Breakthrough in CO2 Electroreduction to Multi-Carbon Products at Ampere-Level Enabled by Active Sites Engineering.

Efficient production of value-added chemicals with high selectivity from CO2 electroreduction at industrial-level current density is highly demanded, yet remains a big challenge. In a recent issue of Angewandte Chemie, Han and colleagues have elegantly increased the Faradaic efficiency (FE) of multi-carbon (C2+) products to over 70 % at amperes level (1.4 A cm-2) by engineering the active sites for the key reactions involved in the CO2 electroreduction. In this study, the highly dispersed Pd atoms have two unique functions: active sites for water dissociation and to induce the electron rearrangement of the surrounding Cu atoms to form new active sites for CO conversion, while the Cu far from Pd are the active sites for efficient CO2 conversion to CO, the synergistic functions of these three active sites result in high FE and yields of C2+ products at industrial-level current density. This research is a remarkable step forward in the methodology for developing efficient and durable catalysts for CO2 electroreduction and beyond.

In situ self-reconstructed hierarchical bimetallic oxyhydroxide nanosheets of metallic sulfides for high-efficiency electrochemical water splitting.

The advancement of economically efficient electrocatalysts for alkaline water oxidation based on transition metals is essential for hydrogen production through water electrolysis. In this investigation, a straightforward one-step solvent method was utilized to spontaneously cultivate bimetallic sulfide S-FeCo1 : 1/NIF on the surface of a nickel-iron foam (NIF). Capitalizing on the synergistic impact between the bimetallic constituents and the highly active species formed through electrochemical restructuring, S-FeCo1 : 1/NIF exhibited remarkable oxygen evolution reaction (OER) performance, requiring only a 310 mV overpotential based on 500 mA cm-2 current density. Furthermore, it exhibited stable operation at 200 mA cm-2 for 275 h. Simultaneously, the catalyst demonstrated excellent hydrogen evolution reaction (HER) and overall water-splitting capabilities. It only requires an overpotential of 191 mV and a potential of 1.81 V to drive current densities of 100 and 50 mA cm-2. Density functional theory (DFT) calculations were also employed to validate the impact of the bimetallic synergistic effect on the catalytic activity of sulfides. The results indicate that the coupling between bimetallic components effectively reduces the energy barrier required for the rate-determining step in water oxidation, enhancing the stability and activity of bimetallic sulfides. The exploration of bimetallic coupling to improve the OER performance holds theoretical significance in the rational design of advanced electrocatalysts.

Synthesis of New Derivatives of Berberine Canagliflozin and Study of Their Antibacterial Activity and Mechanism.

The isoquinoline alkaloid berberine, derived from Coptidis rhizoma, exhibits antibacterial, hypoglycemic, and anti-inflammatory properties. Canagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor. We synthesized compounds B9OC and B9OBU by conjugating canagliflozin and n-butane at the C9 position of berberine, aiming to develop antimicrobial agents for combating bacterial infections worldwide. We utilized clinically prevalent pathogenic bacteria, namely Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, to investigate the antibacterial efficacy of B9OC. This was accomplished through the determination of the MIC80 values, analysis of bacterial growth curves, evaluation of biofilm formation using crystal violet staining, assessment of impact on bacterial proteins via SDS-PAGE analysis, and observation of alterations in bacterial morphology utilizing field emission scanning electron microscopy. Meanwhile, the ADMET of compound B9OC was predicted using a computer-aided method. The findings revealed that B9OC exhibited lower minimal inhibitory concentrations against all three bacteria compared to berberine alone or in combination with canagliflozin. The minimal inhibitory concentrations (MICs) of B9OC against the three experimental strains were determined to be 0.035, 0.258, and 0.331 mM. However, B9OBu exhibited a lower level of antimicrobial activity compared to berberine. The compound B9OC exhibits a broad spectrum of antibacterial activity by disrupting the integrity of bacterial cell walls, leading to cellular rupture and the subsequent degradation of intracellular proteins.

Beauty of Explicit Dispersity (D) Equations in Controlled Polymerizations.

