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To study the chemical constituents of Pteris ensiformis, silica gel, gel, MCI, C18 and other column chromatography were used for separation and purification, and their structures were identified by 1H-NMR, 13C-NMR, MS, IR and othe spectral data; the anti-tumor and anti-coagulation activities of some monomers were screened by MTS, APTT, PT and TT. The results were as follows: (1) A total of 15 compounds were isolated from P. ensiformis, the compounds were 2-hydroxy-acetylpyrrole (1), N-(3-carboxypropyl)-2-acetylpyrrole (2), 3-hydroxy-2-methylpyridine (3), N-methylhydroxylamine (4), pterosin S 13-O-glucoside (5), obtupterosin C (6), ent-11α-hydroxy-15-oxokauran-19-oic acid (7), ent-11α-hydroxy-15-oxokaur-16-en-19-oic acid (8), β-sitosterol (9), ent-11α-hydroxy-15-oxokaur-16-en-19-oic acid-O-glucopyranoside (10), 5, 5′-dibutoxy-2, 2′-bifuran (11), 5, 5′-di (2-ethyl-hexyloxy)-2, 2′-bifuran (12), (-)-loliolide (13), succinic acid (14), fumaric acid (15). Compound 1 is a new natural product of pyrrole alkaloids. Compounds 1-7, 10-15 were isolated from P. ensiformis for the first time, and compounds 1, 3, 4 were isolated from Pteris for the first time. (2) The results of activity test showed that compounds 1, 2, 3, 5, 6 and 10 inhibited the growth of tumor cells HL-60, A549, SMMC-7721, MDA-MB-231 and SW480 in vitro at a concentration of 40 μmol·L-1, At the concentration of 2.0 mmol·L-1, compounds 1, 2, 3 and 6 shortened APTT and compounds 1, 5 and 6 prolonged PT. The study enriches the chemical constituents of P. ensiformis from Guizhou and provides a material basis for the development of anti-tumor drugs.

Based on finite element simulation analysis, laminated ceramic tool materials with different structures were designed and the effect of laminated structure on tool state was investigated. Residual stresses in ceramic tool materials increase with the number of layers and layer–thickness ratio. Based on the simulation results, SiAlON-SiC-SiCw/SiAlON-Al2O3 ceramic tool materials (SCWAs) were prepared using the spark plasma sintering process, and the influence of residual stress on the mechanical properties and microstructure of laminated ceramic tool materials was studied. The mechanical properties of ceramic materials were significantly improved under the effect of residual stresses. The fracture toughness of SCWA4 with 7 layers and a layer–thickness ratio of 6 was 6.02 ± 0.19 MPa·m1/2, and the front and side flexural strengths were 602 ± 19 MPa and 595 ± 17 MPa, 36.3% and 39.0% higher than homogeneous SiAlON ceramics, respectively. [ABSTRACT FROM AUTHOR]

To enhance the fracture toughness of B4C ceramics, B4C/TiB2 ceramics with excellent performance were prepared by using TiO2 as the addition item and using spark plasma sintering to introduce TiB2 based on in situ reaction, which was compared with ceramics directly introduced with TiB2, the impacts of TiO2 content, temperature and holding time on B4C/TiB2 ceramics were studied, and the toughening mechanism of B4C/TiB2 ceramics in situ reaction was discussed. The results showed that compared with the ceramics directly introduced with TiB2, B4C/TiB2 ceramics with reinforcement phase TiB2 introduced through in‐situ reaction were easier to obtain higher relative density and better properties. Due to the existence of a discharge effect and the application of pulse current, B4C/TiB2 ceramics with excellent comprehensive properties can be prepared at lower temperatures and short time. When 15 vol% TiO2 was added, the temperature was 1750°C and the holding time was 10 min, the comprehensive properties were better, and their relative density, Vickers hardness, flexural strength, and fracture toughness were 98.5%, 27.72 GPa, 474 MPa, and 5.08 MPa·m1/2, respectively. Toughening mechanisms such as crack deflection, crack branching, and crack bridging improved the fracture toughness. [ABSTRACT FROM AUTHOR]

