Polycomb group proteins and the related histone modification H3K27me3 can maintain the silencing of key developmental regulators and provide cellular memory. However, how such an epigenetic state is reprogrammed and inherited between generations is poorly understood. Using an ultra-sensitive approach, STAR ChIP-seq, we investigated H3K27me3 across 14 developmental stages along mouse gametogenesis and early development. Interestingly, highly pervasive H3K27me3 is found in regions depleted of transcription and DNA methylation in oocytes. Unexpectedly, we observed extensive loss of promoter H3K27me3 at Hox and other developmental genes upon fertilization. This is accompanied by global erasure of sperm H3K27me3 but inheritance of distal H3K27me3 from oocytes. The resulting allele-specific H3K27me3 patterns persist to blastocysts before being converted to canonical forms in postimplantation embryos, where both H3K4me3/H3K27me3 bivalent promoter marks are restored at developmental genes. Together, these data revealed widespread resetting of epigenetic memory and striking plasticity of epigenome during gametogenesis and early development.
BACKGROUND:Ideal bone repair material should be of good biocompatibility and high bioactivity. Besides, their mechanical properties should be equivalent to those of natural bone. The objective of this study was to fabricate a novel biocomposite suitable for load-bearing bone defect repair. MATERIAL AND METHODS:A novel biocomposite composed of carbon fiber, hydroxyapatite and polyamide46 (CF/HA/PA46) was fabricated, and its mechanical performances and preliminary cell responses were evaluated to explore its feasibility for load-bearing bone defect repair. RESULTS:The resultant CF/HA/PA46 biocomposite showed a bending strength of 159–223 MPa, a tensile strength of 127–199 MPa and a tensile modulus of 7.7–10.8 GPa, when the CF content was 5–20% (mass fraction) in biocomposite. The MG63 cells, showing an osteogenic phenotype, were well adhered and spread on the surface of the CF/HA/PA46 biocomposite. Moreover, the cells vitality and differentiation on the CF/HA/PA46 biocomposite surface were obviously increased during the culture time and there was no significant difference between the CF/HA/PA46 biocomposite and HA/PA (as control) at all the experimental time (P>0.05). CONCLUSIONS:The addition of CF into HA/PA46 composite manifest improved the mechanical performances and showed favorable effects on biocompatibility of MG63 cells. The obtained biocomposite has high potential for bone repair in load-bearing sites.
Abstract Antibacterial fabrics have garnered significant attention due to bacterial infection‐related public safety problems. However, the challenge of creating textiles with efficient and durable antibacterial properties remains significant. In this study, an eco‐friendly calcination technique was applied to synthesize a nanostructured CuO@ZIF‐8 antibacterial agent. The resulting material exhibits both efficient and durable antibacterial performance. Polyethylene terephthalate (PET) was used as the fiber matrix, and PET/CuO@ZIF‐8 fibers were produced using melt spinning technology. The results indicate that the antibacterial material is well dispersed within the PET matrix, which promotes crystallization during the cooling process. With a 99.9% maximum bactericidal rate against E. coli and S. aureus , the altered polyester fibers demonstrated strong antibacterial activity. Furthermore, the modified polyester fibers exhibited excellent wash resistance, maintaining antibacterial rates of 93.7% against S. aureus and 92.6% against E. coli after 50 washes. This work presents a fresh method for producing efficient and durable antibacterial polyester fibers. Highlights Eco‐friendly calcination synthesizes CuO@ZIF‐8 antibacterial agent. PET fibers incorporated with CuO@ZIF‐8 via melt spinning technology. Antibacterial material well‐dispersed in PET, promoting crystallization. The PET fibers exhibit efficient and durable antibacterial performance.
To design and optimize seismic metamaterials, the impacts of nonlinearity in different locations of locally resonant acoustic metamaterials on the dispersions and the variation of amplitude-dependent bandgaps are investigated in this paper. The research used theoretical calculations, namely, Lindstedt–Poincaré perturbation method and prediction method, and combined finite-element simulation. Summarizing from our research, the lower bandgap is sensitive when exposed to amplitude stimulation, when there arise nonlinear characteristics between matrices; while nonlinearity appears within the interior oscillator, amplitudes obtain a more intense influence on the bandgap, introducing an enormous magnitude of deviation between the upper bandgap and the lower bandgap. Based on the peculiar frequency-shift characteristics, an acoustic three-terminal controller is proposed as a conventional subsize acoustical device and nonlinear seismic metamaterials component. This controller enables the realization of modulating the value of output signals by adjusting the quantitative loading on the control port, without changing the input signals and the parameters of the apparatus validated with the finite-element simulation. The work may offer potential applications in low-frequency vibration reduction and external-controllable multi-functional acoustical devices.
Metal–organic cycles/cages (MOCs) are a class of nanoscale molecular entities that possess distinct shapes and sizes and are designed and synthesized through the predictable integration of organic and inorganic ligands. The diverse functionalities of MOCs render them valuable in the fields of biology, chemistry, and materials. First, the cavity renders them suitable for host–guest interactions, which are subsequently employed to induce conformational changes, and this approach is particularly advantageous for catalysis, sensing, and controlled loading and release. Furthermore, MOC- and polymer-based aggregates can be applied in biomedical research and cascaded light-harvesting systems. Benefiting from the high specific surface area, the initial exploration of MOC-based hierarchical assemblies indicates their potential applications in biomedicine and catalysis. MOC-based microsheets and centimeter films can be used for dual-mode catalysis and novel wound dressing for nonhealing wounds. In addition, the design and synthesis of novel MOCs with different shapes and sizes through various strategies are discussed. We summarized the latest progress in the past 5 years in this Review.
Acute kidney injury (AKI) is a syndrome characterized by rapid loss of renal excretory function. Its underlying mechanisms remain unclear. Pyroptosis, a form of programmed cell death, plays an important role in AKI. It is characterized by cell swelling and membrane rupture, triggering the release of cellular contents and activating robust inflammatory responses. Carnosine, a dipeptide with antioxidant and anti-inflammatory properties, has therapeutic effects in AKI. However, the mechanism by which carnosine treats AKI-associated pyroptosis remains unexplored. In this study, we investigated the protective effect of carnosine on renal tubule cells using in vivo and in vitro models of AKI. We found that carnosine therapy significantly alleviated altered serum biochemical markers and histopathological changes in mice with cisplatin-induced AKI. It also reduced the levels of inflammation and pyroptosis. These results were consistent with those seen in human kidney tubular epithelial cells (HK-2) treated with cisplatin. Through molecular docking and cellular thermal shift assay, we identified caspase-1 as a target of carnosine. By knocking down caspase-1 in HK-2 cells using caspase-1 siRNA, we demonstrated that carnosine did not exhibit a protective role in cisplatin-induced HK-2 cells. This study provides the first evidence that carnosine alleviates damage to kidney tubular epithelial cells by targeting caspase-1 and inhibiting pyroptosis. Therefore, carnosine holds promise as a potential therapeutic agent for AKI, with caspase-1 representing an effective therapeutic target in this pathology.
These are the data used in the work "New insights into the sources of atmospheric organic aerosols in East China: a comparison of online molecule-level and bulk measurements". Currently the manuscript is submitted to JGR-A.
Analysis and Diagnosis work are important jobs to find out the energy over consumed steps in the power generating process, and how to avoid these energy over consumptions.A suit of analysis and diagnosis methodology including staged indexes and methods are presented and a diagnosis application example on a 660MW supercritical power generating unit is conducted in this document.Impact factors, their performance effecting ways and corresponding counteracting measures are fully analyzed, can be a useful reference as solving such total performance promotion problem.
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