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Sarcoplasmic proteins (SP) derived from yak meat were oxidized by malondialdehyde (MDA) at different concentrations. The effects of lipid oxidation on physicochemical properties and color stability of SP were investigated by evaluating side-chain amino acid oxidation, protein structure and color of SP and the oxidation status of myoglobin (Mb). The results showed that after MDA oxidation, the a* value, b* value, C* value, and deoxymyoglobin and oxymyoglobin contents of SP significantly decreased (P < 0.05), and the L* value, metmyoglobin content, and ferrylmyoglobin concentration significantly increased (P < 0.05), indicating that MDA oxidation lowered color stability. The contents of carbonyl groups and dimeric tyrosine, the fluorescence intensity of SP-MDA adducts, and the relative contents of β-helix and β-turn significantly increased (P < 0.05), and total sulfhydryl content, surface hydrophobicity, intrinsic fluorescence intensity, and the relative contents of α-helix and random coil significantly declined (P < 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed blurred expansion of small molecule bands and the formation of macromolecular aggregates, suggesting that MDA promoted the oxidation and aggregation of SP. Pearson correlation analysis revealed significant correlations between MDA oxidation and physicochemical properties and color stability of SP (P < 0.05). This study reveals that MDA alters the structure of SP by directly oxidizing it or mediating Mb oxidation, causing cross-linked aggregation of SP and reducing its color stability.

The effects of adding different levels (0.01%, 0.05% and 0.10%) of banana flower extract (BFE) versus dibutylated hydroxy toluene (BHT) on protein oxidation in naturally fermented yak meat sausages were investigated. lys The carbonyl content, Schiff base content, total sulfhydryl content, active sulfhydryl content, surface hydrophobicity, dimeric tyrosine content, endogenous fluorescence intensity and solubility of myofibrillar proteins (MPs) from fermented yak meat sausage were measured at different fermentation times, and the secondary structure and composition of MPs were characterized by Fourier transform infrared (FTIR) spectroscopy, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that compared with the blank control, the addition of BFE decreased the carbonyl group content, Schiff base content, surface hydrophobicity, dimeric tyrosine content and endogenous tryptophan fluorescence intensity of MPs, and increased the total sulfhydryl group content, active sulfhydryl group content and solubility. FTIR spectroscopy showed that the addition of BFE improved the reveal the more stability of the secondary structure of MPs. SDS-PAGE showed that BFE reduced the diffusion of myosin heavy chain and had a protective effect on myosin. This study showed that BFE inhibited protein oxidation in naturally fermented yak sausage, and this effect was positively correlated with BFE concentration, being most pronounced at 0.10% BFE concentration.

To explore the effect of different levels of lipid oxidation on the structural and functional properties of myofibrillar protein (MP) in yak meat, the oxidation of side-chain amino acids, structure, rheological characteristics, and emulsion stability of MP incubated in the presence of different concentrations (0, 0.1, 1, 5, 10 and 20 mmol/L) of malondialdehyde (MDA) were measured. The results showed that with an increase in MDA concentration, the contents of carbonyl group, MDA-MP adducts and dimeric tyrosine and the relative content of β-turn in MP overall increased, while total sulfhydryl content, surface hydrophobicity, endogenous fluorescence intensity, and the relative contents of α-helix and β-sheet decreased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results indicated gradual loss of myosin heavy and light chains, implying that interaction with MDA could induce MP oxidation and cross-linked aggregation and result in structural transition from an ordered to a disordered state. In addition, moderate oxidation (with MAD concentration < 10 mmol/L) increased the storage and loss moduli and improved the gel quality of MP; however, excessive oxidation (with MAD concentration ≥ 10 mmol/L) led to serious aggregation of MP and a decrease in the storage and loss moduli as well as a decrease in the emulsion stability and color deterioration. In conclusion, MDA oxidation can promote the oxidation of MP, and alter the structural and functional properties.

