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Misuse and overuse of antibiotics have contributed to the rise of antimicrobial resistance as one of the top public health threats. Antibiotics and antibiotic resistance genes (ARGs) are prevalent in agricultural soils due to the widespread application of livestock and organic wastes. However, information about the occurrence, distribution, and risk of antibiotics and ARGs in agricultural soils is lacking for many scenarios. In this study, based on 2225 observations from 135 independent studies, we summarized the concentration or abundance of antibiotics or ARGs under different fertilizer sources and land-use patterns, analyzed the contributions of key environmental factors to the occurrence of antibiotics and ARGs in agricultural soils, and highlighted the potential ecological risk of typical antibiotics and the relationship between ARGs and mobile genetic elements (MGEs). Our results showed that cattle manure, chicken manure, swine manure, and sewage sludge were the primary pollution sources of antibiotics and ARGs in agricultural soils, and sulfonamides, tetracyclines, fluoroquinolones, and their corresponding ARGs were the main pollution types. Land-use type, soil, and climatic factors affected antibiotics concentration and ARG abundances. MGEs play a vital role in promoting the dissemination of ARGs, especially the sul1 gene is closely related to intI1. In conclusion, our findings and future research exploring these topics will contribute to better management of antibiotic and ARG contamination in agricultural soils and their risk to human health. [ABSTRACT FROM AUTHOR]

Terahertz modulators possess fascinating physical properties, which is widely used in medical imaging, signal communication and security detection. However, the highprecision control and frequency shift of terahertz wave is still limited in the application field of terahertz devices. Here we propose a metasurface with a cube structure, and the control and frequency shift of terahertz wave are realized by the increase of relative dielectric constant and thickness of the cube structure. The results show that the terahertz frequency response peak of metasurface structure is red shifted, when the dielectric constant of cube structure is increased from 6 to 12.94. Meanwhile, the thickness of the cube structure has an effect on the red shift of the reflection frequency of the terahertz superstructure. When the thickness of the surface material is increased from 1 μm to 3 μm. the reflectance coefficient peak of super surface structure is blue shifted from 11.2 THz to 11.6 THz. This method may be used in advanced applications that need to control electromagnetic waves, such as perfect absorber and smart sensor components. [ABSTRACT FROM AUTHOR]

The effective parameters of artificial medium are designed to realize the perfect absorption of terahertz wave (THz), which has become one of the significant issues related to metamaterial. However, the planar structure of metamaterial has many limitations. Here, we establish a three-dimensional structure of split ring resonators (SRRs) to realize the vertically coupling SRRs and study its absorption characteristics. The results show that the absorption characteristics of three-dimensional split ring resonators have achieved 99.9% at 1.79 THz. Furthermore, by changing direction of the splits of two rings, we can get broadband absorption of more than 99% in the frequency range of 0.6 THz, which provides a design scheme for three-dimensional metamaterials and potential devices. [ABSTRACT FROM AUTHOR]

The phase transformation mechanism and transformation path of Cu-Ni alloys is very important to study for their applications in excellent electrical properties and chemical catalysis. In this paper, the effect of compressive strain on the transformation path and mechanism of Cu1Ni3 alloy is studied by molecular dynamics simulations. The simulation results reveal that the transformation path of alloys is from Fcc-Bcc-Hcp phase to other phase (amorphous state). The simulations not only revealed the processes of atomic displacements and pair correlation function during the transformation, but also elucidated the underlying mechanism of the transformation at the atomic level. The mechanism of phase transformation could be the lattice reconstruction caused by lattice sliding and stretching. The simulation results provide a clear landscape on the transformation mechanism, facilitating our comprehensive understanding on the phase transition in the Cu-Ni system. [ABSTRACT FROM AUTHOR]