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Hydrogenated metal borides have attracted much attention due to their potential high-temperature superconductivity. Here, we propose a new strategy for hydrogen intercalation tuning the stability and superconductivity of the boron honeycomb sublattice, and predict an unprecedented layered compound Na2B2H, which hosts excellent superconductivity. Strikingly, the superconducting transition temperature (Tc) of Na2B2H reaches 42 K at ambient pressure. The Tc value can be further increase to 63 K under 5% biaxial tensile strain. The excellent superconductivity originates from the strong electron-phonon coupling between the σ-bonding bands near the Fermi level and the B-B stretching optical E′ modes. The interstitial electron localization and crystal orbitals of the H-intercalated Na ion layer well match the boron honeycomb lattice and act as a chemical template to stabilize the B layer. Furthermore, the introduction of hydrogen tuned the Fermi level, and the coupling vibration of Na and H ions effectively enhanced the dynamic stability of the structure. Na2B2H represents a new family of layered high-temperature superconductors, and the strategy of stabilizing the honeycomb boron sublattice via chemical template hosts great potential for application to more layered compounds. [ABSTRACT FROM AUTHOR]

Abstract:Quantitative evaluations are of great importance in network security decision-making.In recent years,moving target defense (MTD) has appeared to be a promising defense approach that blocks asymmetrical advantage of attackers and favors the defender-notwithstanding,it has a limited deployment due to its uncertain efficiency and effectiveness in defense.In that case,quantitative metrics and evaluations of MTD are essential to prove its capability and impulse its further research.This article presents a comprehensive survey on state-of-the-art quantitative evaluations.First,taxonomy of MTD techniques is stated according to the software stack model.Then,a concrete review and comparison on existing quantitative evaluations of MTD is presented.Finally,notice-worthy open issues regarding this topic are proposed along with the conclusions of previous studies.

Biochar has gained significant attention in agricultural and environmental research over the last two decades. This comprehensive review evaluates the effects of biochar on soil organic carbon (SOC), emission of non-CO2 greenhouse gases, and crop yield, including related mechanisms and major influencing factors. The impacts of biochar on SOC, methane and nitrous oxide emissions, and crop yield are controlled by biochar and soil properties and management practices. High-temperature biochar produced from lignin-rich feedstocks may decrease methane and nitrous oxide emissions in acidic soils and strengthen long-term carbon sequestration due to its stable aromatic structure. In contrast, low-temperature biochar from manure may increase crop yield in low-fertility soils. Applying biochar to farmlands in China can increase SOC content by 1.9 Pg C and reduce methane and nitrous oxide emissions by 25 and 20 Mt CO2-eq year−1, respectively, while increasing crop yields by 19%. Despite the increasing evidence of the positive effects of biochar, future research needs to explore the potential factors that could weaken or hinder its capacity to address climate change and secure crop production. We conclude that biochar is not a universal solution for global cropland; however, targeted applications in fields, landscapes, or regional scales, especially in low fertility and sandy soils, could realize the benefits of biochar as a climate-smart measure. Highlights The findings of research on biochar's effects on soil C sequestration, GHG mitigation, and crop production were summarized. The factors influencing the impact of biochar on soil functioning were reviewed. The effects of biochar on soil C sequestration and GHG mitigation in farmlands of China were quantified. [ABSTRACT FROM AUTHOR]

A fuzzy PI controller was utilized to realize the modal matching between a driving and detecting model. A simulation model was built to study electrostatic decoupling controlling technology. The simulation results show that the modal matching can be gained by the fuzzy PI controller. The frequency difference between the driving mode and the detection mode is less than 1 Hz, and the offset of the input DC is smaller than 0.6 V. The optimal proportionality factor and integral coefficient are 1.5 and 20, respectively. The fuzzy PI controlling technology provides a good way for the parameter optimization to gain modal matching of micro gyro, via which the detecting accuracy and stability can be improved greatly. [ABSTRACT FROM AUTHOR]

Existing studies suggest that biochar application can reduce soil nitrous oxide (N2O) emissions, mainly based on short‐term results. However, it remains unclear what the effects (i.e., legacy effects) and underlying mechanisms are on N2O emissions after many years of a single application of biochar. Here, we collected intact soil columns from plots without and with biochar application in a subtropical tea plantation 7 years ago for an incubation experiment. We used the N2O isotopocule analysis combined with ammonia oxidizer‐specific inhibitors and molecular biology approaches to investigate how the legacy effect of biochar affected soil N2O emissions. Results showed that the soil in the presence of biochar had lower N2O emissions than the control albeit statistically insignificant. The legacy effect of biochar in decreasing N2O emissions may be attributed to the reduced effectiveness of the soil substrate, nitrification and denitrification activities, and the promotion of the further reduction of N2O. The legacy effect of biochar reduced the relative contribution of nitrifier denitrification/bacterial denitrification, nitrification‐related N2O production, and the relative abundance of several microorganisms involved in the nitrogen cycle. Our global meta‐analysis also showed that the reduction of N2O by biochar increased with increasing application rate but diminished and possibly even reversed with increasing experimental time. In conclusion, our findings suggest that the abatement capacity of biochar on soil N2O emissions may weaken over time after biochar application, but this remains under further investigation. [ABSTRACT FROM AUTHOR]

