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Plant-associated fungi (endophytic fungi) are a biodiversity-rich group of microorganisms that are normally found asymptomatically within plant tissues or in the intercellular spaces. Endophytic fungi promote the growth of host plants by directly producing secondary metabolites, which enhances the plant’s resistance to biotic and abiotic stresses. Additionally, they are capable of biosynthesizing medically important “phytochemicals” that were initially thought to be produced only by the host plant. In this review, we summarized some compounds from endophyte fungi with novel structures and diverse biological activities published between 2011 and 2021, with a focus on the origin of endophytic fungi, the structural and biological activity of the compounds they produce, and special attention paid to the exploration of pharmacological activities and mechanisms of action of certain compounds. This review revealed that endophytic fungi had high potential to be harnessed as an alternative source of secondary metabolites for pharmacological studies.

As a high-precision machining equipment, the turning-milling machine tool requires its bed structure the primary load-bearing component to exhibit excellent dynamic and static characteristics that significantly influence machining accuracy and efficiency. To ensure machining precision, this paper proposes a multi-objective collaborative optimization design methodology integrating Finite Element Analysis(FEA) and Taguchi Method. This approach employs FEA technology to obtain the static and dynamic characteristics of the machine tool bed(MTB) structure, followed by multi-objective collaborative optimization using Taguchi Method to achieve comprehensive performance enhancement. Compared with the traditional research methods for optimizing machine tool beds, the FEA technology can handle more complex geometric shapes and boundary conditions, improve the accuracy and reliability of data, and enhance the optimization efficiency through the Taguchi method, achieving multi-objective joint optimization. Comparative analysis demonstrates that the optimized structure achieves 5.14% reduction in maximum deformation, 1.75% decrease in mass, and 1.04% improvement in fourth-order natural frequency. The results validate the effectiveness of this design methodology in achieving efficient MTB optimization for turning-milling machine tools, simultaneously enhancing dynamic-static performance while realizing lightweight design. This research provides valuable references for advancing precision improvement and green manufacturing research in turning-milling machine tools.

Methicillin-resistant Staphylococcus aureus (MRSA) is a highly threatening foodborne pathogen capable of causing severe organ and life-threatening diseases. Over the past years, various commercial antibiotics have been used to treat MRSA infections. However, these commercial antibiotics have not yielded efficient results and also cause other side effects; therefore, there is a need for the development of effective alternatives to replace these commercial antibiotics. Suberanilic acid, an amide alkaloid obtained from the endophytic fungus Pestalotiopsis trachycarpicola DCL44, has been identified as a significant antimicrobial agent. However, its antibiotic properties on multi-drug-resistant bacteria such as MRSA have not been fully explored. Therefore, to investigate the potential antimicrobial mechanism of suberanilic acid against MRSA, a quantitative proteomics approach using tandem mass tagging (TMT) was used. The results obtained in the study revealed that suberanilic acid targets multiple pathways in MRSA, including disruption of ribosome synthesis, inhibition of membrane translocation for nutrient uptake (ABC transporter system), and causing dysregulation of carbohydrate and amino acid energy metabolism. These results provide new insights into the mechanism of action of suberanilic acid against MRSA and offer technical support and a theoretical basis for the development of novel food antimicrobial agents derived from endophytic fungal origin.

Pipe jacking has been widely used in urban underground engineering construction in recent years. Prediction of ground deformation caused by pipe jacking is particularly important for the safety of construction. With regard to the densely arranged pipes used in the pipe roof structure method, an analytical model of stratum disturbance caused by jacking of parallel rectangular pipes is proposed on the basis of Mindlin’s displacement solution and the stochastic medium theory. The influencing factors such as soil loss, additional thrust on the excavation face, friction between pipe jacking machine and soil, friction between subsequent pipes and soil, and the grouting pressure were comprehensively considered. Then, a 3D numerical simulation and a case study were conducted. The results showed consistent agreement with the analytical solution, and the proposed method can take into account the asymmetry of surface settlement curve induced by construction. A discussion of the ground deformation law shows that the proposed approach can reasonably predict the ground deformation and provide a reference for relevant pipe jacking construction.

