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Neighbor discovery and tracking with directional antennas in flying ad hoc networks (FANETs) is a challenging issue because of dispersed node distribution and irregular maneuvers in three-dimensional (3D) space. In this paper, we propose an adaptive 3D neighbor discovery and tracking algorithm in battlefield FANETs with directional antennas. With time synchronization, a flying node transmits/receives the neighbor discovery packets sequentially in each beam around it to execute a two-way handshake for neighbor discovery. The transmitting or receiving status of each discovery slot depends on the binary code corresponding to the identification of the node. Discovered neighbor nodes exchange their 3D positions in tracking slots periodically for node tracking, and the maximum tracking period is determined by node velocity, beamwidth, and the minimum distance between nodes. By configuring the relevant parameters, the proposed algorithm can also apply to two-dimensional planar ad hoc networks. The simulation results suggest that the proposed algorithm can achieve shorter neighbor discovery time and longer link survival time in comparison with the random scanning algorithm in scenarios with narrow beamwidth and wide moving area. When the frame length increases, the protocol overhead decreases but the average neighbor discovery time increases. The suitable frame length should be determined based on the network range, node count, beamwidth, and node mobility characteristics.

To improve the adsorption efficiency of layered double hydroxides (LDHs) for heavy metals, a novel sodium alginate (SA) intercalated MgAl-LDH (SA-LDH) was synthesized in this work. SA-LDH was characterized by XRD, FTIR, XPS and employed as adsorbent for Cd(II), Pb(II), Cu(II) elimination. Adsorbent dosage, initial pH and contact time, which are regarded as several key parameters, were optimized. The results showed that SA-LDH exhibited better adsorption performance compared with the pristine MgAl-LDH. The maximum adsorption capacities of SA-LDH for Cu(II), Pb(II) and Cd(II) reached 0.945, 1.176 and 0.850 mmol/g, respectively. The possible mechanisms were analyzed by XPS, XRD and FTIR. The results showed that Cd(II), Pb(II) and Cu(II) may be removed by SA-LDH via (i) bonding or complexation with Sur-OH or Sur-O- of SA-LDH, (ii) precipitation of metal hydroxides or carbonates, (iii) isomorphic substitution, and (iv) chelation with −COO− in the interlayers. This work provides an effective method for the development of LDH-based adsorbent and the treatment of wastewater containing heavy metals.

Background SiO 2 nanoparticle is one of the most popular nanomaterial which has been used in various fields, such as wastewater treatment, environmental remediation, food processing, industrial and household applications, biomedicine, disease labeling, and biosensor, etc. In agriculture, the use of SiO 2 nanoparticles as insecticide, carriers in drug delivery, or in uptake and translocation of nutrient elements, etc., has been given attention. However, the effects of nanoparticles on plants have been seldom studied. In this work, the toxicity of SiO 2 nanoparticles and their uptake, transport, distribution and bio-effects have been investigated in Bt-transgenic cotton. Methods The phytotoxic effects of SiO 2 nanoparticles were exhibited in Bt-transgenic cotton with different SiO 2 concentrations of 0, 10, 100, 500 and 2000 mg.L −1 for 3 weeks through dry biomasses, nutrient elements, xylem sap, enzymes activities, and hormone concentrations. The uptake and distribution of nanoparticles by the plants were confirmed using transmission electron microscopy (TEM). Results The SiO 2 nanoparticles decreased significantly the plant height, shoot and root biomasses; the SiO 2 nanoparticles also affected the contents of Cu, Mg in shoots and Na in roots of transgenic cotton; and SOD activity and IAA concentration were significantly influenced by SiO 2 nanoparticles. In addition, SiO 2 nanoparticles were present in the xylem sap and roots as examined by TEM showing that the SiO 2 nanoparticles were transported from roots to shoots via xylem sap. Conclusions This is the first report of the transportation of SiO 2 nanoparticles via xylem sap within Bt-transgenic cotton. This study provides direct evidence for the bioaccumulation of SiO 2 nanoparticles in plants, which shows the potential risks of SiO 2 nanoparticles impact on food crops and human health.

Here, laboratory tests were conducted to examine the effects of natural fracture density (NFD) on the propagation of hydraulic fracture (HF), HF and natural fracture (NF) interaction, and the formation of the stimulated reservoir volume (SRV). Laboratory methods were proposed to prepare samples with dense, medium and spare discrete orthogonal fracture networks. After conducting a true triaxial hydraulic fracturing experiment on the synthetic blocks, the experimental results were analyzed by qualitative failure morphology descriptions, and the quantitative analysis used two proposed new indices. On the pump pressure profiles, it reflected the non-linear interactions between HFs and NFs well. For rock blocks with a dense DFN density, pump pressure curves present fluctuation shape and the degree of interaction between HF and NF is strong; however, for model blocks with a sparse DFN density, the pump pressure curves present a sudden drop shape. In addition, different propagation behaviors of NFs—offset, divert, branch, and cross NF—can be observed from the fractured model blocks. By using a proposed index of “P-SRV”, the relationship between NFD and the fracturing effectiveness was further confirmed. Furthermore, the most striking finding is that mixed mode I–II and I–III fracture types can be formed in the naturally fractured model blocks. The experimental results are beneficial for grasping the influential mechanism of NFD on the propagation of HF and for developing more accurate and full 3D-coupled simulation models for unconventional oil and gas development.

