Electrochemical Nickel-Catalyzed Cross-Electrophile Coupling of Alkenyl Triflates with α-Chloroamides.

Cross-electrophile coupling reactions of different electrophiles have been extensively studied but mainly limited to bromides and iodides. Here, we report an electrochemically induced nickel-catalyzed cross-electrophile coupling strategy between alkenyl triflates and α-chloroamides in an undivided cell under mild reaction conditions, affording the α-functionalized amide derivatives in good to excellent yields with broad substrate scopes and good functional group tolerance. The control experiments were conducted, and a plausible mechanism was proposed.

Weak Interaction Activates Esters: Reconciling Catalytic Activity and Turnover Contradiction by Tailored Chalcogen Bonding.

The activation of esters by strong Lewis acids via the formation of covalent adducts is a classic strategy to give reactivity; however, this approach frequently incurs limited turnover due to the low efficiency in the dissociation of catalyst from a stable catalyst-product complex. While the use of some weak interaction catalysts that can easily dissociate from any bonding complexes in the reaction system would solve this catalyst turnover problem, the poor catalytic activity in the ester activation that can be provided by these noncovalent forces in turn sets up a formidable challenge. Herein, we describe the activation and catalytic transformation of esters by weak interactions, which provides a promising platform to reconcile the catalytic activity and turnover problems. Several tailored chalcogen-bonding catalysts were developed for the activation of esters, enabling achieving several inherently low reactive Diels-Alder reactions as well as the ring-opening polymerization of lactones through weak chalcogen bonding interactions. This supramolecular catalysis approach is particularly highlighted by its capability to promote some uncommon Diels-Alder reactions involving using dienes bearing electron-withdrawing groups coupled by α,ß-unsaturated ester as dienophiles and substrate incorporating competitive Lewis basic sites, in which typical strong Lewis acids showed low catalytic efficiency, while representative hydrogen and halogen bonding catalysts were inactive.

Multi-source information fusion-driven corn yield prediction using the Random Forest from the perspective of Agricultural and Forestry Economic Management.

The objective of this study is to promptly and accurately allocate resources, scientifically guide grain distribution, and enhance the precision of crop yield prediction (CYP), particularly for corn, along with ensuring application stability. The digital camera is selected to capture the digital image of a 60 m × 10 m experimental cornfield. Subsequently, the obtained data on corn yield and statistical growth serve as inputs for the multi-source information fusion (MSIF). The study proposes an MSIF-based CYP Random Forest model by amalgamating the fluctuating corn yield dataset. In relation to the spatial variability of the experimental cornfield, the fitting degree and prediction ability of the proposed MSIF-based CYP Random Forest are analyzed, with statistics collected from 1-hectare, 10-hectare, 20-hectare, 30-hectare, and 50-hectare experimental cornfields. Results indicate that the proposed MSIF-based CYP Random Forest model outperforms control models such as support vector machine (SVM) and Long Short-Term Memory (LSTM), achieving the highest prediction accuracy of 89.30%, surpassing SVM and LSTM by approximately 13.44%. Meanwhile, as the experimental field size increases, the proposed model demonstrates higher prediction accuracy, reaching a maximum of 98.71%. This study is anticipated to offer early warnings of potential factors affecting crop yields and to further advocate for the adoption of MSIF-based CYP. These findings hold significant research implications for personnel involved in Agricultural and Forestry Economic Management within the context of developing agricultural economy.

PVDF Nanofiber Modified with ZnO Nanowires/Polydopamine for the Treatment of Sewage Containing Heavy Metals, Organic Dyes, and Bacteria.

