Search Results (19)

Harmful α-dicarbonyl compounds (α-DCCs) were formed via Maillard reaction (MR) during the production of seafood condiments. The method of reducing α-DCCs could be achieved through optimizing the MR parameters. In this study, Flounder (Pleuronectiformes) steak was chosen as the raw material for developing seafood condiments with lower α-DCCs using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Indicators such as amino acid nitrogen, peptides, and total antioxidant capacity (T-AOC) of enzymolysis hydrolysates were applied to evaluate the enzymolysis effects on Flounder steak in different protease groups. When optimizing the parameters in MR, an optimal formulation with lower α-DCCs was chosen from the flavourzyme group to prepare Flounder seafood condiment at 105 °C, pH 6.5, 1.5% D-xylose addition, and a 20 min reaction time. The concentrations of methylglyoxal (MGO), glyoxal (GO), 2,3-butanedione (2,3-BD), and 3-deoxyglucosone (3-DG) were reduced to 1.23, 0.23, 0.01, and 0.05 μg/g, respectively, which were lower than those identified in 10 commercial seafood condiments (1.84, 0.39, 0.09, and 0.05 μg/g) and conformed to the standards of daily intake in the United States and the European Union. The quality verification demonstrated that the optimal Flounder seafood condiment had a similar odor profile but with higher intensity than that of the products on the market, which scored 89.79 in sensory evaluation. The results indicated that the process optimized in this study could be applied to prepare a Flounder seafood condiment with lower α-DCCs. This processing technology to control α-DCCs may be employed to improve the quality and safety of foods and contribute to human health. Full article

Enhanced disease susceptibility1 (EDS1) is a key node in the plant immune signaling network, regulating salicylic acid (SA) levels and other immune responses in Arabidopsis thaliana. We previously reported that modulation of SA by AGD2-like defense response protein 1 (ALD1) has been shown to influence the immune response in Lotus japonicus, but the role of LjEDS1 in this species remains unclear. Here, we identified and characterized the LjEDS1 gene in L. japonicus. The LjEDS1 protein contains a lipase-like domain and an EP domain similar to the Arabidopsis EDS1 protein. Subcellular localization studies revealed that the LjEDS1 protein is distributed in both the cytoplasm and nucleus. Heterologous expression of LjEDS1 in the Arabidopsis ateds1 mutant increased resistance to Pseudomonas syringae pv. Tomato (Pst) strain DC3000. In L. japonicus, roots of the ljeds1 mutants exhibited heightened susceptibility to Ralstonia solanacearum, with increased lesion areas and bacterial titers. Conversely, the overexpression of LjEDS1 reduced the lesion areas and bacterial titers in roots infected with R. solanacearum compared to those in the wild-type. Gene expression analysis showed that LjEDS1 regulates defense-related, basal immunity, and oxidative stress response genes in L. japonicus roots. These findings establish LjEDS1 as an important regulator of disease resistance in L. japonicus. Full article

Over the past two decades, covalent organic frameworks (COFs) have become the most widely studied porous crystalline materials. Their specific physical and chemical properties are determined by the arrangement of atoms (crystal structure). Therefore, the determination of their structure is arguably the most important characterization step for COFs. Although single-crystal X-ray diffraction is the most widely used method for structure determination, confirmation of the structure of COFs is limited to lattice fringes in transmission electron microscopy (TEM) because of their small crystal size (nanocrystals) or poor crystal quality. At present, many two-dimensional COFs (2D-COFs) have clear powder X-ray diffraction (PXRD) patterns, but specific lattice fringes are not available for all 2D-COFs. This severely hinders the development of the COF field. Here, we discovered the lattice shrinkage behavior of COFs under electron beam irradiation by comparing the lattice fringes of 2D-COFs under different conditions. By comparing the lattice fringes of a 1,3,5-tris-(4-aminophenyl)triazine-1,3,5-tris-(4-formylphenyl)triazine covalent organic framework (TAPT-TFPT COF) at room temperature and under liquid nitrogen freezing conditions, we found that the lattice fringes are in good agreement with the PXRD and the theoretical values of the COF (2.213 nm) under freezing conditions. However, the lattice fringe spacing is only 1.656 nm at room temperature. The discovery not only provides new insights into the TEM characterization of COFs, but also further expands the range of crystalline COF materials. Full article

