Science China Chemistry最新文献

Poly(diethyl fumarate-co-methoxyethyl acrylate-co-vinyl chloroacetate) (PDEFMV), a novel bio-based elastomer with a saturated structure, was synthesized via redox emulsion polymerization. The glass-transition temperatures of PDEFMV, adjusted through the variation of the diethyl fumarate-to-methoxyethyl acrylate feeding ratio, ranged from −36.1 to −14.8 °C. The number-average molecular weights of PDEFMV ranged from 384,000 to 46,000 g/mol. In designing the molecular structure, vinyl chloroacetate was used to provide active sites for subsequent vulcanization and crosslinking. The active chlorine groups within the PDEFMV chain reacted with the crosslinking agent trithiocyanuric acid under high temperature and pressure to form a nonsulfur crosslinked three-dimensional network structure. To achieve the desired properties, carbon black (CB, N330) was incorporated to reinforce PDEFMV, leading to the formation of PDEFMV/CB composites. A comprehensive study was conducted on the high-temperature oil resistance of PDEFMV/CB composites. Following immersion in IRM903 oil at temperatures of 150 and 200 °C for 72 h, the mass and volume changes in PDEFMV/CB were lower than those observed in commercially available acrylate rubber (AR)/CB, indicating that PDEFMV exhibited superior oil resistance. Furthermore, the aging characteristics and mechanisms of oil resistance in the PDEFMV/CB and AR/CB composites were investigated at different temperatures (150, 200, and 250 °C). The results provide insights into the operational temperature ranges suitable for PDEFMV/CB and offer valuable guidance for potential industrial applications.

Liquid biopsy used molecular information in body liquid to perform early diagnosis, screening, monitoring, prognosis, and treatment of various diseases. Circulating free nucleic acids (cfNA) are important diagnostic biomarkers, providing a window to accurately and immediately observe the body’s vital activity status. With the development of gene sequencing technology and bioinformatics technology, genetic, epigenetic, and fragtomics alterations that can be detected in cfDNA, as well as the expression level of miRNA and cf-mRNA can be quantified, this can reflect its tissue origin, gene regulation, genome evolution, and disease pathogenesis. This review focuses on the clinical utility of cfNA in different body liquids (blood, urine, bile), and discusses the diagnostic efficacy and accuracy of cfNA as diagnostic biomarkers in a variety of diseases. Blood is widely used to diagnose various tissue lesions for liquid biopsies as a body fluid circulating throughout the body, reflecting the state of the entire body. Bile and urine, as local circulating body fluids, can better reflect the changing state of tissues around the biliary tract and tissues around the bladder, respectively. In addition, normalized sample preservation, cfNA extraction, and detection procedures will help the practical application of cfNA in the clinic.

Infectious diseases are caused by various pathogenic microorganisms that break through the human immune barrier, then reproduce and mutate in human cells, thus causing invasive disease. Despite many recent scientific and technological advances in fields, such as genetics, chemistry, and protein engineering, and in the efficiency of drug research and development, the discovery and development of novel and potent anti-infectious disease agents have still lagged behind. It is often challenging to keep up with the emergence and mutation of new pathogenic microorganisms, which leads to the emergence of more resistant pathogenic microorganisms. The emergence of aggregation-induced emission (AIE) fluorogens with high luminescence yields and high reactive oxygen species (ROS) production rates provides scientists with a new strategy for the prevention and treatment of pathogenic microorganisms. Due to their advantages in terms of brightness, biocompatibility, photostability, and positive correlation, AIE fluorogens (AIEgens) have great potential in biological applications. This review presents a systemic overview of recent progress in AIEgen-based platforms for the photodynamic therapy (PDT) of infectious diseases, which has emerged as a promising noninvasive alternative to traditional antibiotics for combating the drug resistance of infectious diseases. This review is mainly divided into two parts according to the type of pathogenic microorganisms: a section on bacterial and fungal infections (e.g., eye, skin, oral cavity, and blood infections), and a section on viral infections. The future prospects and potential clinical applications of AIEgens are also discussed in detail. In addition to motivating further interest in this field, this review is intended to promote ideas for the further exploration of AIEgens and the development of more advanced AIEgens in a broader range of biomedical and clinical applications.

