Phytoglycogen (PG) is a food-derived and glycogen-like nanoscale dendrimer. While its unique dendritic nanostructures offer promising structural features to harbor bioactive compounds, the strong ...hydrophilicity limits its applications for encapsulating lipophilic molecules. Here, we report a proof-of-concept study to modify PG with valeric acid (VAPG) and further interact with zein to form novel nanocomplexes for encapsulating hydrophobic antibacterial compounds. To avoid the use of toxic organic solvent, zein was solubilized and partially hydrolyzed by heating in 1 M NaOH at 90 °C or above for at least 4 min. Bioactive compound, thymol and eugenol was each co-solubilized with zein under above alkaline condition, followed by addition of PG and then neutralization by citric acid to induce the pH-driven self-assembly of nanocomplexes for encapsulation. Dynamic light scattering measurements indicated that the as prepared nanocomplexes had small particle size (66 nm) with narrow polydispersity and high zeta potential (−44 mV). Morphological observation revealed that these nanocomplexes had spherical shape and uniform size distribution. Both eugenol- and thymol-loaded VAPG nanocomplexes exhibited significantly improved bioactivity, including higher antioxidant activity and stronger antibacterial efficacy against foodborne human pathogens (Listeria monocytogenes and Salmonella Enteritidis), compared with un-encapsulated compounds and PG nanocomplexes. Our findings demonstrated an innovative strategy to develop dendritic nanoparticles from food biopolymers without using organic solvents or synthetic chemicals. The potential of these nanocomplexes as carriers for lipophilic and phenolic antimicrobial compounds opens up new avenues for nanotechnology-enabled approaches to ensure food safety and quality.
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•PG was modified with valeric acid by esterification without altering its morphology.•Solubilization of zein was optimized by time and temperature in alkaline condition.•Zein hydrolysates and phenolic compounds were successfully complexed with modified PG.•The aqueous dispersibility and antioxidant activity of two essential oils were improved.•Significantly stronger antimicrobial activity was observed after encapsulation.
Periodic structures exhibit frequency band gaps, in which the propagation of certain waves is attenuated. A periodic structure can be designed such that its band gaps cover the excitation frequencies ...and its vibration can be reduced. However, perfectly periodic structures do not exist in reality due to inevitable deviations in the material and geometric properties. The vibration reduction performance can be significantly altered by the disorder, as reported by various authors. Therefore, it is favorable to find approaches that can retune disordered structures to the best possible state. In this way, robust vibration reduction performance can be achieved. In this study, a sorting strategy is proposed to rearrange the disordered unit cells. The aim is to reduce the performance change of vibration reduction. Specifically, a diatomic lumped-mass model has been used, where one mass coefficient in each unit cell is subject to random error. The forced response is computed, and the frequency-averaged spatially maximum amplitude is used as the indicator to quantify the influence of the disorder. Then, we reveal the importance of the deviation at different unit cells by a global sensitivity analysis. A variance-based approach termed Sobol’s sensitivity analysis is used. The results show that the deviation in the unit cell nearest to the excitation source is of the greatest importance. A theoretical interpretation from the perspective of wave propagation is given. Eventually, a simple sorting strategy is proposed, and the rule is to ensure that the unit cell in the first position has the smallest deviation. This strategy can significantly improve the similarity of the dynamic characteristics between the nominal and disordered structures. Overall, the conducted work provides a reference to the manufacture and assembly of periodic structures and a further understanding of the vibration reduction in band gaps.
In this study, thymol-loaded hydrophobically modified phytoglycogen/zein nanocomplexes with a particle size around 100 nm were developed for improving microbial safety of fresh produce. The ...antimicrobial activities, including the determination of minimum inhibitory and bactericidal concentration, growth kinetic curves, and inhibition zone of the nanocomplexes against foodborne pathogens (Listeria monocytogenes, Salmonella enteritidis, and Escherichia coli) were evaluated. The results showed that the antimicrobial activities of the nanocomplexes were significantly stronger than that of free thymol control (without encapsulation), and the antimicrobial efficacy remained unchanged after storage at 4 °C for 60 days. The morphological results from atomic force microscope revealed that small micellar blebs were formed at the surface of bacteria after treatment with nanocomplexes and the gradual disappearance of the cell boundary indicated the occurrence of cytolysis. The potential applications of this nanocomplex as disinfectant agent in wash water were evaluated on different types of fresh produce (lettuce, cantaloupe, and strawberries). Notably, the nanocomplexes also demonstrated efficacy in biofilm removal. Findings from this study clearly demonstrated that the thymol-loaded nanocomplexes hold promising potential for the disinfection of fresh produce to improve their microbial safety and quality.
