging to achieve weight loss or resolve this issue through clinical interventions. Sanghuangpours vaninii (SPV) is a nutritional fungus with multiple pharmacological activities and serves as an ideal dietary intervention for combating obesity. In this study, a long-term high-fat diet (HFD) was administered to induce obesity in mice. Different doses of SPV and the positive drug simvastatin (SV) were administered to mice to explore their potential anti-obesity effects. SPV regulated weight, serum lipids, and adipocyte size while inhibiting inflammation and hepatic steatosis. Compared with the vehicle-treated HFD-fed mice, the lowest decreases in total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) were 9.72%, 9.29%, and 12.29%, respectively, and the lowest increase in high-density lipoprotein cholesterol (HDL-C) was 5.88% after treatment with different doses of SPV. With SPV treatment, the analysis of gut microbiota and serum lipids revealed a significant association between lipids and inflammation-related factors, specifically sphingomyelin. Moreover, Western blotting results showed that SPV regulated the toll-like receptor (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway in HFD-diet mice, which is related to inflammation and lipid metabolism. This research presents empirical proof of the impact of SPV therapy on obesity conditions.

Revealing Brownish Mycena Diversity in China: New Discoveries and Taxonomic Insights.

Within the genus Mycena, species exhibiting brownish basidiomata present considerable challenges in identification due to similar coloration. This study underscores the significance of pileipellis types and cheilocystidia characteristics as critical in delimiting brownish Mycena species. To clarify the principal taxonomic characters and their utility in distinguishing between brownish Mycena species, a morphological taxonomy and phylogenetic analysis were performed. Five new species from China were introduced and characterized through a comprehensive morphological anatomy and phylogenetic substantiation: M. campanulatihemisphaerica sp. nov., M. digitifurcata sp. nov., M. kunyuensis sp. nov., M. limitis sp. nov., and M. oryzifluens sp. nov. Discussions of these taxa are supplemented with morphological illustrations. The phylogenetic relationships were inferred using Bayesian Inference and Maximum Likelihood methods based on sequences from the internal transcribed spacer and the large subunit regions of nuclear ribosomal RNA. With the addition of these five new species, the worldwide count of brownish Mycena increases to 94, and a key to the 29 known species of brownish Mycena from China is presented.

Complete mitochondrial genomic sequence of Auricularia delicata (Auriculariaceae), an edible Chinese mushroom.

Auricularia delicata (Mont.) Henn. 1893 is an edible and medicinal jelly mushroom popular in China. Here, we report the assembly and annotation of a complete A. delicata mitochondrial genome based on data sequenced using an Illumina NovaSeq 6000 platform. The length of the complete circular A. delicata mitochondrial genome is 189,696 bp, with a GC content of 34.1%. The A. delicata mitochondrial genome contains 60 genes, including 32 protein-coding genes, 26 tRNA genes, and two rRNA genes. Phylogenetic analysis indicated that A. delicata clustered with the Auricularia group, alongside A. auricula-judae and A. heimuer. Additionally, A. delicata was found to be genetically distant from other species of Polyporales, Russulales, and Agaricales. This genome will provide an invaluable reference for the continued study and utilization of A. delicata and other Auricularia species.

Nickel-Catalyzed Cross-Electrophile C(sp3)-Si Coupling of Unactivated Alkyl Bromides with Vinyl Chlorosilanes.

Cross-electrophile C-Si coupling has emerged as a promising tool for the construction of organosilanes, but the potential of this method remains largely unexplored. Herein, we report a C(sp3)-Si coupling of unactivated alkyl bromides with vinyl chlorosilanes. The reaction proceeds under mild conditions, and it offers a new approach to alkylsilanes. Functionalities such as Grignard-sensitive groups (e.g., acid, amide, alcohol, ketone, and ester), acid-sensitive groups (e.g., ketal and THP protection), alkyl fluoride and chloride, aryl bromide, alkyl tosylate and mesylate, silyl ether, and amine were tolerated. Incorporation of the -Si(vinyl)R2 moiety into complex molecules and the immobilization of a glass surface by formed organosilanes were demonstrated.

