Genome-wide identification of the B3 transcription factor family in pepper (Capsicum annuum) and expression patterns during fruit ripening.

In plants, B3 transcription factors play important roles in a variety of aspects of their growth and development. While the B3 transcription factor has been extensively identified and studied in numerous species, there is limited knowledge regarding its B3 superfamily in pepper. Through the utilization of genome-wide sequence analysis, we identified a total of 106 B3 genes from pepper (Capsicum annuum), they are categorized into four subfamilies: RAV, ARF, LAV, and REM. Chromosome distribution, genetic structure, motif, and cis-acting element of the pepper B3 protein were analyzed. Conserved gene structure and motifs outside the B3 domain provided strong evidence for phylogenetic relationships, allowing potential functions to be deduced by comparison with homologous genes from Arabidopsis. According to the high-throughput transcriptome sequencing analysis, expression patterns differ during different phases of fruit development in the majority of the 106 B3 pepper genes. By using qRT-PCR analysis, similar expression patterns in fruits from various time periods were discovered. In addition, further analysis of the CaRAV4 gene showed that its expression level decreased with fruit ripening and located in the nucleus. B3 transcription factors have been genome-wide characterized in a variety of crops, but the present study is the first genome-wide analysis of the B3 superfamily in pepper. More importantly, although B3 transcription factors play key regulatory roles in fruit development, it is uncertain whether B3 transcription factors are involved in the regulation of the fruit development and ripening process in pepper and their specific regulatory mechanisms because the molecular mechanisms of the process have not been fully explained. The results of the study provide a foundation and new insights into the potential regulatory functions and molecular mechanisms of B3 genes in the development and ripening process of pepper fruits, and provide a solid theoretical foundation for the enhancement of the quality of peppers and their selection and breeding of high-yield varieties.

Dual Activation for Tuning N, S Co-Doping in Porous Carbon Sheets Toward Superior Sodium Ion Storage.

Porous carbon has been widely focused to solve the problems of low coulombic efficiency (ICE) and low multiplication capacity of Sodium-ion batteries (SIBs) anodes. The superior energy storage properties of two-dimensional(2D) carbon nanosheets can be realized by modulating the structure, but be limited by the carbon sources, making it challenging to obtain 2D structures with large surface area. In this work, a new method for forming carbon materials with high N/S doping content based on combustion activation using the dual activation effect of K2 SO4 /KNO3 is proposed. The synthesized carbon material as an anode for SIBs has a high reversible capacity of 344.44 mAh g-1 at 0.05 A g-1 . Even at the current density of 5 Ag-1 , the capacity remained at 143.08 mAh g-1 . And the ICE of sodium-ion in ether electrolytes is ≈2.5 times higher than that in ester electrolytes. The sodium storage mechanism of ether/ester-based electrolytes is further explored through ex-situ characterizations. The disparity in electrochemical performance can be ascribed to the discrepancy in kinetics, wherein ether-based electrolytes exhibit a higher rate of Na+ storage and shedding compared to ester-based electrolytes. This work suggests an effective way to develop doubly doped carbon anode materials for SIBs.

Bioinspired Additive Manufacturing of Hierarchical Materials: From Biostructures to Functions.

Throughout billions of years, biological systems have evolved sophisticated, multiscale hierarchical structures to adapt to changing environments. Biomaterials are synthesized under mild conditions through a bottom-up self-assembly process, utilizing substances from the surrounding environment, and meanwhile are regulated by genes and proteins. Additive manufacturing, which mimics this natural process, provides a promising approach to developing new materials with advantageous properties similar to natural biological materials. This review presents an overview of natural biomaterials, emphasizing their chemical and structural compositions at various scales, from the nanoscale to the macroscale, and the key mechanisms underlying their properties. Additionally, this review describes the designs, preparations, and applications of bioinspired multifunctional materials produced through additive manufacturing at different scales, including nano, micro, micro-macro, and macro levels. The review highlights the potential of bioinspired additive manufacturing to develop new functional materials and insights into future directions and prospects in this field. By summarizing the characteristics of natural biomaterials and their synthetic counterparts, this review inspires the development of new materials that can be utilized in various applications.

Polyvinyl Alcohol/Graphene Oxide Conductive Hydrogels via the Synergy of Freezing and Salting Out for Strain Sensors.

