Diversity-Oriented Syntheses: Coupling Reactions Between Electron-Deficient Olefins and Aryl Aldehydes via C(sp²)–H Functionalization

A diversity-oriented syntheses by coupling three electron-deficient olefins (vinyl sulfonamides, methacrylamides, and methyl acrylates, respectively) with aryl aldehydes via C­(sp²)–H functionalization were reported. These reactions gave four different skeletal products respectively under environment-friendly and mild conditions. All these reactions are highly regioselective and effective, very suitable for the preparation of synthetic building blocks and compound library, the results will enrich current coupling chemistry of olefins with aldehydes and can be applied to other chemistry areas as well

Simultaneous Preparation and Dispersion of Regenerated Cellulose Nanoparticles Using a Facile Protocol of Dissolution–Gelation–Isolation–Melt Extrusion

As a consequence of an inter- (or intra-) molecular hydrogen bond, cellulose molecular chains or cellulose nanoparticles have a strong force for aggregation. Therefore, on one hand the broad use of cellulose nanoparticles is stifled by the lack of effective methods for the preparation of them. On the other hand, researchers have been struggling to directly disperse nanocellulose in a polymeric matrix. Here a facile method of “dissolution–gelation–isolation–melt extrusion” is proposed to achieve regenerated cellulose (RC) nanoparticles from cellulose hydrogel and disperse them into a polymeric matrix simultaneously. A water-soluble poly­(ethylene oxide) (PEO) molecular chain is used to isolate the cellulose nanoparticle precursors in the hydrogel. The following melt extrusion process provides a shear force to break up cellulose nanoparticles into smaller ones. By means of scanning electron microscopy and transmission electron microscopy, a hierarchical structure of cellulose aggregations with size in the range 50–100 nm composed of cellulose quasi-nanospheres at the nanoscale (10–30 nm) can be clearly observed. The tensile strength and Young’s modulus of the PEO/RC composite films are enhanced by about 146% and 276%, respectively, compared with those of the pure PEO film. X-ray diffraction data show that the crystal structure of RC is cellulose II. The dynamic rheology results reveal that the PEO/RC systems show much more liquid-like behavior with higher gel point frequency and lower viscosity than the contrast samples; thus, a melt compounding process could be accessible for redispersion of the RC nanoparticles into thermoplastic polymers

Parallel Syntheses of Eight-Membered Ring Sultams via Two Cascade Reactions in Water

From vinyl sulfonamides as precursors to vinyl sulfonamide epoxides, two cascade reaction protocols were developed to synthesize eight-membered ring sultams in water. These protocols employ intermolecular Michael addition by NaOH or NaHS in water, followed by rapid proton transfer and intramolecular 8-<i>endo-tet</i> epoxide ring-opening to give medium-size sultams selectively in one-pot. Novel core structures and high synthetic efficiency make these cascade reactions highly suitable for sultam library production. Both reactions proceeded well and afforded the respective sultams in good yields under environmentally friendly conditions

Predicting Spatiotemporal Distributions in a Bubbling Fluidized Bed for Biomass Fast Pyrolysis Using Convolutional Neural Networks

Bubbling fluidized-bed biomass fast pyrolysis is a crucial technology for carbon neutrality and sustainability, and computational fluid dynamics (CFD) is one of the promising approaches to investigate and optimize bubbling fluidized-bed biomass fast pyrolysis. However, traditional CFD is still computationally costly for bubbling fluidized-bed biomass fast pyrolysis, especially for spatiotemporal transport-reaction behaviors, which are critical to clarifying intrinsic characteristics and optimizing operations. To address this issue, a deep learning (DL) model centered on convolutional neural networks was developed based on CFD results to efficiently predict spatiotemporal distributions of quantities of each phase in a bubbling fluidized bed for biomass fast pyrolysis. Input of the DL model is a sequence of spatiotemporal distributions, and only an initial input is required to generate continuous outputs. The model was optimized by adjusting four typical parameters, i.e., length of input sequence, number of neurons, learning rate, and prediction step size. Accuracy of short-term prediction (10 frames) and stability of long-term prediction (1000 frames) were analyzed as well as the relationship between time-averaged distributions and prediction length. It was found that with satisfactory accuracy, several orders of magnitude increase in computation efficiency can be realized. Thus, the developed model paves the way for low-cost and high-accuracy simulations of biomass fast pyrolysis

A [Cu₂O₂]²⁺ Core in Cu/ZSM‑5 for Efficient Selective Catalytic Oxidation of Nitrogen-Containing VOCs and NH₃

