Rhizosphere characteristics of the arsenic hyperaccumulator Pteris vittata L. and monitoring of phytoremoval efficiency

Recently discovered As-hyperaccumulator ferns hold promise for phytoremediation of As-polluted soils. We investigated changes in the rhizosphere characteristics of Pteris vittata (Chinese Brake fern) relevant for its use in phytoextraction. Plants were grown in rhizoboxes filled with soil containing 2270 mg kg(-1) As. Dissolved organic carbon (DOC) concentrations in rhizosphere soil solution were increased by 86% and appeared to enhance total Fe solubility due to complexation reactions. Despite substantial removal of As by the fern, As was not significantly decreased in the rhizsophere soil solution after one cropping, apparently due to the large buffer capacity of the soil and possibly because of ion competition with DOC. However, the difference between 0.05 M (NH4)2SO4-extractable labile As in bulk and rhizosphere soil accounted for 8.9% of total As accumulated in the fern, indicating that As was mainly acquired from less available pools. Moreover, As depletion in the rhizosphere and limited resupply from less available pools were indicated by a 19.3% decreased As flux, measured using the technique of diffusive gradients in thin films (DGT). Modeling of the DGT-soil system was able to show that the rate of release from solid phase to solution in the rhizosphere was one-third of that in the bulk soil. Applying the remedial strategy of bioavailable contaminant stripping, which aims at diminishing the phytoavailable pollutant fraction, DGT can be used as a monitoring tool to evaluate the efficiency of phytoextraction and to study the potential resupply of bioavailable pools after phytoextraction has ceased.     

Solar drying in sludge management in Turkey

Two main wastewater treatment plants in Bursa city in Turkey will start to operate and produce at least 27,000 tons of dry solids per year by the end of 2006. The purpose of this study was to investigate an economical solution to the sludge management problem that Bursa city would encounter. The general trend in Turkey is mechanical dewatering to obtain a dry solid (DS) content of 20%, and liming the mechanically dewatered sludge to reach the legal landfilling requirement, 35% DS content. This study recommends limited liming & solar drying as an alternative to only-liming the mechanically dewatered sludge. Open and covered solar sludge drying plants were constructed in pilot scale for experimental purposes. Dry solids and climatic conditions were constantly measured. Faecal coliform reduction was also monitored. The specially designed covered solar drying plant proved to be more efficient than the open plant in terms of drying and faecal coliform reduction. It was found that, if the limited liming & solar drying method was applied after mechanical dewatering instead of only-liming method, the total amount of the sludge to be disposed would be reduced by approximately 40%. This would lead to a reduction in the transportation, handling, and landfilling costs. The covered drying system would amortize itself in 4 years.     

Structure Prediction,Evaluation, and Validation of GPR18 Lipid Receptor Using Free Programs

The GPR18 receptor, often referred to as the N-arachidonylglycine receptor, although assigned (along with GPR55 and GPR119) to the new class A GPCR subfamily-lipid receptors, officially still has the status of a class A GPCR orphan. While its signaling pathways and biological significance have not yet been fully elucidated, increasing evidence points to the therapeutic potential of GPR18 in relation to immune, neurodegenerative, and cancer processes to name a few. Therefore, it is necessary to understand the interactions of potential ligands with the receptor and the influence of particular structural elements on their activity. Thus, given the lack of an experimentally solved structure, the goal of the present study was to obtain a homology model of the GPR18 receptor in the inactive state, meeting all requirements in terms of protein structure quality and recognition of active ligands. To increase the reliability and precision of the predictions, different contemporary protein structure prediction methods and software were used and compared herein. To test the usability of the resulting models, we optimized and compared the selected structures followed by the assessment of the ability to recognize known, active ligands. The stability of the predicted poses was then evaluated by means of molecular dynamics simulations. On the other hand, most of the best-ranking contemporary CADD software/platforms for its full usability require rather expensive licenses. To overcome this down-to-earth obstacle, the overarching goal of these studies was to test whether it is possible to perform the thorough CADD experiments with high scientific confidence while using only license-free/academic software and online platforms. The obtained results indicate that a wide range of freely available software and/or academic licenses allow us to carry out meaningful molecular modelling/docking studies.     

WSN中兼顾安全和剩余能量的簇头选择算法

通过对无线传感器网络的信任模型和节点的能量消耗的研究,针对能量受限的无线传感器网络容易受到攻击的问题,提出了一种基于信任机制的分布式簇头选举优化算法。簇头的选举综合考虑了节点的信任度和节点的剩余能量两种因素。实验证明,该算法提高了网络安全性,延长了网络生存周期。并且信任模型中的校正机制体现了模型的健壮性。     

Global sensitivity analysis and aggregation of risk in multi-product supply chain networks

Manufacturing firms manage complex supply chain networks which are exposed to a plethora of hazard events. An essential part of the risk management process is the calculation of the stand-alone risk exposures of the product-specific supply chains, but also of the entire multi-product system. In this paper, first, a global sensitivity analysis of the statistical supply chain risk model is conducted. This method helps the decision-makers to understand the risk of the model they are using. Second, a methodology for risk aggregation in multi-product supply chain networks is proposed. The real-world data is used to analyse and validate the model. Supply chain managers equipped with the proposed method will better cope with the risk in supply chains for different product configurations.     

A secure and privacy-preserving lightweight authentication protocol for wireless communications

In wireless networks, seamless roaming allows a mobile user (MU) to utilize its services through a foreign server (FS) when outside his home server (HS). However, security and efficiency of the authentication protocol as well as privacy of MUs are of great concern to achieve an efficient authentication protocol. Conventionally, authentication involves the participation of three entities (MU, HS, and FS); however, involving an HS in the authentication process incurs heavy computational burden on it due to huge amount of roaming requests. Moreover, wireless networks are often susceptible to various forms of passive and active attacks. Similarly, mobile devices have low processing, communication, and power capabilities.