This study compared the nutritional and flavor qualities of Chinese mitten crab ( Eriocheir sinensis ) from three germplasm sources: CJ‐2 (Changjiang Number 2, a selectively bred variety), SX‐P2017 (a new strain bred by Jiangsu Freshwater Fisheries Research Institute), and an unselected cultured group (CG). A total of 120 adults (20 females and 20 males per group) were analyzed for edible yield factors, proximate composition, fatty acids, amino acids, and flavor‐related nucleotides. Results showed that CJ‐2 had higher gonadosomatic index (GSI) and ovaries with the strongest umami (highest equivalent umami concentration [EUC]), while SX‐P2017 exhibited superior n ‐3 polyunsaturated fatty acid (PUFA) profiles and the highest muscle protein levels. Both selectively bred groups (CJ‐2 and SX‐P2017) outperformed CG in umami‐related compounds (AMP and IMP) and taste activity values (TAVs). These findings highlight that selective breeding effectively enhances the nutritional and flavor quality of E. sinensis , providing a strong basis for consumer‐oriented germplasm improvement.

Puerarin is a well-known traditional Chinese medicine which has been used for the treatment of cardiovascular diseases. Recently, a new advantageous crystal form of puerarin, puerarin-V, has been developed. However, the cardioprotective effects of puerarin-V on myocardial infarction (MI) heart failure are still unclear. In this research, we aim to evaluate the cardioprotective effects of puerarin-V on the isoproterenol (ISO)-induced MI mice and elucidate the underlying mechanisms. To induce MI in C57BL/6 mice, ISO was administered at 40 mg/kg subcutaneously every 12 h for three times in total. The mice were randomly divided into nine groups: (1) control; (2) ISO; (3) ISO + puerarin injection; (4–9) ISO + puerarin-V at different doses and timings. After treatment, cardiac function was evaluated by electrocardiogram (ECG), biochemical and histochemical analysis. In vitro inflammatory responses and apoptosis were evaluated in human coronary artery endothelial cells (HCAECs) challenged by lipopolysaccharide (LPS). LPS-induced PPAR-Υ/NF-κB and subsequently activation of cytokines were assessed by the western blot and real-time polymerase chain reaction (PCR). Administration of puerarin-V significantly inhibits the typical ST segment depression compared with that in MI mice. Further, puerarin-V treatment significantly improves ventricular wall infarction, decreases the incidence of mortality, and inhibits the levels of myocardial injury markers. Moreover, puerarin-V treatment reduces the inflammatory milieu in the heart of MI mice, thereby blocking the upregulation of proinflammatory cytokines (TNF-α, IL-1β and IL-6). The beneficial effects of puerarin-V might be associated with the normalization in gene expression of PPAR-Υ and PPAR-Υ/NF-κB /ΙκB-α/ΙΚΚα/β phosphorylation. In the in vitro experiment, treatment with puerarin-V (0.3, 1 and 3 μM) significantly reduces cell death and suppresses the inflammation cytokines expression. Likewise, puerarin-V exhibits similar mechanisms. The cardioprotective effects of puerarin-V treatment on MI mice in the pre + post-ISO group seem to be more prominent compared to those in the post-ISO group. Puerarin-V exerts cardioprotective effects against ISO-induced MI in mice, which may be related to the activation of PPAR-γ and the inhibition of NF-κB signaling in vivo and in vitro. Taken together, our research provides a new therapeutic option for the treatment of MI in clinic.

The Pareto dominance-based evolutionary algorithms can effectively address multiobjective optimization problems (MOPs). However, when dealing with many-objective optimization problems with more than three objectives (MaOPs), the Pareto dominance relationships cannot effectively distinguish the nondominated solutions in high-dimensional spaces. With the increase of the number of objectives, the proportion of dominance-resistant solutions (DRSs) in the population rapidly increases, which leads to insufficient selection pressure. In this paper, to address the challenges on MaOPs, a knee point-driven many-objective evolutionary algorithm with adaptive switching mechanism (KPEA) is proposed. In KPEA, the knee points determined by an adaptive strategy are introduced for not only mating selection but also environmental selection, which increases the probability of generating excellent offspring. In addition, to remove dominance-resistant solutions (DRSs) in the population, an interquartile range method is adopted, which enhances the selection pressure. Moreover, a novel adaptive switching mechanism between angle-based selection and penalty for selecting solutions is proposed, which is aimed at achieving a balance between convergence and diversity. To validate the performance of KPEA, it is compared with five state-of-the-art many-objective evolutionary algorithms. All algorithms are evaluated on 20 benchmark problems, i.e., WFG1-9, MaF1, and MaF4-13 with 3, 5, 8, and 10 objectives. The experimental results demonstrate that KPEA outperforms the compared algorithms in terms of HV and IGD in most of the test instances.

