Latest ArticlesUnderstanding the role of perovskite surface passivators in hot carriers transfer dynamics is important to develop highly efficient perovskite solar cells (PSCs). In this work, we have designed and synthesized a naphthalimide-based organic small molecule (NCN) for perovskite surface defect passivator. We reveal that the introduction of NCN not only reduces the density of perovskite defect-state, but also promotes hot carriers (HCs) cooling in perovskite through the transient absorption spectroscopy measurements. Fast HCs cooling permits HCs transfer from perovskite layer into NCN layer, thus resulting in the decreased charge-carrier recombination in NCN-treated device. As expected, the power conversion efficiency (PCE) of PSCs with NCN is enhanced to 22.02% from 19.95% for the control device. The findings are relevant for developing highly efficient PSCs.
A novel Ce-containing poly(tungstobismuthate) Cs18Na8H20[Ce3(H2O)10W8Bi4O28(B-α-BiW9 O33)4]2·64H2O (1) has been synthesized by a facile one-pot self-assembly reaction strategy. Its structural characterization is realized by virtue of single-crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction and thermogravimetric analysis. The polyoxoanion of 1 is an octameric architecture consisting of two tetrameric entities [Ce3(H2O)10W8Bi4O28(B-α-BiW9O33)4]23− linked by two CeOW bonds, and adjacent polyoxoanions are further combined together by means of Ce3+ linkers, resulting in an infinite 1D chain architecture. Compound 1 is the currently largest tungstobismuthate, and also represents the first example of lanthanide-encapsulated tungstobismuthate exhibiting an extended structure. Furthermore, compound 1 as a heterogeneous catalyst, exhibits high activity for the oxidative decontamination of a sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES) into 2-chloroethyl ethyl sulfoxide (CEESO).
In core-shell silver nanoclusters, the control of core structure presents a more formidable challenge compared to that of the shell structure. Here, we report the successful synthesis and characterization of four distinct silver thiolate nanoclusters [MS4@Ag12@Ag46S24(dppb)12] (M = Mo or W), each incorporating a cup-like [MS4@Ag12]2+ kernel. These nanoclusters were meticulously prepared using (NH4)2MoS4 or (NH4)2WS4 as both a template and a controlled source of S2− ions. Remarkably, we have observed a unique configuration within these eight-electron superatomic Ag58 nanoclusters, where the zero-valent Ag atoms reside exclusively within the inner [MS4@Ag12]2+ kernel. This stands in contrast to other superatomic clusters possessing an Ag(0) core. Notably, the introduction of phenyl-containing compounds during the synthesis process induced a transformation in the space group symmetry from C2/c to I4. This transformative effect was found to originate from the interplay between adjacent 1,4-bis(diphenylphosphino)butane (dppb) ligands, which facilitated enhanced emission through aggregation-induced intermolecular interactions, specifically C−H···π interactions. Collectively, our findings contribute substantively to the understanding of the intricate relationship between nanocluster structures and their corresponding properties, shedding light on the crucial roles played by templates and diphosphine ligands in this context.
Polymeric carbon nitride (PCN) has garnered increasing attention as a metal-free photocatalyst with a suitable band gap. In efforts to enhance its photocatalytic performance, researchers have examined various PCN materials, including poly(heptazine imide) (PHI) and poly(triazine imide) (PTI), two isomers within the PCN family that exhibit distinct and superior photocatalytic activity compared to other forms. The challenge, however, lies in the common practice among researchers to categorize PHI and PTI along with other PCN types under the overarching term "g-C3N4, " which significantly impedes optimization efforts. The objective of this review is to provide comprehensive insights into the structural features, photoelectrochemical properties, and effective characterization methods employed for distinguishing between PHI and PTI materials. The review also summarizes various optimization strategies, such as crystallinity adjustments, defect engineering, morphology control, constructing heterojunction, and atomic-level metal loading dispersion, to elevate the photocatalytic activity of PHI and PTI, in addition to summarizing the history of carbon nitride development. Furthermore, this review highlights the primary applications of PHI and PTI, encompassing nitrogen fixation, biomass conversion, organic synthesis, CO2 reduction, pollutant degradation, H2O2 production, and photocatalytic water splitting. Lastly, the prospects and challenges associated with further advancing PHI and PTI are thoroughly examined.
Three highly oxidized hybrid flavonoids neosophoflavonoids A–C (1, 2a, and 2b) were isolated from the roots of Sophora flavescens. Neosophoflavonoid A possesses a unique highly oxidized heptacyclic 6/6/6/6/6/6/5 system. Neosophoflavonoids B and C are isomers and share the same highly oxidized hexacyclic 6/6/6/6/6/6 systems. Their planar structures were elucidated from 1D/2D nuclear magnetic resonance (NMR), ultraviolet spectroscopy (UV), infrared spectroscopy (IR), and high resolution electrospray ionization mass spectroscopy (HRESIMS) data. Their absolute configurations were determined by thorough GIAO 13C NMR (DP4+) calculation protocol and electronic circular dichroism (ECD) calculation method. The plausible biosynthetic routes for the compounds were also proposed. All compounds exhibited significant protein tyrosine phosphatase-1B (PTP1B) inhibitory activity with half maximal inhibitory concentration (IC50) values 3.94 ± 0.01, 0.38 ± 0.13, and 0.70 ± 0.01 µmol/L, respectively. In addition, compared to a positive control fenofibrate (Feno) at 20 µmol/L, compounds 2a and 2b exhibited stronger inhibitory effects on lipid accumulation in the oleic acid (OA)-induced cell model at 5 and 10 µmol/L.