Highly efficient elimination of nitrogen-containing volatile organic compounds (NVOCs) or NH3 via selective catalytic oxidation (SCO) while avoiding NOx is a strongly desired process for their control. However, limited by a lack of fundamental guidance such as accurate active site and reaction mechanisms, the targeted design of high-performance catalysts faces severe challenges. Herein, ZSM-5 zeolites supported by different copper species were used in the SCO of dimethylformamide (DMF) and NH3. Optimal 8% Cu/ZSM-5 had the highest N2 selectivity of above 94%. Various in situ spectroscopic characterizations and DFT theoretical calculations precisely identified that the active site is a μ-(η2:η2)-peroxo dicopper (bent; [Cu2O2]2+) core, which is associated with two Al sites separated by three SiO4 tetrahedra units in the 10-membered ring of ZSM-5. The dynamic catalytic behavior of DMF-SCO was revealed to be that [Cu2O2]2+ transformed into mono-(μ-oxo) dicopper upon DMF adsorption, while the opposite process occurred when O2 attacked. In situ DRIFTS elucidated the DMF-SCO reaction pathway and indicated that the disassociating N–H bond was the rate-determining step in transforming DMF to N2. This work not only strongly points the way to the design of high-performance catalysts of NVOCs and NH3 elimination but provides methodological implications for in situ study of active sites and their dynamic structures

Cascade Couplings of <i>N</i>‑Alkyl‑<i>N</i>‑methacryloyl Benzamides with Ethers and Benzenesulfonohydrazides To Generate Isoquinoline-1,3(2<i>H</i>,4<i>H</i>)‑dione Derivatives

Two radical-mediated cascade couplings of <i>N-</i>alkyl<i>-N-</i>methacryloylbenzamides with different ethers and arylsulfonohydrazides to generate ether- and arylsulfonyl-substituted isoquinoline-1,3­(2<i>H</i>,4<i>H</i>)-dione derivatives were developed. Both casccades proceeded via initially triggered functionalization of the alkene functions of the <i>N-</i>alkyl<i>-N-</i>methacryloylbenzamides, followed by ortho radical cyclizations onto the aromatic ring to give isoquinoline-1,3­(2<i>H</i>,4<i>H</i>)-dione derivatives in good yields. These highly functionalized drug-like molecules will be valuable in drug discovery in the future

Data_Sheet_1_A Novel qPCR Method for Simultaneous Detection and Quantification of Viable Pathogenic and Non-pathogenic Vibrio parahaemolyticus (tlh+, tdh+, and ureR+).PDF

<p>Pathogenic and non-pathogenic Vibrio parahaemolyticus strains were simultaneously detected and quantified using a novel viable multiplex real-time PCR (novel qPCR). We used a new PCR primer and probe, ureR, as a surrogate for detection of the toxin trh gene as the primer was better at identifying variant V. parahaemolyticus trh strains. The specificity of all primers and probes used in this study were validated on three standard strains of V. parahaemolyticus, 42 clinical strains, 12 wild strains, 4 strains of Vibrio spp., and 4 strains of other bacteria. Then, propidium monoazide (PMA) was applied to inhibit DNA of dead cell, and the results of PMA optimized treatments were 15 μM concentration, 5 min incubation periods, 15 min light exposure periods and 30 RPM rotational speed, which resulted in time and cost savings. Pathogenic and non-pathogenic strains were quantified using a two-reaction tube method where the tlh, tdh, and ureR genes were amplified. Additionally, standard curves with a 7-log dynamic range were generated for quantifying viable V. parahaemolyticus and the amplification efficiencies were 108.68, 105.17, and 115.61% for tlh⁺, tdh⁺, and ureR⁺. This novel qPCR accurately monitored V. parahaemolyticus contamination rates in shrimps (Penaeus vannamei) and clams (Ruditapes philippinarum) sampled from retail stores located in a major district in Shanghai. In conclusion, our assay can prioritize the detection and quantification of viable pathogenic V. parahaemolyticus and can prove to be a more effective tool for reducing infection risks from consumption of seafood in Shanghai.</p

Interfacial Shish-Kebabs Lengthened by Coupling Effect of In Situ Flexible Nanofibrils and Intense Shear Flow: Achieving Hierarchy To Conquer the Conflicts between Strength and Toughness of Polylactide

