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Freeze-thaw damage is one of the most serious issues that can affect pavement made of recycled concrete in cold places. The recycled concrete pavement freeze-thaw deterioration mechanism still needs to be fully understood. In this study, a number of different experimental investigations were conducted. on several concrete specimens that contained differing percentages of RCA replacements by volume (0%, 30%, 50%, 70%, and 100%, respectively). Several freeze-thaw cycles have been exposed to the concrete specimens. In order to assess the performance of the casted specimens, the mass loss, relative dynamic modulus of elasticity (RDME), and length change were estimated. The results demonstrate that the incorporation of recycled coarse aggregate significantly affects the performance of the specimens. Flexural strength tests have been used to evaluate the degree to which the specimens' mechanical properties have deteriorated. After being subjected to several freeze-thaw cycles. For all mixtures, the 28-day flexural strength values were calculated. The test result shows the flexural strength value of the specimens was inversely proportional to the replacement of RA. The flexural strengths of the specimens dropped as the number of RA increased. Furthermore, the specimens with more RA replacement have a greater drop in flexural strengths. Moreover, an analysis of the freeze-thaw cycle's process and its damage mechanism was revealed.

ObjectiveTo investigate the effect of transrectal multimodal ultrasound combined with serum prostate-specific antigen (PSA)-related indicators and machine learning for the diagnosis of clinically significant prostate cancer.MethodsBased on Gleason score of postoperative pathological results, the subjects were divided into clinically significant prostate cancer groups(GS>6)and non-clinically significant prostate cancer groups(GS ≤ 6). The independent risk factors were obtained by univariate logistic analysis. Artificial neural network (ANN), logistic regression (LR), support vector machine (SVM), decision tree (DT), random forest (RF), and K-nearest neighbor (KNN) machine learning models were combined with clinically significant prostate cancer risk factors to establish the machine learning model, calculate the model evaluation indicators, construct the receiver operating characteristic curve (ROC), and calculate the area under the curve (AUC).ResultsIndependent risk factor items (P< 0.05) were entered into the machine learning model. A comparison of the evaluation indicators of the model and the area under the ROC curve showed the ANN model to be best at predicting clinically significant prostate cancer, with a sensitivity of 80%, specificity of 88.6%, F1 score of 0.897, and the AUC was 0.855.ConclusionEstablishing a machine learning model by rectal multimodal ultrasound and combining it with PSA-related indicators has definite application value in predicting clinically significant prostate cancer.

Light activation is an effective method to improve sensor performance at room temperature (RT). This work realized the effective detection of trace-level NO

Inspired by the accuracy and efficiency of the $\gamma$ -norm of a matrix, which is closer to the original rank minimization problem than nuclear norm minimization (NNM), we generalize the $\gamma$ -norm of a matrix to tensors and propose a new tensor completion approach within the tensor singular value decomposition (t-svd) framework. An efficient algorithm, which combines the augmented Lagrange multiplier and closed-resolution of a cubic equation, was developed to solve the associated nonconvex tensor multi-rank minimization problem. Experimental results show that the proposed approach has an advantage over current state of the art algorithms in recovery accuracy.

Recently there has been a growing interest in short-range communication using audio channels for device pairing and as a self-jamming communication medium. Given that such channels are audible to participants they are considered more resistant to active attacks, i.e., the attack signal would be heard by the participants. In this paper, we investigate the validity of this assumption using two prominent acoustic self-jamming systems implementations. We show that basic overshadowing attacks are possible in these systems and that these attacks cannot be effectively detected by the participants if the attacker is close to the receiving device. Finally, we propose a novel physical-layer solution for effectively detecting overshadowing attacks, which can improve state-of-the-art acoustic self-jamming systems by ensuring channel integrity while not requiring fundamental modifications to these schemes.