Osteoporosis commonly occurs in the older people and severe patients, with the main reason of the imbalance of bone metabolism (the rate of bone resorption exceeding the rate of bone formation), resulting in a decrease in bone mineral density and destruction of bone microstructure and further leading to the increased risk of fragility fracture. Recent studies indicate that protein nutritional support is beneficial for attenuating osteoporosis and improving bone health. This review summarized the classical mechanisms of protein intervention for alleviating osteoporosis on both suppressing bone resorption and regulating bone formation related pathways (promoting osteoblasts generation and proliferation, enhancing calcium absorption, and increasing collagen and mineral deposition), as well as the potential novel mechanisms via activating autophagy of osteoblasts, altering bone related miRNA profiles, regulating muscle-bone axis, and modulating gut microbiota abundance. Protein nutritional intervention is expected to provide novel approaches for the prevention and adjuvant therapy of osteoporosis. [ABSTRACT FROM AUTHOR]

Microparticle rotation is an important process in biomedical engineering, such as biosensors, cell injection or cell morphology. Single particle rotation has been widely investigated, while rotation of particle chains has gained rare attention. In this paper, we utilize a noncontact manipulation method to rotate microparticle chains via electrorotation by designing an octuple-electrode array (OEA). Finite element simulations were conducted for analyzing the desired electrode field and optimizing the structure of microelectrode pairs. The direction of the electric field in the workspace is investigated with different voltage signal inputs through specially designed circuits. In the experiment, microparticles are driven to form several chains in the proposed electrode fields. With the rotation of the electric field, particle chains could be rotated synchronously. Automated rotation and detection of polystyrene microspheres and yeast cell chains are achieved using machine vision technology. Results show that the proposed method could be utilized to rotate ordered microparticles with an appropriate input signal. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of the concentration and particle size of h-BN nanoparticles in a nanofluid on the surface integrity of 304 austenitic stainless steel during turning, focusing on the cutting force, friction coefficient, cutting temperature, surface roughness, surface residual stress, work hardening capacity, and 3D surface topography. The results show that, compared to dry cutting, the addition of 3 wt.% h-BN nanofluid can reduce the friction coefficient on the rake face by 38.9%, lower the cutting temperature by 43.5%, decrease the surface roughness by 53.8%, decrease the surface residual stress by 61.6%, and reduce the work hardening degree by 27.5%. Two-dimensional profiles and the 3D surface topography display a more balanced peak–valley distribution. Furthermore, by studying the effect of different h-BN particle sizes in nanofluids on the surface integrity of the machined workpiece, it was found that nanoscale particles have a greater tendency to penetrate the tool–chip interface than submicron particles. Moreover, the h-BN particles in the nanofluid play a "rolling effect" and "microsphere" effect, and the sesame oil will also form a lubricating oil film in the knife-chip contact area, thereby reducing the friction coefficient, reducing the cutting force, and improving the machining surface quality. [ABSTRACT FROM AUTHOR]

Recently, we have successfully achieved the atmospheric pressure catalytic synthesis of nanodiamonds by applying high stress to Ti3C2/Ni composite and then performing chlorine gas etching at atmospheric pressure. In this work, we chose three different catalysts (Fe, Co and Ni), with Ti3C2 as the precursor, aiming to investigate the effect of catalyst type on the synthesis of NDs. The results show that all three catalysts can catalyze the synthesis of NDs and that the crystal type and plasticity of the catalysts may have an important effect on the type and size of the resulting ND. When Fe and Ni were used as catalysts, the percentage of C-type NDs obtained was higher than that of C-type NDs catalyzed by Co (hexagonal close-packed crystal structure) due to its face-centered cubic crystal structure. In contrast, more H-type NDs were catalytically synthesized when Co (hexagonal close-packed crystal structure) was used as the catalyst. In addition, the number of small-size NDs (< 10 nm) catalytically synthesized by Co was significantly more than that catalytically synthesized by Fe and Ni, this may be caused by the poor plasticity of Co with a hexagonal close-packed crystal structure compared to Fe and Ni with a face-centered cubic crystal structure. [ABSTRACT FROM AUTHOR]

