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Abstract The study established experimental transects in undisturbed areas of the Caohai Nature Reserve in Weining, Guizhou Province. The study aims to examine complete successional transects in different landscapes: non-karst, karst, and vegetation restoration, using the spatiotemporal substitution method. It analyzes the distribution patterns of Total potassium (TK) and Avail potassium (AK) in the soil and employs a Generalized Linear Mixed Model (GLMM) to investigate the effects of geomorphology, soil aggregates, and their interactions on the changes in soil potassium(K) elements. Furthermore, it explores the synergistic effects of K cycling during the vegetation restoration process in karst soils. The findings indicated that: (1) In karst areas, the overall TK content was higher than in non-karst areas, while the AK content in the topsoil was higher in non-karst areas. The TK content in the karst areas tended to approach that of the vegetation restoration zone. (2) After restoration, the dominant plants changed from Gramineae to Gramineae + Asteraceae, and the vegetation richness increased, thereby improving the soil fertility and potassium fixation capacity. (3) The GLMM showed that the karst landscape had a significant effect on the TK and AK contents of surface soil. In the early stage of vegetation restoration, the joint effect of soil and vegetation affected the TK and AK contents in soil.

Abstract Biochar and green manure have been widely applied in agricultural production and are important means to achieve sustainable agriculture. However, there is limited research systematically and comprehensively exploring the response of soil microbiota and the changes in soil metabolomics after the addition of two different carbon source amendments to the soil, and the differential mechanisms of soil metabolomics between them remain unclear. In this study, a long-term field experiment (initiated in 2019) was conducted to investigate the effects of biochar and green manure application on soil nutrients and soil functions driven by soil microbes. Compared to the pure fertilizer treatment, biochar increased soil total carbon by 14.54% to 27.04% and soil available potassium by 4.67% to 27.46%. Ryegrass significantly increased soil available phosphorus and organic matter. Under different fertilization regimes, the ecological niches of soil microbes changed significantly. Network analysis revealed that long-term ryegrass returning reduced the complexity of soil microbial networks. Ryegrass and biochar increased dispersal limitation in fungal assemblages (reaching 93.33% and 86.67%, respectively), with biochar particularly enhancing variable selection in bacterial assemblages (accounting for 53.33%). Variation partitioning analysis based on redundancy analysis indicated that humic substances had the highest explanatory power for microbial community variation, with humic substances explaining 38.49% of bacteria and 52.19% of fungi variation. The ryegrass treatment mainly changed the abundance of carbohydrates (CH), amines (AM), c (AH), and lipids (LP), while the BC treatment mainly altered the abundance of organic acids (AC), amines (AM), and carbohydrates (CH). Meanwhile, both treatments significantly reduced the bisphenol A, one of the soil pollutants. Ryegrass incorporation significantly increased the abundance of genes related to soil C, N, P, and S cycling, especially genes involved in carbon decomposition, while biochar significantly enhanced the abundance of nitrogen fixation genes nifH and Hao in soil. Random forest model results indicated that carbohydrates, alcohols, aromatics (AR), and ester (ES) were the main categories of metabolites in soil influenced by differential microbes, and Finegoldia served as a common important metabolic driving species. In summary, this study reveals the processes of soil function, microbial community succession, and metabolism driven by ryegrass and biochar, providing important insights for optimizing soil management and improving soil quality. Graphical Abstract

Tobacco is a special commercial crop that prefers potassium but not chlorine, and excessive chloride (Cl–) accumulation can cause toxicity. Here, we revealed that the structural characteristics of chloroplasts in tobacco leaves were significantly destroyed under high Cl– salinity, but not mitochondria. Large differences in leaf structure, MDA content, and antioxidant enzyme activities were observed for the treatment with highest chloride accumulation at the 14th day. Moreover, RNA-seq analysis of tobacco leaves exposed to high Cl– salinity revealed global changes in gene transcription levels. A total of 1360 DEGs involved in cell wall, lipid, starch, and secondary metabolism processes were unevenly distributed on chromosomes, and were mainly enriched for starch and sucrose metabolism, phenylpropanoid biosynthesis, ribosome and ribosome biogenesis, protein processing in the endoplasmic reticulum, and plant hormone signal transduction pathways. Overall, our study provides valuable insights for further research on the mechanism underlying Cl– salinity and salt-tolerant tobacco development.