Hydrogels of flexibility, strength, and conductivity have demonstrated broad applications in wearable electronics and soft robotics. However, it is still a challenge to fabricate conductive hydrogels with high strength massively and economically. Herein, a simple strategy is proposed to design a strong ionically conductive hydrogel. This ion-conducting hydrogel was obtained under the synergistic action by salting out the frozen mixture of polyvinyl alcohol (PVA) and graphene oxide (GO) using a high concentration of sodium chloride solution. The developed hydrogel containing only 5 wt% PVA manifests good tensile stress (65 kPa) and elongation (180%). Meanwhile, the PVA matrix doped with a small amount of GO formed uniformly porous ion channels after salting out, endowed the PVA/GO hydrogel with excellent ionic conductivity (up to 3.38 S m-1). Therefore, the fabricated PVA/GO hydrogel, anticipated for a strain sensor, exhibits good sensitivity (Gauge factor = 2.05 at 100% strain), satisfying working stability (stably cycled for 10 min), and excellent recognition ability. This facile method to prepare conductive hydrogels displays translational potential in flexible electronics for engineering applications.

Nanocage Ferritin Reinforced Polyacrylamide Hydrogel for Wearable Flexible Strain Sensors.

Biocomposite hydrogels are promising for applications in wearable flexible strain sensors. Nevertheless, the existing biocomposite hydrogels are still hard to meet all requirements, which limits the practical application. Here, inspired by the structure and composition of natural ferritin, we design a PAAm-Ferritin hybrid hydrogel through a facile method. Ferritin is uniformly distributed in the cross-linking networks and acts as a nanocage spring model, leading to the enhanced tensile strength of the hydrogel. The fracture stress is 99 kPa at 1400% maximum elongation. As fabricated PAAm-Ferritin hybrid hydrogels exhibit high toughness and low elastic modulus (21 kPa). The PAAm-Ferritin hybrid hydrogels present excellent biocompatibility and increased conductivity compared with PAAm hydrogel. Impressively, as a wearable flexible strain sensor, the PAAm-Ferritin hybrid hydrogels have high sensitivity (gauge factor = 2.06), excellent reliability, and cycling stability. This study indicates the feasibility of utilizing ferritin to synthesize functional materials, which is conducive to expanding the use of protein synthesis of materials technology and application fields.

Porous and Ultra-Flexible Crosslinked MXene/Polyimide Composites for Multifunctional Electromagnetic Interference Shielding.

Lightweight, ultra-flexible, and robust crosslinked transition metal carbide (Ti3C2 MXene) coated polyimide (PI) (C-MXene@PI) porous composites are manufactured via a scalable dip-coating followed by chemical crosslinking approach. In addition to the hydrophobicity, anti-oxidation and extreme-temperature stability, efficient utilization of the intrinsic conductivity of MXene, the interfacial polarization between MXene and PI, and the micrometer-sized pores of the composite foams are achieved. Consequently, the composites show a satisfactory X-band electromagnetic interference (EMI) shielding effectiveness of 22.5 to 62.5 dB at a density of 28.7 to 48.7 mg cm-3, leading to an excellent surface-specific SE of 21,317 dB cm2 g-1. Moreover, the composite foams exhibit excellent electrothermal performance as flexible heaters in terms of a prominent, rapid reproducible, and stable electrothermal effect at low voltages and superior heat performance and more uniform heat distribution compared with the commercial heaters composed of alloy plates. Furthermore, the composite foams are well attached on a human body to check their electromechanical sensing performance, demonstrating the sensitive and reliable detection of human motions as wearable sensors. The excellent EMI shielding performance and multifunctionalities, along with the facile and easy-to-scalable manufacturing techniques, imply promising perspectives of the porous C-MXene@PI composites in next-generation flexible electronics, aerospace, and smart devices.

Bioprocess-Inspired Room-Temperature Synthesis of Enamel-like Fluorapatite/Polymer Nanocomposites Controlled by Magnesium Ions.

Tooth enamel is composed of arrayed fluorapatite (FAP) or hydroxyapatite nanorods modified with Mg-rich amorphous layers. Although it is known that Mg2+ plays an important role in the formation of enamel, there is limited research on the regulatory role of Mg2+ in the synthesis of enamel-like materials. Therefore, we focus on the regulatory behavior of Mg2+ in the fabrication of biomimetic mineralized enamel-like structural materials. In the present study, we adopt a bioprocess-inspired room-temperature mineralization technique to synthesize a multilayered array of enamel-like columnar FAP/polymer nanocomposites controlled by Mg2+ (FPN-M). The results reveal that the presence of Mg2+ induced the compaction of the array and the formation of a unique Mg-rich amorphous-reinforced architecture. Therefore, the FPN-M array exhibits excellent mechanical properties. The hardness (2.42 ± 0.01 GPa) and Young's modulus (81.5 ± 0.6 GPa) of the as-prepared FPN-M array are comparable to those of its biological counterparts; furthermore, the enamel-like FPN-M array is translucent. The hardness and Young's modulus of the synthetic array of FAP/polymer nanocomposites without Mg2+ control (FPN) are 0.51 ± 0.04 and 43.5 ± 1.6 GPa, respectively. The present study demonstrates a reliable bioprocess-inspired room-temperature fabrication technique for the development of advanced high-performance composite materials.

