Vanadium (V) pollution in groundwater has posed serious risks to the environment and public health. Anaerobic microbial reduction can achieve efficient and cost-effective remediation of V(V) ...pollution, but its interactions with coexisting common electron acceptors such as NO3−, Fe3+, SO42− and CO2 in groundwater remain unknown. In this study, the interactions between V(V) reduction and reduction of common electron acceptors were examined with revealing relevant microbial community and identifying dominant species. The results showed that the presence of NO3− slowed down the removal of V(V) in the early stage of the reaction but eventually led to a similar reduction efficiency (90.0% ± 0.4% in 72-h operation) to that in the reactor without NO3−. The addition of Fe3+, SO42−, or CO2 decreased the efficiency of V(V) reduction. Furthermore, the microbial reduction of these coexisting electron acceptors was also adversely affected by the presence of V(V). The addition of V(V) as well as the extra dose of Fe3+, SO42− and CO2 decreased microbial diversity and evenness, whereas the reactor supplied with NO3− showed the increased diversity. High-throughput 16S rRNA gene pyrosequencing analysis indicated the accumulation of Geobacter, Longilinea, Syntrophobacter, Spirochaeta and Anaerolinea, which might be responsible for the reduction of multiple electron acceptors. The findings of this study have demonstrated the feasibility of anaerobic bioremediation of V(V) and the possible influence of coexisting electron acceptors commonly found in groundwater.
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•Interaction of microbial V(V) reduction with other electron acceptors is studied.•NO3− slows V(V) reduction first but eventually has a minor effect.•Fe3+, SO42−, CO2 decreases V(V) reduction with different inhibition effects.•Geochemical reduction of these electron acceptors is adversely affected by V(V).•Microbial diversity, evenness and functional species are revealed.
The presence of multiple electron acceptors can reduce the efficiency of microbial reduction of Vanadium. The dominant species in microbial community have been identified.
Sonodynamic therapy （SDT） is an emerging approach that involves a combination of low-intensity ultrasound and specialized chemical agents known as sonosensitizers. Ultrasound can penetrate deeply ...into tissues and can be focused into a small region of a tumor to activate a sonosensitizer which offers the possibility of non-invasively eradicating solid tumors in a site-directed manner. In this article, we critically reviewed the currently accepted mechanisms of sonodynamic action and summarized the classification of sonosensitizers. At the same time, the breath of evidence from SDT-based studies suggests that SDT is promising for cancer treatment.
In modern astrophysics, machine learning has increasingly gained popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We describe ...an application of the supervised machine-learning algorithm, random forests (RF), to the star/galaxy/QSO classification and the stellar effective temperature regression based on the combination of Large Sky Area Multi-Object Fiber Spectroscopic Telescope and Sloan Digital Sky Survey spectroscopic data. This combination enables us to obtain reliable predictions with one of the largest training samples ever used. The training samples are built with a nine-color data set of about three million objects for the classification and a seven-color data set of over one million stars for the regression. The performance of the classification and regression is examined with validation and blind tests on the objects in the RAdial Velocity Extension, 6dFGS, UV-bright Quasar Survey and Apache Point Observatory Galactic Evolution Experiment surveys. We demonstrate that RF is an effective algorithm, with classification accuracies higher than 99% for stars and galaxies, and higher than 94% for QSOs. These accuracies are higher than machine-learning results in former studies. The total standard deviations of the regression are smaller than 200 K, which is similar to those of some spectrum-based methods. The machine-learning algorithm with the broad-band photometry provides us with a more efficient approach for dealing with massive amounts of astrophysical data than do traditional color cuts and spectral energy distribution fits.
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•MOFs possess unique chemical properties for fabricating biosensors.•MOFs are used as quenchers for fluorescence “turn-on” detecting biomolecules.•The fluorescence intensity of MOFs ...can be affected by surrounding target biomolecules.•Nanoscale MOFs are intrinsically biodegradable.•Nanoscale MOFs are used as contrast agents for MRI and CT imaging.
Metal–organic frameworks (MOFs) are a class of hybrid materials assembled from metal ion/cluster connecting points and organic bridging ligands. On the basis of their properties of structural flexibility, porosity, controllable synthesis and flexibility of the pore size/wall modification, MOFs have shown great potential applications in biological sensing and imaging applications. Compared with inorganic nanomaterials (e.g., graphene, graphene oxide, gold nanoparticles and MoS2), MOFs are potentially advantageous for biological applications owing to their intrinsic biodegradability and the ability to use biocompatible building blocks. Recently, many types of MOFs were applied for sensing DNA, RNA, enzyme activity and small-biomolecules, as well as for magnetic resonance imaging (MRI) and computed tomography (CT), which are useful techniques for clinical diagnosis. In this review, I aim to present the recent progress achieved in MOF research for biosensing and bioimaging. The compositional tenability of MOF imaging platforms should greatly facilitate their further development for clinical translation.
