Latest ArticlesUlcerative 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.
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.
Single-chain nanoparticles represent an emerging class of nanomaterials designed to mimic protein's folding paradigm. Intrachain covalent crosslinking toward the formation of single-chain nanoparticles encounters complex energy landscapes, leading to the potential occurrence of misfolding issues. While non-covalent crosslinking can circumvent this issue, the resulting single-chain nanoparticles exhibit lower structural stability compared to their covalently crosslinked counterparts. In this study, we present a novel approach for the synthesis of single-chain nanoparticles, achieved through the combination of non-covalent and covalent intramolecular crosslinking. Cyanostilbenes grafted onto the linear polymer form intrachain non-covalent stacks aided by hydrogen bonds, leading to the formation of non-covalently crosslinked single-chain nanoparticles. These nanoparticles undergo conversion to covalently crosslinked nanostructures through subsequent photo-irradiation using [2 + 2] photocycloaddition, a process facilitated by the supramolecular confinement effect. Consequently, the resulting single-chain nanoparticles demonstrate both intrachain folding efficiency and substantial stability, offering significant potential for advancing applications across diverse fields.
Closed pores formed in hard carbons play an essential role in sodium storage at plateau region. However, the effect of different structural features on the diffusion of sodium ions into closed pores remains unclear. Herein, a precursor reconstruction strategy is conducted to regulate carbon microstructures including interlayer spacing, defect concentration, and closed pore volume by changing the ratio of aromatic and polysaccharide components. Aromatic structure parts tend to develop disordered carbons with fewer defects, larger interlayer spacing, and smaller closed pore volume, while polysaccharide components prefer to form disordered carbons with more defects, smaller interlayer spacing, and larger closed pore volume. Through the correlation analysis of microstructure features and the sodium storage capacity below 0.1 V. It finds that the intercalation capacity is proportional to the ratio of pseudo-graphitic domains, whereas the pore filling capacity appeared at lower potential gradually decreases with the increasing defect concentration due to homo-ionic repulsion effect, without linear correlation with short-range microcrystalline and closed pore volume. The optimized sample with suitable interlayer spacing and defect concentration exhibits a high plateau capacity of 241.7 mAh/g. This work provides insights into the exploitation of closed pore sodium storage performance.
In some industrial wastewater, heavy metals combine with organic complexing agents to form heavy metal complexes (HMCs). These HMCs can be difficult to decompose and remove through conventional techniques due to their higher stability than free heavy metal ions. In recent years, persulfate based advanced oxidation processes (PS-based AOPs) have been recognized as a viable technique for HMCs degradation. Nevertheless, a comprehensive and in-depth understanding of the relevant HMCs decomplexation mechanisms in PS-based AOPs is still lacking. This review delineates the current progress of HMCs decomplexation in PS-based AOPs. We discuss the distinctions between the two widely used oxidant types in PS-based AOPs techniques. Moreover, we summarize and highlight the decomplexation mechanisms based on electron and energy transfer, and degradation pathways of HMCs. We also emphasize the effects of environmental water constituents, namely pH, inorganic ions, and natural organic matter (NOM), on HMCs decomplexation. Ultimately, we identify the existing challenges and perspectives that will steer the direction of advancing PS-based AOPs to remove HMCs.
Traditional photo-electcatalyst structures of small noble metal nanoparticles assembling into large-scale photoactive semiconductors still suffer from agglomeration of noble metal nanoparticles, insufficient charge transfer, undesirable photoresponse ability that restricted the photo-electrocatalytic performance. To this end, a novel design strategy is proposed in this work, namely integrating small-scale photoactive materials (doped graphene quantum dots, S,N-GQDs) with large-sized noble metal (PdP) nanoflowers to form novel photo-electrocatalysts for high-efficient alcohol oxidation reaction. As expected, superior electrocatalytic performance of PdP/S,N-GQDs for ethylene glycol oxidation is acquired, thanks to the nanoflower structure with larger specific surface area and abundant active sites. Furthermore, nonmetal P are demonstrated, especially optimizing the adsorption strength, enhancing the interfacial contact, reducing metal agglomeration, ensuring uniform and efficient doping of S,N-GQDs, and ultimately significantly boost the catalytic activity of photo-electrocatalysts.
