Search

As the inevitable mode of the future intelligent transportation system, VANET still exists vehicle access authentication computational overhead, handover authentication inefficiency in the context of continuous development, simply using the traditional VANET architecture has been unable to adapt to the new complexity. Therefore, a hybrid blockchain-based privacy-preserving authentication scheme is proposed. Instead of using a single chain, the scheme combines the consortium and private chains, retaining the decentralization and high security of the consortium chain while leveraging the advantages of faster transactions, lower costs, and higher privacy in the private chain. Importantly, short signature technology and homomorphic encryption technology are proposed to further improve the efficiency of entity communication and protect the delivery of private data, respectively, while pre-authentication mechanism is used to further accelerate the cross-domain authentication of vehicles. The security analysis demonstrates the good privacy protection and attack resistance of this scheme. In addition, performance simulations and evaluations show that the proposed scheme requires the least computational and communication overhead compared to other schemes. It also performs better in terms of authentication delay and packet loss rate. Finally, the availability of the proposed scheme is explained through throughput and transaction cost analysis.

Previous studies have rarely investigated stochastic robustness of flexible cable dome structures under impact loads. In this study, the dynamic responses and failure modes of a Geiger cable dome structure were analysed under impact loads. The number of components damaged by impact and the loss of internal force in components were used to establish a structural damage index and an equation of failure mode control. Following this, by establishing the impact resistance failure limit state equation and combining the probabilistic and statistical characteristics of each design parameter of the structure, the probability of disproportionate failure of the structure undergoing disproportional damage under the impact load was calculated. Then, the stochastic robustness index Irobbased on the probability of structural failure was proposed, and the key factors affecting the structural robustness were analysed through parameter analysis. The research results indicated the following. First, cable dome structures exhibited three types of failure modes under impact loads. Second, the stochastic robustness index fully reflected the probability of a cable dome structure sustaining disproportional damage under impact loads. Increasing the mass or speed of the impactor both increased the probability of the structure sustaining disproportional damage. An impact occurred closer to the centre of the structure, both the probability of overall structural failure and structural robustness performance increase, but the probability of the structure sustaining disproportional damage decreases. Third, increasing the prestress and cross-sectional area of the components might increase their impact resistance and structural robustness performance.

Hot-carrier transistors are a class of devices that leverage the excess kinetic energy of carriers. Unlike regular transistors, which rely on steady-state carrier transport, hot-carrier transistors modulate carriers to high-energy states, resulting in enhanced device speed and functionality. These characteristics are essential for applications that demand rapid switching and high-frequency operations, such as advanced telecommunications and cutting-edge computing technologies1–5. However, the traditional mechanisms of hot-carrier generation are either carrier injection6–11or acceleration12,13, which limit device performance in terms of power consumption and negative differential resistance14–17. Mixed-dimensional devices, which combine bulk and low-dimensional materials, can offer different mechanisms for hot-carrier generation by leveraging the diverse potential barriers formed by energy-band combinations18–21. Here we report a hot-emitter transistor based on double mixed-dimensional graphene/germanium Schottky junctions that uses stimulated emission of heated carriers to achieve a subthreshold swing lower than 1 millivolt per decade beyond the Boltzmann limit and a negative differential resistance with a peak-to-valley current ratio greater than 100 at room temperature. Multi-valued logic with a high inverter gain and reconfigurable logic states are further demonstrated. This work reports a multifunctional hot-emitter transistor with significant potential for low-power and negative-differential-resistance applications, marking a promising advancement for the post-Moore era.

ABSTRACTThermal cracking is one of the most noteworthy distresses in asphalt concrete (AC) pavements. It is caused by the thermal stress in pavement layers, when air temperatures are extremely low [...]

ABSTRACTThe reuse of waste tire and biomass is important to environmental protection. The main objective of this study is to investigate the effect of bio-oil on the high-temperature performance of [...]

