Regulation of Nontraditional Intrinsic Luminescence (NTIL) in Hyperbranched Polysiloxanes by Adjusting Alkane Chain Lengths: Mechanism, Film Fabrication, and Chemical Sensing

Biocompatible polymers with nontraditional intrinsic luminescence (NTIL) possess the advantages of environmental friendliness and facile structural regulation. To regulate the emission wavelength of polymers with NTIL, the alkane chain lengths of hyperbranched polysiloxane (HBPSi) are adjusted. Optical investigation shows that the emission wavelength of HBPSi is closely related to the alkane chain lengths; namely, short alkane chains will generate relatively long-wavelength emission. Electronic communication among functional groups is responsible for the emission. In a concentrated solution, HBPSi molecules aggregate together due to the strong hydrogen bond and amphiphilicity, and the functional groups in the aggregate are so close that their electron clouds are overlapped and generate spatial electronic delocalizations. HBPSi with shorter alkane chains will generate larger electronic delocalizations and emit longer-wavelength emissions. Moreover, these polymers show excellent applications in the fabrication of fluorescent films and chemical sensing. This work could provide a strategy for regulating the emission wavelengths of unconventional fluorescent polymers

Regulation of Photophysical Behaviors in Hyperbranched Aggregation-Induced Emission Polymers for Reactive Oxygen Species Scavenging

Developing nonconjugated materials with large Stokes shifts is highly desired. In this work, three kinds of hyperbranched aggregation-induced emission (AIE) polymers with tunable n/π electronic effects were synthesized. HBPSi-CBD contains alkenyl groups in the backbone and possesses a promoted n−π* transition and red-shifted emission wavelength with a large Stokes shift of 186 nm. Experiments and theoretical simulations confirmed that the planar π electrons in the backbone are responsible for the red-shifted emission due to the strong through-space n···π interactions and restricted backbone motions. Additionally, the designed HBPSi-CBD could be utilized as an ROS scavenger after coupling with l-methionine. The HBPSi-Met exhibits remarkable ROS scavenging properties with a scavenging capacity of 77%. This work not only gains further insight into the structure–property relationship of nonconjugated hyperbranched AIE polymers but also provides a promising ROS-scavenging biomaterial for the treatment of ROS-related diseases

Unanticipated Strong Blue Photoluminescence from Fully Biobased Aliphatic Hyperbranched Polyesters

Nonconventional fluorescent polymers without π-aromatic structure have attracted extensive interest in recent years. Hyperbranched polyesters are generally known because of their industrial applications; however, the luminescent properties of the polyester has not been reported. Herein, we synthesized a series of fully biobased aliphatic hyperbranched polyesters via a one-pot A₂ + B₃ esterification reaction. Intriguingly, the resultant hyperbranched polyesters carrying no conventional fluorescent units exhibited unexpected bright blue fluorescence under 365 nm UV light. It was found that the fluorescence intensity was enhanced with increasing solution concentrations and molecular weights of the polyesters. Moreover, the results suggested that the luminescence of polyesters could be controlled by solvents and metal ions. In particular, the fluorescence of the polyesters was extremely sensitive to Fe³⁺. More interesting is that the fluorescence of the polyesters showed an aggregation-induced enhanced emission in the mixture system. Notably, the resulting polyesters displayed a remarkably enhanced quantum yield (16.75%) as compared with that of other types of these polymers. Preliminary results demonstrate that clustering of the carbonyl groups is responsible for the unusual fluorescence in the aliphatic hyperbranched polyesters, namely, clustering-induced emission (CIE). This study provides a novel perspective for the design of biobased luminescent materials to new application areas

Designing Schiff-Based Hyperbranched Polysiloxane for Simultaneously Enhancing Epoxy Resin with Mechanical Properties, Thermal Stability, and Recyclability

It is indeed challenging to simultaneously enhance the toughness, thermal stability, and recyclability of epoxy resins. This study presents an approach utilizing a hybrid hyperbranched polysiloxane (STHPSi) structure, which incorporates Schiff base structures (comprising two benzene rings bonded to imines), Si–O–Ar (aryl group) segments, and abundant terminal sulfhydryl groups. This structure was employed to fabricate high-quality hybrid epoxy resins (STHPSi/EP). Experimental techniques including universal testing machines, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were utilized to assess the performance of the resulting materials. The incorporation of the STHPSi structure imparted a rigid-flexible nature to the epoxy resins, leading to remarkable mechanical properties. Notably, STHPSi not only significantly improved the impact strength by 59.8% and flexural strength by 20.6% but also contributed to enhanced thermal properties. With a 6 wt % addition of STHPSi, the thermal decomposition temperature at 5% weight loss (Td,5%), glass transition temperature (Tg), and char residues of the hybrid resins increased to 351.0 °C, 128.06 °C, and 9.55%, respectively. Furthermore, the STHPSi/EP composites exhibited complete degradation in 1,3-diaminopropane and the degraded substance was successfully reintroduced into the epoxy matrix as a curing agent, facilitating the recycling of waste epoxy resins. The recycled epoxy resins demonstrated excellent mechanical properties, with the impact strength and flexural strength reaching up to 15.3 kJ/m2 and 149.22 MPa, respectively, and interesting luminescent characteristics. This study presents an effective approach for the preparation and reutilization of high-performance epoxy resins, addressing the critical challenges in enhancing their properties and promoting sustainable materials development

Additional file 1 of Intra-abdominal infection after tumor surgery: tigecycline combined with β-lactam antibiotics versus tigecycline alone

Supplementary Material

Additional file 4: Table S3. of SF3B1 deficiency impairs human erythropoiesis via activation of p53 pathway: implications for understanding of ineffective erythropoiesis in MDS

Differentially spliced genes between stage-matched luciferase control and SF3B1 knockdown erythroid cells. (XLSX 169 kb

Additional file 5: Table S4. of SF3B1 deficiency impairs human erythropoiesis via activation of p53 pathway: implications for understanding of ineffective erythropoiesis in MDS

Upregulated and downregulated pathways of SF3B1 knockdown. (XLSX 30 kb

Additional file 1:Table S1. of SF3B1 deficiency impairs human erythropoiesis via activation of p53 pathway: implications for understanding of ineffective erythropoiesis in MDS

Primers and shRNA sequences. (XLSX 11 kb

Additional file 3: Table S2. of SF3B1 deficiency impairs human erythropoiesis via activation of p53 pathway: implications for understanding of ineffective erythropoiesis in MDS

Differentially expressed genes between stage-matched luciferase control and SF3B1 knockdown erythroid cells. (XLSX 239 kb

Additional file 2: Figure S1. of SF3B1 deficiency impairs human erythropoiesis via activation of p53 pathway: implications for understanding of ineffective erythropoiesis in MDS

Expression of SF3B1 during human erythroid differentiation. Figure S2. A schematic structure of each alternative splicing type, along with the associated names and abbreviations. (ZIP 4064 kb