The challenge of hitherto elaborating a feasible pathway to overcome the conflicts between strength and toughness of polylactide (PLA) still remains among academia and industry. In the current work, a unique hierarchal structure of flexible poly­(butylene adipate-<i>co</i>-terephthalate) (PBAT) in situ nanofibrils integrating with abundant PLA shish-kebabs as a strong building block was disclosed and expresses its capability to conquer this dilemma. Substantially simultaneous enhancement on tensile strength, impact strength, and elongation at break could be achieved up to 91.2 MPa, 14.9 KJ/m², and 15.7%, respectively, compared with pure PLA (61.5 MPa, 4.3 KJ/m², and 6.2%). Through investigating the phase (and crystalline) morphology and molecular chain behavior in the PLA/PBAT system, the formation mechanism of this structure facilitated by a coupling effect of PBAT flexible phase and shear flow was definitely elucidated. The dispersed phase of PBAT would be more inclined to existing as a fibrillar form within the PLA matrix benefiting from low interfacial tension. Interestingly, this phase morphology with large specific surface area changes the crystallization behavior of PLA significantly, once introducing an intense shear flow (∼10³ s^–1), in situ shear-formed nanofibrils of PBAT would show strong coupling effect with shear flow on PLA crystallization: they can not only induce abundant shish-kebabs of PLA at its interfaces, which possesses lengthened shish and more densely arranged kebabs, but also further retard the relaxation of PLA chains through hysteretic relaxation of its PBAT phase, which can effectively prevent the collapse of established shish. Of immense significance is this particular hierarchical-architecture composed by flexible nanofibers (PBAT) and rigid shish-kebabs (PLA), which provides significant guidance for the simultaneous reinforcement and toughness of polymer materials

Data_Sheet_1_The characteristics of soil microbial co-occurrence networks across a high-latitude forested wetland ecotone in China.docx

To understand the effect of seasonal variations on soil microbial communities in a forested wetland ecotone, here, we investigated the dynamics of the diversities and functions of both soil bacterial and fungal communities inhabiting three wetland types (forested wetland, shrub wetland and herbaceous vegetation wetland) from forest-wetland ecotone of northern Xiaoxing’an Mountains spanning different seasons. β-diversity of soil microbial communities varied significantly among different vegetation types (Betula platyphylla–Larix gmelinii, Alnus sibirica, Betula ovalifolia, and Carex schmidtii wetlands). We totally detected 34 fungal and 14 bacterial indicator taxa among distinctive groups by using Linear discriminant analysis effect size (LEfSe) analysis, and identified nine network hubs as the most important nodes detected in whole fungi, bacteria, and fungi–bacteria networks. At the vegetation type-level, bacterial and fungal microbiome living in C. schmidtii wetland soil possessed fewer positive interactions and lower modularity than those in other types of wetland soil. Furthermore, we also discovered that ectomycorrhizal fungi were dominant in the fungal microbiota existing in forested and shrub wetland soils, whereas arbuscular mycorrhizal fungi were predominated in those residing in herbaceous vegetation wetland soil. The distribution of the predicted bacterial functional enzymes also obviously varied among different vegetation-types. In addition, the correlation analysis further revealed that the key fungal network modules were significantly affected by the contents of total N and soil water-soluble K, whereas most of the bacterial network modules were remarkably positively driven by the contents of total N, soil water-soluble K, Mg and Na. Our study suggested that vegetation type are substantive factors controlling the diversity, composition and functional group of soil microbiomes from forest-wetland ecotone of northern Xiaoxing’an Mountains.</p

Unprecedented Access to Strong and Ductile Poly(lactic acid) by Introducing In Situ Nanofibrillar Poly(butylene succinate) for Green Packaging

The notion of toughening poly­(lactic acid) (PLA) by adding flexible biopolymers has generated enormous interest but has yielded few desirable advances, mainly blocked by the sacrifice of strength and stiffness due to uncontrollable phase morphology and poor interfacial interactions. Here the phase control methodology, that is, intense extrusion compounding followed by “slit die extrusion-hot stretching-quenching” technique, was proposed to construct well-aligned, stiff poly­(butylene succinate) (PBS) nanofibrils in the PLA matrix for the first time. We show that generating nanosized discrete droplets of PBS phase during extrusion compounding is key to enable the development of in situ nanofibrillar PBS assisted by the shearing/stretching field. The size of PBS nanofibrils strongly dependent on the PBS content, showing an increased average diameter from 83 to 116 and 236 nm for the composites containing 10, 20, and 40 wt % nanofibrils, respectively. More importantly, hybrid shish-kebab superstructure anchoring ordered PLA kebabs were induced by the PBS nanofibrils serving as the central shish, conferring the creation of tenacious interfacial crystalline ligaments. The exceptional combination of strength, modulus, and ductility for the composites loaded 40 wt % PBS nanofibrils were demonstrated, outperforming pure PLA with the increments of 31, 51, and 72% in strength, modulus, and elongation at break (56.4 MPa, 1702 MPa, and 92.4%), respectively. The high strength, modulus, and ductility are unprecedented for PLA and are in great potential need for packaging applications