The electrochemical reduction of nitrate can be a promising and sustainable alternative for the industrially used, energy-intensive Haber–Bosch process under mild conditions and also solve the issue of nitrate nitrogen pollution in water. We present here the facile construction of an N-doped CuO@Co3O4/NF nanoarray on nickel foam for highly efficient NH3electrosynthesis viaselective NO3−reduction in neutral electrolyte. At −0.85 V (versusthe reversible hydrogen electrode (RHE)), this N-doped CuO@Co3O4/NF nanoarray obtained an outstanding Faraday efficiency (FE) of 99.78% and NH3yield of up to 31.92 mg h−1cm−2when operated in 0.1 M phosphate buffer solution with added 50 mM NaNO3. In addition, its excellent electrochemical performance was maintained for at least 12 h. Furthermore, according to the characterization, the enhanced electrocatalytic performance could be attributed to the synergistic effect of N-dopant and relatively large amounts of Co(ii) and oxygen vacancies (OVs) in the heterostructure, leading to the suppression of the hydrogen evolution reaction (HER) and the improvement of electron/mass transfer at the N-doped CuO@Co3O4/NF heterostructure.

With the continuous upgrading and development of malware attack methods, traditional detection methods have shown a series of serious problems such as low classification accuracy, easy overfitting, and high false alarm rate when facing new malware attacks. To address these challenges, this study introduces an innovative deep convolutional neural network (D-CNN) method that cleverly integrates permission features and API call graphs. Learn high-level abstract representation through DNN and combine it with CNN to build multiscale feature representation, aiming to improve the performance of the detection model and enhance the resistance to new malicious attacks. In order to ensure the standardization and representativeness of the data, the Min–Max method is first used to normalize the permission characteristics to ensure the standardization of the data. Second, the ant colony optimization method is used to achieve dimensionality reduction and prevent over-fitting. This article conducts experiments on Drebin and Google Play Store datasets. The results prove that the hybrid structure of D-CNN exhibits a deeper understanding of the data structure and achieves an accuracy of 96.80%, enabling more comprehensive and accurate malware detection and classification. It outperforms single deep learning methods in detection performance.

Abstract: The approximately analytical bound and scattering state solutions of the arbitrary l-wave Klein-Gordon equation for the mixed Manning-Rosen potentials are carried out by an improved new approximation to the centrifugal term. The normalized analytical radial wave functions of the l-wave Klein-Gordon equation with the mixed Manning-Rosen potentials are presented and the corresponding energy equations for bound states and phase shifts for scattering states are derived. It is shown that the energy levels of the continuum states, reduce to the bound states of those at the poles of the scattering amplitude. Some useful figures are plotted to show the improved accuracy of our results and the special case for wave is studied briefly.

CAPZA2encodes the α2 subunit of CAPZA, which is vital for actin polymerization and depolymerization in humans. However, understanding of diseases associated with CAPZA2remains limited. To date, only three cases have been documented with neurodevelopmental abnormalities such as delayed motor development, speech delay, intellectual disability, hypotonia, and a history of seizures. In this study, we document a patient who exhibited seizures, mild intellectual disability, and impaired motor development yet did not demonstrate speech delay or hypotonia. The patient also suffered from recurrent instances of respiratory infections, gastrointestinal and allergic diseases. A novel de novo splicing variant c.219+1 G > A was detected in the CAPZA2gene through whole-exome sequencing. This variant led to exon 4 skipping in mRNA splicing, confirmed by RT-PCR and Sanger sequencing. To our knowledge, this is the third study on human CAPZA2defects, documenting the fourth unambiguously diagnosed case. Furthermore, this splicing mutation type is reported here for the first time. Our research offers additional support for the existence of a CAPZA2-related non-syndromic neurodevelopmental disorder. Our findings augment our understanding of the phenotypic range associated with CAPZA2deficiency and enrich the knowledge of the mutational spectrum of the CAPZA2gene.

Because wireless communication network attacks continue to evolve, cyber security is becoming more and more important, requiring network security solutions to be constantly updated. In addition, wireless communication network traffic in high-speed networks is massive, high-dimensional, dynamic, and so on, making attacks difficult to detect in real-time. Unknown attacks are also difficult to identify. This article proposes a framework for abnormal traffic detection based on deep reinforcement learning, mainly consisting of four stages: data collection, dataset pre-processing, feature selection, and model detection. Experimental results show that the abnormal traffic detection framework has improved detection performance.

Road network maintenance scheduling mainly considers budget limits in the previous studies and largely ignores the capital constraints. This study proposes a bi-objective mixed integer programming model, in which the net present value (NPV) is maximized and the increased total system travel time (ITSTT) due to maintenance activities under the capital constraints is minimized. Since the road network flows cannot reach an equilibrium state overnight due to the variation of network capacity, a link-based day-to-day dynamics model is developed to simulate the transient fluctuation in the traffic flows and calculate the total system travel time of each day. The bi-objective model is solved by the nondominated sorting genetic algorithm-II (NSGA-II) that generates a set of optimal Pareto solutions. The TOPSIS method is then adopted to determine the best compromise solution. Finally, a case study is conducted to demonstrate the effects of key parameters on the values of the two objectives.