Rolling bearings are critical in maintaining smooth operation of rotating machinery and considerably influence its reliability. The signals collected from rolling bearings in field conditions are often subjected to noise, creating a challenge to extract weaker fault features. This paper proposes a rolling bearing fault diagnosis method that addresses the above-mentioned problem through the moth-flame optimization algorithm optimized variational mode decomposition (MFO-optimized VMD) and an ensemble differential evolution online sequential extreme learning machine (DE-OSELM). By using the dynamic adaptive weight factor and genetic algorithm cross operator, the optimization accuracy and global optimization ability of the moth-flame optimization (MFO) are improved, and the two basic parameters of VMD decomposition level and quadratic penalty factor are adaptive selected. Since the vibration characteristics of the signal cannot be fully interpreted by a single index, The effective weighted correlation sparsity index (EWCS) is utilized to extract the relevant intrinsic mode functions (IMF) of VMD decomposition and extract their energies as features. In order to improve the classification accuracy, The energy feature set is subsequently inputted into DE-OSELM for training and classification purposes, and the proposed method is assessed via a sample set with four different health states of actual rolling bearings. Our proposed method results are compared with other diagnosis methods, proving its feasibility to diagnose rolling bearing faults with higher classification accuracy. Full article

A core–shell nanowire heterostructure is an important building block for nanowire-based optoelectronic devices. In this paper, the shape and composition evolution induced by adatom diffusion is investigated by constructing a growth model for alloy core–shell nanowire heterostructures, taking diffusion, adsorption, desorption and incorporation of adatoms into consideration. With moving boundaries accounting for sidewall growth, the transient diffusion equations are numerically solved by the finite element method. The adatom diffusions introduce the position-dependent and time-dependent adatom concentrations of components A and B. The newly grown alloy nanowire shell depends on the incorporation rates, resulting in both shape and composition evolution during growth. The results show that the morphology of nanowire shell strongly depends on the flux impingement angle. With the increase in this impingement angle, the position of the largest shell thickness on sidewall moves down to the bottom of nanowire and meanwhile, the contact angle between shell and substrate increases to an obtuse angle. Coupled with the shell shapes, the composition profiles are shown as non-uniform along both the nanowire and the shell growth directions, which can be attributed to the adatom diffusion of components A and B. The impacts of parameters on the shape and composition evolution are systematically investigated, including diffusion length, adatom lifetime and corresponding ratios between components. This kinetic model is expected to interpret the contribution of adatom diffusion in growing alloy group-IV and group III-V core–shell nanowire heterostructures. Full article

Piezo-actuated stage (P-AS) has become the topic of considerable interest in the realm of micro/nanopositioning technology in the recent years owing to its advantages, such as high positioning accuracy, high response speed, and large output force. However, rate-dependent (RD) hysteresis, which is an inherent nonlinear property of piezoelectric materials, considerably restricts the application of P-AS. In this research paper, we develop a Hammerstein model to depict the RD hysteresis of P-AS. An improved differential evolution algorithm and a least-squares algorithm are used to identify the static hysteresis sub-model and the dynamic linear sub-model for the Hammerstein model, respectively. Then, a hysteresis compensator based on the inverse Bouc–Wen model is designed to compensate for the static hysteresis of the P-AS. However, the inevitable modeling error presents a hurdle to the hysteresis compensation. In addition, external factors, such as environmental noise and measurement errors, affect the control accuracy. To overcome these complications, a hybrid adaptive control approach based on the hysteresis compensator is adopted to increase the control accuracy. The closed-loop system stability is analyzed with the help of the Lyapunov stability theory. Finally, experimental results indicate that the raised control approach is effective for the accurate positioning of P-AS. Full article