The formation and evolution of the foreland basin in the south of the Dabie Orogen are both closely related to the uplift of the orogenic belt. However, the Late Triassic paleoenvironment and the provenance of the sediments in the foreland basin remain controversial. Nine samples from the Upper Triassic Puqi Group of the foreland basin were analysed for whole‐rock major and trace elements and three sandstone samples were selected for zircon dating by U–Pb laser ablation inductively coupled plasma mass spectrometry. The concentrations of some major (e.g., CaO and Na2O) and trace (e.g., Rb, Sr and Ba) elements varied over a large range and showed different degrees of depletion. A series of major and trace element indicators, as well as the patterns of the rare earth elements, suggested derivation from felsic igneous rocks. The Late Triassic experienced fluctuations between cold warm climates, as indicated by the chemical weathering index ranging from 51.33 to 88.65. The CaO/(FeO + CaO), Rb/Sr and Ba/K ratios indicated that the paleosalinity changed from high to low. The Fe2O3/FeO, U/Th, V/Cr and Ni/Co ratios indicated an oxidizing sedimentary environment. The cathodoluminescence images, Th/U ratios and rare earth elements patterns of the detrital zircons all indicated a magmatic origin. Three samples showed significant peak ages of 224, 440, 748, 1870 and 2492 Ma, corresponding to the development of the Dabie Orogen. Our comprehensive analyses suggest that the Upper Triassic Puqi Group was formed by deposition during continental–continental collision. The Dabie Orogen was exhumed in the Late Triassic and supplied detrital sediments to the foreland basin. [ABSTRACT FROM AUTHOR]

The interfacial mechanical properties of the alumina/graphene (Al2O3/GR) nanocomposite ceramic tool materials were studied by molecular dynamic simulations. The effects of pull‐out velocity of graphene, system temperature, vacancy defect, and wrinkled graphene on the interfacial mechanical properties were investigated. Results show that a large interfacial shear stress (382 MPa) exists between the Al2O3/GR interface. The maximum pull‐out force and interfacial shear stress increase with increasing graphene pull‐out velocity. The increase of temperature reduces the maximum pull‐out force and interfacial shear stress. Moreover, the load transfer capacity is reduced and the creep of the matrix occurs. These factors reduce the fracture toughness of the Al2O3/GR nanocomposites. A moderate amount of vacancy defects in graphene increases the interfacial pull‐out force and shear stress of Al2O3/GR nanocomposite ceramic tool. Compared with Al2O3/GR nanocomposite ceramic tools, the interfacial interaction energy and shear stress of pleated graphene and Al2O3 were increased by 13.87% and 41.08% respectively, with better toughening and reinforcement. The results are of significance in further understanding of the interfacial mechanical properties at the nanoscale and then beneficial to improve the mechanical properties and engineering performance of Al2O3/GR composite ceramic materials. [ABSTRACT FROM AUTHOR]

To improve the mechanical characteristics and machinability of Ti(C,N) cermet and broaden its application range, Al2O3@Ni core–shell powders with varying Ni concentrations were generated using the heterogeneous precipitation-thermal reduction method, and Al2O3@Ni core–shell powders-reinforced Ti(C,N) cermet was created using spark plasma sintering (SPS). The mechanical, microstructural, and sintering characteristics of Ti(C,N) cermet were examined using core–shell powders with varying Ni contents. Al2O3@Ni core–shell powders with appropriate Ni content may uniformly distribute Ni with magnetic solid characteristics in cermet materials, resulting in rapid and uniform discharge that increases interface bonding, improves sintering, and greatly improves overall mechanical qualities. After adding core–shell powders, the cutting force of the TA@30N cermet tool is reduced compared to the TA30N cermet tool, but the surface quality of the machined workpiece improves. The effective cutting distance of the TA@30N cermet tool on heat-treated 45# steel is 36,000 m, 33.33% greater than that of the homogeneous TA30N cermet tool. [ABSTRACT FROM AUTHOR]