To mitigate the water pollution problem by photocatalytic degradation of typical antibiotics of tetracycline (TC), we prepared defective Bi2Sn2O7 (BSO) quantum dots (QDs) with a full spectral response due to Bi metal deposition, using a one-pot hydrothermal method, labeled as Bi@BSO-OV. The optimized Bi@BSO-OV showed 73.4% removal of TC in 1 h under irradiation with a 50 W LED lamp in the wavelength band in the visible-near-infrared (vis-NIR) light, a rate that is substantially greater than that of pure BSO (14.7%). The synergistic interaction of Bi metal and oxygen vacancies (OVs) is crucial to boosting photocatalytic performance. The near-infrared region of the photo-response is extended by the surface plasmon resonance (SPR) effect of Bi metal, enhancing the photocatalytic performance and dramatically raising the efficiency of solar energy utilization. In addition to inducing defect levels in BSO, the OVs also activate the surface adsorbed O2 to promote the production of •O2− and 1O2. DFT calculations reveal that Bi metal and OVs can mutually tune the charge transfer pathways. On the one hand, Bi metal can act as both a charge transfer bridge and an electron donor to assist charge separation. On the other hand, OVs-induced defect levels allow electrons that leap to the conduction band (CB) to first leap from the valence band (VB) to the defect levels, notably improving interfacial charge separation and transfer. The concept of design executed in this study for altering the catalyst by introducing both OVs and Bi metal can provide a rational design idea and potential insight for improving the photocatalytic activity for environmental applications.
Glycosyl radicals, produced under mild photoredox conditions, show unique utility in the preparation of C-linked glycoconjugates. We herein report the construction of C-glycosidic bonds on α,β-dehydroalanine (DHA) of peptides with easily available glycosyl bromides as glycosyl radical precursors under highly anomeric control, leading to C-glycosylation modifications of peptides. This method not only has outstanding functional group compatibility, but also is feasible in near-physiological conditions (pH ~ 7 and temperature T ≤ 37 ℃ in aqueous media).
A variety of research reports on novel supramolecular topologies have been published over the last years. However, it is still a great challenge to tap into the inner functional properties of these complexes. Herein, two tetranuclear metallamacrocycles 1 and 2 and four octonuclear [2]catenanes 3–6 were constructed successfully via a coordination-driven self-assembly strategy, by conscious design and use of the tetramethyl bidentate pyridine ligand L1, and the appropriate selection of six binuclear half-sandwich rhodium building units with different longitudinal dimensions. The complexes have been fully characterized by single crystal X-ray diffraction analysis and NMR spectroscopy. Furthermore, near-infrared photothermal studies of the obtained [2]catenanes reveal different photothermal response in solid and solution states, which may be attributed to a strong fluorescence quenching effect of the half-sandwich organometallic fragment and different conjugated effect of Cp*Rh based building blocks in the interlocking structures. The photothermal conversion efficiencies of [2]catenanes 4–6 fall in the range 30.5%–16.5% respectively. This contribution aims to play a key role in the experimental development of Cp*-based photothermal materials.
Single atom catalysts (SACs) have been in the forefront of catalysts research because of their high efficiency and low cost and provide new ideas for development of renewable energy conversion and storage technologies. However, the relationship between the intrinsic properties of materials such as lattice thermal conductivity and catalysis remains to be explored. In this work, the lattice thermal conductivity of BN and graphene was calculated by ShengBTE. In addition, the adsorption properties of 3d-TM (TM = V, Cr, Mn, Fe, Co, Ni) on BN and graphene were investigated using first-principles methods, and it was found that Ni atom can form relatively stable SACs compared to other TMs. The molecular dynamics (MD) simulation and migration barrier of Ni loaded on BN and graphene were calculated. Our study found that graphene has higher thermal conductivity and is easier to form SACs than BN, but the SACs formed on BN surface have higher thermodynamic stability.
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