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•Thymol was successfully encapsulated by PG-zein nanocomplexes (NCs).•Thymol-NCs showed significantly lower MBC than the free control for all bacteria.•NCs triggered the cytolysis and leakage of intracellular compounds of bacterial cells.•Thymol-loaded NCs can inhibit the formation of biofilm on fresh produce.
For decades, the influences of chemical structures and compositions, blend components and ambient environments on phase transition of polybutene-1 (PB-1) from Form II to I have been reported. ...Nevertheless, in terms of polymer processing, how to expedite the phase transition with a facile way is still a challenging task. In this study, four times the phase transition rate can be achieved by simply extruding the near melting point melt (NMP melt) of PB-1 through a capillary die. The melting survived Form I nanocrystals within the amorphous melt at the partially melting temperature (Tp) between the nominal melting temperature (Tm) and the equilibrium melting temperature (Tm0) allow accelerating the phase transition which was investigated by means of in situ small/wide angle X-ray scattering (SAXS/WAXS). Upon extruding of NMP melt, Form II transformed even faster than in the quiescent NMP melt. The number of flow-induced oriented crystalline structures (cylindrites) increased by reducing Tp. Kinetically, the half-transformation time (τ1/2) increased with rising Tp. Furthermore, τ1/2 of the core layer is large compared to τ1/2 of the skin layer. Our results suggest that both melting survived Form I nanocrystals and shear flow play integral roles in accelerating the phase transition of PB-1. We tentatively concluded that the higher nucleation probability of Form I during phase transition can be generated by more tie molecules distributed in the oriented lamellae caused by shear flow and the introducing extra internal stresses depended on the mismatch in the thermal expansion coefficients of Form I nanocrystals and Form II lamellar crystals.
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•Four times the phase transition rate can be achieved by simply extruding the near melting point melt.•The melting survived Form I nanocrystals within the amorphous melt allow accelerating the phase transition.•Both melting survived Form I nanocrystals and shear flow play integral roles in accelerating the phase transition of PB-1.
Nitric oxide (NO) and S-nitrosothiol (SNO) are signal molecules and the products of nitrogen metabolism. Nitrate (NO3−) is the main nitrogen source, and nitrate transporters (NRTs) are responsible ...for NO3− absorption or transport. However, the interactive effect between NO3−/NRT and NO/SNO in tree plants remains ambiguous. In the present study, 25 mmol L−1 NO3− and 1 mmol L−1 NO donor sodium nitroprusside (SNP) treatment that was conducted for 24 h enhanced NO/SNO and NO3− metabolism, whereas 2.5 mmol L−1 NO3− and 80 μmol L−1 N6022 (a compound that increases SNO content) treatment reduced them in seedling leaves of Fraxinus mandshurica and Betula platyphylla. Among the nine NRT family members examined, the gene expression level of NRT2.1 had a greater response to NO/SNO and NO3− treatment in the seedling leaves of F. mandshurica and B. platyphylla. Meanwhile, FmNRT2.1 mediated NO and SNO production in seedling leaves of F. mandshurica using Agrobacterium-mediated transient transformation. These findings shed light on the reciprocal regulation between NO3− and NO/SNO in seedlings of F. mandshurica and B. platyphylla, and NRT2.1 may act as a key regulatory hub.
This study revealed the regulatory relationship between NO3− and NO/SNO in seedling leaves of Fraxinus mandshurica and Betula platyphylla. High concentrations of NO3− accelerated NO/SNO metabolism, whereas low concentrations of NO3− decelerated them. NO improved NO3− metabolism, whereas SNO reduced it. NRT2.1 mediated reciprocal regulation of nitrate and NO/SNO. Display omitted
•The regulatory relationship between NO3− and NO/SNO in Fraxinus mandshurica and Betula platyphylla seedlings were uncovered.•High concentrations of NO3− accelerated NO/SNO metabolism, whereas low concentrations of NO3− slowed down them.•NO improved NO3− metabolism, whereas SNO reduced it.•NRT2.1 mediated reciprocal regulation of nitrate and NO/SNO.