In various countries worldwide, the issue of wastewater contamination poses a significant threat due to its intricate composition of heavy metals, organic dyes, and microorganisms, thereby complicating the purification process. Consequently, researchers have expressed considerable interest in materials capable of eliminating organic, heavy metal, and microbial pollutants. This study focuses on the fabrication of a water purification membrane (PDA/ZnO-NWs/PVDF) with a hierarchical structure and the ability to remove multiple pollutants. The membrane was created by modifying poly(vinylidene fluoride) (PVDF) nanofiber with zinc oxide nanowires (ZnO-NWs) and reinforcing it with polydopamine (PDA). The experimental results demonstrate that the PDA/ZnO-NWs/PVDF membrane exhibits a range of functionalities, including long-lasting superhydrophilicity, Cu(II) adsorption, photocatalytic degradation, and antibacterial ability. The manipulation of the DA synthesis procedure allows for the adjustment of the wettability, adsorption, and photocatalytic and antibacterial activities of the PDA/ZnO-NWs/PVDF composite. According to the Langmuir isotherm, the maximum Cu(II) adsorption capacity of the PDA/ZnO-NWs/PVDF membrane is determined to be 65.75 mg/g, which is significantly higher (27.26 mg/g) than that of the ZnO-NWs/PVDF membrane (38.49 mg/g). The PDA/ZnO-NWs/PVDF composite exhibited a notable degradation capacity toward rhodamine B under natural sunlight, reaching a maximum of 5.97 mg/g. Additionally, the degradation rate achieved during daylight hours was as high as 90.42%. Furthermore, the antibacterial efficacy of the PDA/ZnO-NWs/PVDF composite against both Gram-positive and Gram-negative bacteria approached 100%. This work presents a promising approach for the treatment of wastewater containing various coexisting contaminants.

Supramolecular catalysis with ethers enabled by dual chalcogen bonding activation.

The activation of ethers by weak interactions is a long-standing objective in supramolecular catalysis, but yet it remains an underdeveloped topic. The obstacles towards solving this problem are prominent since it is difficult for a weak interaction to cleave a relatively strong C-O σ-bond and moreover, the ionic intermediate composing of an alkoxide ion and an electrophilic carbocation would deactivate weak interaction donors. Herein, we describe a distinctive activation mode, dual Se···π and Se···O bonding, that could activate benzylic as well as allylic ether C-O σ-bonds to achieve cyclization, coupling and elimination reactions. This dual Se···π and Se···O bonding catalysis approach could tolerate various alkoxide leaving groups, while the other representative weak interaction donors showed no catalytic activity.

Photocatalytic C-C Bond Cleavage and Fluorosulfonylation of Strained Cycloalkanols for Carbonyl-Containing Aliphatic Sulfonyl Fluorides.

In this report, we present a photocatalytic ring-opening fluorosulfonylation of strained cycloalkanols with sulfur dioxide and NFSI under mild conditions for the synthesis of carbonyl-containing aliphatic sulfonyl fluorides. The synthetic potential of the carbonyl-containing aliphatic sulfonyl fluoride products has been examined by diverse transformations, including SuFEx reactions and Baeyer-Villiger oxidation reactions. Mechanistic studies demonstrate that the reaction operates through a radical C-C bond cleavage/SO2 insertion/fluorination cascade process.

Transferring From Textual Entailment to Biomedical Named Entity Recognition.

Biomedical Named Entity Recognition (BioNER) aims at identifying biomedical entities such as genes, proteins, diseases, and chemical compounds in the given textual data. However, due to the issues of ethics, privacy, and high specialization of biomedical data, BioNER suffers from the more severe problem of lacking in quality labeled data than the general domain especially for the token-level. Facing the extremely limited labeled biomedical data, this work studies the problem of gazetteer-based BioNER, which aims at building a BioNER system from scratch. It needs to identify the entities in the given sentences when we have zero token-level annotations for training. Previous works usually use sequential labeling models to solve the NER or BioNER task and obtain weakly labeled data from gazetteers when we don't have full annotations. However, these labeled data are quite noisy since we need the labels for each token and the entity coverage of the gazetteers is limited. Here we propose to formulate the BioNER task as a Textual Entailment problem and solve the task via Textual Entailment with Dynamic Contrastive learning (TEDC). TEDC not only alleviates the noisy labeling issue, but also transfers the knowledge from pre-trained textual entailment models. Additionally, the dynamic contrastive learning framework contrasts the entities and non-entities in the same sentence and improves the model's discrimination ability. Experiments on two real-world biomedical datasets show that TEDC can achieve state-of-the-art performance for gazetteer-based BioNER.

Mussel-Inspired Multifunctional Hydrogels with Adhesive, Self-Healing, Antioxidative, and Antibacterial Activity for Wound Healing.

