Rhizoma Drynariae-derived nanovesicles reverse osteoporosis by potentiating osteogenic differentiation of human bone marrow mesenchymal stem cells via targeting ERα signaling.

Although various anti-osteoporosis drugs are available, the limitations of these therapies, including drug resistance and collateral responses, require the development of novel anti-osteoporosis agents. Rhizoma Drynariae displays a promising anti-osteoporosis effect, while the effective component and mechanism remain unclear. Here, we revealed the therapeutic potential of Rhizoma Drynariae-derived nanovesicles (RDNVs) for postmenopausal osteoporosis and demonstrated that RDNVs potentiated osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) by targeting estrogen receptor-alpha (ERα). RDNVs, a natural product isolated from fresh Rhizoma Drynariae root juice by differential ultracentrifugation, exhibited potent bone tissue-targeting activity and anti-osteoporosis efficacy in an ovariectomized mouse model. RDNVs, effectively internalized by hBMSCs, enhanced proliferation and ERα expression levels of hBMSC, and promoted osteogenic differentiation and bone formation. Mechanistically, via the ERα signaling pathway, RDNVs facilitated mRNA and protein expression of bone morphogenetic protein 2 and runt-related transcription factor 2 in hBMSCs, which are involved in regulating osteogenic differentiation. Further analysis revealed that naringin, existing in RDNVs, was the active component targeting ERα in the osteogenic effect. Taken together, our study identified that naringin in RDNVs displays exciting bone tissue-targeting activity to reverse osteoporosis by promoting hBMSCs proliferation and osteogenic differentiation through estrogen-like effects.

Hierarchically Structured Graphene Aerogel Supported Nickel-Cobalt Oxide Nanowires as an Efficient Electrocatalyst for Oxygen Evolution Reaction.

The rational design of a heterostructure electrocatalyst is an attractive strategy to produce hydrogen energy by electrochemical water splitting. Herein, we have constructed hierarchically structured architectures by immobilizing nickel-cobalt oxide nanowires on/beneath the surface of reduced graphene aerogels (NiCoO2/rGAs) through solvent-thermal and activation treatments. The morphological structure of NiCoO2/rGAs was characterized by microscopic analysis, and the porous structure not only accelerates the electrolyte ion diffusion but also prevents the agglomeration of NiCoO2 nanowires, which is favorable to expose the large surface area and active sites. As further confirmed by the spectroscopic analysis, the tuned surface chemical state can boost the catalytic active sites to show the improved oxygen evolution reaction performance in alkaline electrolytes. Due to the synergistic effect of morphology and composition effect, NiCoO2/rGAs show the overpotential of 258 mV at the current density of 10 mA cm-2. Meanwhile, the small values of the Tafel slope and charge transfer resistance imply that NiCoO2/rGAs own fast kinetic behavior during the OER test. The overlap of CV curves at the initial and 1001st cycles and almost no change in current density after the chronoamperometric (CA) test for 10 h confirm that NiCoO2/rGAs own exceptional catalytic stability in a 1 M KOH electrolyte. This work provides a promising way to fabricate the hierarchically structured nanomaterials as efficient electrocatalysts for hydrogen production.

Functional analyses of TRAF6 gene in Argopecten scallops.

The tumor necrosis factor (TNF) receptor-associated factor (TRAF) family has been reported to be involved in many immune pathways. In a previous study, we identified 5 TRAF genes, including TRAF2, 3, 4, 6, and 7, in the bay scallop (Argopecten irradians, Air) and the Peruvian scallop (Argopecten purpuratus, Apu). Since TRAF6 is a key molecular link in the TNF superfamily, we conducted a series of studies targeting the TRAF6 gene in the Air and Apu scallops as well as their hybrid progeny, Aip (Air ♀ × Apu ♂) and Api (Apu ♀ × Air ♂). Subcellular localization assay showed that the Air-, Aip-, and Api-TRAF6 were widely distributed in the cytoplasm of the human embryonic kidney cell line (HEK293T). Additionally, dual-luciferase reporter assay revealed that among TRAF3, TRAF4, and TRAF6, only the overexpression of TRAF6 significantly activated NF-κB activity in the HEK293T cells in a dose-dependent manner. These results suggest a crucial role of TRAF6 in the immune response in Argopecten scallops. To investigate the specific immune mechanism of TRAF6 in Argopecten scallops, we conducted TRAF6 knockdown using RNA interference. Transcriptomic analyses of the TRAF6 RNAi and control groups identified 1194, 2403, and 1099 differentially expressed genes (DEGs) in the Air, Aip, and Api scallops, respectively. KEGG enrichment analyses revealed that these DEGs were primarily enriched in transport and catabolism, amino acid metabolism, peroxisome, lysosome, and phagosome pathways. Expression profiles of 28 key DEGs were confirmed by qRT-PCR assays. The results of this study may provide insights into the immune mechanisms of TRAF in Argopecten scallops and ultimately benefit scallop breeding.