The effects of the addition of different amounts (0.01%, 0.05% and 0.10%) of banana flower extract (BFE) on the physicochemical quality of fermented yak meat sausage were investigated using butylated hydroxy toluene (BHT) as a positive control, and the changes in the pH, moisture content, color, water retention, texture, rheological properties, total bacterial count, volatile flavor substances and sensory quality of the sausage during fermentation and storage were evaluated. The results showed that the sausage with 0.10% BFE had stronger water retention and bacterial inhibition ability, while increasing BFE addition reduced the textural characteristics and storage modulus of the fermented sausage. A total of seven classes of volatile flavor substances, including alcohols, aldehydes, acids and esters, were detected in all samples during fermentation, and three principal components were obtained by principal component analysis, with a cumulative contribution of 75.014%. In conclusion, BFE has strong antioxidant activity and significantly improves the physicochemical properties of fermented yak meat sausage, and the most pronounced effect is obtained with 0.01% BFE addition.

Geotextile tubes are one of the emerging and promising technologies to build fine-grain tailings dams. In this study, shaking table model tests are conducted to evaluate the seismic performance as characterized by horizontal acceleration and displacement of the tailings dam subject to horizontal peak ground accelerations (HPGAs). The test results indicate that the tailings dam is sustainable, whereas the whole dam tends to slide forward. Test results reveal a W-pattern variation of acceleration amplification coefficient (A m) at the same elevation despite different HPGA, whereas A m on the geotextile tubes exhibits minimal changes with increasing HPGA. A m inside the dam is highly variable in terms of the elevation and the specific position. The maximum vertical displacement occurs at the top of the geotextile tubes as the side of the geotextile tubes tilting upward. The highest horizontal displacement is observed in the middle section of the geotextile tubes, resulting in an overall convex deformation pattern. Two reinforcement schemes are proposed accordingly including strengthening the drainage and installing the anti-slide piles. The dynamic behaviors of the tailings dam subject to earthquakes from this study can serve as guidance for seismic design and technology promotion.

Traditional multi-label feature selection is usually performed under the condition of given label information, but nowadays, labeling multi-label data is a huge project, which is both time-consuming and labor-intensive, but if there is no label information condition, it will lead to poor feature selection, in order to solve this problem, this paper proposes a new semi-supervised multi-label feature selection method, i.e., semi-supervised multi-label feature selection algorithm based on dual dynamic graph. In this paper, a semi-supervised multi-label feature selection algorithm is proposed by constructing a dual dynamic graph. First, the method selects the most discriminative features for dimensionality reduction through the feature selection method of least squares regression, combined with the redundancy penalty of highly correlated features. Second, the label information is added to the construction of sample matrix similarity to learn the similarity. A semi-supervised multi-label feature selection framework is constructed by designing iterative updates of dual dynamic graphs to learn more accurate pseudo-label matrices to guide feature selection. Finally, the paper validates the above model using the alternating iteration optimization algorithm and verifies the effectiveness of the algorithm through experiments. [ABSTRACT FROM AUTHOR]

Sudan I is a cancer-causing chemical synthetic dye that is often illegally added to foods as a colorant. In this manuscript, based on molecularly imprinted polymers coated carbon dots (CDs@SiO2@MIPs), a novel fluorescence sensor is reported for the selective and sensitive determination of Sudan I. The sensor was prepared upon the surface of silica-coated carbon dots (CD@SiO2) by a one-pot sol-gel method using Sudan I as the template, 3-aminopropyl triethoxysilane (APTES) as the monomer, and tetraethyl orthosilicate (TEOS) as the crosslinker. Due to fluorescence resonance energy transfer, quenching occurred when CDs@SiO2@MIPs combined with Sudan I. The established sensor showed excellent recognition and performance for Sudan I with a wide linear range (1 to 120 μM) and low detection limit (0.61 μM). Furthermore, the sensor was successfully applied to determine Sudan I in chili powder and ketchup with recoveries from 89.7 to 101.7%. This work provides broad applications of fluorescence sensors based on CDs@SiO2@MIPs for the rapid analysis of food. [ABSTRACT FROM AUTHOR]