The dithiophosphinic acids (HS2PR2) have been used for the selective separation of trivalent actinides (AnIII) from lanthanides (LnIII) over the past decades. The substituents on the dithiophosphinic acids dramatically impact the separation performance, but the mechanism is still open for debate. In this work, two dithiophosphinic acids with significantly different AnIII/LnIII separation performance, i.e. diphenyl dithiophosphinic acid (HS2PPh2) and bis(ortho‐trifluoromethylphenyl) dithiophosphinic acid [HS2P(o‐CF3C6H4)2], are employed to understand the substituent effect on the bonding covalency between the S2PR2− anions (R = Ph and o‐CF3C6H4) and the uranyl ion by sulfur K‐edge X‐ray absorption spectroscopy (XAS) in combination with density functional theory calculations. The two UO2(S2PR2)(EtOH) complexes display similar XAS spectra, in which the first pre‐edge feature with an intensity of 0.16 is entirely attributed to the transitions from S 1s orbitals to the unoccupied molecular orbitals due to the mixing between U 5f and S 3p orbitals. The Mulliken population analysis indicates that the amount of S 3p character in these orbitals is essentially identical for the UO2(S2PPh2)2(EtOH) and UO2[S2P(o‐CF3C6H4)2]2(EtOH) complexes, which is lower than that in the U 6d‐based orbitals. The essentially identical covalency in U—S bonds for the two UO2(S2PR2)2(EtOH) complexes are contradictory to the significantly different AnIII/LnIII separation performance of the two dithiophosphinic acids, thus the covalency seems to be unable to account for substituent effects in the AnIII/LnIII separation by the dithiophosphinic acids. The results in this work provide valuable insight into the understanding of the mechanism in the AnIII/LnIII separation by the dithiophosphinic acids. The first pre‐edge feature with an intensity of 0.16 in the S K‐edge X‐ray absorption spectra of UO2(S2PR2) (R = Ph and o‐CF3C6H4) is entirely attributed to the transitions from S 1s orbitals to the unoccupied molecular orbitals due to the mixing between U 5f and S 3p orbitals.

Since the spindle thermal error of CNC machine tools has a significant impact on machining precision, this paper introduces a unique approach for modeling spindle thermal error. Several key steps are involved in the proposed approach. First, the Fluke thermal imaging camera is employed for acquiring thermal image information of the spindle system. Second, the Gaussian filter is employed to denoise the thermal image sequence. Next, the temperature values at the measurement points are extracted from the thermal image sequence according to the mapping relationship between the grayscale value and the temperature value. Subsequently, critical temperature points are identified from thermal images using the density-based spatial clustering of applications with noise (DBSCAN) algorithm and the correlation coefficient method. Finally, the multi-verse optimized NARX neural network is employed to investigate the nonlinear prediction of thermal deformation. The research is conducted on the VMC-850E vertical machining center as the subject of study. The performance of the model is validated under conditions of idle spindle and 5000 r/min, comparing prediction results against traditional algorithms. The findings demonstrate that the non-contact measurement method based on thermal imaging successfully establishes the thermal error model, achieving a prediction accuracy of 0.1517 μm for the MVO-NARX model.