The Xiashu loess is an important aeolian deposit in eastern China. Research on the provenance of the Xiashu loess, located along the lower reaches of the Yangtze River, has entered into a new stage, compelling us to review the previous research findings in order to provide direction for future research. In this study, we enumerate three different viewpoints regarding the major sources of the loess in eastern China, including distant sources, proximal sources, and mixed sources. We also discuss disturbance factors, methods, and research on the provenance of the Xiashu loess. Previous research has showed that, on the basis of geochronology and meticulous grain grading data, good results as to the loess’ provenance can be obtained using immobile geochemical index tracers that are not affected by chemical weathering or grain size effects. Examples include detrital zircon U-Pb age spectra, major and trace element ratios, stable isotopic composition, and slowly weatherable minerals. However, differences in the data do exist, e.g., for the immobile geochemical provenance tracing indexes of the loess. Also still under debate is the age of the lower boundary of the loess. Therefore, exploring the spatial-temporal variations of the provenance, along with the coupling relationship between the paleoclimate environment evolution and the onset of the loess accumulation, should be comprehensively considered in future research.

Defect inspection of existing buildings is receiving increasing attention for digitalization transfer in the construction industry. The development of drone technology and artificial intelligence has provided powerful tools for defect inspection of buildings. However, integrating defect inspection information detected from UAV images into semantically rich building information modeling (BIM) is still challenging work due to the low defect detection accuracy and the coordinate difference between UAV images and BIM models. In this paper, a deep learning-based method coupled with transfer learning is used to detect defects accurately; and a texture mapping-based defect parameter extraction method is proposed to achieve the mapping from the image U-V coordinate system to the BIM project coordinate system. The defects are projected onto the surface of the BIM model to enrich a surface defect-extended BIM (SDE-BIM). The proposed method was validated in a defect information modeling experiment involving the No. 36 teaching building of Nantong University. The results demonstrate that the methods are widely applicable to various building inspection tasks.

In southwest China, vegetation restoration is widely used in karst rocky desertification control projects. This technology can effectively fix the easily lost soil, gradually restore the plant community and improve soil fertility. However, the change law of soil heavy metals in the restoration process remains to be further studied. Therefore, in this work, Guizhou Caohai Nature Reserve as a typical karst area was taken as the research object to investigate the influence of vegetation restoration technology on repairing soil heavy metal pollution. The spatial distribution characteristics of soil heavy metals (chromium, nickel, arsenic, zinc, lead) before and after vegetation restoration in karst area were studied by comparative analysis and linear stepwise regression analysis. The main influencing factors and spatial distribution characteristics of heavy metals in karst area were further discussed. The results showed that: (1) heavy metals in karst soils are affected by surface vegetation, root exudates, microorganisms and leaching. Only heavy metals nickel (Ni) and lead (Pb) showed the tendency of surface enrichment and bottom precipitation enrichment in non-karst soils. Path analysis suggested that non-metallic soil factors such as soil bulk density (BD), total nitrogen (TN) and ammonium nitrogen (NH4+-N) had direct effect on the content of heavy metals in soil. (2) The proportion of 0.25–2 mm aggregates in the surface soil of vegetation restoration belt was more than 40%, and the proportion of surface soil ≤2 mm aggregates in this increased to 83% and 88%, respectively, which could improve the soil structure and properties effectively. (3) Vegetation restoration effectively restored the nutrient elements such as carbon and nitrogen in the soil, and enhanced the soil material circulation. Furthermore the content of heavy metals in the surface soil higher than that in the 10–20 cm soil layer. Plant absorption, biosorption mechanism of microorganisms, coupling of root exudates, dissolution of soil soluble organic carbon and pH make the contents of heavy metals Cr, Ni and Pb in vegetation restoration belt slightly lower than those in karst soil. At the same time, affected by vegetation coverage, residual heavy metals in soil are further leached by surface runoff. Therefore, the content of heavy metals in soil could reduce combined heavy metal enrichment plants for extraction with remediation. This study elucidates the advantages and remedy mechanism of vegetation restoration in the remediation of heavy metal contaminated soils in Caohai area of Guizhou, and this plant activation and enrichment extraction remediation technology would be popularized and applied in the remediation of heavy metal contaminated soils in other karst areas.

A scheme of 5G upstream bandwidth detection technology and application was proposed, which could effectively solve the problem of 5G network fluctuation in video monitoring data transmission process.It will help the deployment of 5G video monitoring application.By obtaining the radio resource information of 5G NR, the terminal can count the transmission resource and estimate the change trend of uplink bandwidth.Combined with the intelligent coding technology and bit-stream adaptive technology of streaming media application, the scheme ensures no stuck and continuous picture at the cost of losing a little video definition, and ensures the overall experience of customers.The scheme can be widely used in the scene of heavy 5G public service, large network fluctuation and wide network coverage, such as campus video surveillance.

