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Background: Cervical spondylosis (CS) is a prevalent disorder that can have a major negative impact on quality of life. Traditional conservative treatment has limited efficacy, and electroacupuncture (EA) is a novel treatment option. We investigated the application and molecular mechanism of EA treatment in a rat model of cervical intervertebral disk degeneration (CIDD).Methods: The CIDD rat model was established, following which rats in the electroacupuncture (EA) group received EA. For overexpression of IL-22 or inhibition of JAK2-STAT3 signaling, the rats were injected intraperitoneally with recombinant IL-22 protein (p-IL-22) or the JAK2-STAT3 (Janus kinase 2—signal transducer and activator of transcription protein 3) inhibitor AG490 after model establishment. Rat nucleus pulposus (NP) cells were isolated and cultured. Cell counting kit-8 and flow cytometry were used to analyze the viability and apoptosis of the NP cells. Expression of IL-22, JAK2 and STAT3 was determined using RT-qPCR. Expression of IL-22/JAK2-STAT3 pathway and apoptosis related proteins was detected by Western blotting (WB).Results: EA protected the NP tissues of CIDD rats by regulating the IL-22/JAK2-STAT3 pathway. Overexpression of IL-22 significantly promoted the expression of tumor necrosis factor (TNF)-α, IL-6, IL-1β, matrix metalloproteinase (MMP)3 and MMP13 compared with the EA group. WB demonstrated that the expression of IL-22, p-JAK2, p-STAT3, caspase-3 and Bax in NP cells of the EA group was significantly reduced and Bcl-2 elevated compared with the model group. EA regulated cytokines and MMP through activation of IL-22/JAK2-STAT3 signaling in CIDD rat NP cells.Conclusion: We demonstrated that EA affected apoptosis by regulating the IL-22/JAK2-STAT3 pathway in NP cells and reducing inflammatory factors in the CIDD rat model. The results extend our knowledge of the mechanisms of action underlying the effects of EA as a potential treatment approach for CS in clinical practice.

Single-atom catalysts, characterized by transition metal–(N/O)4units on nanocarbon (M–(N/O)4–C), have emerged as efficient performers in water electrolysis. However, there are few guiding principles for accurately controlling the ligand fields of single atoms to further stimulate the catalyst activities. Herein, using the Ni–(N/O)4–C unit as a model, we develop a further modification of the P anion on the outer shells to modulate the morphology of the ligand. The catalyst thus prepared possesses high activity and excellent long-term durability, surpassing commercial Pt/C, RuO2, and currently reported single-atom catalysts. Notably, mechanistic studies demonstrated that the pseudocapacitive feature of multiscale anion-hybrid nanocarbon is considerable at accumulating enough positive charge [Q], contributing to the high oxygen evolution reaction (OER) order (β) through the rate formula. DFT calculations also indicate that the catalytic activity is decided by the suitable barrier energy of the intermediates due to charge accumulation. This work reveals the activity origin of single atoms on multihybrid nanocarbon, providing a clear experiential formula for designing the electronic configuration of single-atom catalysts to boost electrocatalytic performance.

Global navigation satellite system interferometric reflectometry (GNSS-IR) retrieves soil moisture (SM) by calculating the phase of the signal-to-noise ratio (SNR) modulation term induced by ground reflection. The nonlinear least squares (NLS) algorithm is commonly adopted to extract the phase; however, the limitation of the NLS algorithm leads to phase jumps in different periods. To enhance the reliability of phase retrieval, we propose a two-step abnormal phase correction approach according to the analyzed phase error characteristics. First, the SNR period method is developed to correct phase jumps caused by NLS limitations, including entire period and half-period shifts. Subsequently, residual errors induced by multipath effects are identified through the standard score (Z-score) and repaired via the Savitzky-Golay filter (SGF). The proposed technique significantly improves the correlation of the reconstructed phase time series with ground-truth SM. This two-step method effectively solves abnormal phase correction for GNSS-IR-based SM retrieval.

Constructing natural polymers such as cellulose, chitin, and chitosan into hydrogels with excellent stretchability and self-healing properties can greatly expand their applications but remains very challenging. Generally, the polysaccharide-based hydrogels have suffered from the trade-off between stiffness of the polysaccharide and stretchability due to the inherent nature. Thus, polysaccharide-based hydrogels (polysaccharides act as the matrix) with self-healing properties and excellent stretchability are scarcely reported. Here, a solvent-assisted strategy was developed to construct MXene-mediated cellulose conductive hydrogels with excellent stretchability (∼5300%) and self-healability. MXene (an emerging two-dimensional nanomaterial) was introduced as emerging noncovalent cross-linking sites between the solvated cellulose chains in a benzyltrimethylammonium hydroxide aqueous solution. The electrostatic interaction between the cellulose chains and terminal functional groups (O, OH, F) of MXene led to cross-linking of the cellulose chains by MXene to form a hydrogel. Due to the excellent properties of the cellulose–MXene conductive hydrogel, the work not only enabled their strong potential in both fields of electronic skins and energy storage but provided fresh ideas for some other stubborn polymers such as chitin to prepare hydrogels with excellent properties.

Trade-off of high-strength and dynamic crosslinking of hydrogels remains an enormous challenge. Motivated by the self-healing property of biological tissues, the strategy of combining multiple dynamic bond mechanisms and a polysaccharide network is proposed to fabricate biomimetic hydrogels with sufficient mechanical strength, injectability, biodegradability, and self-healing property for bone reconstruction engineering. Stable acylhydrazone bonds endowed hydrogels with robust mechanical strength (>10 kPa). The integration of dynamic imine bonds and acylhydrazone bonds optimized the reversible characteristic to protect the cell during the injection and mimicked ECM microenvironment for cell differentiation as well as rapid adapting bone defect area. Furthermore, due to the slow enzymatic hydrolysis kinetics of chitosan and the self-healing properties of resulting networks, hydrogels exhibited a satisfactory biodegradation period (>8 weeks) that highly matches with bone regeneration. Additionally, rBMSC-laden hydrogels exhibited splendid osteogenic induction and bone reconstruction without prefabrication scaffolds and incubation, demonstrating tremendous potential for clinical application. This work proposes an efficient strategy for the construction of a low-cost multifunctional hydrogel, making polysaccharide-based hydrogels as the optimal carrier for enabling cellular functions in bone repair.