Dynamic tuning of single-color and multi-color (including white-light) luminescence has attracted much attention for applications in various fields; however, effective systems are still scarcity to date. Herein, we report the construction of host-guest metal-organic frameworks (MOFs) serves as an effective strategy to achieve the excitation- and time-dependent long afterglow and white light emitting, simultaneously. The guest-induced structural distortion modulates the single-triplet state intersystem crossing, promotes ligand-to-ligand charge transfer (LLCT) in layer-column MOFs, and further boosts multiple exciton generation of triplet states for multi-color ultralong phosphorescence, as indicated by both experiment and density functional theory (DFT) calculation. By further doping of dyes into MOFs, white-light emitting with tunable color temperature can be facilely obtained, which has been further fabricated into white-light light-emitting diode (LED) with color rendering index of 88.4, higher than that of most as-reported pure inorganics and inorganic-organic hybrid systems. Therefore, this work not only describes a host-guest energy transfer route for dynamic tailoring wide range of color-tunable long-afterglow, but also explores the application prospect of new white-light materials with high color rendering and low blue light for promising display and lighting applications.

Fluorescence imaging is a non-invasive and highly sensitive bioimaging technique that has shown remarkable strides in plant science. It enables real-time monitoring and analysis of biological and pathological processes in plants by labeling specific molecular or cellular structures with fluorescent probes. However, tissue scattering and phytochrome interference have been obstacles for conventional fluorescence imaging of plants in the ultraviolet and visible spectrum, resulting in unsatisfactory imaging quality. Fortunately, advances in near-infrared (NIR) fluorescence imaging technology (650–900 nm) offer superior spatial-temporal resolution and reduced tissue scattering, which is sure to improve plant imaging quality. In this review, we summarize recent progress in the development of NIR fluorescence imaging probes and their applications for in vivo plant imaging and the identification of plant-related biomolecules. We hope this review provides a new perspective for plant science research and highlights NIR fluorescence imaging as a powerful tool for analyzing plant physiology, adaptive mechanisms, and coping with environmental stress in the near future.

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic scaffolds. Structurally diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results (up to 99:1 e.r., >95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(III) complexes.

Herein, we disclose a novel copper-catalyzed C(sp)–H aryl amination of terminal alkynes with anthranils, enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structurally diverse C2-substituted quinolines and 2-quinolinones. The in-situ formed carbonyl-ynamines are prone to tautomerize to carbonyl-ketenimines, which can efficiently react with a series of nucleophiles, including amines, alcohols, phenols, thiols, thiophenols, active-methylene compounds, and even water to produce various quinoline derivatives with the generation of H₂O as a sole and green byproduct. This method also unlocks a practical route to create various quinoline-fused heterocycles and can be successfully applied to the late-stage modification of complex molecules and the concise synthesis of bioactive targets. Mechanistic studies reveal a copper-catalyzed inner-sphere nitrene transfer process by using anthranils as novel aryl nitrene precursors.

Organic room temperature phosphorescence (RTP) materials with persistent afterglow exhibit good biocompatibility, high signal to noise ratio and time resolved imaging characteristics in bio-applications. Moreover, they can serve as hypoxia detection probes and photodynamic therapy agents for the sensitivity of triplet excitons toward oxygen in the surroundings. In this review, the recent progress of in vitro and in vivo afterglow bioimaging is presented by utilizing organic RTP materials. The strategies of molecular design and controlling methods of molecular packing were summarized, to prompt this new rising research field, with the emphasis on high intensity, ultralong lifetimes and red-shifted wavelengths of phosphorescence emission.

Accommodating target analytes within the pores of metal-organic frameworks (MOFs) to improve the sensing performance is an important but challenging task. Here, we report a novel molecular imprinting strategy to create target recognition sites in a tailored multicomponent MOF with the inter-ligand synergistic antenna effect to lanthanide ions, enabling selective recognition of trace biomarkers, which is critical to the early diagnosis of age-related diseases in blood samples with high sensitivity and ultralow limit of detection (LOD) of 69 nmol L⁻¹. Compared with MOF-based sensors without imprinted recognition sites, the significantly enhanced sensing performance (both sensitivity and LOD) was attributed to a dynamic-static coupled sensing mechanism: the dynamic interactions involve concentrating the trace biomarkers at the imprinted recognition sites to enhance the sensing performance at ultralow concentration, and the static interactions are derived from electron/energy exchange between the molecularly imprinted MOF and the biomarker to govern the sensing performance. This work establishes a new molecular imprinting strategy to attain advanced materials for sensing trace bio-analytes.