Glazed hollow bead (GHB) is an innovative material that gives concrete very good thermal-insulation properties and improves concrete frost resistance, when used as a partial replacement of ordinary fine aggregate. The improvement in frost resistance under freeze-thaw cycles and the deterioration mechanisms of recycled aggregate thermoinsulating concretes (RATICs) is the objective of this study, after adding GHBs to the mix. Fifteen cubes and ninety prisms made of five RATIC mixes (GHB content = 0, 40, 65, 90 and 130 kg/m3) were tested in compression, to identify the optimum content of GHB. The degradation mechanisms of RATIC were identified based on mass loss, dynamic elastic modulus and uniaxial compressive strength. In addition, RATIC mesostructure was investigated by means of Computed Tomography Scanning, and the deterioration mechanisms by analyzing pore amount, average and maximum pore area and porosity. The experimental results demonstrate that adding glazed hollow beads to recycled aggregate concrete (RAC) moderately changes the mesostructure of the concrete, to the advantage of frost resistance, and that the optimum content of GHB is around 90 kg/m3.

Purpose This paper aims to predict the 28-day compressive strength of recycled thermal insulation concrete more accurately. Design/methodology/approach The initial weights and thresholds of BP neural network are improved by genetic algorithm on MATLAB 2014 a platform. Findings Genetic algorithm–back propagation (GA-BP) neural network is more stable. The generalization performance of the complex is better. Originality/value The GA-BP neural network based on the training sample data can better realize the strength prediction of recycled aggregate thermal insulation concrete and reduce the complex orthogonal experimental process. GA-BP neural network is more stable. The generalization performance of the complex is better.

Sensors in smart devices can help people in their lives. But data collected by these sensors can be sensitive and cause information leakage. In this paper, when inputting keystrokes on an ATM keyboard, we consider data from the accelerometer and microphone in mobile phone and smart watch concurrently. We extract features from this sensor data, show the nature of this data and analyzed the possibility of using this data to distinguish keystrokes. Furthermore, we launched a simple experiment, trained a set of classifiers to infer keystrokes using the time difference of arrival features. The result shows the potential and feasibility of using this data to perform side-channel attack and infer keystrokes on ATM keyboard.

Based on the research of mix ratio and mechanical properties of glazed hollow bead thermal insulation concrete (GIC), the quasi-static tests of six GIC frame columns and one normal concrete (NC) frame column are carried out. The stress of frame columns under earthquake is simulated by applying a constant vertical load and cyclic horizontal load, and the hysteresis behavior, skeleton curve, ductility coefficient, stiffness degradation, and energy dissipation capacity of frame columns are studied. Contrast variables include axial compression ratio, stirrup reinforcement ratio and concrete material. The results show that the seismic performance of GIC frame columns is similar to that of ordinary concrete frame columns and frame columns. The stiffness degradation rate and ductility of GIC column are higher than that of NC column with the same parameter; higher axial compression ratio can increase the initial stiffness of GIC and reduce ductility; higher reinforcement ratio can increase ductility, but can limit plastic hinge development and reduce energy dissipation capacity of GIC column. The results can provide theoretical basis for elastic-plastic analysis of GIC column under earthquake action.

The diffusion-based algorithm is a promising member of the family of recommendation algorithms. It makes recommendations through the diffusion process on user-object bipartite graphs. However, a user's taste is often influenced by his/her trusted friends in social networks. In this paper, we propose a new trust-based diffusion on tripartite graphs, which integrates explicit trust relations and implicit trust relations into the diffusion process. Explicit trust relations are obtained from the social networks while implicit trust relations are inferred from implicit feedback. The experimental results indicate that our proposed method has a remarkable improvement in accuracy, and even only implicit trust relations employed, that is, diffusion on user-object bipartite graphs, the recommendation accuracy is still enhanced. We further present a general framework of applying implicit trust relations and explicit trust relations into basic network-based diffusion method, which is more general and flexible, and specific parameters can be selected to meet actual requirements for different datasets and real-world online platforms.