A grain-based model (GBM) is generally employed by many researchers to simulate the microcracking process of crystalline brittle rock by the distinct element method. In this study, a novel ...grain-based model (nGBM) in two-dimensional Particle Flow Code 5.0 (PFC2D 5.0) is proposed to emulate the brittle failure of crystalline rock. First, the nGBM scheme is introduced, in which the flat-joint model is employed to model the contacts in mineral grains and the smooth-joint model is assigned to the grain interface contacts. Then, compressive tests are performed using Alxa porphyritic granite, and the strength values are fitted with the Hoek-Brown failure criterion. Third, a nGBM was generated based on the petrographic texture of realistic rock, such as mineral constituents, grain size, and distribution. The input microscale parameters are carefully calibrated according the experimental results. Finally, this model is applied to study the microcracking process of Alxa porphyritic granite and the influence of spatial distribution of minerals. It is found that a relatively high ratio of uniaxial compressive strength to tensile strength of each mineral or synthetic samples can be reproduced by the nGBM. Moreover, the simulated results show this model can capture the nonlinear characteristic of the Hoek-Brown failure criterion. After modeling, numerous mineral grains were cut across, which is consistent with the actual experimental observation; the tensile crack is over the shear crack in the models, while the number of intra-grain shear crack increases dramatically with increasing confining pressure. In addition, the numerical results indicate that the effect of spatial distribution of minerals has limited influence on the evolution of microcracks but has great impact on microcrack distribution. In summary, the proposed nGBM in PFC2D can well reproduce the realistic failure process of granitic rocks under different loading conditions.
•We propose a novel grain-based model (nGBM) in PFC2D to emulate the brittle failure of crystalline rock;•Compressive tests are performed using Alxa porphyritic granite to calibrate the nGBM model;•The nGBM model well reproduce the failure process and microcracks distribution of granitic rocks under various conditions;•The proposed model not limited to simulate the failure process of granitic rock but the complex rock engineering.
The Fengcheng Formation in the Mahu Sag of the Junggar Basin is composed of a set of fine-grained sedimentary rocks located under a layer of alkaline lacustrine rocks. There are alternating dolomite ...lamina, siltstone and organic matter laminae that show strong heterogeneity. The lamina structure determines reservoir quality and oil-bearing potential in shales. Therefore, the identification of lamina structure is a crucial basis for identifying reserves of shale oil. Identified as massive, layered and laminated, three different types of lamina structures are divided according to core observations in terms of the density of the laminae and the overlapping relationships. High-resolution processing is also performed on dynamic image log data to form slab images for recognizing the various types of lamina structures. Compared to core slab photos, it is believed that slab images offer an excellent thin-layer resolution of up to a millimeter in scale and can effectively identify the lamina structure of the shale reservoir. There are no evident beddings on the core of the massive pattern, and the slab image shows a bright or dark block pattern. There are centimeter-level felsic bands of fine silt sand on the thin-layered sedimentary fabric core, and the slice image shows a band-like pattern. A large number of millimeter-level dolomitic laminae are enriched on the core of the laminated type, and the slab image shows millimeter-level light and dark lamina. Slab images were used for the division and identification of lamina structures in a single well. Then, the relationships between the three types of lamina structures and the two-dimensional nuclear magnetic resonance logs and oil test data were recorded. The results show that massive and laminated pores are dominated by intergranular pores with low porosity and movable oil content. Therefore, only low oil flow can be obtained during an oil test. However, the layered type due to centimeter-level silty bands, T1 and T2, is bimodal with high porosity, movable oil content, and high levels of hydrocarbon production. Therefore, the optimal areas of shale reservoirs are closely related to the layered type. The more significant the proportion of layered types in shale reservoirs, the higher the quality of the reservoir. The present study is intended to identify lamina structure-controlled reservoir quality and oil accumulation and to provide insights into the exploration and development of shale oil.
•Three types of multi-scale lamina structure are divided.•The continuous multi-scale lamina structure type is recognized by slab images.•Relationship between lamina structure and reservoir quality are unraveled.
Recently, the rapid emergence of antibiotic-resistant pathogens has caused a serious health problem. Scientists respond to the threat by developing new antimicrobial materials to prevent or control ...infections caused by these pathogens. Polymer-based nanocomposite hydrogels are versatile materials as an alternative to conventional antimicrobial agents. Cross-linking of polymeric materials by metal ions or the combination of polymeric hydrogels with nanoparticles (metals and metal oxide) is a simple and effective approach for obtaining a multicomponent system with diverse functionalities. Several metals and metal oxides such as silver (Ag), gold (Au), zinc oxide (ZnO), copper oxide (CuO), titanium dioxide (TiO₂) and magnesium oxide (MgO) have been loaded into hydrogels for antimicrobial applications. The incorporation of metals and metal oxide nanoparticles into hydrogels not only enhances the antimicrobial activity of hydrogels, but also improve their mechanical characteristics. Herein, we summarize recent advances in hydrogels containing metal ions, metals and metal oxide nanoparticles with potential antimicrobial properties.