Antibacterial hydrogel wound dressings with adhesive and antioxidant activity are desirable for treating skin injuries in clinical care. Hereby, a series of multifunctional hydrogel wound dressings with high adhesive, self-healing, antioxidant, and antibacterial activity were designed and fabricated using dopamine (DA) and quercetin (QT). The multifunctional hydrogels were constructed by the interpenetrated quaternized chitosan chain segments and polyacrylamide network. The catechol groups on DA, QT, and the quaternary ammonium groups in the hydrogel system endow hydrogels with high strength, excellent adhesion, and self-healing ability. The results confirmed the admirable hemocompatibility and remarkable antibacterial activity of the multifunction hydrogels against Staphylococcus aureus and Escherichia coli. Consequently, multifunction hydrogels with satisfactory adhesive and antibacterial activity are appropriate alternative materials in the fields of tissue adhesive and wound dressing applications.

A tribenzocoronene-based 2D conductive metal-organic framework for efficient energy storage.

We have developed a new 2D c-MOF (Cu-TBC) via coordination polymerization of a highly conjugated tribenzocoronene-type organic ligand (6OH-TBC) and Cu2+, which exhibits excellent stability and performance as the electrode for a supercapacitor.

Quarternized chitosan/quercetin/polyacrylamide semi-interpenetrating network hydrogel with recoverability, toughness and antibacterial properties for wound healing.

Antibiotic abuse has posed enormous burdens on patients and healthcare systems. Hence, the design and development of non-antibiotic wound dressings to meet clinical demand are urgently desired. However, there remains one of the impediments to hydrogel wound dressings that integrated with good recoverability, toughness, and excellent antibacterial properties. Herein, a series of semi-interpenetrating network (semi-IPN) hydrogels with exceptional mechanical performance and remarkable antibacterial activity based on quaternized chitosan (QCS) and polyacrylamide (PAM) were developed using a one-pot method. Additionally, the antibacterial activity of semi-IPN hydrogel against S. aureus and E. coli was enhanced by integrating it with quercetin (QT). The semi-IPN hydrogels also exhibited high recoverability and toughness, outstanding liquid absorbability (the swelling ratio reached 565 ± 12 %), and a satisfying water vapor transmission rate. Moreover, the semi-IPN hydrogels presented ideal hemocompatibility and cytocompatibility. These high-elastic hydrogels are promising candidates for potential applications in wound dressing, tissue repair, chronic wound care, as well as other biomedical fields.

Electrochemical Corrosion Behavior of MIG-Welded 7N01-T4 Aluminum Alloy by ER5356 and ER5087 Welding Wires.

7N01-T4 aluminum alloy plates were welded by the metal inert gas (MIG) welding method, with ER5087 and ER5356 welding wires, respectively. The electrochemical corrosion behavior of the weld zones in the two kinds of welded joints using 3.5 wt.% and 5 wt.% NaCl solutions were investigated by polarization curve, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), and laser confocal scanning microscope (LCSM). The results indicated the better corrosion resistance of the weld zone in the ER5356 welded joint than that in the ER5087 welded joint, which was related to the different contents of Mn and Zn elements and the distribution of precipitates for the weld zones in the two kinds of welded joints. Based on the LSCM of the weld zones, the maximum depth (dmax) of corrosion pits for the weld zone in the ER5356 welded joint was lower than that in the ER5087 welded joint when immersed in the same NaCl concentrations. The dmax of the corrosion pit of the weld zone in the ER5356 welded joint using the 5 wt.% NaCl solution was 78.5 ± 0.96 µm, which was much bigger than that using the 3.5 wt.% NaCl solution. For the weld zone in the ER5087 welded joint with 5 wt.% NaCl solution, more Cl- was adsorbed onto the active surface of weld zones, which accelerated the corrosion, resulting in the corrosion mechanism from pitting to intergranular corrosion.

Microstructure, Mechanical and Tribological Properties of Si3N4/Mo-Laminated Composites.