Effects of Selenium Auricularia cornea Culture Supplementation on Growth Performance, Antioxidant Status, Tissue Selenium Concentration and Meat Quality in Growing-Finishing Pigs.

Selenium Auricularia cornea culture (SAC) is a new source of organic selenium. Two experiments were conducted to determine the available energy of SAC fed to pigs and to evaluate the effects of dietary SAC supplementation on growth performance, serum biochemical profiles, fecal short chain fatty acids (SCFA), meat quality, tissue selenium concentration, and oxidative stability of fresh meat in growing-finishing pigs. In Experiment (Exp.) 1, 12 barrows with average body weight (BW) of 42.40 ± 5.30 kg were randomly allotted to two groups and fed the basal diet and SAC-supplemented diet, individually. In Exp. 2, 96 growing-finishing pigs (BW: 91.96 ± 7.55 kg) were grouped into four dietary treatments; each treatment contained six replicates with four pigs per replicate. The four treatments fed a control diet and three experimental diets supplemented with 0.6%, 1.2%, and 2.4% SAC, respectively. The trial lasted for 45 days. The results revealed that digestible energy (DE) of SAC was 11.21 MJ/kg. The average daily gain (ADG) was improved in pigs fed 1.2% and 2.4% SAC during day 24 to 45 and the overall period. Dietary 1.2% and 2.4% SAC supplementation had a lower F/G (p < 0.05) than the control diet during different stages. Dietary SAC supplementation increased fecal butyrate contents (p < 0.05), and pigs fed 1.2% and 2.4% SAC diets had a higher MCT1 mRNA expression (p = 0.04) in the colon. Pigs fed 2.4% SAC had higher GSH-Px contents (p < 0.05) in serum, liver, and longissimus dorsi muscle (LDM) than those in the control group. The 2.4% SAC-supplemented group revealed a higher Se content (p < 0.05) in LDM and a lower MDA concentration (p < 0.05) in fresh meat during the simulated retail display on day six. In conclusion, this study suggested that SAC was more effective in improving growth, enhancing the antioxidant status, depositing Se in muscle, and increasing meat oxidative stability of pigs.

Two new Inosperma (Inocybaceae) species with unexpected muscarine contents from tropical China.

An accurate identification of poisonous mushrooms and the confirmation of the toxins involved are both of great importance in the treatment of mushroom poisoning incidents. In recent years, cases of mushroom poisoning by Inosperma spp. have been repeatedly reported from tropical Asia. It is urgent to know the real species diversity of Inosperma in this region. In the present study, we proposed two new Inosperma species from tropical Asia, namely I.muscarium and I.hainanense. They were described based on morphology and multilocus phylogeny. Detailed descriptions, color photographs and the discussion with other closely related species of the two new taxa were provided. In addition, a comprehensive muscarine determination of these two new species using ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach has been performed. Results showed that these two species were muscarine positive, with a content of 16.03 ± 1.23 g/kg in I.muscarium and a content of 11.87 ± 3.02 g/kg in I.hainanense, much higher than the known species I.virosum. Recovery of muscarine ranged from 93.45% to 97.25%, and the average recovery is 95.56%.

First record of the rare genus Typhrasa (Psathyrellaceae, Agaricales) from China with description of two new species.

Typhrasa is a rare genus that comprises two species and that has previously been reported only from Europe and North America. The present study expands the geographical scope of the genus by describing two new species - T. polycystis and T. rugocephala - from subtropical China. The new species are supported by morphological characteristics and phylogenetic analyses (ITS, LSU and tef-1α). The new species have very similar morphological characteristics and are 98% similar in their ITS region. However, T. rugocephala has two types of long gills at the same time, rarely fusiform pleurocystidia with rostrum. Detailed descriptions, colour photos, illustrations and a key to related species are presented in this paper.

