Latest ArticlesInspired by biological ion channels, numerous artificial asymmetric ion channels have been synthesized to facilitate the fabrication of ionic circuits. Nevertheless, the creation of biomimetic asymmetric ion channels necessitates expensive scientific apparatus and intricate material processing procedures, which constrains its advancement within the realm of ionic devices. In this study, we have devised dynamic asymmetric ion channels with mechanical responsiveness by combining polymers of varying elastic modulus along the longitudinal axis of carbon nanotube fiber (CNTF). The ion rectification can be modulated via the disparate response of CNTF-based ion channels to mechanical stress. We have effectively employed these asymmetric ion channels with mechanical sensitivity in the design of a logic gate device, achieving logic operations such as “AND” and “OR”. The conception of these dynamic asymmetric ion channels with mechanical sensitivity offers a straightforward, cost-effective, and versatile approach for generating ion channels, highlighting their potential application in intricate, highly integrated ionic circuits.
Tryptophan (Trp) carries a unique heteroaromatic indole side chain and plays a critical role in peptide or protein modification. Herein, we have reported a metal-free photoinduced N-H alkylation strategy using N-aryl glycines for specific modification of tryptophan-containing peptides. The robustness of our approach is demonstrated by its wide substrate scope, excellent isolated yields, as well as almost unobservable side effects. Using this highly efficiently metal-free condition, alkylated Trp-containing peptides can be smoothly assembled. This study provides a reliable and practical tool for the chemo-selective modification of various tryptophan containing oligopeptides.
With the deep integration of electrochemical research with energy, environment, catalysis, and other fields, more and more new electrochemical catalytic reactions have entered our research field. Alloy catalysts have recently emerged as a new type of nanomaterial due to the rapid development of kinetic controlled synthesis technology. These materials offer several advantages over monometallic catalysts, including larger element combinations, complex geometries, bifunctional sites, and reduced use of precious metals. This paper provides a review of alloy electrocatalysts that are designed and prepared specifically for electrocatalytic applications. The use of alloy materials in electrocatalyst design is also discussed, highlighting their widespread application in this field. First, various synthesis methods and synthesis mechanisms are systematically summarized. Following that, by correlating the properties of materials with the structure, relevant strategies toward advanced alloy electrocatalysts including composition regulation, size, morphology, surface engineering, defect engineering, interface engineering and strain engineering are classified. In addition, the important electrocatalytic applications and mechanisms of alloy electrocatalysts are described and summarized. Finally, the current challenges and prospects regarding the development of alloy nanomaterials are proposed. This review serves as a springboard from a fundamental understanding of alloy structural dynamics to design and various applications of electrocatalysts, particularly in energy and environmental sustainability.
Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by persistent inflammation of the colon and disrupted intestinal function. Ramulus mori (Sangzhi) alkaloids (SZ-A), derived from twigs of mulberry, were approved by the National Medical Products Administration in 2020 for treating type 2 diabetes mellitus. Accumulated evidence has confirmed that SZ-A also alleviates non-alcoholic fatty liver disease and ameliorates inflammation, indicating its potential to address inflammation in UC. However, the treatment of UC faces challenges due to low drug delivery efficiency and short retention time. To overcome these challenges, an injectable and adherent in-situ thermo-sensitive hydrogel containing SZ-A was developed for rectal drug delivery, utilizing the thermo-sensitive polymers Poloxamer 407 and 188. The thermo-sensitive hydrogel system was designed with a moderate gelation temperature of 32 ± 0.5 ℃, a short gelation time of 64 s, a pH range of 7–10, high moisturizing capability exceeding 90%, and moderate mechanical strength of 4–5 s. In a rat model with UC, the in situ thermo-sensitive hydrogel significantly extended the retention time at the colonic site and enabled sustained release after rectal administration. Symptoms of UC were markedly reduced following rectal administration of SZ-A thermo-sensitive hydrogel. Furthermore, the release of inflammatory factors, such as interleukin-1β (IL-1β), IL-6, IL-18, tumor necrosis factor-α (TNF-α), and transforming growth factor-β1 (TGF-β1), significantly decreased in the SZ-A thermo-sensitive hydrogel group. The integrity of the colonic mucosal barrier was significantly enhanced following the application of SZ-A thermo-sensitive hydrogel. In conclusion, rectal administration of SZ-A in situ thermo-sensitive hydrogel effectively alleviated UC symptoms, inhibited the secretion of inflammatory factors, and promoted the repair of the colonic mucosal barrier. This approach holds promise as a potential treatment for UC.