Abstract:Fertility policies in China have changed substantially over recent years, with the intention of allowing individuals to bear more children and, thereby, to increase the total fertility rate. Using a sample of young adults, this study examines changes in fertility aspirations (the desired number of children, and the timing of first birth) across the three fertility policy periods (One-Child, Two-Child, and Three-Child). The results show that both young females and males increasingly prefer fewer children, and a later age at first birth. Both parental and peer factors are shown to significantly affect fertility aspirations, yet individual factors, such as gender attitudes and pronatal beliefs, yield stronger associations. The implications of the findings, along with the possible future of fertility patterns in China, are discussed with the developmental paradigm.Résumé:Les politiques de fécondité en Chine ont considérablement changé au cours des dernières années, dans le but de permettre aux individus d'avoir plus d'enfants et, par conséquent, d'augmenter le taux de fécondité total. À l'aide d'un échantillon de jeunes adultes, cette étude examine les évolutions des aspirations en matière de fécondité (le nombre d'enfants désiré et le moment de la première naissance) au cours de trois périodes correspondant à différentes politiques de fécondité (un enfant, deux enfants et trois enfants). Les résultats révèlent que les jeunes femmes et les jeunes hommes préfèrent de plus en plus avoir moins d'enfants et retarder l'âge de la première naissance. Les facteurs parentaux et les facteurs liés aux pairs ont une incidence significative sur les aspirations en matière de fécondité, mais les facteurs individuels, tels que les attitudes à l'égard du sexe et les croyances prénatales, sont davantage associés à ces aspirations. Les implications des résultats, ainsi que l'avenir possible des modèles de fécondité en Chine, sont discutés avec le paradigme du développement.

The detection of sealed cracks in pavement images can be complicated by the presence of objects on the pavement that have similar morphology or texture to cracks, leading to false positive results. To address this issue, this paper proposes a High Resolution-Pixel to Pixel (HR-Pix2Pix) pavement distress image enhancement algorithm. The algorithm improves the proportion of effective semantics by reducing the semantic interference caused by pseudo pavement distress such as pavement stains, brake marks, and shadows. The proposed HR-Pix2Pix generative adversarial neural network involves a novel generator architecture for fusing multi-level semantic features. The generator is capable to automatically locate the pseudo-distress in the image and fill (generate) the region as normal pavement texture with reference to the pavement texture surrounding the pseudo-distress. To further improve the quality of the semantic distribution-enhanced images, a hybrid loss function is designed and used to train the network. The results of the study show that by using HR-Pix2Pix enhanced images for sealed crack detection can significantly reduce false detections and improve the accuracy of the detection, consequently.

As Vehicular Ad-hoc Networks (VANETs) bring fantastic revolution to intelligent transportation systems, their own security has become an important research topic. However, authentication security, as the key issue of VANETs’ security, is still facing great challenges. Therefore, this survey first starts with the background of VANETs and then introduces the main security concerns. To distinguish from existing surveys, this paper proposes the security challenges and security properties of VANETs from the perspective of builders and attackers, respectively. Then, we present the necessary and important characteristics of a VANET’s security system including the authenticity of nodes and information, the availability of network systems, the integrity and confidentiality of information, and the non-repudiation of information after transmission. Specifically, attack methods and detection schemes for these characteristics are highlighted in detail and analyzed in terms of their advantages and limitations, which fill the gaps in the existing survey. More importantly, we focus on the authentication schemes proposed in recent years, reporting the latest advances in VANETs. These schemes are analyzed and compared in depth in terms of the security characteristics and attack resistance of authentication, as well as in terms of overhead and efficiency. Finally, this paper summarizes some lessons and discusses several future research directions.

ABSTRACT Bio-oil is a sustainable and environment-friendly material. The application of bio-oil in paving material, especially into asphalt binder territory, has attracted great attentions. This study focuses on the effect [...]

ABSTRACT Mud-pumping is one of major distresses of concrete bridge deck pavement, which not only influences the riding comfort of vehicles but also affects the appearance of bridge pavement and [...]