Natural hydrogels have emerged as a pivotal innovation in wound care, offering a unique combination of high absorbency, biocompatibility, and versatility. However, due to the complexity of wound healing, the physiological state of the wound varies dynamically, and the mechanism of natural hydrogels that boost wound healing is still unclear. In this review, we firstly provide a comprehensive introduction to the biological process of wound healing, emphasizing the critical stages and factors affecting healing. This work concludes the composition and properties of natural hydrogels, including collagen, gelatin, hyaluronic acid, chitosan, alginates, cellulose, and fibroin, highlighting their biocompatibility and biodegradability. The focus shifts to the various crosslinking strategies employed to enhance the structural integrity and functionality of natural hydrogels. This review further investigates the biological effects of natural hydrogels in wound healing, detailing their antibacterial, antioxidant, anti-inflammatory, adhesive, and hemostatic functions. Furthermore, we propose the challenges and future perspectives of natural hydrogels in practical applications. This review offers a comprehensive overview of the current state and potential future advancements in natural hydrogel dressings for wound care, highlighting their critical role in addressing complex and hard-to-heal wounds.
Metronidazole (MNZ) is a type of antibiotic that can help people and animals cure bacterial infections, however, abuse of MNZ has posed a threat to human health. Hence, portable and visual detection of MNZ is meaningful for food safety and rational administration of drugs, but full of challenges. Hence, a porous three-dimensional Tb-based metal-organic framework (MOF) {(CH3)2NH2·[Tb5(TDA)8(H2O)2]·6DMF·2C2H5OH}n (TDA-Tb) with good solvent and pH stabilities was prepared, and the framework possesses one-dimensional channels with a diameter of 12 Å along the c-axis. Experiment results suggest that the synthesized TDA-Tb can selectively and sensitively detect MNZ in water, and the limit of detection (LOD) is as low as 4.1 × 10−7 mol/L. Moreover, a flexible sensor TDA-Tb-M was also constructed by incorporating TDA-Tb into membrane materials for convenient usage. And the TDA-Tb-M firstly realized portable and visual detection of MNZ through smartphone scanning, which may inspire more probes with wide application ranges.
Histone H3K79 modifications are essential to regulate chromatin structure and gene transcription, but understanding of the molecular mechanisms is limited. Because H3K79 is at globular domain, short histone peptide cannot mimic H3K79 in chromatin. Instead, reconstituted nucleosome-based chemical tools are ideally used to investigate H3K79 modifications. In consequence, H3K79-modified histone H3 with additional chemical handles are required, but such synthesis is challenging and laborious. Here we report a facile semisynthesis method that enables multifunctional histone H3 readily available. H3K79-containing fragment is short for straight peptide synthesis that was later ligated to recombinant expressed H3 fragments for full-length product in large scale. As a result, nucleosomes with H3K79 modifications as well as photo-reactive group and affinity tag were obtained to investigate potential binding proteins. We believe this method that enhances synthetic accessibility of nucleosome probes will accelerate understanding of the underexplored H3K79 modifications.
Photothermal hydrogels with excellent photo responsive and thermal conversion ability had attract a great deal of attention from researchers to explore their biological applications. This review aimed to provide a comprehensive overview of photothermal hydrogels, focusing on their design principles, various functions, and biological applications. Firstly, several classifications of photothermal hydrogels were given according to different photothermal agents (metal, metal sulfide/oxide, MXene, carbon-based, dyes, black phosphorus, and polymer) utilized in hydrogel construction. The photothermal conversion mechanism and hydrogel fabrication were also discussed in detail. Then, the relationship between their photothermal conversion property and functions, together with some indispensable property such as biocompatibility, adhesion, mechanical properties, and self-healing properties was fully introduced. Furthermore, the applications of photothermal hydrogels in the biomedical (i.e., wound healing, antibacterial treatments, controlled drug release, bone repair, and tumor treatment) was summarized. Finally, the future opportunities and challenges of photothermal hydrogels were proposed. We believe that this review could provide a new horizon for further preparation of photothermal hydrogels, and could promote their applications in wider fields.
As a promising imaging technology, the low sensitivity of fluorine-19 magnetic resonance imaging (19F MRI) severely hinders its biomedical applications. Herein, we have developed an unprecedented rotaxane-based strategy to improve the sensitivity of 19F MRI agents. By threading the fluorinated macrocycle into 2-blade pinwheel [2]rotaxanes, the 19F longitudinal relaxation rate R1 was dramatically increased, resulting in a significant 19F MRI signal intensity enhancement of up to 79%. Through comparative molecular dynamics studies using a series of solution and solid-state 1H/19F nuclear magnetic resonance (1H/19F NMR) and molecular dynamics simulations, it was found that the formation of mechanical bonds dramatically restricts the motion of the wheel fluorines and thus increasing the R1 for higher 19F MRI sensitivity. Besides a novel strategy for improving 19F MRI sensitivity, this study has established 19F NMR/MRI as a valuable technology for monitoring the molecular dynamics of rotaxanes, which may shed new light on high-performance 19F MRI agents and molecular devices.
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