In this paper, we propose an efficient, secure, and privacy-preserving lightweight authentication protocol for roaming MUs in wireless networks without engaging an HS. The proposed authentication protocol uses unlinkable pseudo-IDs and lightweight time-bound group signature to provide strong user anonymity, and a cost-effective cryptographic scheme to achieve security of the authentication protocol. Similarly, we implement a better billing system for MUs and a computationally efficient revocation scheme. Our analysis shows that the protocol has better performance than other related authentication protocols in wireless communications in terms of security, privacy, and efficiency.     

Analysis of fractional Navier–Stokes equations

In this study, we apply the fractional Laplace variational iteration method (FLVIM), a computer methodology for exploring fractional Navier–Stokes equation solutions. In light of the theory of fixed points and Banach spaces, this paper also explores the uniqueness and convergence of the solution of general fractional differential equations obtained by the suggested method. In addition, the fractional Laplace variational iteration method solution's error analysis is covered. The computational technique also clearly demonstrates the validity and dependability of the suggested method for solving fractional Navier-Stokes equations. Furthermore, the obtained solutions are a perfect fit with previously established solutions.     

Single- and multi-GPU computing on NVIDIA- and AMD-based server platforms for solidification modeling application

This work explores the performance of single- and multi-GPU computing on state-of-the-art NVIDIA- and AMD-based server-class hardware using various programming interfaces to accelerate a real-world scientific application for solidification modeling based on the phase-field method. The main computations of this memory-bound application correspond to 20 stencils computed across grid nodes. We investigate the application's scalability for two basic schemes of organizing computation: without and with hiding data transfers behind computation, combined with using either peer-to-peer inter-GPU data transfers through NVIDIA NVLink and AMD Infinity interconnects or communication over the PCIe and main memory. Among the studied programming interfaces is CUDA, HIP, and OpenMP Accelerator Model. While the first two are designed to write the codes for a specific hardware platform, OpenMP enables code portability between NVIDIA and AMD GPUs. The resulting performance is experimentally assessed on computing platforms containing NVIDIA V100 (up to 8 GPUs) and A100 (one GPU), as well as AMD MI210 (one device) and MI250 (up to 8 logical GPUs).     

Hybrid rubber-concrete isolation slab system with various shape factors for structures subjected to horizontal and vertical vibrations

The present framework proposed the development of a Hybrid Rubber-Concrete Isolation Slab System (HRCISS) to support building structures subjected to horizontal and vertical vibration due to ground motion and machine or equipment operation in the structure. Given that the effect of the shape factor on both horizontal and vertical stiffness has yet to be reported, the proposed composite system was comprised of two layers under the nodal points of the upper layer near the slab corners with four High Damping Rubber (HDR) components positioned between the slab layers to dissipate multidirectional (horizontal and vertical directions) vibrations. The ABAQUS software was utilized to model the finite element model (FEM) and simulate the HRCISS subjected to cyclic horizontal and vertical displacements. For the optimal HDR design, the model was applied in five 3-story buildings, and the effect of distinct shape factors (0 $<$ S $<$ 2) of the HDR bearings—the ratio of bearing's loaded area to unloaded area (free to bulge)—within the hybrid system was evaluated. For each building with a specific HDR shape factor, the HRCISS was installed in the first, second, and third stories, separately, to investigate the influence of the installation level of the isolation system on the overall structural performance. The multistory buildings were subjected to two types of vibration loads: the interior machine-induced vibrations, and the exterior seismic-induced vibrations in the horizontal and vertical directions. Based on the results, the FEM results proved the significant influence of the shape factors on the dynamic response of the HRCISS under both interior and exterior 3D vibrations when applied in multistory buildings. The lateral drift of the three-story one-bay buildings decreased with the decrement of shape factor with buildings of HRCISS installed in 1st story recording more reduction. Moreover, the deflection in the structural slab under the HRCISS decreased for lower shape factor bearings. Nevertheless, the reduced deflection was less affected by the level of the machine-equipped story. The rubber layer also stiffened in shear and compression directions with a higher shape factor.     

A Spiky Silver-Iron Oxide Nanoparticle for Highly Efficient Targeted Photothermal Therapy and Multimodal Imaging of Thrombosis

Thrombosis and its complications are responsible for 30% of annual deaths. Limitations of methods for diagnosing and treating thrombosis highlight the need for improvements. Agents that provide simultaneous diagnostic and therapeutic activities (theranostics) are paramount for an accurate diagnosis and rapid treatment. In this study, silver-iron oxide nanoparticles (AgIONPs) are developed for highly efficient targeted photothermal therapy and imaging of thrombosis. Small iron oxide nanoparticles are employed as seeding agents for the generation of a new class of spiky silver nanoparticles with strong absorbance in the near-infrared range. The AgIONPs are biofunctionalized with binding ligands for targeting thrombi. Photoacoustic and fluorescence imaging demonstrate the highly specific binding of AgIONPs to the thrombus when functionalized with a single chain antibody targeting activated platelets. Photothermal thrombolysis in vivo shows an increase in the temperature of thrombi and a full restoration of blood flow for targeted group but not in the non-targeted group. Thrombolysis from targeted groups is significantly improved (p < 0.0001) in comparison to the standard thrombolytic used in the clinic. Assays show no apparent side effects of AgIONPs. Altogether, this work suggests that AgIONPs are potential theranostic agents for thrombosis.