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Steel slag (SS) as solid waste, has low resource utilization efficiency and seriously endangers environmental safety and human health. To explore the potential utilization value of SS and address the flammability challenge of rigid polyurethane foam (RPUF), with a novel flame‐retardant system composed by SS and dimethyl methyl phosphonate (DMMP) was explored. The DMMP/SS system effectively improved the high temperature stability of the RPUF composites. When the mass ratio of SS and DMMP was 1:1, the limiting oxygen index of RPUF/DMMP/SS reached 23.1 vol% and UL‐94 vertical combustion tests passed V‐2 level. Upon incorporation of 15 wt% DMMP, the initial decomposition temperature (T−5 wt%) reduced to 165.3°C, a decrease of 32.2%, while the Tmax2 and residue yield at 700°C exhibited negligible alteration. The peak heat release rate of RPUF/DMMP/SS composite (118.20 W g−1) was 11.02% lower than that of pure RPUF, indicating the significant enhancement of fire safety of the composites. Results confirmed that a synergistic flame‐retardant mechanism was existed between DMMP and SS in enhancing the fire safety of RPUF composite. Introducing a 20 wt% SS content reduces the ID/IG ratio to 1.85, thereby markedly enhancing its heat resistance. This work provides a new application field of SS and paves a novel approach to enhance fire safety of polymers. [ABSTRACT FROM AUTHOR]

In the era of Internet information technology, the IT background of directors plays a significant role in corporate governance. However, existing research lacks sufficient discussion on the financing constraints faced by Internet startups. This paper examines Internet entrepreneurial enterprises listed on the New Third Board as the research sample. Using content analysis coding methods and Python software for text mining, the study empirically analyzes the impact of directors' IT backgrounds and media reports on the financing constraints of these enterprises. The results indicate the following: First, directors with IT backgrounds help reduce the financing constraints of Internet startups. The higher the directors' proficiency in information technology, the more favorable it is for obtaining financing. Second, directors with IT backgrounds have a significant positive impact on the tone of media reports. Third, the tone of media reports reflects the spirit and development of the enterprises, serving as a mediating factor between directors' IT backgrounds and the financing constraints of the enterprises. The findings of this study are valuable for guiding Internet startups to better leverage the IT expertise of their directors. Additionally, they provide useful insights for reducing the financing constraints faced by these startups. [ABSTRACT FROM AUTHOR]

Aim: To discover the populations of mesenchymal stem cells (MSCs) derived from different layers of human maxillary sinus membrane (hMSM) and evaluate their osteogenic capability. Materials and Methods: hMSM was isolated into a monolayer using the combined method of physical separation and enzymatic digestion. The localization of MSCs in hMSM was performed by immunohistological staining and other techniques. Lamina propria layer‐derived MSCs (LMSCs) and periosteum layer‐derived MSCs (PMSCs) from hMSM were expanded using the explant cell culture method and identified by multilineage differentiation assays, colony formation assay, flow cytometry and so on. The biological characteristics of LMSCs and PMSCs were compared using RNA sequencing, reverse transcription and quantitative polymerase chain reaction, immunofluorescence staining, transwell assay, western blotting and so forth. Results: LMSCs and PMSCs from hMSMs were both CD73‐, CD90‐ and CD105‐positive, and CD34‐, CD45‐ and HLA‐DR‐negative. LMSCs and PMSCs were identified as CD171+/CD90+ and CD171−/CD90+, respectively. LMSCs displayed stronger proliferation capability than PMSCs, and PMSCs presented stronger osteogenic differentiation capability than LMSCs. Moreover, PMSCs could recruit and promote osteogenic differentiation of LMSCs. Conclusions: This study identified and isolated two different types of MSCs from hMSMs. Both MSCs served as good potential candidates for bone regeneration. [ABSTRACT FROM AUTHOR]

Lignocellulose nanofibrils (LCNFs), as an emerging member of the green nanofibril family, have tremendous potential in improving the dispersibility, adsorption and photogenerated carrier separation efficiency of BiOBr because of the combination of the advantages of nanocellulose (NC) and nanolignins. Herein, sulfated lignocellulose nanofibrils (SLCNFs) were obtained from the poplar alkaline peroxide mechanical pulp (APMP) using a deep eutectic solvent (DES) and a mechanical defibrillation strategy, and flower-like BiOBr/SLCNF composites with oxygen vacancies were prepared by in situ synthesis. Due to the well-preserved lignin structure, abundant oxygen-containing functional groups, and the interconnected three-dimensional mesh structure in SLCNFs, the composites exhibited flower-like morphology, good dispersion and excellent adsorption performance after the introduction of SLCNFs. EPR analysis showed that the introduction of SLCNFs increased the number of oxygen vacancies in BiOBr, which improved the visible light absorption and reduced the recombination of photogenerated carriers. In addition, the photocatalytic activity improved with interfacial interaction between BiOBr and SLCNFs promoting the separation of electrons and holes. Therefore, BiOBr/SLCNF can effectively remove RhB in the dynamic continuous process of adsorption enrichment and photocatalytic oxidation. Under visible light, 99% of RhB was degraded within 30 min and 88.5% of tetracycline hydrochloride (TCH) was degraded within 60 min. Importantly, the main active species which removed RhB by BiOBr/SLCNF were ˙O2− and h+, and the BiOBr/SLCNF composites still have good stability and recyclability after 5 times of repeated use. Overall, the BiOBr/SLCNF composite photocatalyst has great potential for the purification of organic wastewater. [ABSTRACT FROM AUTHOR]

It is of great technical interest but still challenging to develop a cost-effective and eco-friendly method to extract high-aspect-ratio elementary nanofibrils with native-state microstructure from recalcitrant lignocellulosic biomass because established chemical/biological/mechanical approaches inevitably give rise to the breakage of cellulose chains during the nanofibrillation of lignocellulose. Nature has designed hierarchical and heterogeneous lignocellulose structures, among which hemicellulose significantly affects interfibrillar interactions due to its unique molecular structure and micro-distribution pattern. Inspired by this fact, we amplify the hemicellulose stimulation effect on nanofibrillation using an on-demand regulated ionic liquid/water cosolvent and dissociate ultrahigh aspect ratio (2213) elementary fibrils (diameter = 4.7 nm) comprising approaching native-state structural carbohydrates from mildly delignified lignocellulose fibers (i.e. holocellulose) by a low-energy blender. We elucidated the mechanism for the exceptional disassembly behavior of holocellulose fibers: the high-level swelling of the amorphous and negatively charged hemicellulose phase weakens fibril–fibril interactions. The high-aspect-ratio morphology, well-preserved cellulose molecular structure, and hemicellulose-rich surface chemistry of the as-prepared nanofibrils significantly affect their self-assembly behavior and contribute to the extraordinary mechanical and optical performances of the corresponding nanopaper that conventional cellulose nano-papers/composites retain unsurpassed, e.g., overcome general conflicts between strength (310 MPa) and toughness (53 MJ m−3) and between transparency (86%) and haze (77%). This work provides a scale-up, ecologically and economically efficient lignocellulose nanostructure-engineered strategy for manufacturing high-performance structural nanomaterials towards a high-tech and carbon-neutral future. [ABSTRACT FROM AUTHOR]