In this study, the comprehensive performance of cold mix asphalt (CMA) is evaluated by seven laboratory test methods, namely the Hveem cohesion test, water immersion splitting test, freeze–thaw splitting test, indirect tensile fatigue test, semi-circular bending (SCB) test, dynamic modulus test, and rutting test. The CMA is modified using the regenerant (RE), Buton rock asphalt (BRA), and styrene–butadiene rubber (SBR) latex. In addition, we have proposed an evaluation model based on the grey target theory to quantitatively assess the effects of the modification approaches. The results show that the CMA modified with 8% RE has the best comprehensive property. RE is a potential modifier and reduces the content of emulsified asphalt for CMA, which can significantly improve the cohesion, moisture susceptibility, dynamic mechanical properties, and durability of CMA. Additionally, the grey target theory is an effective method to evaluate the comprehensive performance of CMA quantitatively.

Mobile edge computing (MEC) deploys servers on the edge of the mobile network to reduce the data transmission delay between servers and mobile devices, and can meet the computing demand of mobile computing tasks. It alleviates the problem of computing power and delay requirements of mobile computing tasks and reduces the energy consumption of mobile devices. However, the MEC server has limited computing and storage resources and mobile network bandwidth, making it impossible to offload all mobile computing tasks to MEC servers for processing. Therefore, MEC needs to reasonably offload and schedule mobile computing tasks, to achieve efficient utilization of server resources. To solve the above-mentioned problems, in this article, the task offloading problem is formulated as an optimization problem, and particle swarm optimization (PSO) and quantum PSO based task offloading strategies are proposed. Extensive simulation results show that the proposed algorithm can significantly reduce the system energy consumption, task completion time, and running time compared with recent advanced strategies, namely ant colony optimization, multiagent deep deterministic policy gradients, deep meta reinforcement learning-based offloading, iterative proximal algorithm, and parallel random forest.

The shape characteristics of wear spot in the four-ball wear test are often qualitatively identified by human testers based on experience, which are subjective, unquantifiable and biased. This paper proposes an automated method for extracting and expressing the shape features, which is effective for the deformed classification of the wear images. First, the wear spot is segmented from the background, and the geometric parameters of the wear spot are extracted. Based on this, the optimal standard wear spot which match the segmented (or actual) wear spot best is constructed. The established feature variables (i.e. abnormality rate and eccentricity rate) are used to quantitatively assess the deformation degree of segmented wear spot, by comparing the segmented wear spot with the constructed standard wear spot. Finally, Kmeans clustering algorithm is used to verify the validity of deformation features in the classification application. Simulation test results show that feature variables are valuable for identifying the deformation of wear images, and three effect evaluation indicators (CH/SI/DB) shows that the classification effect of the wear images is better.

In the process of hot-dip Zn-Al-Mg alloy coating, the plating solution dissipates heat in the direction perpendicular to the steel plate, which is considered to be a process of directional solidification. To understand the relationship between microstructure and cooling rate of Zn-Al-Mg alloys, both the phase constitution and microstructure characteristic length scales of Zn-9.5Al-3Mg-0.01Ce (wt.%) alloy were investigated by the directional solidification experiments at different growth velocities (V=40, 80, 160, 250 µm·s−1). The experimental results show that the microstructure of directionally solidified Zn-9.5Al-3Mg-0.01Ce alloy is composed of primary Al dendrites and (Zn-Al-Mg2Zn11) ternary eutectics at the growth velocities ranging from 40 to 250 µm·s−1. The primary Al dendrites are aligned regularly along the growth direction, accompanied with obvious secondary dendrites. The relationship between the microstructure length scale and the thermal parameters of solidification is obtained: λ1=374.66V−0.383, and λ2=167.5V−0.563(λ1is the primary dendrite arm spacing, and λ2is the secondary dendrit arm spacing). In addition, through the interface response function (IRF) and the nucleation and constitutional undercooling (NCU), the phase selection of Zn-9.5Al-3Mg-0.01Ce is obtained: (Zn+Al+Mg2Zn11) ternary eutectics in the Zn-9.5Al-3Mg-0.01Ce alloy will be replaced by ternary eutectics (Zn+Al+MgZn2) when the growth rate is lower than 7.53 µm·s−1.