The development of the effective 3D printing strategy for diverse functional monomers is still challenging. Moreover, the conventional 3D printing hydrogels are usually soft and fragile due to the lack of an energy dissipation mechanism. Herein, a microsphere mediating ink preparation strategy is developed to provide tailored rheological behavior for various monomer direct ink writings. The chitosan microspheres are used as an exemplary material due to their tunable swelling ratio under the acid-drived electrostatic repulsion of the protonated amino groups. The rheological behaviors of the swollen chitosan microsphere (SCM) are independent on the monomer types, and various functional secondary polymers could be carried at a wide loading ratio by the acid driving. The SCM reinforces the hydrogel as the sacrificial bonds. With the adjustable composition, the 3D printing hydrogel mechanical properties are tunable in wide windows: strength (0.4–1.01 MPa), dissipated energy (0.11–3.25 MJ m–3), and elongation at break (47–626%). With the excellent printing and mechanical properties, the SCM inks enable multi-functional integration for soft device production, such as 4D printing robots and wearable strain sensors. We anticipate that this microsphere mediating 3D printing strategy can inspire new possibilities for the design of the robust hydrogels with a broad range of functionalities and mechanical performances.

The heterogeneity and mechanisms for the generation of CD4 memory T (CD4 Tm) cells remain elusive. Distinct subsets of dendritic cells (DCs) have been found to regulate a distinct T-helper (Th)–cell subset differentiation by influencing cytokine cues around CD4 T cells; however, whether and how the regulatory DC subset can regulate Tm-cell differentiation remains unknown. Further, there is no ideal in vitro experimental system with which to mimic the 3 phases of the CD4 T-cell immune response (expansion, contraction, memory generation) and/or to culture CD4 Tm cells for more than a month. By analyzing CD4 T cells programmed by long-term coculture with regulatory DCs, we identified a population of long-lived CD4 T cells with a CD44hiCD62L−CCR7− effector memory phenotype and rapid, preferential secretion of the Th2 cytokines interleukin-4 (IL-4), IL-5, IL-10, and IL-13 after antigenic stimulation. These regulatory DC-programmed Tm cells suppress CD4 T-cell activation and proliferation in vitro via IL-10 and inhibit the delayed-type hypersensitivity response once infused in vivo. We also identify their natural counterpart, which is up-regulated by regulatory DC transfusion and negatively regulates the recall response in vivo. Different from interferon-γ–producing conventional Tm cells, these IL-4–producing CD4 Tm cells act as alternative Tm cells with a regulatory function, suggesting a new way of negative immune regulation by memory T cells.

The heterogeneity and mechanisms for the generation of CD4 memory T (CD4 Tm) cells remain elusive. Distinct subsets of dendritic cells (DCs) have been found to regulate a distinct T-helper (Th)–cell subset differentiation by influencing cytokine cues around CD4 T cells; however, whether and how the regulatory DC subset can regulate Tm-cell differentiation remains unknown. Further, there is no ideal in vitro experimental system with which to mimic the 3 phases of the CD4 T-cell immune response (expansion, contraction, memory generation) and/or to culture CD4 Tm cells for more than a month. By analyzing CD4 T cells programmed by long-term coculture with regulatory DCs, we identified a population of long-lived CD4 T cells with a CD44hiCD62L−CCR7−effector memory phenotype and rapid, preferential secretion of the Th2 cytokines interleukin-4 (IL-4), IL-5, IL-10, and IL-13 after antigenic stimulation. These regulatory DC-programmed Tm cells suppress CD4 T-cell activation and proliferation in vitro via IL-10 and inhibit the delayed-type hypersensitivity response once infused in vivo. We also identify their natural counterpart, which is up-regulated by regulatory DC transfusion and negatively regulates the recall response in vivo. Different from interferon-γ–producing conventional Tm cells, these IL-4–producing CD4 Tm cells act as alternative Tm cells with a regulatory function, suggesting a new way of negative immune regulation by memory T cells.

2-Phenylethanol (2-PE) with a pleasant rose-like odor is a valuable aroma compound used in many fields. 2-PE production by yeast is considered a promising alternative to chemical synthesis and extraction from natural materials. In this report, the strain YF1702 produced a significantly higher level of 2-PE when compared with other strains isolated from Baijiu-producing environments. According to morphological properties, physiological and biochemical characteristics, and 26S rDNA sequence analysis, strain YF1702 was identified as Pichia kudriavzevii. The optimal fermentation conditions of YF1702 for producing 2-PE were obtained by single-factor experiments, Plackett–Burman design, steepest ascent design, and response surface methodology. The optimal inoculation conditions for strain YF1702 were 50 g/L glucose, 6.0 g/L yeast extract, 10.7 g/L L-Phe, and 32 g/L Tween-60. The optimal fermentation conditions were pH 2.3, 26 °C, 210 rpm shaking, an inoculum size of 0.4% (v/v), and a loading volume of 25.5 mL/250 mL for 56 h. Under these optimal conditions 2-PE production by YF1702 was 5.09 g/L. This strain has the potential to increase the content of 2-PE in Baijiuproduction and enhance the aroma characteristics of Baijiu.