RESUMO
Pyrrole-based polymers (PBPs), a type of fascinating functional polymers, play a crucial role in materials science. However, efficient synthetic strategies of PBPs with diverse structures are mainly focused on conjugated polypyrroles and still remain challenging. Herein, an atom and step economy protocol is described to access various 2,4-disubstituted PBPs by in situ formation of pyrrole core structure via copper-catalyzed [3+2] polycycloaddition of dialkynones and diisocyanoacetates. A series of PBPs is prepared with high molecular weight (Mw up to 18 200 Da) and moderate to good yield (up to 87%), which possesses a fluorescent emission located in the green to yellow light region. Blending the PBPs with polyvinyl alcohol, the stretchable composite films exhibit a significant strengthening of the mechanical properties (tensile stress up to 59 MPa, elongation at break >400%) and an unprecedented stress-responsive luminescence enhancement that over fourfold fluorescent emission intensity is maintained upon stretching up to 100%. On the basis of computational studies, the unique photophysical and mechanical properties are attributed to the substitution of carbonyl chromophores on the pyrrole unit.
Assuntos
Cobre , Polímeros , Pirróis , Pirróis/química , Cobre/química , Catálise , Polímeros/química , Polímeros/síntese química , Estrutura Molecular , Reação de CicloadiçãoRESUMO
Scorpio is a valuable Chinese animal medicine commonly used in clinical practice in China. It is the main drug in the treatment of liver wind internal movement caused by various reasons throughout the history of traditional Chinese medicine(TCM), with the effects of relieving wind and spasm, dredging collaterals, relieving pain, and eliminating toxin and mass. Scorpio is poisonous and often used as medicine after processing. There are records of its processing as early as the Song Dynasty. Afterward, there were more than 15 processing methods, including frying with vinegar, neat processing, and stir-frying. After processing, the fishy smell could be removed to correct the taste, and the toxicity could be reduced, which was beneficial to clinical application. At present, the main reported components in Scorpio are protein polypeptides, alkaloids, and lipids, with many pharmacological effects, such as anti-cancer, anti-coagulation, anti-thrombosis, anti-atherosclerosis, and anti-bacteria. In this study, the historical evolution of processing, chemical constituents, and pharmacological action of Scorpio were discussed in order to provide references for the related research on Scorpio.
Assuntos
Alcaloides , Medicamentos de Ervas Chinesas , Animais , Evolução Química , Medicamentos de Ervas Chinesas/farmacologia , Medicina Tradicional Chinesa , Alcaloides/farmacologiaRESUMO
A Pd-catalyzed highly regio- and stereoselective hydrocyanation was developed, providing a novel approach to the stereodivergent synthesis of ß-cyano-substituted acrylates in good yields with a wide substrate scope. The judicious selection of ligands was crucial for elegant control over the stereodivergence. Furthermore, the success of the E-hydrocyanation hinges on the right matching of Pd and L1, which not only ensured the catalytic activity but also prevented the formation of α-cyanation products.
RESUMO
The aging process profoundly impacts the systemic milieu, with specific blood-borne factors playing critical roles in its regulation. Platelet Factor 4 (PF4), released by platelets, has emerged as a novel blood-borne factor that contributes to the rejuvenation of aging brains in rodents. However, the age-related disparity in PF4 levels in humans remains poorly understood. To explore the relationship between PF4 and the natural aging process in humans, we collected peripheral blood (PB) samples from young (23.40 ± 2.13 years, n = 15) and elderly (75.23 ± 4.19 years, n = 13) individuals, along with cord blood (CB) samples (n = 15). ELISA analysis revealed higher PF4 levels in platelet-rich plasma lysate from young PB compared with that from elderly PB. Consistent with this, qPCR results demonstrated the highest PF4 expression in young PB among the three groups. In addition, FACS analysis showed increased expression of CXCR3 in mononuclear cells of young PB, indicating a greater responsiveness to PF4. Finally, our RNA-sequencing analysis corroborated platelets as a sensitive element during the natural aging process, and indicated platelets play a pivotal role in antioxidant response during aging, as evidenced by significant enrichment of several age-related pathways. These findings reveal that, alongside PF4 levels, platelets undergo substantial alterations during aging. Taken together, our data identified age-related disparities in platelets and PF4-related elements during natural aging and underscored the potential of targeting platelet modulation as an intervention in the aging process.