Quercetin, a flavonoid that is present in vegetables and fruits, has been found to have anti-inflammatory effects. However, the mechanism by which it inhibits colitis is uncertain. This study aimed to explore the effect and pharmacological mechanism of quercetin on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC). Mice were given a 4% (w/v) DSS solution to drink for 7 days, followed by regular water for the following 5 days. Pharmacological mechanisms were predicted by network pharmacology. High-throughput 16S rDNA sequencing was performed to detect changes in the intestinal microbiota composition. Enzyme-linked immunosorbent assay and western blotting were performed to examine the anti-inflammatory role of quercetin in the colon. Quercetin attenuated DSS-induced body weight loss, colon length shortening, and pathological damage to the colon. Quercetin administration modulated the composition of the intestinal microbiota in DSS-induced mice and inhibited the growth of harmful bacteria. Network pharmacology revealed that quercetin target genes were enriched in inflammatory and neoplastic processes. Quercetin dramatically inhibited the expression of phosphorylated protein kinase B (AKT) and phosphatidylinositol 3-kinase (PI3K). Quercetin has a role in the treatment of UC, with pharmacological mechanisms that involve regulation of the intestinal microbiota, re-establishment of healthy microbiomes that favor mucosal healing, and the inhibition of PI3K/AKT signaling. Full article

Struvite is a chemically bonded ceramic product in the pipeline of a sewage treatment plant. In order to explore the fire extinguishing potential of struvite, a new type of struvite ultrafine dry powder with excellent performance was prepared by a simple process, and its fire extinguishing performance and mechanism were analyzed in depth. Under the same process conditions, the refinement degree (D50 = 5.132 μm) and the specific surface area (BET = 25.72 m²/g) of ultrafine struvite were larger than those of NH₄H₂PO₄ (D50 = 8.961 μm, BET = 13.64 m²/g), making struvite more suitable for fire extinguishing. Besides, the pyrolysis process of struvite was relatively concentrated and absorbed more heat in a short time. Its heat absorption (458.4 J/mg) was higher than that of NH₄H₂PO₄ (156.4 J/mg). Water, ammonia, and PO· were released during the pyrolysis of struvite, which effectively reduced fire temperature, diluted oxygen concentrations and captured free radicals. At the same time, the final products were magnesium orthophosphate and magnesium pyrophosphate, which formed a dense flame-retardant ceramic layer with good thermal insulation and environmental protection functions. In these cases, the fire extinguishing mechanism of struvite was determined to have three stages: the cooling effect, the asphyxiation effect, and the chemical effect. Correspondingly, the fire extinguishing time of struvite was three seconds faster than that of ammonium phosphate under 0.2 MPa based on the local oil basin test. Full article

Arabidopsis AGD2 (Aberrant Growth and Death2) and its close homolog ALD1 (AGD2-like defense response protein 1) have divergent roles in plant defense. We previously reported that modulation of salicylic acid (SA) contents by ALD1 affects numbers of nodules produced by Lotus japonicus, but AGD2′s role in leguminous plants remains unclear. A combination of enzymatic analysis and biological characterization of genetic materials was used to study the function of AGD2 (LjAGD2a and LjAGD2b) in L. japonicus. Both LjAGD2a and LjAGD2b could complement dapD and dapE mutants of Escherichia coli and had aminotransferase activity in vitro. ljagd2 plants, with insertional mutations of LjAGD2, had delayed flowering times and reduced seed weights. In contrast, overexpression of LjAGD2a in L. japonicus induced early flowering, with increases in seed and flower sizes, but reductions in pollen fertility and seed setting rates. Additionally, ljagd2a mutation resulted in increased expression of nodulin genes and corresponding increases in infection threads and nodule numbers following inoculation with Rhizobium. Changes in expression of LjAGD2a in L. japonicus also affected endogenous SA contents and hence resistance to pathogens. Our results indicate that LjAGD2a functions as an LL-DAP aminotransferase and plays important roles in plant development. Moreover, LjAGD2a activates defense signaling via the Lys synthesis pathway, thereby participating in legume–microbe interaction. Full article