Bioinspired 3D Printable, Self-Healable, and Stretchable Hydrogels with Multiple Conductivities for Skin-like Wearable Strain Sensors.

Bioinspired hydrogels have promising prospects in applications such as wearable devices, human health monitoring equipment, and soft robots due to their multifunctional sensing properties resembling natural skin. However, the preparation of intelligent hydrogels that provide feedback on multiple electronic signals simultaneously, such as human skin receptors, when stimulated by external contact pressure remains a substantial challenge. In this study, we designed a bioinspired hydrogel with multiple conductive capabilities by incorporating carbon nanotubes into a chelate of calcium ions with polyacrylic acid and sodium alginate. The bioinspired hydrogel consolidates self-healing ability, stretchability, 3D printability, and multiple conductivities. It can be fabricated as an integrated strain sensor with simultaneous piezoresistive and piezocapacitive performances, exhibiting sensitive (gauge factor of 6.29 in resistance mode and 1.25 kPa-1 in capacitance mode) responses to subtle pressure changes in the human body, such as finger flexion, knee flexion, and respiration. Furthermore, the bioinspired strain sensor sensitively and discriminatively recognizes the signatures written on it. Hence, we expect our ideas to provide inspiration for studies exploring the use of advanced hydrogels in multifunctional skin-like smart wearable devices.

MXene Frameworks Promote the Growth and Stability of LiF-Rich Solid-Electrolyte Interphases on Silicon Nanoparticle Bundles.

Silicon-based materials are the desirable anodes for next-generation lithium-ion batteries; however, the large volume change of Si during the charging/discharging process causes electrode fracture and an unstable solid-electrolyte interphase (SEI) layer, which severely impair their stability and Coulombic efficiency. Herein, a bundle of silicon nanoparticles is encapsulated in robust micrometer-sized MXene frameworks, in which the MXene nanosheets are precrumpled by capillary compression force to effectively buffer the stress induced by the volume change, and the abundant covalent bonds (Ti-O-Ti) between adjacent nanosheets formed through a facile thermal self-cross-linking reaction further guarantee the robustness of the MXene architecture. Both factors stabilize the electrode structure. Moreover, the abundant fluorine terminations on MXene nanosheets contribute to an in situ formation of a highly compact, durable, and mechanically robust LiF-rich SEI layer outside the frameworks upon cycling, which not only shuts down the parasitic reaction between Si and an organic electrolyte but also enhances the structural stability of MXene frameworks. Benefiting from these merits, the as-prepared anodes deliver a high specific capacity of 1797 mA h g-1 at 0.2 A g-1 and a high capacity retention of 86.7% after 500 cycles at 2 A g-1 with an average Coulombic efficiency of 99.6%. Significantly, this work paves the way for other high-capacity electrode materials with a strong volume effect.

Rational Design of the Robust Janus Shell on Silicon Anodes for High-Performance Lithium-Ion Batteries.

The high-capacity silicon anode is regarded as a promising electrode material for next-generation lithium-ion batteries. Unfortunately, its practical application is still severely hindered by electrode fracture and unstable solid electrolyte interphase during cycling. Herein, we design a structure of encapsulating silicon in a robust "janus shell", in which an internal graphene shell with sufficient void space is used to absorb the mechanical stress induced by volume expansion, and the conformal carbon outer shell is introduced to strongly bond the loosely stacked graphene shell and simultaneously seal the nanopores on the surface. With the ultrastable janus carbon shell, the excellent structural integrity of the electrode and stable solid electrolyte interphase layer could be effectively preserved, resulting in an impressive cycling behavior. Indeed, the as-synthesized anodes demonstrate superior cycle stability and excellent rate performance, delivering a high reversible capacity of 1416 mA h g-1 at a current density of 0.2 A g-1 and 852 mA h g-1 at a high current density of 5 A g-1. Remarkably, the superior capacity retention of 88.5% could be achieved even after 400 cycles at a high current density of 2 A g-1. More importantly, this work opens up a novel avenue to address high-capacity anodes with a large volume change.