In the verification of identity, the aim is to increase effectiveness and reduce involvement of verified users. A good compromise between these issues is ensured by dynamic signature verification. The dynamic signature is represented by signals describing the position of the stylus in time. They can be used to determine the velocity or acceleration signal. Values of these signals can be analyzed, interpreted, selected, and compared. In this paper, we propose an approach that: (a) uses an evolutionary algorithm to create signature partitions in the time and velocity domains; (b) selects the most characteristic partitions in terms of matching with reference signatures; and (c) works individually for each user, eliminating the need of using skilled forgeries. The proposed approach was tested using Biosecure DS2 database which is a part of the DeepSignDB, a database with genuine dynamic signatures. Our simulations confirmed the correctness of the adopted assumptions.

A highly integrated RF power and information receiving system is proposed in this paper. The system consists of an antenna, a rectifier, and an information receiving module. The information receiving module acts as part of the dc load. To realize high integration, a dual-band, dual-circular-polarized shared- aperture antenna is implemented. The antenna consists of a left-circular-polarized element operating at 2.4-GHz band, and a high-gain, right-circular-polarized $2\times 2$ array operating at 5.8-GHz band. The lower-frequency antenna is for communication, while the higher-frequency one is for power transmission. All the elements share the same aperture, and the radiator of lower- frequency antenna acts as the reflector of higher-frequency elements. Accordingly, a class-F rectifier that matches the higher- frequency array is designed and verified, and a system-level demonstration is implemented. Owing to the high isolation on frequency splitting and polarization diversity, the baseband signal can be successfully demodulated under a 30-dB input-power-level difference at two frequency bands. The base-band information can be displayed by an ink screen. The received RF power can be effectively rectified and power the data-processing modules. [ABSTRACT FROM AUTHOR]

Purpose: The choice of continuous renal replacement therapy (CRRT) anticoagulation program for patients at high risk of bleeding has always been a complex problem in clinical practice. Clinical regimens include regional citrate anticoagulation (RCA) and nafamostat mesylate (NM). This study aimed to evaluate the efficacy and safety of these two anticoagulants for CRRT in patients at high risk of bleeding to guide their clinical use better. Patients and methods: Between January 2021 and December 2022, 307 patients were screened for this study. Forty-six patients were finally enrolled: 22 in the regional citrate anticoagulation group and 24 in the nafamostat mesylate group. We collected patients’ baseline characteristics, laboratory indicators before CRRT, and CRRT-related data. We then performed a statistical analysis of the data from both groups of patients. Results: In our study, the baseline characteristics did not differ significantly between the two groups; the baseline laboratory indicators before CRRT of patients in the two groups were not significantly different. The duration of CRRT was 600 min in the regional citrate anticoagulation (RCA) group, 615 min in the nafamostat mesylate (NM) group; the success rate was 90.7% in the RCA group, and 85.6% in the NM group, the anticoagulant efficacy between the two groups was comparable. There was no significant difference in the safety of anticoagulation between the two groups. We used Generalized Estimating Equations (GEE) to test whether different anticoagulation methods significantly affected the success rate of CRRT and found no statistical difference between RCA and NM. Conclusion: Our study suggests that nafamostat mesylate's anticoagulant efficacy and safety are not inferior to regional citrate anticoagulation for continuous renal replacement therapy in patients at high risk of bleeding.

By structural design, a new type of highly functional ionic liquid (NHFIL) was synthesized by combining 1-vinylimidazole with tris(2-chloroethyl) phosphate through a one-pot method. When it is melted into the polymer composite, the highly reactive vinyl of NHFIL promotes the cross-linking within the polymer system to enhance the compatibility between the inorganic filler and polymer matrix and further improve the mechanical properties of the composite, additionally, the N and P elements would generate non-flammable gas phase and carbonized layer during combustion, which endows the polymer composites with remarkable flame-retardant performance. On this basis, the low-smoke flame retardant ethylene–vinyl acetate (EVA)-based composites were prepared by introducing NHFIL into the industrial formula of the cable sheath material for maglev trains. The effects of the composition and molecular structure of NHIFL on the interfacial compatibility, microstructure, mechanical properties, and flame retardancy of composite materials have been studied in detail. The results indicate that with the addition of NHFIL, the cross-linking degree, gel content, thermal stability, mechanical properties, oil resistance, and the flame retardancy of the EVA-based composites were comprehensively improved. Significantly, with a low addition of 3.5% NHFIL, the gel content reaches 90.3%, the carbon residue reaches 42.7%, and the limiting oxygen index (LOI) reaches 36.3%, and surprisingly, the oil resistance increased by five times, which endows the composites with great application potential in cables of major transportation equipment.