Invasive species are a major driver of ecological and environmental changes that affect human health, food security, and natural biodiversity. The success and impact of biological invasions depend on adaptations to novel abiotic and biotic selective pressures. However, the molecular mechanisms underlying adaptations in invasive parasitic species are inadequately understood. Small hive beetles, Aethina tumida, are parasites of bee nests. Originally endemic to sub‐Saharan Africa, they are now found nearly globally. Here, we investigated the molecular bases of the adaptations to novel environments underlying their invasion routes. Genomes of historic and recent adults A. tumida from both the endemic and introduced ranges were compared. Analysis of gene–environment association identified 3049 candidate loci located in 874 genes. Functional annotation showed a significant bias toward genes linked to growth and reproduction. One of the genes from the apoptosis pathway encodes an “ecdysone‐related protein,” which is a crucial regulator in controlling body size in response to environmental cues for holometabolous insects during cell death and renewal. Genes whose proteins regulate organ size, ovary activation, and oviposition were also detected. Functions of these enriched pathways parallel behavioral differences between introduced and native A. tumida populations, which may reflect patterns of local adaptation. The results considerably improve our understanding of the underlying mechanisms and ecological factors driving adaptations of invasive species. Deep functional investigation of these identified loci will help clarify the mechanisms of local adaptation in A. tumida., Small hive beetles, Aethina tumida, invasive parasites of pollinating bees have recently invaded multiple continents, across a wide range of climates. The molecular mechanisms underlying the adaptation of this invasive beetle remain poorly understood. Here, the identification of genetic basis, analyses of gene ontology, and pathway enrichment of identified genes provide a mechanistic understanding of a biological invasion.

Two new nonenolides named Diaportheolide A ( 1 ) and B ( 2 ), were isolated from the endophytic fungus Diaporthe sp. SXZ-19 of Camptotheca acuminate . The chemical structures of 1 and 2 were elucidated by spectroscopic analyses, including 1D- and 2D-NMR experiments and HR-ESI-MS data analysis. Their in vitro antibacterial activities are established as insignificant.

RFID is widely used in many security sensitive areas. Researchers proposed many theoretical attacks and security implementation models on RFID devices. To test these theories and models is challenging and difficult task. In this paper, we use three common-off-the-shelf security testing platforms i.e. PN532, TI RF430CL330H and Chameleon Mini, to test the most widely used standards ISO14443A, ISO14443B and ISO18092. We present a detailed workflow of each platform. Furthermore, we highlight the advantages and disadvantages of each platform in regards fast implementation, delays and support for different types of RFIDs.

A new streptovaricin analogue, namely 3-desmethyl protostreptovaricin I (

A new ring-fused streptovaricin analogue, named ansavaricin J, was unprecedently isolated from the culture of the genetically modified strains ΔstvP5 which derived from Streptomyces spectabilis CCTCC M2017417. Its structure was elucidated via comprehensive spectroscopic analyses, including 1D- and 2D-NMR tests, and HR-ESI-MS data analysis. Notably, ansavaricin J and E represent the only two reported examples of heterocyclic ring-fused streptovaricins thus far, however, it only showed insignificant antibacterial activities against Staphylococcus aureus.

Additional file 2: Table S2. RNA-Seq results of S. hominis S34-1 wild-type versus S34-1Δ comparison

Additional file 1: Table S1. Bacteria isolated in this study

A new streptovaricin analogue, namely 3-desmethyl protostreptovaricin I (1), was isolated from the culture of the genetically engineered strain ΔstvM2 derived from Streptomyces spectabilis CCTCC M2017417. Its structure was elucidated on the basis of extensive spectroscopic analyses, including 1D and 2D NMR tests, and high resolution mass spectrometry analysis. Compound 1 is the first example of 3-desmethyl streptovaricin analogues reported so far, however, it showed no antibacterial activities against Staphylococcus aureus ATCC 29213.