Vegetation restoration has always been the focus of ecological research, but the synergistic effect of the soil carbon cycle and vegetation restoration succession process in karst area is still unclear. In this study, the complete succession zones of non-karst, karst, and karst vegetation restoration landforms in a National Nature Reserve, Caohai (Guizhou Province, China), were compared. The content distribution characteristics of SOC, ROC and DOC were investigated, as well as the geomorphology, spatial location and interaction were studied by using GLMM. The results show that the soil types and vegetation coverage of different landforms lead to a decrease in SOC in karst area with an increase in depth. The soil content in karst area was low, and in order to maintain the normal growth of vegetation, the proportion of soil ROC and DOC in SOC must be high, which leads to the order of soil ROC content in unrepaired area > vegetation restoration area > non-karst area. In addition, the content of SOC in the surface layer of the vegetation restoration area was lower than that of the unrepaired area and the non-karst area. The soil microbial activity in the vegetation restoration area is stronger, and more organic carbon was fixed in the plant. The vegetation coverage and diversity increased obviously and markedly as a result of dominant plants changing (from Gramineae to Gramineae + Compositae) in the karst vegetation restoration area, but the soil in the karst area could not provide sufficient nutrition for plants, ultimately resulting in an inverse ratio between surface SOC and vegetation diversity. This study aims to enhance understandings of ecological functions and vegetation restoration in karst areas, as well as responses to regional carbon cycling.

NK cells can broadly target and kill malignant cells via release of cytolytic proteins. NK cells also release extracellular vesicles (EVs) that contain cytolytic proteins, previously shown to induce apoptosis of a variety of cancer cells in vitro and in vivo. The EVs released by NK cells are likely very heterogeneous, as vesicles can be released from the plasma membrane or from different intracellular compartments. In this study, we undertook a fractionation scheme to enrich for cytolytic NK-EVs. NK-EVs were harvested from culture medium from the human NK-92 cell line or primary human NK cells grown in serum-free conditions. By combining ultracentrifugation with downstream density-gradient ultracentrifugation or size-exclusion chromatography, distinct EV populations were identified. Density-gradient ultracentrifugation led to separation of three subpopulations of EVs. The different EV isolates were characterized by label-free quantitative mass spectrometry and western blotting, and we found that one subpopulation was primarily enriched for plasma membrane proteins and tetraspanins CD37, CD82, and CD151, and likely represents microvesicles. The other major subpopulation was enriched in intracellularly derived markers with high expression of the endosomal tetraspanin CD63 and markers for intracellular organelles. The intracellularly derived EVs were highly enriched in cytolytic proteins, and possessed high apoptotic activity against HCT-116 colon cancer spheroids. To further enrich for cytolytic EVs, immunoaffinity pulldowns led to the isolation of a subset of EVs containing the cytolytic granule marker NKG7 and the majority of vesicular granzyme B content. We therefore propose that EVs containing cytolytic proteins may primarily be released via cytolytic granules.

The development and utilization of urban underground space is an important way to solve the “great urban disease”. As one of the most important types of urban underground foundations, utility tunnels have become increasingly popular in municipal construction. The investigation of utility tunnels is a general task and three-dimensional laser scanning technology has played a significant role in surveying and data acquisition. However, three-dimensional laser scanning technology suffers from noise and occlusion in narrow congested utility tunnel spaces, and the acquired point clouds are imperfect; hence, errors and redundancies are introduced in the extracted geometric elements. The topology of reconstructed BIM objects cannot be ensured. Therefore, in this study, a hierarchical segmentation method for point clouds and a topology reconstruction method for building information model (BIM) objects in utility tunnels are proposed. The point cloud is segmented into facades, planes, and pipelines hierarchically. An improved mean-shift algorithm is proposed to extract wall line features and a local symmetry-based medial axis extraction algorithm is proposed to extract pipelines from point clouds. A topology reconstruction method that searches for the neighbor information of wall and pipeline centerlines and establishes collinear, perpendicular, and intersecting situations is used to reconstruct a topologically consistent 3D model of a utility tunnel. An experiment on the Guangzhou’s Nansha District dataset successfully reconstructed 24 BIM wall objects and 12 pipelines within the utility tunnel, verifying the efficiency of the method.

Previous research has mostly focused on Internet use behaviors, such as usage time of the Internet or social media after individuals experienced offline social exclusion. However, the extant literature has ignored online response behaviors, such as online review responses to social exclusion. To address this gap, drawing on self-protection and self-serving bias, we proposed three hypotheses that examine the effect of offline social exclusion on online reviews, which are verified by two studies using different simulating scenarios with 464 participants. The results show that when individuals are socially excluded offline, regardless of where the exclusion comes from (businesses or peers), they will be more likely to give negative online reviews. In addition, brand awareness moderates the effect of offline social exclusion on online reviews. Specifically, if the brand is less known, compared with social inclusion, offline social exclusion will lead individuals to give more negative online reviews; conversely, for well-known brands, no significant difference exists in the online reviews between social exclusion and inclusion.