Efficient Regulation of Polysulfides by Anatase/Bronze TiO2 Heterostructure/Polypyrrole Composites for High-Performance Lithium-Sulfur Batteries.

Despite having ultra-high theoretical specific capacity and theoretical energy density, lithium-sulfur (Li-S) batteries suffer from their low Coulombic efficiency and poor lifespan, and the commercial application of Li-S batteries is seriously hampered by the severe "shuttle effect" of lithium polysulfides (LiPSs) and the large volume expansion ratio of the sulfur electrode during cycling. Designing functional hosts for sulfur cathodes is one of the most effective ways to immobilize the LiPSs and improve the electrochemical performance of a Li-S battery. In this work, a polypyrrole (PPy)-coated anatase/bronze TiO2 (TAB) heterostructure was successfully prepared and used as a sulfur host. Results showed that the porous TAB could physically adsorb and chemically interact with LiPSs during charging and discharging processes, inhibiting the LiPSs' shuttle effect, and the TAB's heterostructure and PPy conductive layer are conducive to the rapid transport of Li+ and improve the conductivity of the electrode. By benefitting from these merits, Li-S batteries with TAB@S/PPy electrodes could deliver a high initial capacity of 1250.4 mAh g-1 at 0.1 C and show an excellent cycling stability (the average capacity decay rate was 0.042% per cycle after 1000 cycles at 1 C). This work brings a new idea for the design of functional sulfur cathodes for high-performance Li-S battery.

Realizing Ultrafast and Robust Sodium-Ion Storage of Iron Sulfide Enabled by Heteroatomic Doping and Regulable Interface Engineering.

Fe-based sulfides are a promising type of anode material for sodium-ion batteries (SIBs) due to their high theoretical capacities and affordability. However, these materials often suffer from issues such as capacity deterioration and poor conductivity during practical application. To address these challenges, an N-doped Fe7S8 anode with an N, S co-doped porous carbon framework (PPF-800) was synthesized using a template-assisted method. When serving as an anode for SIBs, it delivers a robust and ultrafast sodium storage performance, with a discharge capacity of 489 mAh g-1 after 500 cycles at 5 A g-1 and 371 mAh g-1 after 1000 cycles at 30 A g-1 in the ether-based electrolyte. This impressive performance is attributed to the combined influence of heteroatomic doping and adjustable interface engineering. The N, S co-doped carbon framework embedded with Fe7S8 nanoparticles effectively addresses the issues of volumetric expansion, reduces the impact of sodium polysulfides, improves intrinsic conductivity, and stimulates the dominant pseudocapacitive contribution (90.3% at 2 mV s-1). Moreover, the formation of a stable solid electrolyte interface (SEI) film by the effect of uniform pore structure in ether-based electrolyte produces a lower transfer resistance during the charge-discharge process, thereby boosting the rate performance of the electrode material. This work expands a facile strategy to optimize the electrochemical performance of other metal sulfides.

Characterization of TRAF genes and their responses to Vibrio anguillarum challenge in Argopecten scallops.