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 pathological retinal angiogenesis often causes blindness. Current anti‐angiogenic therapy for proliferative retinopathy targets the vascular endothelial growth factor (VEGF), but many patients do not radically benefit from this therapy. Herein, we report that circulating prostaglandin (PG) F2α metabolites were increased in type 2 diabetic patients with proliferative retinopathy, and the PGF2α receptor (Ptgfr) was upregulated in retinal endothelial cells (ECs) from a mouse model of oxygen‐induced retinopathy (OIR). Further, disruption of the PTGFR receptor in ECs attenuated OIR in mice. PGF2α promoted the proliferation and tube formation of human retinal microvascular endothelial cells (HRMECs) via the release of ELR+ CXC chemokines, such as CXCL8 and CXCL2. Mechanistically, the PGF2α/PTGFR axis potentiated ELR+ CXC chemokine expression in HRMECs through the Gq/CAMK2G/p38/ELK‐1/FOS pathway. Upregulated FOS‐mediated ELR+ CXC chemokine expression was observed in retinal ECs from PDR patients. Moreover, treatment with PTGFR inhibitor lessened the development of OIR in mice in a CXCR2‐dependent manner. Therefore, inhibition of PTGFR may represent a new avenue for the treatment of retinal neovascularization, particularly in PDR. Synopsis: The pathological retinal angiogenesis often causes blindness. Here we showed that PGF2α/PTGFR axis promotes to oxygen‐induced retinopathy (OIR) in mice, and PTGFR receptor may represent a novel therapeutic target for pathological retinal neovascularization, particularly for proliferative diabetic retinopathy (PDR). PGF2α/PTGFR signaling is upregulated in retina tissues from OIR mice and patients with PDR.PTGFR deletion specifically in endothelial cells markedly attenuates OIR in mice.PGF2α promotes proliferation and cord formation of human retinal microvascular endothelial cells (HRMECs) via release of ELR+ CXC chemokines.PGF2α/PTGFR axis potentiates ELR+ CXC chemokine expression in HRMECs through the Gq/CAMK2G/p38/ELK‐1/FOS pathway. [ABSTRACT FROM AUTHOR]

Brown adipose tissue (BAT) functions as a thermogenic organ and is negatively associated with cardiometabolic diseases. N6‐methyladenosine (m6A) modulation regulates the fate of stem cells. Here, we show that the prostaglandin E2 (PGE2)–E‐prostanoid receptor 3 (EP3) axis was activated during mouse interscapular BAT development. Disruption of EP3 impaired the browning process during adipocyte differentiation from pre‐adipocytes. Brown adipocyte‐specific depletion of EP3 compromised interscapular BAT formation and aggravated high‐fat diet‐induced obesity and insulin resistance in vivo. Mechanistically, activation of EP3 stabilized the Zfp410 mRNA via WTAP‐mediated m6A modification, while knockdown of Zfp410 abolished the EP3‐induced enhancement of brown adipogenesis. EP3 prevented ubiquitin‐mediated degradation of WTAP by eliminating PKA‐mediated ERK1/2 inhibition during brown adipocyte differentiation. Ablation of WTAP in brown adipocytes abrogated the protective effect of EP3 overexpression in high‐fat diet‐fed mice. Inhibition of EP3 also retarded human embryonic stem cell differentiation into mature brown adipocytes by reducing the WTAP levels. Thus, a conserved PGE2‐EP3 axis promotes BAT development by stabilizing WTAP/Zfp410 signaling in a PKA/ERK1/2‐dependent manner. Synopsis: Development of brown adipose tissue (BAT) is tightly regulated by transcriptional and epigenetic reprogramming, but its upstream regulation remains poorly understood. Here, prostaglandin receptor signalling is shown to be a key promoter of brown adipogenesis enhancing expression of thermogenic gene programs. The PGE2/EP3 axis is activated during the development of interscapular BAT in mice.BAT‐specific depletion of EP3 results in adipocyte whitening and aggravated diet‐induced obesity.Loss of EP3 accelerates ubiquitin‐mediated degradation of N6‐methyladenosine methyltransferase WTAP, decreasing m6A‐dependent mRNA stability of brown gene transcription factor Zfp410.EP3 receptor‐mediated control of brown adipogenesis is conserved in human embryonic stem cell differentiation. [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]