Pinus Koraiensis seeds have physiological dormancy. Cold stratification releases seed dormancy. The changes in metabolite profiles of dormant seeds and cold stratified seeds during shorter incubation time in a favorable condition for seed germination have been studied. However, a more-long-term detection of the changes in metabolites in dormant seeds can identify the real metabolic pathways responsible for dormancy. Metabolite composition was investigated in embryo and megagametophyte of primary physiological dormant seeds (DS) of P. Koraiensis collected at 0, 1, 2, 4, and 6 weeks of incubation and of non-primary physiological dormant seeds (NDS) sampled at 0 and 1 week of incubation, seed coat rupture stage, and radicle protrusion stage. Embryos contained higher levels of most metabolites than megagametophyte. Strong accumulation of most metabolites in DS occurred at 1 and 4 weeks of incubation. A larger reduction in the relative levels of most phosphorylated sugars and amino acids in NDS was found between 1-week-incubation and seed coat rupture stage. The relative levels of metabolites involved in carbohydrate metabolism, especially the pentose phosphate pathway (PPP) and tricarboxylic acid (TCA) cycle, were higher in the embryos of 4-week-incubated DS, but the relative contents of intermediate metabolites of most amino acid metabolism were lower compared to 1-week-incubated NDS. We suggested that the disturbed carbohydrate metabolism and amino acid metabolism in the embryos of DS after 4 weeks of incubation maybe related to primary dormancy. Our study provides information for a better understanding of the mechanism of seed dormancy.

The purpose of this paper is to improve the classical VIKOR method with a holistic view, and evaluate the alternatives with invariant reference points and scales to achieve the rank preservation. The VIKOR method, as a commonly used multi-attribute decision making model, is prone to rank reversal when the alternative is added, deleted or replaced. The phenomenon of rank reversal indicates that there is a contradiction in the consistency and credibility of the evaluation results. First, the new improved VIKOR called R-VIKOR focuses on the selection of historical extreme values of indicators, the process of data normalization, and the determination of virtual ideal solutions. It should be emphasized that the improved method is the improvement and extension of VIKOR. In addition, the theoretical basis of R-VIKOR with the ability to preserve rank is discussed. The R-VIKOR can ensure that the evaluation result of the selected alternative can be fixed, which is just like a unified ruler measuring objects, and the problem of rank reversal can be solved naturally. Finally, several examples and random experiments are examined to verify the validity and credibility of R-VIKOR.

In this paper, we focus on the study of UAV ground target tracking under obstacle environments using deep reinforcement learning, and an improved deep deterministic policy gradient (DDPG) algorithm is presented. A reward function based on line of sight and artificial potential field is constructed to guide the behavior of UAV to achieve target tracking, and a penalty term of action makes the trajectory smooth. In order to improve the exploration ability, multiple UAVs, which controlled by the same policy network, are used to perform tasks in each episode. Taking into account that the history observations have a great degree of correlation with the policy, long short-term memory networks are used to approximate the state of environments, which improve the approximation accuracy and the efficiency of data utilization. The simulation results show that the propose method can make the UAV keep target tracking and obstacle avoidance effectively.

This paper investigates the velocity and altitude tracking control problem for air-breathing hypersonic vehicle (AHV) under external disturbances and uncertainties. An improved smooth super-twisting based disturbance observer (SSTDOB) is proposed to estimate the unknown external disturbances. With the assistance of SSTDOB, an effective fixed-time sliding mode backstepping control (FSMBC) is designed to guarantee the tracking errors converge to a small neighbor of the origin. Meanwhile, a fixed-time tracking differentiator (FTD) is employed to estimate the virtual control inputs, which can eliminate the differential explosion problem. The overall stability of the closed-loop system is analyzed by utilizing Lyapunov stability theory. Simulation results demonstrate the effectiveness of the composite method.