To design a gigantic microwave power transmitting array for space solar power station, modular design procedure is discussed. Besides microwave power channels, radiating array and thermal control, functions such as DC power source and beam steering should also be included in the design of the microwave power transmitting array. Smart composite structures integrate electronics, structures, thermal control and other functions into a module, providing an advanced design and integration paradigm. Modular smart composite structure antenna is an ideal candidate for its light weight and other performance.

Thioamitides are apoptosis-inducing ribosomally synthesized and post-translationally modified peptides (RiPPs) with substantial post-translational modifications (PTMs), whose biosynthetic details remain elusive. We reconstituted their key PTMs through in vitroenzymatic reactions and gene coexpressions in E. coliand rigorously demonstrated the order of those modifications. Notably, thioamitide biosynthesis involves N- to C-terminal thioamidations and employs both leader-dependent and leader-independent reactions followed by leader removal by successive degradation. Our study provides a comprehensive overview of thioamitide biosynthesis and lays the foundation for thioamitide engineering in E. coli.

The angle-sensitive photonic bandgap (PBG) is one of the typical features of one-dimensional photonic crystals. Based on the phase-variation compensation effect between the dielectric and hyperbolic metamaterials (HMMs), angle-insensitive PBGs can be realized in photonic hypercrystals. However, since hypercrystals are usually constructed using metal components, these angle-insensitive PBGs are mostly limited to narrow bandwidths in visible range. Here, we replace metal with indium tin oxide (ITO) to construct HMMs in the near-infrared range. In these ITO-based HMMs, we experimentally demonstrate the negative refraction of light in transverse magnetic polarization. With this HMM component, we realize a photonic hypercrystal with an angle-insensitive PBG in the wavelength range of 1.15–2.02 µm. These ITO-based hypercrystals with large angle-insensitive PBGs can find applications in near-infrared reflectors or filters.

Choriogenesis is the last step of insect oogenesis, a process by which the chorion polypeptides are produced by the follicular cells and deposited on the surface of oocytes in order to provide a highly specialized protective barrier to the embryo. The essential features of chorion genes have yet to be clearly understood in the diamondback moth, Plutellaxylostella, a worldwide Lepidoptera pest attacking cruciferous crops and wild plants. In this study, complete sequences for 15 putative chorion genes were identified, and grouped into A and B classes. Phylogenetic analysis revealed that both classes were highly conserved and within each, branches are also species-specific. Chorion genes from each class were located in pairs on scaffolds of the P. xylostellagenome, some of which shared the common promoter regulatory region. All chorion genes were highly specifically expressed in the P. xylostellaadult females, mostly in the ovary with full yolk, which is a crucial period to build the shells of the eggs. RNAi-based knockdown of chorion-1, which is located on the Px_scaffold 6 alone, although had no effect on yolk deposition, resulted in smaller eggs and sharply reduced hatchability. Additionally, inhibition of PxCho-1expression caused a less dense arrangement of the columnar layers, reduced exochorion roughness and shorter microvilli. Our study provides the foundation for exploring molecular mechanisms of female reproduction in P. xylostella, and for making use of chorion genes as the potential genetic-based molecular target to better control this economically important pest.

Cassava is an important tropical cash crop. Severe drought stresses affect cassava productivity and quality, and cause great economic losses in agricultural production. Enhancing the drought tolerance of cassava can effectively improve its yield. Long non-coding RNAs (lncRNAs) are present in a wide variety of eukaryotes. Recently, increasing evidence has shown that lncRNAs play a critical role in the responses to abiotic stresses. However, the function of cassava lncRNAs in the drought response remains largely unknown. In this study, we identified a novel lncRNA, DROUGHT-INDUCED INTERGENIC lncRNA(DIR). Gene expression analysis showed that DIRwas significantly induced by drought stress treatment, but did not respond to abscisic acid (ABA) or jasmonic acid (JA) treatments. In addition, overexpression of the DIRgene enhanced proline accumulation and drought tolerance in transgenic cassava. RNA-seq analysis revealed that DIRpreferentially affected drought-related genes that were linked to transcription and metabolism. Moreover, RNA pull-down mass spectrometry analysis showed that DIRinteracted with 325 proteins. A protein–protein interaction (PPI) analysis found a marked enrichment in proteins associated with the mRNA export and protein quality control pathways. Collectively, these results suggest that DIRand its interacting proteins that regulate mRNA or protein metabolism are involved in mediating the drought stress response. Thus, regulating DIRexpression has potential for improving cassava yield under drought conditions.