Dispersity (D) as a critical parameter indicates the level of uniformity of the polymer molar mass or chain length. In the past several decades, the development of explicit equations for calculating D experiences a continual revolution. This viewpoint tracks the historical evolution of the explicit equations from living to reversible-deactivation polymerization systems. Emphasis is laid on displaying the charm of explicit D equations in batch reversible-deactivation radical polymerization (RDRP), with highlights of the relevant elegant mathematical manipulations. Some representative emerging applications enabled by the existing explicit equations are shown, involving nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (RAFT) polymerization systems. Stemming from the several outlined challenges and outlooks, sustained concerns about the explicit D equations are still highly deserved. It is expected that these equations will continue to play an important role not only in traditional polymerization kinetic simulation and design of experiments but also in modern intelligent manufacturing of precision polymers and classroom education.

Long-Term Stable Hydrogen Production from Water and Lactic Acid via Visible-Light-Driven Photocatalysis in a Porous Microreactor.

Photocatalytic hydrogen (H2 ) production is significant to overcome challenges like fossil fuel depletion and carbon dioxide emission, but its efficiency is still far below that which is needed for commercialization. Herein, we achieve long-term stable H2 bubbling production from water (H2 O) and lactic acid via visible-light-driven photocatalysis in a porous microreactor (PP12); the catalytic system benefits from photocatalyst dispersion, charge separation, mass transfer, and dissociation of O-H bonds associated with H2 O. With the widely used platinum/cadmium-sulfide (Pt/CdS) photocatalyst, PP12 leads to a H2 bubbling production rate of 602.5 mmol h-1 m-2 , which is 1000 times higher than that in a traditional reactor. Even when amplifying PP12 into a flat-plate reactor with an area as large as 1 m2 and extending the reaction time to 100 h, the H2 bubbling production rate still remains at around 600.0 mmol h-1 m-2 , offering great potential for commercialization.

Ring Repeating Unit: An Upgraded Structure Representation of Linear Condensation Polymers for Property Prediction.

Unique structure representation of polymers plays a crucial role in developing models for polymer property prediction and polymer design by data-centric approaches. Currently, monomer and repeating unit (RU) approximations are widely used to represent polymer structures for generating feature descriptors in the modeling of quantitative structure-property relationships (QSPR). However, such conventional structure representations may not uniquely approximate heterochain polymers due to the diversity of monomer combinations and the potential multi-RUs. In this study, the so-called ring repeating unit (RRU) method that can uniquely represent polymers with a broad range of structure diversity is proposed for the first time. As a proof of concept, an RRU-based QSPR model was developed to predict the associated glass transition temperature (Tg) of polyimides (PIs) with deterministic values. Comprehensive model validations including external, internal, and Y-random validations were performed. Also, an RU-based QSPR model developed based on the same large database of 1321 PIs provides nonunique prediction results, which further prove the necessity of RRU-based structure representation. Promising results obtained by the application of the RRU-based model confirm that the as-developed RRU method provides an effective representation that accurately captures the sequence of repeat units and thus realizes reliable polymer property prediction by data-driven approaches.

CtBP2 interacts with TGIF to promote the progression of esophageal squamous cell cancer through the Wnt/ß­catenin pathway.

C­terminal­binding protein 2 (CtBP2), a transcriptional co­repressor, plays a main role in tumorigenesis and in the development of multiple tumors. Transforming growth interacting factor (TGIF) is involved in a number of cellular signal transduction pathways and is related to tumor occurrence and development. In the present study, the proteins interacting with CtBP2 were identified and the mechanisms underlying the biological activity of CtBP2 in esophageal squamous cell carcinoma (ESCC) were investigated. The Search Tool for the Retrieval of Interacting Genes (STRING) database was used to search for known proteins interacting with CtBP2, and co­immunoprecipitation (Co­IP) assay was performed to validate the interactions. Reverse transcription­quantitative PCR (RT­qPCR), immunohistochemistry (IHC) and western blot analysis were performed to examine the expression levels of CtBP2 and TGIF in ESCC. The correlation between CtBP2 and TGIF was analyzed using Gene Expression Profiling Interactive Analysis (GEPIA) by Pearson's correlation analysis, and the co­localization of CtBP2 with TGIF in the ECA109 cells was identified using immunofluorescence staining. XAV939 treatment, CCK­8, 5­ethynyl­2'­deoxyuridine (EdU) staining, wound healing and Transwell assays were performed to investigate the signaling pathways involved in the biological activity of CtBP2 in ECA109 cells. According to the results obtained from STRING and Co­IP analysis, an interaction between CtBP2 and TGIF was indicated, and these proteins were co­localized in the nucleus. CtBP2 and TGIF mRNA and protein expression levels were robustly and simultaneously increased in both ESCC tissues and cell lines. There was a direct correlation between CtBP2 and TGIF expression levels in ESCC tissues, and both were significantly associated with metastasis and survival. The TGIF and CtBP2 expression levels were significantly increased or decreased simultaneously, in ECA109 cells transfected with LV­CtBP2 or sh­CtBP2, and vice versa. According to the results of CCK­8 assay, EdU staining and Transwell assay, CtBP2 promoted the proliferation, migration and invasion of ECA109 cells through the Wnt/ß­catenin pathway. On the whole, the present study demonstrates that CtBP2 interacts with TGIF and promotes the malignant progression of ESCC through the Wnt/ß­catenin pathway.