To solve the high error phenomenon of microelectromechanical systems (MEMS) due to their poor signal-to-noise ratio, this paper proposes an online compensation algorithm wavelet threshold back-propagation neural network (WT-BPNN), based on a neural network and designed to effectively suppress the random error of MEMS arrays. The algorithm denoises MEMS and compensates for the error using a back propagation neural network (BPNN). To verify the feasibility of the proposed algorithm, we deployed it in a ZYNQ-based MEMS array hardware. The experimental results showed that the zero-bias instability, angular random wander, and angular velocity random wander of the gyroscope were improved by about 12 dB, 10 dB, and 7 dB, respectively, compared with the original device in static scenarios, and the dispersion of the output data was reduced by about 8 dB in various dynamic environments, which effectively verified the robustness and feasibility of the algorithm.

Objective The European Society of Intensive Care Medicine (ESICM) recently recommended changes to the criteria of acute respiratory distress syndrome (ARDS), patients with high-flow oxygen were included, however, the effect of these changes remains unclear. Our objectives were to evaluate the performance of these new criteria and to compare the outcomes of patients meeting the new ARDS criteria with those meeting the Berlin ARDS criteria. Methods This was a retrospective cohort. The patients admitted to the intensive care unit (ICU) were diagnosed with ARDS. Patients were classified as meeting Berlin criteria ARDS ( n  = 4279), high-flow nasal oxygen (HFNO) criteria ARDS ( n  = 559), or new criteria ARDS ( n  = 4838). Results In comparison with HFNO criteria ARDS and new criteria ARDS, patients with Berlin criteria ARDS demonstrated lower blood oxygen levels assessed by PaO 2 /FiO 2 , SpO 2 /FiO 2 , and ROX (SpO 2 /FiO 2 /respiratory rate) ( p  < 0.001); and higher severity of illness assessed by the Sequential Organ Failure Assessment (SOFA) score, Acute Physiology And Chronic Health Evaluations (APACHE II), Simplified Acute Physiology Score (SAPS II) ( p  < 0.001), ( p  < 0.001), and longer ICU and hospital stays ( p  < 0.001). In comparison with the HFNO criteria, patients meeting Berlin criteria ARDS had higher hospital mortality (10.6% vs. 16.9%; p  = 0.0082), 28-day mortality (10.6% vs. 16.5%; p  = 0.0079), and 90-day mortality (10.7% vs. 17.1%; p  = 0.0083). ARDS patients with HFNO did not have severe ARDS; Berlin criteria ARDS patients with severe ARDS had the highest mortality rate (approximately 33%). PaO 2 /FiO 2 , SpO 2 /FiO 2 , and ROX negatively correlated with the SOFA and APACHE II scores. The SOFA and APACHE II scores had high specificity and sensitivity for prognosis in patients with new criteria ARDS. Conclusion The new criteria of ARDS reduced the severity of illness, length of stay in the ICU, length of hospital stays, and overall mortality. SOFA and APACHE II scores remain important in assessing the prognosis of patients with new criteria ARDS. Trial registration Registration number: ChiCTR2200067084.

The distribution of proppant during hydraulic fracturing may directly contribute to the flow conductivity of the proppant fracture, so research on the migration and sedimentation of proppant in the fracture and the final distribution pattern is of great relevance. The mass conservation equations of proppant solids and fracturing fluid were adopted to describe the distribution of proppant migration and sedimentation in the fracture, improving the additional gravity coefficient by utilizing the density difference between proppant and fracturing fluid and the concentration of proppant, together with the proppant sedimentation velocity at different Reynolds numbers in this study. The flow coefficients were obtained by discretizing the system of equations through the finite volume method combined with the harmonic mean method and the upstream weight method. The concentration additional pressure gradient term was computed by using the Superbee format innovatively to improve the solution convergence of the model. Numerical simulations with identical parameters were compared with indoor test results, which fully verified the correctness of the model and the accuracy of the discrete solution based on the finite volume method. The effects of flow rate of fracturing fluid, ratio of injected sand, viscosity of fracturing fluid, grain size of proppant and density of proppant on proppant migration and sedimentation based on three elliptical fracture morphologies: even-wide, top-wide and bottom-narrow as well as top-narrow and bottom-wide were investigated and analyzed through comparing the rate of proppant front movement, the level of sweeping range and the degree of inhomogeneity in the range under different conditions. Findings of this study suggest that: (1) top-wide and bottom-narrow fractures are more preferable for homogenous sanding in the early stage of proppant injection, and top-narrow and bottom-wide fractures are best for sanding in the later stage; (2) the viscosity of fracturing fluid is the most influential factor on proppant migration and sedimentation, which increases in the range of 100 mPa.s to enhance the sweeping range and homogeneity of proppant sanding and therefore achieve a better fracturing effect.