Small hive beetles (SHB, Aethina tumida Murray, Coleoptera: Nitidulidae) are parasites of social bee colonies endemic to sub-Saharan Africa and have become an invasive species. Even though the global spread of SHB seems inevitable, the origin of novel introductions and their impact on new host populations need to be investigated to foster mitigation. Here, we report a case of SHBs from China and use COI gene sequencing to trace their origin. Since July 2018, beetle infestations of Eastern (Apis cerana) and Western (Apis mellifera) honey bee colonies with clinical symptoms were repeatedly reported from two Chinese provinces. These infestations apparently had a severe impact on A. cerana. Using morphometrics, genetics and clinical symptoms in the field, the beetles were confirmed to be A. tumida. The DNA sequences suggest an introduction from a yet unidentified African source similar to the Philippines, but very different to any other previously reported SHB haplotypes. The establishment of SHB in China underlines the need to limit novel introductions. Given that Eastern honey bees and possibly other Apis spp. are susceptible to SHB infestations, our findings highlight the need for adequate protection measures of endemic Asian honey bees.

In this study, expanded perlite filled with aerogel is used as a new material as the aggregate in concrete. Graded and non-graded expanded perlite filled with aerogel are added into concrete separately. The natural aggregate is partially replaced by the new material, and both the mechanical strength and the thermal conductivity of the concrete decreased when the new material’s content increased. When the aggregate content and the water-cement ratio are the same, the mechanical strength and the thermal conductivity of the non-graded material concrete is larger than for the graded material. The water-cement ratios of 0.5 and 0.7 are applied to explore the influence of the water-cement ratio on the properties of the new concrete material. The role of aerogel in complexes is analysed, and the results show that the concrete with a 100% volume content of graded expanded perlite filled with aerogel has a thermal conductivity of 0.098 W/(m K) and compressive strength of 3.71 MPa.

An experimental study on the durability of thermal insulation concrete with recycled aggregates (RATIC) subjected to the combined action of chloride salt erosion with 3.5% NaCl solution and freeze-thaw cycles (referred to as salty F-T cycles) has been carried out. In this study, the volume of the natural coarse aggregates has been replaced by recycled coarse aggregates (RCA) at replacement rates of 0%, 30%, 50%, 70%, and 100%. The results show that thermal insulation aggregate glazed hollow beads (GHBs) had a positive effect on the durability of concrete and RCA had an enormous negative influence on the durability of RATIC exposed to the salty F-T cycles. After 100 salty F-T cycles, the relative dynamic modulus of the elasticity of samples with RCA was below 60% compared to at the start of the F-T cycles. RCA has a significant effect on the chloride permeability of RATIC compared to natural aggregates. This phenomenon was caused by the special multi-interfaces structure of RATIC that are the result of the old interfacial translation zones (ITZs). These aggravate frost damage and negatively affect the durability of concrete in the salty F-T cycles environment.

In this work, the effect of physical properties of recycled coarse aggregate (RCA) on the workability and mechanical properties of recycled aggregate thermal insulation concrete (RATIC) was studied. Two kinds of RCAs from different concrete waste plants were studied and the density, water absorption and crushing index of RCAs were analyzed. Then, the workability and mechanical properties of RATIC having different gradations, original strength grades and degree of saturation of RCA were investigated. The results showed that the gradation and degree of saturation of RCA exhibited a significant influence on the workability and mechanical properties of RATIC. For the RATIC, the optimum A/B ratio was found to be 4/6. The original strength grade of RCA had little influence on the workability, though it exhibited a significant influence on the mechanical properties of RATIC.