Role of External Field in Polymerization: Mechanism and Kinetics.

The past decades have witnessed an increasing interest in developing advanced polymerization techniques subjected to external fields. Various physical modulations, such as temperature, light, electricity, magnetic field, ultrasound, and microwave irradiation, are noninvasive means, having superb but distinct abilities to regulate polymerizations in terms of process intensification and spatial and temporal controls. Gas as an emerging regulator plays a distinctive role in controlling polymerization and resembles a physical regulator in some cases. This review provides a systematic overview of seven types of external-field-regulated polymerizations, ranging from chain-growth to step-growth polymerization. A detailed account of the relevant mechanism and kinetics is provided to better understand the role of each external field in polymerization. In addition, given the crucial role of modeling and simulation in mechanisms and kinetics investigation, an overview of model construction and typical numerical methods used in this field as well as highlights of the interaction between experiment and simulation toward kinetics in the existing systems are given. At the end, limitations and future perspectives for this field are critically discussed. This state-of-the-art research progress not only provides the fundamental principles underlying external-field-regulated polymerizations but also stimulates new development of advanced polymerization methods.

A new cycloartane triterpenoid glycoside from Souliea vaginata.

One new cycloartane triterpenoid glycoside, soulieoside Q (1), together with four known compounds (2-5) were isolated from the ethanolic extract of the rhizomes of Souliea vaginata Maxim. The structure of the new compound was determined by extensive spectroscopic analysis including 1D and 2D NMR and HRESIMS, as well as chemical methods. Compound 1 was evaluated for its cytotoxic activities against HepG2 and A549 cancer cell lines.

Soulieoside O, a new cyclolanostane triterpenoid glycoside from Souliea vaginata.

A new cyclolanostane triterpenoid glycoside, soulieoside O (1), together with 25-O-acetylcimigenol-3-O-ß-d-xylopyranoside (2) and cimigenol-3-O-ß-d-xylopyranoside (3), was isolated from the rhizomes of Souliea vaginata. Their structures were characterized by spectroscopic analysis and chemical methods. The new compound showed moderate inhibitory activity against three human cancer cell lines with IC50 values of 9.3-22.5 µM.

Electrospun Fibrous Mat with pH-Switchable Superwettability That Can Separate Layered Oil/Water Mixtures.

Oil/water separation has inspired much research interest because of the damages caused to our natural environment due to oily wastewater. As a leader of advanced separation materials, electrospun polymeric fibrous mats having the properties of special surface wettability, high specific surface area, and high porosity will be a good membrane material for the separation of oily wastewater. Herein, we first prepared pH-responsive polymer poly(dimethylsiloxane)-block-poly(4-vinylpyridine) (PDMS-b-P4VP) mat using electrospinning technology. The PDMS-b-P4VP fibrous mat with a thickness of around 250 µm exhibits good pH-switchable oil/water wettability and is able to effectively separate oil or water from layered oil/water mixtures by gravity driven through adjusting the pH value. Stemming from its porous structure and pH-switchable superwettability, the electrospun PDMS-b-P4VP fibrous mat achieved controllable separations with high fluxes of approximately 9000 L h-1 m-2 for oil (hexane) and 27 000 L h-1 m-2 for water. In addition, extended studies on the polymer/silica nanoparticulate (silica NP) composite fibrous mats show that the addition of an inorganic component improves the thermal stability, pH-switchable wettability, and separation performance of the fibrous mats (approximately 9000 L h-1 m-2 for hexane and 32 000 L h-1 m-2 for water). It can be concluded from the results that both polymer fibrous mats and silica-filled composite fibrous mats are good candidates for on-demand layered oil/water mixture separation.