Improving the toughness of thermosetting epoxy resins via blending triblock copolymers.

In this study, the triblock copolymer poly(methyl methacrylate)-b-poly(butyl acrylate)-b-poly(methyl methacrylate) (MAM) was used to modify bisphenol A epoxy resin to improve its toughness. The effects of MAM on the curing behaviors, mechanical properties, fracture morphology and thermal properties of epoxy were carefully studied. The results of dissolution experiments show that MAM has good compatibility with epoxy resin under certain conditions. FT-IR and DSC analyses show that adding MAM to epoxy hinders the curing reaction of epoxy resin, without participating in the curing reaction and changing the curing mechanism. The mechanical properties indicated by K IC and impact strength with an MAM content of 10 phr for the toughened system increase by 91.5% and 83.5%, respectively, compared to the situation without MAM, which may ascribed to the nanoparticles formed during the process of MAM/epoxy blending. In the curing process of an epoxy resin, the typical phase structure that occurs through the self-assembly process can be clearly observed in the MAM/epoxy blends. As the MAM content increases, the amount of nanoparticles gradually increases. This work further confirms that the toughness of the composite material was enhanced to a large extent without significantly decreasing the glass transition temperature of the blends.

Effect of Fibres on the Failure Mechanism of Composite Tubes under Low-Velocity Impact.

Filament-wound composite tubular structures are frequently used in transmission systems, pressure vessels, and sports equipment. In this study, the failure mechanism of composite tubes reinforced with different fibres under low-velocity impact (LVI) and the radial residual compression performance of the impacted composite tubes were investigated. Four fibres, including carbon fiber-T800, carbon fiber-T700, basalt fibre, and glass fibre, were used to fabricate the composite tubes by the winding process. The internal matrix/fibre interface of the composite tubes before the LVI and their failure mechanism after the LVI were investigated by scanning electric microscopy and X-ray micro-computed tomography, respectively. The results showed that the composite tubes mainly fractured through the delamination and fibre breakage damage under the impact of 15 J energy. Delamination and localized fibre breakage occur in the glass fibre-reinforced composite (GFRP) and basalt fibre-reinforced composite (BFRP) tubes when subjected to LVI. While fibre breakage damage occurs globally in the carbon fibre-reinforced composite (CFRP) tubes. The GFRP tube showed the best impact resistance among all the tubes investigated. The basalt fibre-reinforced composite (BFRP) tube exhibited the lowest structural impact resistance. The impact resistance of the CFRP-T700 and CFRP-T800 tube differed slightly. The radial residual compression strength (R-RCS) of the BFRP tube is not sensitive to the impact, while that of the GFRP tube is shown to be highly sensitive to the impact.

Three new species of Cortinarius subgenus Telamonia (Cortinariaceae, Agaricales) from China.

Cortinarius is an important ectomycorrhizal genus that forms a symbiotic relationship with certain trees, shrubs and herbs. Recently, we began studying Cortinarius in China and here we describe three new species of Cortinarius subg. Telamonia based on morphological and ecological characteristics, together with phylogenetic analyses. Cortinarius laccariphyllus sp. nov. (section Colymbadini) is associated with broadleaf trees, with strongly hygrophanous basidiomata, special Laccaria-like lamellae and white and extremely sparse universal veil. Cortinarius neotorvus sp. nov. (section Telamonia) is associated with broadleaf trees and is easily confused with C. torvus, but can be distinguished by the colour of the fresh basidiomes and the stipe usually somewhat tapering towards the base. Cortinarius subfuscoperonatus sp. nov. (section Fuscoperonati) is associated with coniferous trees, with subglobose to broadly ellipsoid spores and is closely related to C. fuscoperonatus. A key to the new species and similar species in sections Colymbadini, Telamonia and Fuscoperonati is provided.