Multidrug-resistant bacteria such as Staphylococcus aureus (MRSA) cause infections that are difficult to treat globally, even with current available antibiotics. Therefore, there is an urgent need to search for novel antibiotics to tackle this problem. Endophytes are a potential source of novel bioactive compounds; however, the harnessing of novel pharmacological compounds from endophytes is infinite. Therefore, this study was designed to identify endophytic fungi (from Ageratina adenophora) with antibacterial activity against multidrug-resistant bacteria. Using fungal morphology and ITS-rDNA, endophytic fungi with antibacterial activities were isolated from A. adenophora. The results of the ITS rDNA sequence analysis showed that a total of 124 morphotype strains were identified. In addition, Species richness (S, 52), Margalef index (D/, 7.3337), Shannon–Wiener index (H/,3.6745), and Simpson’s diversity index (D, 0.9304) showed that A. adenophora have abundant endophytic fungi resources. Furthermore, the results of the agar well diffusion showed that the Penicillium sclerotigenum, Diaporthe kochmanii, and Pestalotiopsis trachycarpicola endophytic fungi’s ethyl acetate extracts showed moderate antibacterial and bactericidal activities, against methicillin-resistant Staphylococcus aureus (MRSA) SMU3194, with a MIC of 0.5–1 mg/mL and a MBC of 1–2 mg/mL. In summary, A. adenophora contains endophytic fungi resources that can be pharmacologically utilized, especially as antibacterial drugs.

Seed security is of prime importance for agriculture. To protect true seeds from being faked, more secure dual anti-counterfeiting technologies for tobacco (Nicotiana tabacum L.) pelleted seed were developed in this paper. Fluorescein (FR), rhodamine B (RB), and magnetic powder (MP) were used as anti-counterfeiting labels. According to their different properties and the special seed pelleting process, four dual-labeling treatments were conducted for two tobacco varieties, MS Yunyan85 (MSYY85) and Honghua Dajinyuan (HHDJY). Then the seed germination and seedling growth status were investigated, and the fluorescence in cracked pellets and developing seedlings was observed under different excitation lights. The results showed that FR, RB, and MP had no negative effects on the germination, seedling growth, and MDA content of the pelleted seeds, and even some treatments significantly enhanced seedling dry weight, vigor index, and shoot height in MS YY85, and increased SOD activity and chlorophyll content in HHDJY as compared to the control. In addition, the cotyledon tip of seedlings treated with FR and MP together represented bright green fluorescence under illumination of blue light (478 nm). And the seedling cotyledon vein treated with RB and MP together showed red fluorescence under green light (546 nm). All seeds pelleted with magnetic powder of proper concentration could be attracted by a magnet. Thus, it indicated that those new dual-labeling methods that fluorescent compound and magnetic powder simultaneously applied in the same seed pellets definitely improved anti-counterfeiting technology and enhanced the seed security. This technology will ensure that high quality seed will be used in the crop production.

In this article, a new class of silica gel adsorbent functionalized with macrocyclic receptors was developed for cesium recognition. A calixcrown molecule, with strong affinity to cesium cation, was decorated precisely at the 1,3-alternate benzene rings with reactive amino substituents, followed by the anchoring to the silica matrix to obtain a high functionalization degree. Structural characterization of the monomers and the organosilicas was carried out by 1 H/ 13 C NMR, 29 Si/ 13 C solid-state NMR, and FT-IR spectra. Besides, XPS survey, BET, TGA and ESEM were employed to investigate the surface property, thermal stability and micro-morphology of the organosilicas. Due to the host–guest interaction between the calixcrown receptor and cesium cation, efficient separation of cesium in the presence of competing alkali metals including sodium and potassium was realized. Mechanism regarding the recognition effect was discussed. The calixcrown-grafted organosilica material possesses the potential to be applied for the separation of cesium in radioactive liquid waste.

Based on the comprehensive analysis of the heat sources of the motorized spindle system, the thermal loads, including the heat generation of bearing friction and the electromagnetic loss of the built-in motor, are carried out for a machining center motorized spindle system. And then, the convective heat transfer coefficients of the whole spindle system are analyzed. The thermal characteristics of the motorized spindle system are calculated by finite element analysis. The steady state temperature field distribution of the motorized spindle is obtained. It provides some references for improving the thermal characteristics of the motorized spindle and reducing the difficulty of thermal error compensation.