The tumor necrosis factor receptor-related factor (TRAF) family has been reported to be involved in many immune pathways, such as TNFR, TLR, NLR, and RLR in animals. However, little is known about the roles of TRAF genes in the innate immune of Argopecten scallops. In this study, we first identified five TRAF genes, including TRAF2, TRAF3, TRAF4, TRAF6 and TRAF7, but not TRAF1 and TRAF5, from both the bay scallop A. irradians (Air) and the Peruvian scallop A. purpuratus (Apu). The phylogenetic analysis showed that the TRAF genes in Argopecten scallops (AiTRAF) belong to the branch of molluscan TRAF family, which lacks TRAF1 and TRAF5. Since TRAF6 is a key bridge factor in the tumor necrosis factor superfamily and plays an important role in innate and adaptive immunity, we cloned the ORFs of the TRAF6 gene in both A. irradians and A. purpuratus, as well as in two reciprocal hybrids (Aip for the hybrid Air × Apu and Api for the hybrid Apu × Air). Differences in conformational and post-translational modification resulted from the variation in amino acid sequences may cause differences in activity among them. Analysis of conserved motifs and protein structural domains revealed that AiTRAF contains typical structural domains similar to those of other mollusks and has the same conserved motifs. Tissue expression of TRAF in Argopecten scallops challenged by Vibrio anguillarum was examined by qRT-PCR. The results showed that AiTRAF were higher in gill and hepatopancreas. When challenged by Vibrio anguillarum, the expression of AiTRAF was significantly increased compared with the control group, indicating that AiTRAF may play an important role in the immunity of scallops. In addition, the expression of TRAF was higher in Api and Aip than in Air when challenged by Vibrio anguillarum, suggesting that TRAF may have contributed to the high resistance of Api and Aip to Vibrio anguillarum. The results of this study may provide new insights into the evolution and function of TRAF genes in bivalves and ultimately benefit scallop breeding.

Synergistic Structure and Iron-Vacancy Engineering Realizing High Initial Coulombic Efficiency and Kinetically Accelerated Lithium Storage in Lithium Iron Oxide.

Transition metal oxides with high capacity still confront the challenges of low initial coulombic efficiency (ICE, generally <70%) and inferior cyclic stability for practical lithium-storage. Herein, a hollow slender carambola-like Li0.43 FeO1.51 with Fe vacancies is proposed by a facile reaction of Fe3+ -containing metal-organic frameworks with Li2 CO3 . Synthesis experiments combined with synchrotron-radiation X-ray measurements identify that the hollow structure is caused by Li2 CO3 erosion, while the formation of Fe vacancies is resulted from insufficient lithiation process with reduced Li2 CO3 dosage. The optimized lithium iron oxides exhibit remarkably improved ICE (from 68.24% to 86.78%), high-rate performance (357 mAh g-1 at 5 A g-1 ), and superior cycling stability (884 mAh g-1 after 500 cycles at 0.5 A g-1 ). Paring with LiFePO4 cathodes, the full-cells achieve extraordinary cyclic stability with 99.3% retention after 100 cycles. The improved electrochemical performances can be attributed to the synergy of structural characteristics and Fe vacancy engineering. The unique hollow structure alleviates the volume expansion of Li0.43 FeO1.51 , while the in situ generated Fe vacancies are powerful for modulating electronic structure with boosted Li+ transport rate and catalyze more Li2 O decomposition to react with Fe in the first charge process, hence enhancing the ICE of lithium iron oxide anode materials.

Remaining Life Assessment for Steel After Low-Cycle Fatigue by Surface Crack Image.

After pre-fatigue cycles at different strain amplitudes with different N/Nf values (33.3%, 50%, and 75%), specimens of HRB335 steel were subjected to uniaxial tension until failure. By this method the mechanical properties of the specimens after pre-fatigue testing were measured, and the fracture morphology and microscopic morphology in the vicinity of the specimen's neck surface near the fracture were observed. The verification of the characteristics to be used to estimate the damage caused during the loading cycles was conducted. By observing optical microscope images of the surface area near the neck of the specimens, it was found that the images of surface cracks were significantly different and strongly depended on the number of pre-fatigue cycles the specimen had undergone. In response to this phenomenon, both the microscopic images taken directly from the photos of the surface crack distribution and the binary images based on them were statistically analyzed, and then a parameter, S, denoted as the "unit crack area", characterizing the cumulative fatigue damage was suggested. Furthermore, the test procedure and the calculation formula for determining the image parameters were summarized, and a method for evaluating the remaining life of steel after low-cycles of reversed tension and compression was proposed.