Towards Effective Management: Toxicity, Causal Mechanism and Controlling Strategy of Toxic Rangeland Weeds in Western China

Toxic rangeland weeds (TRWs) pose a great threat to animal husbandry. Currently, an estimated 33 million hectares of pasture (10%) in western China is infested by a variety of toxic weeds, including Stellera chamaejasme, Oxytropis spp., Astragalus spp., Achnatherum inebrians. The spread of these toxic weeds results in huge annual economic losses of more than $2.4 billion USD (direct and indirect). A combination of ecology, molecular biology, biochemistry and field practise methods will be used to identify and evaluate TRWs, explore the mechanism of toxicity, and more importantly, understand the causal mechanism by which TRWs flourish. The knowledge will underpin the development of effective management strategies

Hydrophobic multiscale cavities for high-performance and self-cleaning surface-enhanced Raman spectroscopy (SERS) sensing

Cavity array, with excellent optical capture capability, has received increasing attention for the surface-enhanced Raman spectroscopy (SERS)-active substrates. Here, we proposed molybdenum disulfide (MoS2) nanocavities growing on pyramid Si (PSi) composed of in situ reduced Au nanoparticles (AuNPs), which can form the multiscale cavities (MSCs), and is facile for the couple of the plasmon. We demonstrated that the PSi/MoS2/Au MSCs can serve as highly sensitive, uniform, and stable SERS substrates for rhodamine 6G (R6G), crystal violet, and adenosine triphosphate detection, benefiting from the synergistic effect of the enhanced light trapping and the effective plasmonic couple. The couple of the plasmon in the MSCs is evidently proved by finite-difference time domain simulation, showing the strong electromagnetic field is located around the cavity wall. Moreover, the excellent hydrophobicity of the PSi/MoS2/AuNPs substrate endows it with the ability for the directional monitoring of organic pollutant in a mixture of oil and water. Finally, we demonstrated the MSCs with outstanding photocatalytic performance could achieve the renewable utilization by self-cleaning, which was attributed to the fast electron transfer and effective light absorption. The proposed PSi/MoS2/AuNPs MSC represents a robust mean using the plasmonic metal/semiconductor heterostructure for high-performance SERS sensors and photodegradation

Development of an FEM-DEM Model to Investigate Preliminary Compaction of Asphalt Pavements

Variations in pavement density have been widely monitored and investigated, both in laboratory and in field experiments, since the compaction of pavement is so critical to its long-term performance quality. In contrast to field testing, laboratory tests are simpler to produce but less accurate. Destructive drilled samples are used to conduct field testing; however, they are limited in their ability to assess density information at specific areas. The use of computationally aided approaches, such as the Finite Element Method (FEM) and the Discrete Element Method (DEM), in research involving asphalt mixtures is increasing, since these methods simulate and evaluate the characteristics of asphalt mixtures at macroscopic and microscopic scales. Individual particle behavior at the microscopic level cannot be fully represented using the FEM alone, and the computing cost of utilizing the DEM approach alone is prohibitively high. The objective of this work is to simulate the pre-compaction process by using the coupled FEM-DEM approach. In order to investigate the impact of the asphalt mixtures’ gradation, a dense-graded asphalt mixture (AC 11) and a gap graded asphalt mixture (PA 11) were simulated. Different paving speeds (4, 5, and 6 m/min) were applied on the preliminary compaction model of AC 11 to study the effect of the paving speeds on the compaction process. By comparing the angular velocity, which worked as a reference of compaction quality, it was demonstrated that the grade AC 11 asphalt mixtures performed better in the preliminary compaction process compared to the grade PA 11 asphalt mixtures. Moreover, since it has an effect on compaction, paving speed was carefully monitored and kept within a reasonable range in order to maximize both pavement quality and project efficiency

Investigation of the bonding properties of bitumen using a novel modified binder bond strength test