(1) Background: the applications of ceramic materials in a friction pair and a moving pair are limited, just because of their poor toughness and unsatisfactory tribological characteristics. In view of this, Mo as a soft metal layer was added into a Si3N4 matrix to improve its toughness and tribological characteristics. (2) Methods: The microstructure and metal/ceramic transition layer were examined using X-ray diffraction, scanning electron microscope, electron dispersive X-ray spectroscopy, and Vickers hardness. Bending strength and fracture toughness were also measured. Tribological characteristics were obtained on the pin-on-disc wear tester. (3) Results: It can be found that the multilayer structure could improve the fracture toughness of laminated composite compared with single-phase Si3N4, but the bending strength was significantly reduced. Through microstructure observation, the transition layer of Si3N4/Mo-laminated composite was revealed as follows: Si3N4→MoSi2→Mo5Si3→Mo3Si→Mo. Moreover, the addition of the Mo interface to silicon nitride ceramic could not significantly improve the tribological properties of Si3N4 ceramic against titanium alloy in seawater, and the friction coefficients and wear rates of the sliding pairs increased with the increase in load. (4) Conclusions: The process failed to simultaneously improve the comprehensive mechanical properties and tribological performance of Si3N4 ceramic by adding Mo as the soft interfacial layer. However, the utilization of metal interfacial layers to enhance the toughness of ceramics was further recognized and has potential significance for the optimization of ceramic formulation.

Nonplanar Rhombus and Kagome 2D Covalent Organic Frameworks from Distorted Aromatics for Electrical Conduction.

Two-dimensional (2D) covalent organic frameworks (COFs) are an emerging class of promising 2D materials with high crystallinity and tunable structures. However, the low electrical conductivity impedes their applications in electronics and optoelectronics. Integrating large π-conjugated building blocks into 2D lattices to enhance efficient π-stacking and chemical doping is an effective way to improve the conductivity of 2D COFs. Herein, two nonplanar 2D COFs with kagome (DHP-COF) and rhombus (c-HBC-COF) lattices have been designed and synthesized from distorted aromatics with different π-conjugated structures (flexible and rigid structure, respectively). DHP-COF shows a highly distorted 2D lattice that hampers stacking, consequently limiting its charge carrier transport properties. Conversely, c-HBC-COF, with distorted although concave-convex self-complementary nodes, shows a less distorted 2D lattice that does not interfere with interlayer π-stacking. Employing time- and frequency-resolved terahertz spectroscopy, we unveil a high charge-carrier mobility up to 44 cm2 V-1 s-1, among the highest reported for 2D COFs.

Track-Etch Membranes as Tools for Template Synthesis of Highly Sensitive Pressure Sensors.

Flexible pressure sensors with high sensitivity are highly desired in wearable electronics and human-machine interaction. Introducing the surface microstructures to the capacitive-type sensors can improve sensitivity and reduce response time. However, conventional techniques for the fabrication of highly sensitive and large-area pressure sensors still remain challenging. Here, a template synthesis approach is reported for fabrication of a large-area and low-cost ionic micropillar array templated from track-etch membranes. The pressure sensors based on the ionic micropillars gel dielectric layers exhibit a low limit of detection (∼0.5 Pa) and high sensitivity (14.83 kPa-1) in the low-pressure regime (0-5 kPa) and linear sensitivity (1.96 kPa-1) over a wide pressure range of 24-230 kPa. The versatility of the sensors is demonstrated in various human physiological signal detection scenarios and spatial pressure distribution. Furthermore, a real-time pressure mapping insole was fabricated on the basis of a large-area micropillared ionic gel dielectric layer combined with the screen-printing technique. The scalable and low-cost fabrication of pressure sensors with micropillars templated from a track-etch membrane provides new insights into the future development of health monitoring and human-machine interaction.

Effect of Sacubitril/Valsartan vs Standard Medical Therapies on Plasma NT-proBNP Concentration and Submaximal Exercise Capacity in Patients With Heart Failure and Preserved Ejection Fraction: The PARALLAX Randomized Clinical Trial.