Network slicing in 5G is a solution to accommodate a wide range of services. It also enables the network operators to establish multiple end-to-end (e2e) logically isolated and customized networks ...with shared or dedicated resources over the same infrastructure. Although, many tools and platforms have been developed to accomplish the management and orchestration (MANO) of e2e network slicing automatically, it is still challenging. Each of these platforms requires expertise and manual effort to define the requirements for the provisioning of the resources. The other issue is the generation of well-defined network slice configurations with lifecycle parameters. To this end, this paper proposes an efficient solution that automates the configuration process and performs the management and orchestration of network slices. This solution contains a one-touch Intent-based Networking (IBN) platform that effectively orchestrates and manages the lifecycle of multi-domain slice resources. IBN automates the process of slice configuration generation, service provisioning, service update, and service assurance by eliminating experts and manual effort. Furthermore, it has an intelligent Deep Learning (DL) based resource update and assurance mechanism which handles the run-time resource scalability and assurance.
Abstract
The occurrence of X-class solar flares and their potential impact on space weather often receive greater attention than other flares. But predicting when and where an X-class flare will ...occur is still a challenge. With the multiwavelength observation from the Solar Dynamics Observatory and FengYun-3E satellite, we investigate the triggering of a GOES X1.0 flare occurring in the NOAA active region (AR) 12887. Our results show that this unique X-class flare is bred in a relatively small but complex quadrupolar AR. Before the X-class flare, two filaments (F1 and F2) exist below a null-point topology of the quadrupolar AR. Magnetic field extrapolation and observation reveal that F1 and F2 correspond to two magnetic flux ropes with the same chirality and that their adjacent feet are respectively rooted at nonconjugated opposite polarities. Interestingly, these two polarities collide rapidly, accompanied by photospheric magnetic flux emergence, cancellation, and shear motion in the AR center. Above this site, F1 and F2 subsequently intersect with each other and merge into a longer filament (F3) via a tether-cutting-like reconnection process. As a result, F3 rises and erupts upward, eventually leading to a coronal mass ejection and the X-class flare. This observation suggests that the rapid collision of nonconjugated opposite polarities provides a key condition for the triggering of this X-class flare and also provides a featured case for a flare trigger mechanism and space weather forecasting.
We integrate textural and in situ compositional information from plagioclase and clinopyroxene (Cpx) phenocrysts together with groundmass compositions in early Cretaceous andesite dykes within the ...Sulu belt of China to propose a new petrogenetic model for andesite. Plagioclase phenocrysts are mostly andesine; they are depleted in high field strength elements (HFSE). However, Cpx phenocrysts are either reversely zoned (type I) or homogeneous (type II), with the zoned Cpx divided into subtypes IA and IB. All Cpx has high Mg#, low Na2O and generally low Al2O3, with depletions in HFSE and variably high 87Sr/86Sr ratios, suggesting crystallization above the Moho from magmas derived from enriched lithospheric mantle. The cores of type IA/IB and type II Cpx have normal major‐ and trace‐element compositional variations and similar 87Sr/86Sr ratios to each other and to plagioclase, consistent with fractional crystallization from a common magma (magma 1). The rims of type IA and IB Cpx also have normal major‐ and trace‐element compositional variations, but these are not as evolved as the cores, and the rims have lower 87Sr/86Sr ratios, demonstrating crystallization from an isotopically distinct magma (magma 2). Based on modeled major and rare earth element compositions of magmas inferred to have been in equilibrium with different Cpx (±plagioclase) domains, the measured groundmass compositions can be reproduced by variable mixing between the two magmas. Our study demonstrates for the first time that andesite magma can be made through fractionation and shallow hybridization of magmas derived from variably enriched lithospheric mantle.
Plain Language Summary
Andesite is the characteristic volcanic rock that is formed where Earth's tectonic plates are thrust one under another, as occurs along the Andes, the Cordillera of Central and North America, and the western margin of the Pacific Ocean, but how the magmas form remains controversial. In the mantle model, an enriched source is thought to form by reaction between mantle peridotite and metamorphic fluids derived from seafloor sediments and/or altered oceanic lithosphere during under‐thrusting of an ocean plate beneath a continental margin. By contrast, the shallow model proposes that andesite magmas are formed by differentiation of basaltic magmas or mixing of magmas from mantle and crustal sources in the lithosphere of an overriding continental plate. In either case, the composition of the magma may evolve due to crystal fractionation or be modified by crustal assimilation. Here, we use petrographic observations and in situ major‐ and trace‐element, and Sr isotope compositions of plagioclase and clinopyroxene phenocrysts and groundmass in early Cretaceous andesite dykes from the Sulu belt of China, to show for the first time that andesite can be made through fractionation and shallow hybridization of two different magmas derived from variably enriched lithospheric mantle of the underlying continental plate.
Key Points
Using compositions of plagioclase/clinopyroxene phenocrysts and the groundmass in andesite we develop a new model of andesite petrogenesis
This model requires polybaric crystallization and hybridization between 2 enriched lithospheric mantle‐derived magmas at crustal depth
We demonstrate that andesite of similar composition to continental crust can be made through mixing magmas derived from the enriched subcontinental lithospheric mantle
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