In social networks, the community detection algorithm is very important for understanding the structures and the functions of these networks. A lot of researches have been done on the overlapping community detection algorithms as the overlapping is a significant feature of such networks. However, though many algorithms have been introduced to detect overlapping communities, the detection of the overlapping community is still a challenging task. In fact, the traditional static methods which partitioned the network structure could not efficiently obtain the latest community structure. The problems of high computational complexity and low identification accuracy need to be solved. To address these issues, in this paper, we propose a New Overlapping Community Detection algorithm based on improved KNN (called NOCD), which can timely adjust the community structure based on different network changes, and ultimately obtains the results of the community partitions with a high degree of Q module. To deal with the weighted social networks, NOCD adopts similarity instead of distance to evaluate the network. The experimental results show that the proposed NOCD algorithm compared with the COPRA, the CPM, the DeCom, the PLPA, and the AI-LPA algorithms can effectively improve the detection accuracy, the efficiency of parallel computing, and reduce the time complexity.

Direct laser deposition (DLD), as a popular metal additive manufacturing process, shows advantages of technical flexibility and high efficiency to gain a high-performance alloy steel component. However, during the processing of DLD, the deposited steel layer is affected by the subsequent layer depositing. The DLD block shows different microstructure and mechanical properties at the bottom, middle and top of the deposited parts. To date, there are few research works about the effects of inter-layer interval time and laser power on the microstructure evolution and mechanical properties of the deposited layers. In this study, the idle time and laser power layer by layer during DLD of 12CrNi2 steel were controlled to cause the deposited layers to maintain a high cooling rate, while the bottom deposited layer was subjected to a weak tempering effect. Results show that a high proportion of martensite is produced, which improves the strength of the deposited layer. Under the laser scanning strategy of laser power 2,500 W, scanning velocity 5 mm·s−1, powder feeding rate 11 g·min−1, overlap rate 50%, and a laser power difference of 50 W and a 2 min interval, the tensile strength of the deposited layer of 12CrNi2 steel is in the range of 873–1,022 MPa, and the elongation is in the range of 16.2%–18.9%. This study provides a method to reduce the tempering effect of the subsequent deposition layers on the bottom layers, which can increase the proportion of martensite in the low-alloy high-strength steel, so as to improve the yield strength of the alloy steel.

Researchers have noted that paid employment during the teen years is associated with a combination of both positive and negative consequences, including higher rates of substance use among adolescents who are actively employed. Using a sample of high school seniors, drawn from 130 public and private schools throughout the USA, this study examines the relative impact of job characteristics and peer influence on the substance use patterns of female and male adolescents. The analyses show that males report higher usage of alcohol, cigarettes, and marijuana, as compared to females. The type of job, number of work hours, and job satisfaction all yield significant associations with substance use, yet peer disapproval also is shown to substantially detract from such usage. Comparatively, work characteristics appear to yield a more substantial impact upon male substance usage, while peer influence seems to affect females and males in a similar manner. The findings and implications of these results are discussed within the framework of ecological theory.

YcaO enzymes catalyze several post-translational modifications on peptide substrates, including thioamidation, which substitutes an amide oxygen with sulfur. Most predicted thioamide-forming YcaO enzymes are encoded adjacent to TfuA, which when present, is required for thioamidation. While activation of the peptide amide backbone is well established for YcaO enzymes, the function of TfuA has remained enigmatic. Here we characterize the TfuA protein involved in methyl-coenzyme M reductase thioamidation and demonstrate that TfuA catalyzes the hydrolysis of thiocarboxylated ThiS (ThiS-COSH), a proteinaceous sulfur donor, and enhances the affinity of YcaO toward the thioamidation substrate. We also report a crystal structure of a TfuA, which displays a new protein fold. Our structural and mutational analyses of TfuA have uncovered conserved binding interfaces with YcaO and ThiS in addition to revealing a hydrolase-like active site featuring a Ser–Lys catalytic pair.