Importance: There is limited evidence on the benefits of sacubitril/valsartan vs broader renin angiotensin system inhibitor background therapy on surrogate outcome markers, 6-minute walk distance, and quality of life in patients with heart failure and mildly reduced or preserved left ventricular ejection fraction (LVEF >40%). Objective: To evaluate the effect of sacubitril/valsartan on N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, 6-minute walk distance, and quality of life vs background medication-based individualized comparators in patients with chronic heart failure and LVEF of more than 40%. Design, Setting, and Participants: A 24-week, randomized, double-blind, parallel group clinical trial (August 2017-October 2019). Of 4632 patients screened at 396 centers in 32 countries, 2572 patients with heart failure, LVEF of more than 40%, elevated NT-proBNP levels, structural heart disease, and reduced quality of life were enrolled (last follow-up, October 28, 2019). Interventions: Patients were randomized 1:1 either to sacubitril/valsartan (n = 1286) or to background medication-based individualized comparator (n = 1286), ie, enalapril, valsartan, or placebo stratified by prior use of a renin angiotensin system inhibitor. Main Outcomes and Measures: Primary end points were change from baseline in plasma NT-proBNP level at week 12 and in the 6-minute walk distance at week 24. Secondary end points were change from baseline in quality of life measures and New York Heart Association (NYHA) class at 24 weeks. Results: Among 2572 randomized patients (mean age, 72.6 years [SD, 8.5 years]; 1301 women [50.7%]), 2240 (87.1%) completed the trial. At baseline, the median NT-proBNP levels were 786 pg/mL in the sacubitril/valsartan group and 760 pg/mL in the comparator group. After 12 weeks, patients in the sacubitril/valsartan group (adjusted geometric mean ratio to baseline, 0.82 pg/mL) had a significantly greater reduction in NT-proBNP levels than did those in the comparator group (adjusted geometric mean ratio to baseline, 0.98 pg/mL) with an adjusted geometric mean ratio of 0.84 (95% CI, 0.80 to 0.88; P < .001). At week 24, there was no significant between-group difference in median change from baseline in the 6-minute walk distance with an increase of 9.7 m vs 12.2 m (adjusted mean difference, -2.5 m; 95% CI, -8.5 to 3.5; P = .42). There was no significant between-group difference in the mean change in the Kansas City Cardiomyopathy Questionnaire clinical summary score (12.3 vs 11.8; mean difference, 0.52; 95% CI, -0.93 to 1.97) or improvement in NYHA class (23.6% vs 24.0% of patients; adjusted odds ratio, 0.98; 95% CI, 0.81 to 1.18). The most frequent adverse events in the sacubitril/valsartan group vs the comparator group were hypotension (14.1% vs 5.5%), albuminuria (12.3% vs 7.6%), and hyperkalemia (11.6% vs 10.9%). Conclusions and Relevance: Among patients with heart failure and left ventricular ejection factor of higher than 40%, sacubitril/valsartan treatment compared with standard renin angiotensin system inhibitor treatment or placebo resulted in a significantly greater decrease in plasma N-terminal pro-brain natriuretic peptide levels at 12 weeks but did not significantly improve 6-minute walk distance at 24 weeks. Further research is warranted to evaluate potential clinical benefits of sacubitril/valsartan in these patients. Trial Registration: ClinicalTrials.gov Identifier: NCT03066804.

Topology modulation of 2D covalent organic frameworks via a "two-in-one" strategy.

Topology modulation of covalent organic frameworks (COFs) still remains barely explored, probably due to the lack of appropriate building blocks. A "two-in-one" strategy applies bifunctional monomers to endow ideal stoichiometry and has recently demonstrated great potential in the facile preparation of highly crystalline two-dimensional (2D) COFs with different topologies. Herein, we employ this approach to modulate the topology of 2D COFs by varying the solvents or the monomer concentrations. To our delight, 2D COFs featuring a Kagome (kgm) lattice with both hexagonal and triangular dual pores (DP) or featuring a rhombic square (sql) single pore (SP) structure can be selectively formed by varying the solvents. Furthermore, adjusting the monomer concentrations also successfully tuned the topology of the COFs. In addition, the highly porous dual-pore COF showed potential applications for controlled drug delivery.

Enhancing the light extraction efficiency for AlGaN-based DUV LEDs with a laterally over-etched p-GaN layer at the top of truncated cones.