The application of glazed hollow bead insulation concrete can improve the seismic performance of the structure, simultaneously ensuring characteristics such as structural durability, fire resistance, thermal insulation, antifreezing, and impermeability. However, with change in material’s physical and mechanical properties, the shear resistance of vitrified microbead thermal insulation concrete members should be paid attention to. The literature search reveals only a few studies on the shear resistance of glazed hollow bead insulation concrete members. In this study, 14 glazed hollow bead insulation concrete beams and four ordinary concrete beams with C35 strength grade were tested. The mechanical failure process, failure form, failure mechanism, and the difference between vitrified microbead insulated concrete beam and ordinary concrete beam were compared. The effects of shear span ratio, hoop ratio and reinforcement ratio on the cracking load, ultimate load and failure mode were investigated. Combined with the “truss-arch” model, the shear bearing capacity of steel bar and concrete is described, and after considering the softening coefficient of glass microbead insulation concrete, based on the “truss-arch” model, a formula for calculating the shear capacity of inclined section of vitrified microbead insulated concrete beam was obtained. The results show that the shear failure test results of glazed hollow bead insulation concrete beams are similar to those of ordinary concrete beams; the shear bearing capacity of vitrified microbeads thermal insulation concrete beams is ∼13% higher than that of ordinary concrete beams under the same conditions, and stiffness degradation is slow in the later stage. After the constitutive relation and softening coefficient are modified, the “truss-arch” calculation model can be used to calculate the shear capacity of vitrified microbead insulated concrete beams, and the results are in good agreement with the experimental results. The study of the shear behavior of glazed hollow bead insulation concrete beams can provide data and technical basis for engineering application and has important theoretical significance and practical value to further understand the characteristics of this type of concrete structure, guiding engineering design, and promoting engineering application.

Thermal insulation concrete (TIC) with glazed hollow beads (GHBs) is a new type of building materials meeting the needs of energy-saving building. The TIC is advantageous in applications due to its excellent bearing capacity and thermal insulation properties. This paper discusses the seismic performance of the shear wall with TIC. Based on the seismic tests of two specimens under low frequency cyclic horizontal loads with constant vertical actions, the hysteretic behavior, energy dissipation capacity, stiffness degradation and failure pattern of the shear wall were investigated. A finite element model was developed and nonlinear analyses were made to simulate the quasi-static test of the shear wall using ABAQUS software. Both modal and time-history analyses of a test building with TIC were also performed using SAP2000 software. The test results show that, compared with the normal concrete shear wall (SW), the shear wall with TIC (specimens named GSW) has better energy dissipation capacity and ductility, while the failure pattern is similar.

Corrosion of steel bars is one of the key factors undermining the stability of reinforced concrete structures. Internal defects of the recycled aggregates used in recycled aggregate concrete (RAC) decrease the durability of concrete structures, and may accelerate steel corrosion. The use of corrosion-resistant materials as substitutes for steel bars in RAC may solve this problem. Basalt fiber reinforced Polymer (BFRP) is a corrosion-resistant material. This study assessed the bonding properties between BFRP bars and RAC using pull-out tests. The following five factors were considered: RAC strength grade, the RAC cover thickness, bond anchorage length of BFRP bars, diameter of BFRP bars, and replacement rate of the recycled concrete aggregate (RCA). The effects of these factors on failure mode, bond strength, and the bond-slip curve were assessed. Finally, the bond-slip relationship between BFRP bars and RAC was established by improving the mBPE model, which can describe the bond behavior between BFRP bars and RAC with satisfactory accuracy.

The occurrence of fire often leads to the damage and deterioration of micro- and meso-structures of concrete materials, leading to the decomposition of hydrates, coarsening of porous structure, and thermal cracking induced by water vapor pressure, resulting in the decline of macro-physical and mechanical properties and durability. The meso-regulatory function of the lightweight, high-strength, internally porous and thermally stable glazed hollow beads (GHB) can improve the high-temperature resistance of concrete. In order to study the degradation characteristics of recycled aggregate concrete mixed with glazed hollow beads (RATIC), mechanical properties and internal meso-structural changes at high temperatures, the cube compressive strength test and CT test are carried. According to the improved image segmentation algorithm based on adaptive threshold and region growing methods, the influence of different recycled coarse aggregate (RCA) and GHB contents on the mesostructure of RATIC, such as thermal crack development and pore distribution, is systematically analyzed. Based on the self-compiled box dimension program, the corresponding relationship between compressive strength, fractal dimensions of mesostructure and temperature is obtained. The results reveal that the GHB can alleviate the stress concentration of coarse aggregates and cement paste caused by temperature expansion and deformation, provide a release channel for vapor pressure, alleviate cracks in the mortar area and pore boundaries, and slow down the spread of heat in the concrete. Overall, the GHB renders a positive effect on the heat-induced damage resistance of concrete.