Chinese herbal medicines (CHMs), known for their safety, low toxicity, and minimal impact on the environment, are often used as a natural feed additive in aquaculture to prevent or control diseases ...of aquatic animals. However, their effect on cell responses of Chinese soft-shelled turtle (Pelodiscus sinensis) remains unexplored. In this study, the extract mixed with four Chinese herbs of Astragalus membranaceus, Lycium barbarum, Rhizoma polygonati and Codonopsis pilosula in proportions (7:8:3:2) was used as a feed additive for 60 days to study their effects on the growth performance and immune response of P. sinensis in greenhouse mode. Results showed that the weight gain rate and the specific growth rate in the CHMs group were 46.63 % and 0.64 %, which were 1.13- and 1.15-fold of that in the control group, respectively. Besides, CHMs could significantly improve the survival rate by 76.94 % after artificial infection of Aeromonas hydrophila. The CHMs group also exhibited significant increases in the activities of total superoxide dismutase (27.76 %), catalase (41.28 %), glutathione peroxidase (14.62 %), and glutathione sulfur transferase (36.75 %) compared to the control group. Conversely, malondialdehyde concentration was reduced to 67.82 % of that in the control group. Moreover, the concentration of lysozyme and complement C3, as well as the activity of acid phosphatase, rose by 16.43 %, 24.30 %, and 27.68 %, respectively. Comparative transcriptome analysis revealed that growth, immunity, and lipid metabolism-related pathways are involved in the response to CHMs. Among these, the two pathways of the cell cycle and the cytokine-cytokine receptor interaction may play important roles in the growth and immunity of P. sinensis. SMOX, STAT3, and HMGCS1 may serve as key genes in CHMs-stimulated immune response in P. sinensis; GADD45B, ARG1, ACVR1C, and BMP7 may be crucial genes in promoting the growth of P. sinensis. This study provides a theoretical and practical basis for the green and efficient culture of P. sinensis.
•The weight gain of CHMs group was 1.13-fold of that of control group.•CHMs significantly increased the antioxidative capacity of P. sinensis.•The content of serum lysozyme and complement C3 could be increased by CHMs.•SMOX, STAT3, and HMGCS1 may be the key genes affecting immune response.•GADD45B, ARG1, ACVR1C, and BMP7 may be key genes affecting the growth.
As an important part of transmission lines, preformed helical fitting plays an indispensable role in the safe and stable operation of electronic circuits. However, due to the poor service environment ...of transmission lines, preformed helical fitting can often slip, scatter, and detwist. This paper explores variations in the holding force of the preformed helical fitting under different geometric parameters. First, the geometric structure of preformed helical fitting is analyzed, and the secondary development is conducted using the ABAQUS finite element software. The script program is written in Python language to realize the parametric modeling. Based on the experimental results, the changing trend of the holding force is consistent, which confirms the correctness of the finite element model. In addition, the preformed helical fitting is studied under different values of molding aperture, pitch length, pitch number, and armor rod diameter, and changes in the holding force under different parameters are analyzed. The results show that the holding force of the preformed helical fitting increases with the decrease in the molding aperture and pitch length, and the molding aperture has a negative linear correlation with the overall holding force. The holding force increases linearly with the pitch number; so, reducing the pitch length can increase the holding force of preformed helical fitting. Moreover, the results indicate that the holding force increases with the armor rod diameter. The research results presented in this study have important guiding value for the design of performed helical fitting.
Evidence supporting nitric oxide (NO) as a mediator of plant biochemistry continues to grow, but its functions at the molecular level remains poorly understood and, in some cases, controversial. To ...study the role of NO at the transcriptional level in Betula platyphylla cells, we conducted a genome-scale transcriptome analysis of these cells. The transcriptome of untreated birch cells and those treated by sodium nitroprusside (SNP) were analyzed using the Solexa sequencing. Data were collected by sequencing cDNA libraries of birch cells, which had a long period to adapt to the suspension culture conditions before SNP-treated cells and untreated cells were sampled. Among the 34,100 UniGenes detected, BLASTX search revealed that 20,631 genes showed significant (E-values≤10-5) sequence similarity with proteins from the NR-database. Numerous expressed sequence tags (i.e., 1374) were identified as differentially expressed between the 12 h SNP-treated cells and control cells samples: 403 up-regulated and 971 down-regulated. From this, we specifically examined a core set of NO-related transcripts. The altered expression levels of several transcripts, as determined by transcriptome analysis, was confirmed by qRT-PCR. The results of transcriptome analysis, gene expression quantification, the content of triterpenoid and activities of defensive enzymes elucidated NO has a significant effect on many processes including triterpenoid production, carbohydrate metabolism and cell wall biosynthesis.
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•A 3D pillar-layer terbium MOF was synthesized and characterized.•The Tb-MOF has strong luminescence and excellent water stability.•The Tb-MOF has been applied as a luminescent sensor ...for Fe3+ and Cr2O72− in water.