It is known that light extraction efficiency (LEE) for AlGaN-based deep ultraviolet light-emitting didoes (DUV LEDs) can be enhanced by using truncated cone arrays with inclined sidewalls. In this work, the air-cavity-shaped inclined sidewall is applied and the p-GaN layer at the top of the truncated cone is laterally over-etched so that more light escape paths are generated for AlGaN-based DUV LEDs. The experimental results manifest that when compared with DUV LEDs only having the air-cavity-shaped inclined sidewall, the optical power for the DUV LEDs with laterally over-etched p-GaN at the top of the truncated cone is enhanced by 30% without sacrificing the forward bias. It is because the over-etched p-GaN makes little effect on the carrier injection and does not affect the ohmic contact resistance. Moreover, the simulation results show that the truncated cone with laterally over-etched p-GaN layer can enhance the LEE because the reduced p-GaN area can suppress the optical absorption and supplies additional light paths for DUV photos. Then, more light will be reflected into escape cones at the sapphire side.

Copper-Catalyzed Aminosulfonylation of O-Homoallyl Benzimidates with Sodium Sulfinates to Access Sulfonylated 1,3-Oxazines.

A facile copper-catalyzed aminosulfonylation of O-homoallyl benzimidates with sodium sulfinates in the presence of tert-butyl peroxybenzoate (TBPB) and XPhos ligand has been developed. By using this protocol, a variety of potentially bioactive 1,3-oxazines were directly synthesized. This method has the merits of a cheap catalyst, easily available and stable sulfone reagents, and simple operation.

Baseline characteristics of patients in the PARALLAX trial: insights into quality of life and exercise capacity in heart failure with preserved ejection fraction.

AIMS: We sought to describe the baseline characteristics of PARALLAX [a randomized controlled trial of sacubitril/valsartan vs. individualized medical therapy in heart failure (HF) with mildly reduced and preserved ejection fraction (HFpEF)]; compare PARALLAX to recent HFpEF trials; and examine the clinical characteristics associated with quality of life (QOL) and 6-min walk test distance (6MWD). METHODS AND RESULTS: A total of 2566 patients with HF and left ventricular ejection fraction (LVEF) >40% were randomized, of whom 96% had an LVEF ≥45%. Multivariable linear regression was used to determine characteristics associated with Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS) and 6MWD. Mean age was 73 ± 8 years, 51% were female, and comorbidities were common. Of the QOL measures tested in PARALLAX, the Short Form Health Survey-36 physical functioning score was most closely correlated with 6MWD (R = 0.41, P < 0.001), and outperformed the KCCQ physical limitation score (R = 0.33) and KCCQ-CSS (R = 0.31) on multivariable analyses. Female sex, higher body mass index, history of coronary artery disease, lower LVEF, and higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) were associated with worse (lower) KCCQ-CSS; older age, female sex, higher body mass index, diabetes, coronary artery disease, chronic obstructive pulmonary disease, prior HF hospitalization, lower LVEF, and higher NT-proBNP were associated with shorter 6MWD (P < 0.05 for all associations). CONCLUSIONS: PARALLAX is the largest HFpEF study to date to examine 6MWD together with QOL. The KCCQ-CSS and 6MWD were modestly correlated, and several factors were associated with worse values of both. These results provide insight into the association between QOL and exercise capacity in HFpEF.

[Biodegradation of Polystyrene by Geobacillus stearothermophilus].

Biodegradation is the most sustainable treatment method for waste polystyrene (PS). Thermophiles possess highly efficient biotransformation capabilities that could enhance the biodegradation efficiency of organic solid wastes. However, detailed research on the degradation of PS plastics by thermophile is scarce. Here, the degradation performance of a strain of Geobacillus stearothermophilus FAFU011 (FAFUA011) isolated from compost was examined. The results showed that strain FAFUA011 could utilize PS as the sole carbon source for growth and formed a stable biofilm on the surface of PS fragments. During 56 days of degradation, FAFU0011 caused a total mass loss of PS of 4.2% and decrease in molecular weight of 17.4%-18.2%. Based on SEM observations, FAFUA011 causes erosion hollows on the surface of PS, thus increasing the type and number of oxygen-containing structures that alter its hydrophilic properties. These changes facilitate the colonization of other microorganisms and further promote biodegradation. Based on 2D-COS analysis, the chronological order of the change in functional groups during the degradation process were identified as follows:1491 cm-1(C-H) > 1450 cm-1(C-H) > 1601 cm-1(C=C) > 1027 cm-1(C-O) > 1068 cm-1(C=O) > 1366 cm-1(C-OH). Overall, these results reveal that FAFU011 could promote the thermophilic bio-oxidative degradation of PS plastic.