Background and Purpose: An appropriate inflammatory response is necessary for cardiac healing after acute myocardial infarction (MI). Resolvin E1 (RvE1) is an anti-inflammatory and pro-resolution lipid mediator derived from eicosapentaenoic acid. Here we have investigated the effects of RvE1 on the recovery of cardiac function after MI in mice.Experimental Approach: Acute MI was induced by surgical ligation of the left anterior descending artery in male C57BL/6 mice. RvE1 (5 ng·g-1 ·day-1 ; i.p.) was given to mice at different times following MI. Cardiac function was monitored by transthoracic echocardiography at days 3, 7 and 14 after MI. Effects of RvE1 on the migration of subpopulations of monocytes/macrophages (Mos/Mps, Ly6Chi and Ly6Clow ) were examined by flow cytometry and transwell assay.Key Results: RvE1 administration from days 1 to 7 post-MI improved cardiac function, whereas treatment from days 7 to 14 markedly inhibited recovery of cardiac function. Early treatment with RvE1 post-MI suppressed the infiltration of dominant Ly6Chi Mos/Mps and secretion of pro-inflammatory cytokines in injured hearts, which protected cardiomyocytes against apoptosis in the peri-infarct zones. Contrastingly, treatment with RvE1 1 week after MI decreased infiltration of Ly6Clow Mos/Mps and expression of pro-angiogenic factors in cardiac tissue, consequently reducing neovascularization in the peri-infarct zones. Additionally, RvE1 inhibited Mp migration by activating ChemR23 receptors.Conclusion and Implications: Treatment with RvE1 during the initial 7 days after MI facilitated cardiac healing by suppressing pro-inflammatory cytokine secretion, indicating that RvE1 may serve as an early therapeutic agent for acute MI.Linked Articles: This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc. [ABSTRACT FROM AUTHOR]

Based on the electrohydrodynamic (EHD) theory, a novel method of near-field electrospray is proposed to fabricate micropatterns with micro/nano-scale particles. Compared with conventional electrospray technology, the deposition area can be decreased to print a regular pattern according to the moving trajectory of the substrate by shortening the distance between the nozzle and the collector to several millimeters in near-field electrospray. The controlling strategies in the near-field electrospray deposition process were investigated. The line width of printed pattern increased with the increase of applied voltage, deposition time, and flow rate of solution. However, it decreased with the increase of motion velocity of the substrate. By applying a suitable matching of electrospray parameters, the regular patterns with a line width under 500 μm were printed controllably on the substrate. Thereby, atomized particles from near-field electrospray were successfully deposited in specific patterns. Characters of '2', '7', and '9' with uniform width and steady shape were patterned. This work provides an excellent way to promote the precision integrated manufacturing of electronic system. [ABSTRACT FROM AUTHOR]

Electrospray is a simple and cost-effective method to fabricate micro-structured thin films. This work investigates the electrospray process of ZnO patterns. The effects of experimental parameters on jet characteristics and electrosprayed patterns are studied. The length of stable jets increases with increasing applied voltage and flow rate, and decreases with increasing nozzle-to-substrate distance, while electrospray angles exhibit an opposite trend with respect to the stable jet lengths. The diameter of electrosprayed particles decreases with increasing applied voltage, and increases with flow rate. Furthermore, an alcohol gas sensor is presented. The ZnAc is calcined into ZnO, which reveals good repeatability and stability of response in target gas. The sensing response, defined as the resistance ratio of R0/Rg, where R0 and Rg are resistance of ZnO in air and alcohol gas, increases with the concentration of alcohol vapors and electrospray deposition time. [ABSTRACT FROM AUTHOR]

A continuous near-field electrospray process has been developed to deposit micropatterns. Different from traditional electrospray technologies, the nozzle-to-substrate distance was shortened to less than 5 mm, and a glass capillary nozzle with a diameter of tens of microns was used. Steady and continuous ejection was achieved, and patterns with line widths of sub-100 μm were generated. The influence of experimental parameters was investigated. The critical voltage for electrospray increased with nozzle-to-substrate distance and flow rate. The line width of electrosprayed patterns increased with the increases in applied voltage, flow rate, nozzle diameter, and deposition time. This work provides a simple and potential route for on-demand deposition of micro-/nano-patterns in the electrospray process. [ABSTRACT FROM AUTHOR]