A 3D terbium metal–organic framework, {Tb(CPBi)(DMF)(H2O)·H2O}n. (namely Tb-MOF, H3CPBi = 2-(3,5-dicarboxyphenyl)-6-carboxybenzimidazole, DMF = N,N-Dimethylformamide) was synthesized under solvothermal conditions for the luminescent study. By virtue of the strong luminescence and excellent water stability, Tb-MOF has been applied as a multi-responsive luminescent sensor for Fe3+ and Cr2O72− in aqueous solutions, which exhibits outstanding detection effect with high selectivity and sensitivity. The Ksv values of Tb-MOF for Fe3+ and Cr2O72− are 7.435 × 103 M−1 and 1.1652 × 104 M−1 in water systems, respectively. Meanwhile, the possible detecting mechanisms of Tb-MOF for Fe3+ and Cr2O72− were further speculated.
Abstract Objective Osteoporosis is a global health issue characterized by decreased bone mass and microstructural degradation, leading to an increased risk of fractures. This study aims to explore ...the molecular mechanism by which P2X7 receptors influence osteoclast formation and bone resorption through the PI3K-Akt-GSK3β signaling pathway. Methods An osteoporosis mouse model was generated through ovariectomy (OVX) in normal C57BL/6 and P2X7 f/f ; LysM-cre mice. Osteoclasts were isolated for transcriptomic analysis, and differentially expressed genes were selected for functional enrichment analysis. Metabolite analysis was performed using liquid chromatography-tandem mass spectrometry (LC–MS/MS), and multivariate statistical analysis and pattern recognition were used to identify differential lipid metabolism markers and their distribution. Bioinformatics analyses were conducted using the Encyclopedia of Genes and Genomes database and the MetaboAnalyst database to assess potential biomarkers and create a metabolic pathway map. Osteoclast precursor cells were used for in vitro cell experiments, evaluating cell viability and proliferation using the Cell Counting Kit 8 (CCK-8) assay. Osteoclast precursor cells were induced to differentiate into osteoclasts using macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-beta ligand (RANKL), and tartrate-resistant acid phosphatase (TRAP) staining was performed to compare differentiation morphology, size, and quantity between different groups. Western blot analysis was used to assess the expression of differentiation markers, fusion gene markers, and bone resorption ability markers in osteoclasts. Immunofluorescence staining was employed to examine the spatial distribution and quantity of osteoclast cell skeletons, P2X7 protein, and cell nuclei, while pit assay was used to evaluate osteoclast bone resorption ability. Finally, in vivo animal experiments, including micro computed tomography (micro-CT), hematoxylin and eosin (HE) staining, TRAP staining, and immunohistochemistry, were conducted to observe bone tissue morphology, osteoclast differentiation, and the phosphorylation level of the PI3K-Akt-GSK3β signaling pathway. Results Transcriptomic and metabolomic data collectively reveal that the P2X7 receptor can impact the pathogenesis of osteoporosis through the PI3K-Akt-GSK3β signaling pathway. Subsequent in vitro experiments showed that cells in the Sh-P2X7 + Recilisib group exhibited increased proliferative activity (1.15 versus 0.59), higher absorbance levels (0.68 versus 0.34), and a significant increase in resorption pit area (13.94 versus 3.50). Expression levels of osteoclast differentiation-related proteins MMP-9, CK, and NFATc1 were markedly elevated (MMP-9: 1.72 versus 0.96; CK: 2.54 versus 0.95; NFATc1: 3.05 versus 0.95), along with increased fluorescent intensity of F-actin rings. In contrast, the OE-P2X7 + LY294002 group showed decreased proliferative activity (0.64 versus 1.29), reduced absorbance (0.34 versus 0.82), and a significant decrease in resorption pit area (5.01 versus 14.96), accompanied by weakened expression of MMP-9, CK, and NFATc1 (MMP-9: 1.14 versus 1.79; CK: 1.26 versus 2.75; NFATc1: 1.17 versus 2.90) and decreased F-actin fluorescent intensity. Furthermore, in vivo animal experiments demonstrated that compared with the wild type (WT) + Sham group, mice in the WT + OVX group exhibited significantly increased levels of CTX and NTX in serum (CTX: 587.17 versus 129.33; NTX: 386.00 versus 98.83), a notable decrease in calcium deposition (19.67 versus 53.83), significant reduction in bone density, increased trabecular separation, and lowered bone mineral density (BMD). When compared with the KO + OVX group, mice in the KO + OVX + recilisib group showed a substantial increase in CTX and NTX levels in serum (CTX: 503.50 versus 209.83; NTX: 339.83 versus 127.00), further reduction in calcium deposition (29.67 versus 45.33), as well as decreased bone density, increased trabecular separation, and reduced BMD. Conclusion P2X7 receptors positively regulate osteoclast formation and bone resorption by activating the PI3K-Akt-GSK3β signaling pathway.
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