The binder bond strength (BBS) test can directly quantify the bonding of bitumen-stone joints. However, the index "bond strength" used in this method cannot provide a clear distinction when evaluating the performance of various bitumen, and some results do not correspond to the field feedback related to the bonding performance. This study introduces a novel modified BBS test using the universal testing machine (UTM). The results of the standard BBS test and the BBS-UTM test on six unmodified bitumens and a styrene-butadiene-styrene modified bitumen (SBSMB) are compared, with the Cantabro loss test to validate the accuracy of the BBS-UTM test. The results show that the "bond energy" can be considered the critical indicator for characterising the bonding performance of different binders. The force-displacement curve in the BBS-UTM test is analysed and provides a mechanistic explanation for the mechanical response of bitumen during pull-off. The four-component test is conducted to link the bitumen composition characteristics to its bonding performance. It is found that bitumen adhesion is correlated to the content of asphaltenes. A higher saturates content shows more contribution of tenacity in the total bond energy, and an excessively high ratio of asphaltenes to resins may result in low bond energy

The Mediator Med23 controls a transcriptional switch for muscle stem cell proliferation and differentiation in muscle regeneration

Summary: Muscle stem cells (MuSCs) contribute to a robust muscle regeneration process after injury, which is highly orchestrated by the sequential expression of multiple key transcription factors. However, it remains unclear how key transcription factors and cofactors such as the Mediator complex cooperate to regulate myogenesis. Here, we show that the Mediator Med23 is critically important for MuSC-mediated muscle regeneration. Med23 is increasingly expressed in activated/proliferating MuSCs on isolated myofibers or in response to muscle injury. Med23 deficiency reduced MuSC proliferation and enhanced its precocious differentiation, ultimately compromising muscle regeneration. Integrative analysis revealed that Med23 oppositely impacts Ternary complex factor (TCF)-targeted MuSC proliferation genes and myocardin-related transcription factor (MRTF)-targeted myogenic differentiation genes. Consistently, Med23 deficiency decreases the ETS-like transcription factor 1 (Elk1)/serum response factor (SRF) binding at proliferation gene promoters but promotes MRTF-A/SRF binding at myogenic gene promoters. Overall, our study reveals the important transcriptional control mechanism of Med23 in balancing MuSC proliferation and differentiation in muscle regeneration

Study on pre-compaction of pavement graded gravels via imaging technologies, artificial intelligent and numerical simulations

Pavement compaction cannot be neglected during the motorway manufacture stage because it can determine pavement service quality and durability. Concerning the compaction scenario, the paving compaction is responsible for offering the preliminary strength of the pavement. Ignoring paving compaction quality control can lead to over compaction. This paper introduces an integral system to study and simulate the paving compaction of asphalt motorways in Discrete Element Model two-dimensional (DEM2D). This method includes the whole procedure from aggregate image acquisition database establishment to the DEM2D simulation of paving compaction. To this end, this study fulfils the creation of the aggregate database applied in DEM via the Aggregate Image Measuring System (AIMS) method. In addition, the artificial intelligent (AI) technology called Generative Adversarial Networks (GANs) method is proposed to expand the developed DEM aggregate database. Three different approaches are applied to calibrate the accuracy of the extended database. According to the aggregate database, the pavement paving compaction with different aggregate gradations can be simulated in DEM2D

Development of an FEM-DEM Model to Investigate Preliminary Compaction of Asphalt Pavements

Variations in pavement density have been widely monitored and investigated, both in laboratory and in field experiments, since the compaction of pavement is so critical to its long-term performance quality. In contrast to field testing, laboratory tests are simpler to produce but less accurate. Destructive drilled samples are used to conduct field testing; however, they are limited in their ability to assess density information at specific areas. The use of computationally aided approaches, such as the Finite Element Method (FEM) and the Discrete Element Method (DEM), in research involving asphalt mixtures is increasing, since these methods simulate and evaluate the characteristics of asphalt mixtures at macroscopic and microscopic scales. Individual particle behavior at the microscopic level cannot be fully represented using the FEM alone, and the computing cost of utilizing the DEM approach alone is prohibitively high. The objective of this work is to simulate the pre-compaction process by using the coupled FEM-DEM approach. In order to investigate the impact of the asphalt mixtures’ gradation, a dense-graded asphalt mixture (AC 11) and a gap graded asphalt mixture (PA 11) were simulated. Different paving speeds (4, 5, and 6 m/min) were applied on the preliminary compaction model of AC 11 to study the effect of the paving speeds on the compaction process. By comparing the angular velocity, which worked as a reference of compaction quality, it was demonstrated that the grade AC 11 asphalt mixtures performed better in the preliminary compaction process compared to the grade PA 11 asphalt mixtures. Moreover, since it has an effect on compaction, paving speed was carefully monitored and kept within a reasonable range in order to maximize both pavement quality and project efficiency