Smart Fiber Membrane for pH-Induced Oil/Water Separation.

Wastewater contaminated with oil or organic compounds poses threats to the environment and humans. Efficient separation of oil and water are highly desired yet still challenging. This paper reports the fabrication of a smart fiber membrane by depositing pH-responsive copolymer fibers on a stainless steel mesh through electrospinning. The cost-effective precursor material poly(methyl methacrylate)-block-poly(4-vinylpyridine) (PMMA-b-P4VP) was synthesized using copper(0)-mediated reversible-deactivation radical polymerization. The pH-responsive P4VP and the underwater oleophilic/hydrophilic PMMA confer the as-prepared membrane with switchable surface wettability toward water and oil. The three-dimensional network structure of the fibers considerably strengthens the oil/water wetting property of the membrane, which is highly desirable in the separation of oil and water mixtures. The as-prepared fiber membrane accomplishes gravity-driven pH-controllable oil/water separations. Oil selectively passes through the membrane, whereas water remains at the initial state; after the membrane is wetted with acidic water (pH 3), a reverse separation is realized. Both separations are highly efficient, and the membrane also exhibits switchable wettability after numerous cycles of the separation process. This cost-effective and easily mass-produced smart fiber membrane with excellent oil-fouling repellency has significant potential in practical applications, such as water purification and oil recovery.

Light-responsive smart surface with controllable wettability and excellent stability.

Novel fluorinated gradient copolymer was designed for smart surface with light-responsive controllable wettability and excellent stability. The switchable mechanism and physicochemical characteristics of the as-prepared surface decorated by designed polymeric material were investigated by ultraviolet-visible (UV-vis) spectrum, scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray photoelectron spectroscopy (XPS). Thanks to the functional film and surface roughening, etched silicon surface fabricated by copolymer involving spiropyran (Sp) moieties possesses a fairly large variation range of WCA (28.1°) and achieves the transformation between hydrophilicity (95.2° < 109.2°) and hydrophobicity (123.3° > 109.2°) relative to blank sample (109.2°). The synthetic strategy and developed smart surface offer a promising application in coating with controllable wettability, which bridge the gap between chemical structure and material properties.

A light and pH dual-stimuli-responsive block copolymer synthesized by copper(0)-mediated living radical polymerization: solvatochromic, isomerization, and "schizophrenic" behaviors.

A "schizophrenic" block copolymer (poly[1'-(2-methacryloxyethyl)-3',3'-dimethyl-6-nitrospiro-(2H-1-benzopyran-2,2'-indoline)]-b-poly(acrylic acid) (PSPMA-b-PAA)) was synthesized by sequential copper(0)-mediated living radical polymerization (Cu(0)-mediated LRP) at 30 °C in an oxygen-tolerant system followed by hydrolysis of the resulting polymer. The solvatechromic behaviors of the PSPMA10-b-poly(t-butyl acrylate)40 (PSPMA10-b-PtBA40) and PSPMA10-b-PAA40 block copolymers in organic solvents were investigated by UV-vis spectroscopy. The PSPMA10-b-PtBA40 stabilizes the nonpolar photoisomer and is not sensitive to the polarity of the solvent, while the PSPMA10-b-PAA40 stabilizes the planar zwitterionic form without irradiation. Furthermore, light-induced isomerization of spiropyran (Sp) moieties from Sp to merocyanine (Mc) was demonstrated. Finally, the "schizophrenic" micellization behavior of as-prepared copolymer in aqueous solution regulated by light and pH stimuli was vividly demonstrated, and the reversibility of micellization processes performed in this study was also examined. The large compound micelles can bring out a gradually extended and even transformed conformation with increasing deprotonation degree at pH > pKa.