Performance Evaluation of a Cicada-Inspired Subsoiling Tool Using DEM Simulations.

Subsoiling practice is an essential tillage practice in modern agriculture. Tillage forces and energy consumption during subsoiling are extremely high, which reduces the economic benefits of subsoiling technology. In this paper, a cicada-inspired biomimetic subsoiling tool (CIST) was designed to reduce the draught force during subsoiling. A soil-tool interaction model was developed using EDEM and validated using lab soil bin tests with sandy loam soil. The validated model was used to optimize the CIST and evaluate its performance by comparing it with a conventional chisel subsoiling tool (CCST) at various working depths (250-350 mm) and speeds (0.5-2.5 ms-1). Results showed that both simulated draught force and soil disturbance behaviors agreed well with those from lab soil bin tests, as indicated by relative errors of <6.1%. Compared with the CCST, the draught forces of the CIST can be reduced by 17.7% at various working depths and speeds; the design of the CIST obviously outperforms some previous biomimetic designs with largest draught force reduction of 7.29-12.8%. Soil surface flatness after subsoiling using the CIST was smoother at various depths than using the CCST. Soil loosening efficiencies of the CIST can be raised by 17.37% at various working speeds. Results from this study implied that the developed cicada-inspired subsoiling tool outperforms the conventional chisel subsoiling tool on aspects of soil disturbance behaviors, draught forces, and soil loosening efficiencies. This study can have implications for designing high-performance subsoiling tools with reduced draught forces and energy requirements, especially for the subsoiling tools working under sandy loam soil.

Analyzing the mechanism by which oyster peptides target IL-2 in melanoma cell apoptosis based on RNA-seq and m6A-seq.

Melanoma is a kind of skin cancer with high malignancy and strong proliferation and invasion abilities. Chemotherapy drugs in the clinic have the disadvantages of high price and high toxicity. Peptides are natural active ingredients that have many functions and are safe and effective. Previous studies have shown that oysters are rich in protein and have antitumor effects. In this study, a high-throughput strategy combined with MALDI TOF/TOF-MS and molecular docking was developed to screen peptides with antitumor functions from oyster hydrolysate. Three dominant peptides were predicted to have similar functions to IL-2 via molecular docking. Then, the activity of the peptides was confirmed in B16 cells, and we found that the three peptides increased the apoptosis of B16 cells. Furthermore, via RNA-seq and m6A-seq of B16 cells treated with the peptides, we found that ILADSAPR downregulates the expression of Pcna, Tlr4, and Ncbp2 and upregulates the expression of Bax, Bad, Pak4, Rasa2, Cct6, and Gbp2. ILADSAPR inhibited B16 cell proliferation and promoted cell apoptosis by regulating the expression of these genes. In addition, the result of metabolic pathway analysis also proved this point. This study provides a preliminary reference for antitumor research on oyster peptides.

Modelling and analysis of penetration resistance of probes in cultivated soils.

At present, the measurement of tillage depth is mainly based on manual measurement, but the manual raking method results in low measurement accuracy and high labor intensity. Due to the complexity of soil, theoretical research on tillage depth is relatively scarce. In order to provide a new research direction and research idea for soil stratification, topsoil was taken as the research object of this paper. The correlation between penetration resistance and penetration depth of a probe in a cultivated soil was studied, and a mathematical model was established. There is a certain similarity between the process of spherical cavity expansion and the process of probe penetration, so we introduced the theory of spherical cavity expansion into the modeling of penetration resistance of the cultivated soil. In this paper, the spherical cavity expansion theory of unsaturated soil was used as the basis for solving the penetration resistance. And the unified strength criterion was employed as a yield condition of the soil to set a stress solution and a displacement solutionin into of the probe penetrating into the elasto-plastic zone of the cultivated soil to determine the model of expansion force. We have carried out indoor tests to revise the expansion force model. Firstly, according to the range of soil density and water content in the field, the soil densities were classified into 1.1×103kg/m3, 1.2×103kg/m3 and 1.3×103kg/m3, and the water contents were divided into 10%, 15% and 20%. In addition, the orthogonal tests were performed at different levels. The soil was put into the barrel, and the probe was inserted into the soil in the barrel at the speed of 8mm/s to determine the test values of the change of the probe penetration resistance with depth. Finally, the expansion force model was fitted with the results of the indoor test, and coefficient B was introduced to express the influence degree of density and water content on the resistance. Coefficient B was substituted into the expansion force model to obtain the penetration resistance model of the cultivated soil. Through the goodness of fit analysis of the penetration resistance model, the results show that the overall average goodness of fit of the penetration resistance modelat was up to 0.871 at different water contents and densities, which was a good fit and could present novel insights into the study relating to soil stratification theory.

iTRAQ-Based Quantitative Proteomic Profiling of Staphylococcus aureus Under Different Osmotic Stress Conditions.

Staphylococcus aureus (S. aureus) is an extremely halotolerant pathogenic bacterium with high osmotic stress tolerance, and it is frequently encountered in aquatic production and preservation. However, the mechanism underlying the extremely high osmotic stress tolerance of S. aureus remains unclear. In this study, the isobaric tags for relative and absolute quantification (iTRAQ) method was used to identify the differentially expressed proteins (DEPs) under different sodium chloride (NaCl) concentrations. Compared with the control group (0% NaCl), the 10 and 20% NaCl groups had 484 DEPs and 750 DEPs, respectively. Compared with the 10% NaCl group, the 20% NaCl group had 361 DEPs. Among the DEPs, proteins involved in fatty acid synthesis, proline/glycine betaine biosynthesis and transportation, stress tolerance, cell wall biosynthesis and the TCA cycle were upregulated, whereas proteins associated with biofilm formation and pathogenic infections were downregulated. The results obtained in this study indicate that under extremely high osmotic stress, modification of the cell membrane structure, increased biosynthesis and transportation of osmotic protectants, and redistribution of energy metabolism contribute to the osmotic stress tolerance of S. aureus, and the infectious ability of the bacteria may be limited. The aim of this study was to provide new insight into how S. aureus tolerates the high-salt conditions involved in aquatic production and preservation.