Comparison of Mechanical Responses of Asphalt Mixtures under Uniform and Non-Uniform Loads Using Microscale Finite Element Simulation

Continuously increasing traffic volumes necessitate accurate design methods to ensure the optimal service life and efficient use of raw materials. Numerical simulations commonly pursue a simplified approach with homogeneous pavement materials and homogeneous loading. Neither the pavement geometry nor the loading is homogeneous in reality. In this study, the mechanical response of the asphalt mixtures due to homogeneous loads is compared with their mechanical response to inhomogeneous loads. A 3D finite element model was reconstructed with the aid of X-ray computed tomography. Sections of a real tire’s pressure distribution were used for the inhomogeneous loads. The evaluation of the material response analyzes the stress distribution within the samples. An inhomogeneous load evokes an increased proportion of high stresses within the sample in every case, particularly at low temperatures. When comparing the two types of loads, the average stresses on the interior (tension and compression) exhibit significant differences. The magnitude of the discrepancies shows that this approach yields results that differ significantly from the common practice of using homogeneous models and can be used to improve pavement design

The Mode of Promotion Industrial Targeted Poverty Alleviation through Land Circulation in Western Mountainous Region of China—A Case Study of Luquan Yi and Miao Autonomous County in Yunnan Province

In the industrial targeted poverty alleviation, land circulation is a key process. Based on the national strategy of targeted poverty alleviation, this paper combined the industrial development of targeted poverty alleviation with land circulation. According to the field survey on the current situation of land circulation and promotion of the industrial poverty alleviation in the typical project area of Zhongping Village in Zhongping Town and Jiaowuying Village in Jiulong Town in Luquan Yi and Miao Autonomous County in Yunnan Province, it summarized and analyzed the organization and operation mechanism, basic practices and main results of the land circulation and promotion of industrial poverty alleviation model in the typical project area of the county. It also summarized the innovation and successful experience of the model, and then came up with measures to further promote the implementation of the model, so as to provide necessary reference for the implementation of land circulation and industrial targeted poverty alleviation for the poverty-stricken counties in Yunnan Province and similar provinces (cities, regions)

Properties of flash roasted products from low-grade refractory iron tailings and improvement method for their magnetic separation index

The properties of flash-roasted products from low-grade refractory iron tailings (IGRIT) and the improved method for their magnetic separation index were investigated by the MLA, XRD, iron phase analysis, and magnetic separation test. The results show the siderite and hematite in the IGRIT have been converted to magnetic iron after the flash roasting treatment with a time of 3-5 s; magnetic iron in roasted products has a monomeric dissociation of 37.20%, and a 75−100% exposed area of contiguous bodies as rich intergrowth was 29.83%, and that a 32.97 poor intergrowth; moreover, magnetic iron is mainly associated with muscovite and quartz. It is also found that the regrindingmagnetic separation (1500 Oe) treatment of the middling was beneficial to obtain more qualified iron concentrate products. Therefore, roasted products magnetic separation process in the absence/ presence of the middling regrinding-magnetic separation treatment obtains an iron concentrate with 60.10%/ 60.12% iron grade and 72.04%/81.13% iron recovery. The iron concentrate from the magnetic separation process with middling regrinding-magnetic separation can have a 9% higher recovery than the process without middling regrinding-magnetic separation. The work is significant for helping to improve the utilization of IGRIT