The differences in gut microbiota among different populations, to a certain extent, reflect the degree of interaction between individuals within populations. To assess the interaction levels among several small populations of Przewalski's gazelle ( Procapra przewalskii ) ( n  = 105, from seven different regions) based on differences in gut microbiota, we used the closely related Tibetan gazelle ( P. picticaudata ) ( n  = 52, from seven different regions) as a control. We then compared the gut microbial communities between different populations of the two species using high-throughput sequencing of the 16S rRNA gene. The results showed that within a 100 km geographical distance, the intergroup differences in relative abundance of dominant bacteria, α-diversity, β-diversity, and functional metabolism abundance were higher or significantly higher in Przewalski's gazelle (narrowly distributed species) compared to the Tibetan gazelle (widely distributed species). Additionally, the proportion of shared OTUs between groups in Przewalski's gazelle was significantly lower than in Tibetan gazelle ( p  < 0.05). Additionally, neutral community model results also showed lower dispersal limitation in the Tibetan gazelle compared to Przewalski's gazelle. Therefore, based on the above results, we comprehensively speculate that the spatial interaction degree of Przewalski's gazelle in different habitat patches is relatively low. This study, starting from the perspective of gut microbiota, adopts a non-genetic perspective or method to assess whether there is, or to what extent there is, close interaction between species populations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhang, Song, Jiang and Zhang.)

Understanding how per- and polyfluoroalkyl substances (PFASs) enter aquatic ecosystems is challenging due to the complex interplay of physical, chemical, and biological processes, as well as the influence of hydraulic and hydrological factors and pollution sources at the catchment scale. The spatiotemporal dynamics of PFASs across various media remain largely unknown. Here we show the fate and transport mechanisms of PFASs by integrating monitoring data from an estuarine reservoir in Singapore into a detailed 3D model. This model incorporates hydrological, hydrodynamic, and water quality processes to quantify the distributions of total PFASs, including the major components perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), across water, particulate matter, and sediments within the reservoir. Our results, validated against four years of field measurements with most relative average deviations below 40%, demonstrate that this integrated approach effectively characterizes the occurrence, sources, sinks, and trends of PFASs. The majority of PFASs are found in the dissolved phase (>95%), followed by fractions sorbed to organic particles like detritus (1.0-3.5%) and phytoplankton (1-2%). We also assess the potential risks in both the water column and sediments of the reservoir. The risk quotients for PFOS and PFOA are <0.32 and < 0.00016, respectively, indicating an acceptable risk level for PFASs in this water body. The reservoir also exhibits substantial buffering capacity, even with a tenfold increase in external loading, particularly in managing the risks associated with PFOA compared to PFOS. This study not only enhances our understanding of the mechanisms influencing the fate and transport of surfactant contaminants but also establishes a framework for future research to explore how dominant environmental factors and processes can mitigate emerging contaminants in aquatic ecosystems., Competing Interests: The authors declare that we have no financial interests or personal relationships that could have any influence on the work reported in this paper., (© 2024 The Authors.)

Rosa roxburghii Tratt, a valuable plant in China with long history, is famous for its fruit. It possesses various secondary metabolites, such as L-ascorbic acid (vitamin C), alkaloids and poly saccharides, which make it a high nutritional and medicinal value. Here we characterized the chromosome-level genome sequence of R. roxburghii, comprising seven pseudo-chromosomes with a total size of 531 Mb and a heterozygosity of 0.25%. We also annotated 45,226 coding gene loci after masking repeat elements. Orthologs for 90.1% of the Complete Single-Copy BUSCOs were found in the R. roxburghii annotation. By aligning with protein sequences from public platform, we annotated 85.89% genes from R. roxburghii. Comparative genomic analysis revealed that R. roxburghii diverged from Rosa chinensis approximately 5.58 to 13.17 million years ago, and no whole-genome duplication event occurred after the divergence from eudicots. To fully utilize this genomic resource, we constructed a genomic database RroFGD with various analysis tools. Otherwise, 69 enzyme genes involved in L-ascorbate biosynthesis were identified and a key enzyme in the biosynthesis of vitamin C, GDH (L-Gal-1-dehydrogenase), is used as an example to introduce the functions of the database. This genome and database will facilitate the future investigations into gene function and molecular breeding in R. roxburghii., (© 2024. The Author(s).)