Running MapReduce programs in the cloud introduces this unique problem: how to optimize resource provisioning to minimize the monetary cost or job finish time for a specific job? We study the whole process of MapReduce processing and build up a cost function that explicitly models the relationship among the time cost, the amount of input data, the available system resources (Map and Reduce slots), and the complexity of the Reduce function for the target MapReduce job. The model parameters can be learned from test runs. Based on this cost function, we can solve a number of decision problems, such as the optimal amount of resources that can minimize monetary cost within a job finish deadline, minimize time cost under a certain monetary budget, or find the optimal tradeoffs between time and monetary costs. Experimental results show that the proposed approach performs well on a number of sample MapReduce programs in both the in-house cluster and Amazon EC2. We also conducted a variance analysis on different components of the MapReduce workflow to show the possible sources of modeling error. Our optimization results show that with the proposed approach we can save a significant amount of time and money, compared to randomly selected settings. [ABSTRACT FROM AUTHOR]

With the wide deployment of public cloud computing infrastructures, using clouds to host data query services has become an appealing solution for the advantages on scalability and cost-saving. However, some data might be sensitive that the data owner does not want to move to the cloud unless the data confidentiality and query privacy are guaranteed. On the other hand, a secured query service should still provide efficient query processing and significantly reduce the in-house workload to fully realize the benefits of cloud computing. We propose the random space perturbation (RASP) data perturbation method to provide secure and efficient range query and kNN query services for protected data in the cloud. The RASP data perturbation method combines order preserving encryption, dimensionality expansion, random noise injection, and random projection, to provide strong resilience to attacks on the perturbed data and queries. It also preserves multidimensional ranges, which allows existing indexing techniques to be applied to speedup range query processing. The kNN-R algorithm is designed to work with the RASP range query algorithm to process the kNN queries. We have carefully analyzed the attacks on data and queries under a precisely defined threat model and realistic security assumptions. Extensive experiments have been conducted to show the advantages of this approach on efficiency and security. [ABSTRACT FROM AUTHOR]

The stable and continuous ejection of multiple jets with high densities is the key to the application of electrospinning technology. An arced multi-nozzle spinneret was designed to increase the production efficiency of electrospinning. The distribution of the electrical field was simulated to optimize the nozzles' distribution of the spinneret. When the nozzles were arranged in an arc array, a relatively uniform electrical field could be obtained, which was beneficial for the weakening of electrical interference among the nozzles. Under the optimized electrical field, multiple jets from each nozzle could be ejected in a stable and continuous way. With the increase of the applied voltage, the electrical stretching force became larger, and there were fewer bonding structures. The average diameter of the electrospun nanofibers decreased with the increase of the applied voltage. When the distance between the inner nozzle and the collector increased, the charged jets suffered a larger stretching effect, resulting in the decrease of the average diameter of the electrospun nanofibers. The electrospinning current increased with the applied voltage and decreased with the distance between the inner nozzle and the collector, which is an important aspect for the monitoring of electrospinning jets. This work provides an effective way to promote the production efficiency of electrospun nanofibrous membranes. [ABSTRACT FROM AUTHOR]

The micro/nano current is an important characteristic to reflect the electrohydrodynamic direct-writing (EDW) process. In this paper, a direct-written current measurement system with a high signal to noise ratio was proposed to monitor the charged jets, providing the data basis for the promotion of stability and precision of the EDW jet. The electrical characteristics of the printing process were studied, the electrohydrodynamic direct-written current was associated with the stability of charged jet and the accuracy of direct-written patterns. There was an impulse current when the front end of the jet reached the collector and then a stable jet could be gained. With the increase of applied voltage, the severe fluctuation of measured current increased, the charged jet became more unstable and the accuracy of direct-written parallel lines was lower. The effects of processing parameters on direct-written current were also investigated. The average direct-written current at the stable stage increased as the applied voltage and polymer concentration increased, and it decreased as the distance from the nozzle to the collector increased. This research will promote the development and applications of EDW technology in the fields of micro/nano manufacturing. [ABSTRACT FROM AUTHOR]

Recycling and remanufacturing of end-of-life products are value-added processes and have great environmental benefits. Although comparative analyses of manufacturing and remanufacturing of these products are common, only a few are based on a quantitative model that comprehensively evaluates the environmental benefits of remanufacturing under quality uncertainty and explore how the environmental benefits will be affected by the fluctuations in the quality coefficient. This study has developed a complex quality coefficient measurement method to describe the quality uncertainty in returned items. Followed by real-life data analysis and validated by numerical experiments, this study comparatively analyzes the carbon emissions between whole machine remanufacturing and cannibalization and between component remanufacturing and recycling. It also investigates the internal relationship between the quality condition and environmental benefits of the remanufacturing system. The results show that the reductions in carbon emissions increase with rising complex quality coefficient but its marginal increase rate decreases rapidly. The model provides a guideline for the government to implement environmental regulations and a reference for firms to effectively fulfill their environmental responsibility. [ABSTRACT FROM AUTHOR]