Abstract: Three previously undescribed cytochalasins, named xylariasins A‒C (1‒3), together with six known ones (4‒9) were isolated from Xylariasp. CFL5, an endophytic fungus of Cephalotaxus fortunei. The chemical structures of all new compounds were elucidated on the basis of extensive spectroscopic data analyses and electronic circular dichroism calculation, as well as optical rotation calculation. Biological activities of compounds 1, 4‒9were evaluated, including cytotoxic, LAG3/MHC II binding inhibition and LAG3/FGL1 binding inhibition activities. Compounds 6and 9possessed cytotoxicity against AGS cells at 5 μM, with inhibition rates of 94% and 64%, respectively. In addition, all tested isolates, except compound 6, exhibited obvious inhibitory activity against the interaction of both LAG3/MHC II and LAG3/FGL1. Compounds 1, 5, 7, and 8inhibited LAG3/MHC II with IC50values ranging from 2.37 to 4.74 μM. Meanwhile, the IC50values of compounds 1, 7, and 8against LAG3/FGL1 were 11.78, 4.39, and 7.45 μM, respectively. Graphic Abstract:

Composite material is widely used to maintain damaged structures of aircraft. The 3D finite element model of composite cement maintenance for aircraft is established by finite element method software ANSYS Workbench. The structural characteristics and usage status of the composite cement maintenance model is analyzed, and then the optimal structural parameters of the composite patch are obtained, including the length, width and thickness. The results show that the composite cement maintenance method could effectively restore the rigidity, and improve the strength of the structure. Furthermore, the optimal design for composite patch ensures safety of aircraft, economics of maintenance, and operability of repair methods.

Many bacteria use membrane-diffusible small molecule quorum signals to coordinate gene transcription in response to changes in cell density, known as quorum sensing (QS). Among these, acyl-homoserine lactones (AHL) are widely distributed in Proteobacteriaand are involved in controlling the expression of virulence genes and biofilm formation in pathogens, such as Pseudomonas aeruginosa. AHL molecules are specifically biosynthesized by the cognate LuxI type AHL synthases using S-adenosylmethionine (SAM) and either acyl carrier protein (ACP)- or CoA-coupled fatty acids through a two-step reaction. Here, we characterize a CoA-dependent LuxI synthase from Rhodopseudomonas palustristhat utilizes an aryl-CoA substrate that is environmentally derived, specifically p-coumaric acid. We leverage structures of this aryl-CoA-dependent synthase, along with our prior studies of an acyl-CoA-dependent synthase, to identify residues that confer substrate chain specificity in these enzymes. We test our predictions by carrying out biochemical, kinetic, and structural characterization of representative AHL signal synthases. Our studies provide an understanding of various AHL synthases that may be deployed in synthetic biological applications and inform on the design of specific small molecule therapeutics that can restrict virulence by targeting quorum signaling.

Localization technology is crucial in wireless sensor networks (WSN) by forming the basis of various WSN applications. With the advancements of WSN, WSN attacks for node localization have increasingly become an important security issue. The Sybil attack is an example of such attacks where a reputation system is subverted by creating multiple pseudonymous identities. In this paper, a detection and defense algorithm against Sybil attacks based on the distance vector-hop (DV-Hop) method is presented. Experimental results show that the algorithm can effectively improve the security of the node localization in WSN. When the number of beacon nodes is 50, our proposed algorithm reduces the average localization error by 3% than the traditional DV-Hop.

With the constant development of wireless communication technologies, the Vehicular Ad-hoc Networks (VANETs) will become an inevitable paradigm for intelligent transportation systems. Privacy-preserving and authentication security has been a core concern in VANETs, and pseudonym-based and group signature-based privacy-preserving authentication schemes have been widely proposed. However, most research schemes rely excessively on the Trusted Authority, and vehicle request and authentication information is almost transparent in front of TAs, while they cannot guarantee the security of vehicle request information after it is intercepted. To address these issues, this paper proposes a lightweight privacy-preserving authentication scheme that mitigates TA dependency, aiming to achieve mutual privacy protection and authentication between vehicles and TAs in VANETs by improving the oblivious transfer algorithm. The security analysis proves that this scheme has good privacy protection and attack resistance, and in addition, the performance simulation and evaluation show that this scheme spends lower computation and communication overheads while ensuring lower authentication delay and packet loss rate, which is a better overall performance compared with other schemes.