Extracellular Vesicles (EVs) are a heterogenous population of particles that play an important role in cell-cell communication in physiological and pathophysiological situations. In this study we reveal that the peptidyl prolyl isomerase Cyclophilin A (CypA) is enriched in cancer-derived EVs from a range of haematopoietic malignancies. CypA-enriched blood cancer EVs were taken up by normal monocytes independent of EV surface trypsin-sensitive proteins and potently stimulated pro-inflammatory MMP9 and IL-6 secretion. Further characterisation revealed that CypA is intravesicular, however, it is not present in all EVs derived from the haematopoietic cells, instead, it is predominantly located in high density EVs with a range of 1.15–1.18 g/ml. Furthermore, loss of CypA expression in haematological cancer cells attenuates high density EV-induced pro-inflammatory MMP9 and IL-6 secretion from monocytes. Mechanistically, we reveal that homozygous loss or siRNA knockdown of CypA expression significantly reduced the secretion of EVs in the range of 100–200 nm from blood cancer cells under normal and hypoxic conditions. Overall, this work reveals a novel role for CypA in cancer cell EV biogenesis.

Trophic state index (TSI) can assess lake trophic status and trace in-situ metabolism, exhibiting a high potential in explaining autochthonous carbon dioxide (CO2) in aquatic environments. However, there remains a knowledge gap in how TSI links to the partial pressure of CO2 (pCO2) generated and consumed in lakes. Here we explored the temporal variations of lake pCO2 and TSI, as well as their linkages in a karst plateau lake. Lake pCO2 ranged from 90.1 to 7169.3 μatm and was significantly high in the post-wet period (2534.3 ± 1637.9 μatm). Over 58% of samples were found to be supersaturated in CO2 with respect to the atmospheric equilibrium (410 μatm). Biological and hydrological processes regulated lake trophic status, resulting in mesotrophic state (30 50) in the drought and initial-wet periods. Coupled carbonate dissolution and photosynthesis consumed the pCO2, whereas groundwater and respiration contributed the pCO2 in the karst lake. Our results highlighted that lake TSI could decipher trophic status and further partially explain the pCO2 dynamics and sources.

This paper aims to establish an effective guidance law to accomplish the interception guidance mission for a missile intercepting a target with impact angle constraint and autopilot dynamics. To achieve this purpose, a fixed-time disturbance observer-based adaptive finite-time guidance law is presented. First, a fixed-time disturbance observer (FTDO) is designed to guarantee the fast estimation of the lumped disturbance caused by the target maneuver. Then, the FTDO-based adaptive integral sliding mode backstepping (AISMB) guidance law is constructed for the interception guidance problem. Besides, several adaptive laws are established to estimate the derivative of virtual control inputs, making the “differential explosion problem” of conventional backstepping get avoided. The finite-time convergence characteristic of the closed-loop system is analyzed by utilizing the Lyapunov stability theory. Finally, the simulation examples are conducted to demonstrate the effectiveness of the proposed composite guidance law.

Polychlorinated biphenyls (PCBs) are infamous industry by-products or additives, and increasing evidences demonstrated that their exposure is associate with adverse effects on human health. Liver, as the dominate site for xenobiotic metabolism, is apt to be the primary target of PCBs insult. Although PCBs’ hepatic toxic effects have been extensively studied, however, the biotransformation of PCBs in liver and the toxicities of associated PCB metabolites are neglected at some extent. Thus, we choose 2,3,5-trichloro-6-phenyl-[1,4]-benzoquinone (PCB29-pQ), a surrogate PCB29 metabolite, and evaluated its contribution on hepatotoxicity. In the current study, we discovered PCB29-pQ-induced lipid peroxidation and iron overload both in vivo and in vitro. Further mechanistic research confirmed iron overload is caused by reactive oxygen species (ROS)-driven hepcidin disorder in hepatic cells, and the increase of hepcidin is regulated by the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2).

This paper is concerned with the distributed consensus problems for second-order multi-aircraft systems in the presence of sensor data loss and time-varying communication topology. A novel model-based game strategy is proposed to handle the distributed problem regardless of the time-varying topology. An anti-disturbance sliding-mode controller is designed to realize the ability of disturbance rejection and state estimation. The extended state observer combines two methods together and finally produces an independent decision-making architecture for each individual such that better convergence is achievable. Theoretical analyses are given to guarantee both individual stability and distributed stability. The simulation and experimental results are presented to show the effectiveness of the proposed control scheme.

The title compound, C22H20F2O3, a derivative of curcumin, crystallized with two independent molecules in the asymmetric unit. The mean planes of the two 2-fluoro-5-methoxyphenyl groups are aligned at 24.88 (11)° in one molecule and 24.19 (15)° in the other. The dihedral angles between the mean plane of the penta-1,4-dien-3-one group and those of the two 2-fluoro-5-methoxyphenyl rings are 51.16 (11) and 49.16 (10)° in the first molecule, and 45.69 (15) and 54.00 (14)° in the second. The molecules adopt E configurations about the central olefinic bonds.