Fluorinated porous materials, which can provide specific fluorine‐fluorine interaction, hold great promise for fluoride analysis. Here, a novel fluorinated covalent‐organic polymer was prepared by using 2,4,6‐tris(4‐aminophenyl)‐1,3,5‐triazine and 2,3,5,6‐tetrafluorotelephtal aldehyde as the precursors and introduced as stationary phase for open‐tubular capillary electrochromatography. The as‐synthesized fluorinated covalent‐organic polymer and the modified capillary column were characterized by infrared spectroscopy, scanning electron microscopy, and energy dispersive X‐ray spectrometry. Based on strong hydrophobic interaction and fluorine–fluorine interaction provided by fluorinated covalent‐organic polymer coating layer, the modified column showed powerful separation selectivity toward hydrophobic compounds, organic fluorides, and fluorinated pesticides. Additionally, the fluorinated covalent‐organic polymer with good porosity and regular shape was uniformly and tightly coated on the capillary inner wall. The obtained highest column efficiency could reach up to 1.2 × 105 plates⋅m−1 for fluorophenol. The loading capacity of the modified column can reach 141 pmol for trifluorotoluene. Besides, the relative standard deviations of retention times for intraday run (n = 5), interday run (n = 3), and between columns (n = 3) were all less than 2.55%. Significantly, this novel fluorinated material‐based stationary phase shows great application potential in fluorides analysis. [ABSTRACT FROM AUTHOR]

Abstract: Elevated C[O.sub.2] levels can improve growth and water use efficiency (WUE). However, the influence of atmospheric C[O.sub.2] concentrations higher than 800 ppm has been less of a concern and [...]

Construction using geofabriform is a new promising technology to build fine grain tailings dam. Large-scale shaking table tests are conducted in this study to investigate the dynamic performances in terms of horizontal acceleration and displacement of the tailings dam with and without geofabriform subject to horizontal earthquakes. Test results indicate that the seismic performance of the tailings dam with geofabriform is significantly better than that of tailings dam without geofabriform. The two types of tailings dams have different failure modes under the action of earthquake. The acceleration amplification factor(Am), vertical displacement and horizontal displacement of the tailings dam with geofabriform under the same seismic acceleration input are smaller than that of the tailings dam without geofabriform, the maximum attenuation amplitude of the Am at the dam slope reaches to 81%. The horizontal displacements of the two types of dams are nonlinearly distributed in the height direction and the geotextile bags of the tailings dam have an upward displacement and are tilted upward. According to the failure mode of the tailings dam with geotextile bags, it is recommended to strengthen the drainage measures and set up anti-slide piles at the bottom of the geotextile bags body to strengthen the tailings dam.

Selecting appropriate features can better describe the characteristics and structure of data, which play an important role in further improving models and algorithms whether for supervised or unsupervised learning. In this paper, a new unsupervised feature selection regression model with nonnegative sparse constraints (URNS) is proposed. The algorithm combines nonnegative orthogonal constraint, L2,1-norm minimum optimization and spectral clustering. Firstly, the linear regression model between the features and the pseudo labels is given, and the indicator matrix, which describes feature weight, is subject to nonnegative and orthogonal constraints to select better features. Secondly, in order to reduce redundant and even noisy features, L2,1-norm for indicator matrix is added to the regression model for exploring the correlation between pseudo labels and features by the row sparsity property of L2,1-norm. Finally, pseudo labels of all samples are established by spectral clustering. In order to solve the regression model efficiently and simply, the method of nonnegative matrix decomposition is used and the complexity of the given algorithm is analysed. Moreover, a large number of experiments and analyses have been carried out on several public datasets to verify the superiority of the given model. [ABSTRACT FROM AUTHOR]