Carbon materials have been used as the support for catalysts in the field of acetylene hydrochlorination, the influence of inevitable oxygen-containing moieties on the reaction is often ignored and the mechanism of the oxygen-doping structure remains ambiguous. Herein, we explored the effect of the oxygen-containing group (C–O–C) in the support on the activity of single-atom dispersed Cu catalysts. By immersing the Cu single-atom catalyst in an alkaline solution, the epoxy species on the carbon support was cleaved to obtain a pure ether species while the Cu site was modified to a more electron-deficient state. The turnover frequency value of Cu/O-FLP catalyst with epoxy groups was 1.6-fold higher than that of alkaline treated catalyst. Our result indicated that the epoxy groups could assist adjacent single-atom Cu sites to synergistically promote the adsorption and cleavage of the reactant hydrogen chloride toward form C–OH and Cu–Cl bonds, and reduce the reaction energy barrier. The presence of electron deficient Cu sites and ether species could induce competitive adsorption of the acetylene and hydrogen chloride, thereby reducing the activity of the catalyst. This study highlights the influence of surface oxygen species and the tunability of the support, providing the foundation for the fabrication of higher-activity Cu catalysts for acetylene hydrochlorination.
Dicarboxylic acids have a wide range of applications in the polymer industry to construct valuable materials. Photocatalysis has recently emerged as an efficient and sustainable strategy to generate dicarboxylic acids. However, photocatalytic dicarboxylation with CO2 is mainly limited to unsaturated bonds, and the dicarboxylation of C–C single bonds still remains a challenge. Herein, we report a photocatalytic dicarboxylation of C–C single bonds in strained rings with CO2 units via consecutive photo-induced electron transfer (ConPET). It is also the first photocatalytic reductive ring-opening reaction of cyclobutanes. Notably, this transition-metal-free protocol exhibits good functional group tolerance, broad substrate scope, facile scalability, and easy product derivatizations. Moreover, diacids can easily be derivatized to main-chain liquid crystalline polyesters.
Ynones are important skeletons in bioactive molecules and valuable building blocks for organic synthesis, thus great efforts have been devoted to their preparation. While, introducing prochiral substrates to construct ynones bearing a chiral framework is unrealized to date. Herein, we reported the first example of Pd/SOP-catalyzed asymmetric carbonylative alkynylation via a non-classical carbonylative Sonogashira-type approach (acyl-Pd(Ⅱ) species generated from nucleophiles). By using cyclic diaryliodonium salts as prochiral substrates, various axial chiral ynones with good functional group tolerance (39 examples), satisfied yields (71%-96%) and excellent enantioselectivities (generally 94%-99% ee) were produced. Synthesis of bioactive compounds, scale-up experiment and useful transformations were also conducted to demonstrate the utility of this process.
The H-bond promoted electrochemical [2 + 2 + 1] annulation of benzo[d]isothiazole 1,1-dioxides, N-arylglycines and paraformaldehyde for the synthesis of various benzo[d]imidazo[1,5-b]isothiazole 5,5-dioxide derivatives under redox mediator, catalyst and electrolyte-free conditions was developed.
Long-term excessive intake of nitrite (NO2−) poses a great threat to human health, needing a simple and fast method to detect NO2− in food. Herein, via a simple and feasible strategy, Mn/Yb/Er triple-doped CeO2 nanozyme (Mn/Yb/Er/CeO2) was synthesized for highly sensitive ratiometric detection of nitrite. By doping Mn, Yb, Er into CeO2 lattice structure, Mn/Yb/Er/CeO2 nanozyme showed enhanced oxidase-like activity, obtaining a higher density of oxygen vacancy and a higher ratio of Ce3+ to Ce4+ than that of CeO2. The 3,3′,5,5′-tetramethylbenzidine (TMB) can be effectively oxidized by Mn/Yb/Er/CeO2 to produce the oxidized TMB (oxTMB), showing a significant absorption signal at 652 nm. Additionally, nitrite can react with oxTMB to produce yellow diazotized oxTMB, which is accompanied by an elevated absorption signal at 445 nm and a decreased absorption signal at 652 nm. Thus, based on the oxidase-mimetic activity of Mn/Yb/Er/CeO2 and the diazotization reaction between NO2− and oxTMB, a ratiometric colorimetric assay was established for NO2− detection in food. Furthermore, by integrating Mn/Yb/Er/CeO2 with a smartphone, a colorimetric smartphone-sensing platform was successfully fabricated for visualization and quantitative detection of NO2−. Notably, this two-detection mode showed excellent sensitivity, selectivity, reliability and practicability in monitoring the NO2− in real samples, impling its great potential for food safety.
Artificial macrocycle with high binding selectivity in water is often challenging but urgently needed in various research and application areas. Herein, we report a new water-soluble biomimetic tetralactam macrocycle and realize the ultra-high selectivity to nucleosides over corresponding monophosphate nucleotides by rational modification. The introduction of charged groups at the periphery of endo-functionalized cavity makes the selectivity (guanosine to guanosine 5′-monophosphate) increase remarkably from 100 to 1119. Based on the ultra-high selectivity of biomimetic tetralactam macrocycle, the sensitive CD73 enzyme activity assay was then achieved through product-selective fluorescence indicator displacement assay. Furthermore, the capability of the proposed method for inhibitor screening was successfully displayed.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