Electrospun nanofiber materials have been considered as advanced dressing candidates in the perspective of wound healing and skin regeneration, originated from their high porosity and permeability to air and moisture, effective barrier performance of external pathogens, and fantastic extracellular matrix (ECM) fibril mimicking property. Gelatin is one of the most important natural biomaterials for the design and construction of electrospun nanofiber-based dressings, due to its excellent biocompatibility and biodegradability, and great exudate-absorbing capacity. Various crosslinking approaches including physical, chemical, and biological methods have been introduced to improve the mechanical stability of electrospun gelatin-based nanofiber mats. Some innovative electrospinning strategies, including blend electrospinning, emulsion electrospinning, and coaxial electrospinning, have been explored to improve the mechanical, physicochemical, and biological properties of gelatin-based nanofiber mats. Moreover, numerous bioactive components and therapeutic agents have been utilized to impart the electrospun gelatin-based nanofiber dressing materials with multiple functions, such as antimicrobial, anti-inflammation, antioxidation, hemostatic, and vascularization, as well as other healing-promoting capacities. Noticeably, electrospun gelatin-based nanofiber mats integrated with specific functions have been fabricated to treat some hard-healing wound types containing burn and diabetic wounds. This work provides a detailed review of electrospun gelatin-based nanofiber dressing materials without or with therapeutic agents for wound healing and skin regeneration applications. Full article

Electrospun nanofiber mats have attracted intense attention as advanced wound dressing materials. The objective of this study was to fabricate methacrylated gelatin (MeGel)/poly(L-lactic acid) (PLLA) hybrid nanofiber mats with an extracellular matrix (ECM) mimicking nanofibrous structure and hydrogel-like properties for potential use as wound dressing materials. MeGel was first synthesized via the methacryloyl substitution of gelatin (Gel), a series of MeGel and PLLA blends with various mass ratios were electrospun into nanofiber mats, and a UV crosslinking process was subsequently utilized to stabilize the MeGel components in the nanofibers. All the as-crosslinked nanofiber mats exhibited smooth and bead-free fiber morphologies. The MeGel-containing and crosslinked nanofiber mats presented significantly improved hydrophilic properties (water contact angle = 0°; 100% wettability) compared to the pure PLLA nanofiber mats (~127°). The swelling ratio of crosslinked nanofiber mats notably increased with the increase of MeGel (143.6 ± 7.4% for PLLA mats vs. 875.0 ± 17.1% for crosslinked 1:1 MeGel/PLLA mats vs. 1135.2 ± 16.0% for crosslinked MeGel mats). The UV crosslinking process was demonstrated to significantly improve the structural stability and mechanical properties of MeGel/PLLA nanofiber mats. The Young’s modulus and ultimate strength of the crosslinked nanofiber mats were demonstrated to obviously decrease when more MeGel was introduced in both dry and wet conditions. The biological tests showed that all the crosslinked nanofiber mats presented great biocompatibility, but the crosslinked nanofiber mats with more MeGel were able to notably promote the attachment, growth, and proliferation of human dermal fibroblasts. Overall, this study demonstrates that our MeGel/PLLA blend nanofiber mats are attractive candidates for wound dressing material research and application. Full article

Based on density functional theory, we theoretically investigate the electronic structures of free-standing armchair Janus MoSSe nanoribbons (A-MoSSeNR) with width up to 25.5 nm. The equilibrium structures of nanoribbons with spontaneous curling are obtained by energy minimization in molecular dynamics (MD). The curvature is 0.178 nm⁻¹ regardless of nanoribbon width. Both finite element method and analytical solution based on continuum theory provide qualitatively consistent results for the curling behavior, reflecting that relaxation of intrinsic strain induced by the atomic asymmetry acts as the driving force. The non-edge bandgap of curled A-MoSSeNR reduces faster with the increase of width compared with planar nanoribbons. It can be observed that the real-space wave function at the non-edge VBM is localized in the central region of the curled nanoribbon. When the curvature is larger than 1.0 nm⁻¹, both edge bandgap and non-edge bandgap shrink with the further increase of curvature. Moreover, we explore the spontaneous curling and consequent sewing process of nanoribbon to form nanotube (Z-MoSSeNT) by MD simulations. The spontaneously formed Z-MoSSeNT with 5.6 nm radius possesses the lowest energy. When radius is smaller than 0.9 nm, the bandgap of Z-MoSSeNT drops rapidly as the radius decreases. We expect the theoretical results can help build the foundation for novel nanoscale devices based on Janus TMD nanoribbons. Full article

