Synthesis of Bridged Five-Membered Ring Systems by Type II [3 + 2] Annulation of Allenylsilane-ene.

The first type II intramolecular [3 + 2] annulation of allenylsilane-ene has been achieved, enabling diastereoselective and efficient construction of synthetically challenging bridged five-membered ring systems such as bicyclo[3.2.1]. This mild and direct process shows a broad substrate scope and is highly stereospecific. Particularly, this work represents the first stereoselective method for the direct synthesis of bicyclo[3.2.1] ring systems from acyclic precursors. Additionally, the first asymmetric total syntheses of (+)- and (-)-strepsesquitriol, and the efficient formation of the synthetically challenging tetracyclic core of pierisjaponol D are achieved by this type II [3 + 2] annulation reaction.

J-Aggregates Formed by NaCl Treatment of Aza-Coating Heptamethine Cyanines and Their Application to Monitoring Salt Stress of Plants and Promoting Photothermal Therapy of Tumors.

The cationic nature of heptamethine cyanines gives them the capacity to form aggregates with salts by electrostatic interactions. In this work, NaCl promoted J-aggregate formation of aza-coating heptamethine cyanines is explored. NaCl can induce the N-benzyloxycarbonyl Cy-CO2 Bz to assemble into a J-aggregate having an absorption at 890 nm. Its excellent fluorescence response to NaCl implies that it has great potential for use as a probe for tracing salt stress in plants. Moreover, NaCl also promotes formation of J-aggregates from the N-ethyloxycarbonyl Cy-CO2 Et. The aggregate shows an intense absorption at 910 nm compared to the monomer which absorbs at 766 nm. Its J-aggregated form can serve as a photothermal agent. And the photothermal conversion efficiency is increased from 29.37 % to 57.59 %. This effort leads to the development of two applications of new cyanine J-aggregates including one for tracing salt stress of plants and the other for promoting photothermal therapy of tumors.

Recent progress in fluorescent probes for bacteria.

Food fermentation, antibiotics, and pollutant degradation are closely related to bacteria. Bacteria play an irreplaceable role in life. However, some bacteria seriously threaten human health and cause large-scale infectious diseases. Therefore, there is a pressing need to develop strategies to accurately monitor bacteria. Technology based on molecular probes and fluorescence imaging is noninvasive, results in little damage, and has high specificity and sensitivity, so it has been widely applied in the detection of bacteria. In this review, we summarize the recent progress in bacterial detection using fluorescence. In particular, we generalize the mechanisms commonly used to design organic fluorescent probes for detecting and imaging bacteria. Moreover, a perspective regarding fluorescent probes for bacterial detection is discussed.

A visible light-activated azo-fluorescent switch for imaging-guided and light-controlled release of antimycotics.

Azo switches are widely employed as essential components in light-responsive systems. Here, we develop an azo-fluorescent switch that is visible light-responsive and its light-responsive processes can be monitored using fluorescence imaging. Visible light irradiation promotes isomerization, accompanied by changes in fluorescence that enable the process to be monitored through fluorescence imaging. Furthermore, we document that the nanocavity size of liposome encapsulated nanoparticles containing azo changes in the isomerization process and show that this change enables construction of a light-responsive nanoplatform for optically controlled release of antimycotics. Also, natural light activation of nanoparticles of the switch loaded with an antimycotic agent causes death of Rhizoctonia solani. The results show that these nanoparticles can double the holding period in comparison to small molecule antimycotics. The strategy used to design the imaging-guided light-controlled nano-antimycotic release system can be applicable to protocols for controlled delivery of a wide variety of drugs.

The Aggregates of Near-Infrared Cyanine Dyes in Phototherapy.

Cyanines in the near-infrared region are a typical example of a classic fluorescent dye that has garnered significant attention and widespread use in the life sciences and biotechnology. Their character to form assemblies or aggregates has inspired the development of various functional cyanine dye aggregates in phototherapy. This article provides a brief summary of the strategies used to prepare these cyanine dye aggregates. The reports in this concept suggest that the self-assembly of cyanine dyes can enhance their photostability, opening up new possibilities for their application in phototherapy. This concept may encourage researchers to explore the development of functional fluorescent dye aggregates further.

[Precision oncology from a proteogenomics perspective].

Cancer is a heterogeneous disease with complex mechanisms that requires targeted precision medicine strategies. The growth of precision medicine is indispensable from the rapid development of genomics. However, genomics has certain limitations in molecular phenotype analysis, proteogenomics thus arose at the right time. Proteogenomics is the merging of proteomics and genomics. This review describes the limitations of genomic analysis and highlights the importance of proteogenomics to re-understand precision oncology from a proteogenomic perspective. In addition, the application of proteogenomics in precision oncology is briefly introduced, the related public data projects are described, and finally, the challenges that need to be addressed at this stage are proposed.

Interactions of microplastics and main pollutants and environmental behavior in soils.

Microplastics (MPs) are emerging global contaminants, attracting more and more attention because of their difficulty in degradation, extensive and persistent pollution. In freshwater environment, especially in the ocean, they have become a global, public and even political research hotspot. However, the distribution, fate and ecological hazards of MPs in agricultural land and other soils have not been explored fully. Although the occurrence of MPs in different habitats has been reviewed at home and abroad, little attention has been paid to its environmental behavior, ecotoxicology and interaction with biological and chemical pollutants in soil. This review summaries the research progress on the source, accumulation, degradation and migration of MPs in soil, the potential risks of ecological environment and food chain. In order to provide theoretical basis and practical suggestions for related research and regulatory countermeasures, the detection and treatment methods and mechanism of microplastics in soil need to be further explored.

Molecular Design and Photothermal Application of Thienoisoindigo Dyes with Aggregation-Induced Emission.

Organic fluorescent dyes with aggregation-induced emission (AIE) property have an extensive application range, especially in the fields of imaging, labeling, and adjusting microprocesses in aggregated environments. In particular, the thienoisoindigo skeleton, which exhibits an outstanding electron-withdrawing capacity in optoelectronic materials, has been defined as a promising AIE candidate. For instance, by installing AIE blocks or other rotatable groups at two terminal sites, such as various arylamine groups, thienoisoindigo derivatives can be efficiently turned to be functional AIE structures. In this work, a thienoisoindigo derivative with AIE characteristics, namely, TII-TPE, was developed. This AIE system was expanded by linking typical AIE fragments, namely, tetraphenylethene, with the proposed thienoisoindigo derivative, which exhibited typical AIE fluorescence in the 600-850 nm range and maintained high photostability. Then, employing the reported derivative TII-TPA coating thienoisoindigo and triphenylamine as a contrast, aggregated TII-TPE and TII-TPA nanoparticles were prepared and demonstrated photothermal conversion efficiencies of 36.2 and 35.6%, respectively. Moreover, both nanoparticles were evaluated as photothermal therapeutic (PTT) agents in a tumor mouse model, which showed to significantly inhibit tumor growth after four treatment cycles in vivo. This work not only presents an enriched thienoisoindigo system but also provides a pattern for subsequent construction of functional AIE molecules.