For food quality and safety issues, the emergence of foodborne pathogenic bacteria has further accelerated the spread of antibiotic residues and drug resistance genes. To alleviate the harm caused by bacterial infections, it is necessary to seek novel antimicrobial agents as biopreservatives to prevent microbial spoilage. Nanoantimicrobials have been widely used in the direct treatment of bacterial infections. CNMs, formed by chitosan nanoparticles and peptides, are promising antibiotic alternatives for use as excellent new antibacterial drugs against pathogenic bacteria. Herein, the current study evaluated the function of CNMs in the protection of foodborne pathogen Escherichia coli (E. coli) O157 infection using an intestinal epithelial cell model. Antibacterial activity assays indicated that CNMs exerted excellent bactericidal activity against E. coli O157. Assessment of the cytotoxicity risks toward cells demonstrated that 0.0125–0.02% of CNMs did not cause toxicity, but 0.4% of CNMs caused cytotoxicity. Additionally, CNMs did not induced genotoxicity either. CNMs protected against E. coli O157-induced barrier dysfunction by increasing transepithelial electrical resistance, decreasing lactate dehydrogenase and promoting the protein expression of occludin. CNMs were further found to ameliorate inflammation via modulation of tumor factor α, toll-like receptor 4 and nuclear factor κB (NF-κB) expression via inhibition of mitogen-activated protein kinase and NF-κB activation and improved antioxidant activity. Taken together, CNMs could protect the host against E. coli O157-induced intestinal barrier damage and inflammation, showing that CNMs have great advantages and potential application as novel antimicrobial polymers in the food industry as food biopreservatives, bringing new hope for the treatment of bacterial infections. Full article

Automatic registration of optical and synthetic aperture radar (SAR) images is a challenging task due to the influence of SAR speckle noise and nonlinear radiometric differences. This study proposes a robust algorithm based on phase congruency to register optical and SAR images (ROS-PC). It consists of a uniform Harris feature detection method based on multi-moment of the phase congruency map (UMPC-Harris) and a local feature descriptor based on the histogram of phase congruency orientation on multi-scale max amplitude index maps (HOSMI). The UMPC-Harris detects corners and edge points based on a voting strategy, the multi-moment of phase congruency maps, and an overlapping block strategy, which is used to detect stable and uniformly distributed keypoints. Subsequently, HOSMI is derived for a keypoint by utilizing the histogram of phase congruency orientation on multi-scale max amplitude index maps, which effectively increases the discriminability and robustness of the final descriptor. Finally, experimental results obtained using simulated images show that the UMPC-Harris detector has a superior repeatability rate. The image registration results obtained on test images show that the ROS-PC is robust against SAR speckle noise and nonlinear radiometric differences. The ROS-PC can tolerate some rotational and scale changes. Full article

There is a lack of literature reporting the measurement and prediction of biochemical methane potential (BMP) of vegetable crop residues (VCRs) and similarly, the kinetic assessment on the anaerobic digestion process of VCR is rarely investigated. In this paper, the BMP tests of five different vegetable (snap bean, capsicum, cucumber, eggplant, and tomato) crop residues were conducted at feed to inoculum ratio (F/I) of 2.0 under mesophilic (36 ± 1 °C) conditions. A series of single-variable and multiple-variable regression models were built based on organic components (hemicellulose, cellulose, lignin, total fat, total sugar, and crude protein) for BMP prediction. Three kinetic models, including the first-order kinetic model, the Chen and Hashimoto model, and the modified Gompertz model, were used to simulate the methane yield results of VCR and obtain valuable model parameters simultaneously. As a result, the BMPs and volatile solids (VS) degradation degree of different VCRs were respectively in the range of 94.2–146.8 mL g⁻¹ VS and 40.4–49.9%; the regression prediction models with variables lignin (R² = 0.704, p = 0.076), variables crude protein and lignin (R² = 0.976, p = 0.048), and variables total fat, hemicellulose, and lignin (R² = 0.999, p = 0.027) showed the best performance on BMP prediction among the single-factor, two-factor, and three-factor models, respectively. In addition, compared to the other two kinetic models, the modified Gompertz model could be excellently fitted (R² = 0.986–0.998) to the results of BMP experiment, verification deviations within 0.3%. Full article