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Nowadays, unmanned aerial vehicles (UAVs), empowered with the capability of high-definition image transmission, are used to capture the rapidly changing physical environment by leveraging its high flexibility to reconstruct an immersive realistic virtual environment for metaverse users. In this paper, we consider a novel UAV-assisted image acquisition system where a UAV is dispatched to take off from an initial location to capture real-time images of multiple ground targets and then transfer the captured images back to the ground user for virtual environment reconstruction. We aim to minimize the time for the UAV to complete the image acquisition task by optimizing the three-dimensional UAV trajectory under the constraints of image quality, information causality and energy consumption. To this end, we first formulate the investigated scenario into a mixed integer optimization problem, which, however, is difficult to solve due to the infinite time-varying variables closely coupled with each other. Then, a three-stage progressive algorithm is proposed to obtain an efficient solution to the formulated mixed integer optimization problem, where the constraints of image quality, information causality and energy consumption can be sequentially satisfied. Finally, comprehensive performance evaluation is conducted to verify the effectiveness of the proposed three-stage progressive trajectory design algorithm, and the results show that the proposed algorithm significantly outperforms the benchmark schemes.

As a typical demand of the next-generation wireless networks, numerous emerging applications impose stringent requirements on the timely and accurate sensing of the dynamical channel and the moving target. And radar with massive arrays could satisfy these requirements, imposing large power consumption and complexity. To this end, thanks to the energy-efficient and cost-effective characteristics, reconfigurable intelligent surface (RIS) has been considered as one of the most promising candidates for assisting environment sensing owing to its ability of manipulating the impinging signal. Inspired by this, we investigate a novel application of RIS for target tracking in high-mobility and three-dimensional scenario. Specifically, we consider a RIS-assisted integrated sensing and communication (ISAC) system where a RIS is deployed at the base station (BS) side. Exploiting the proposed predictive phase design strategy and collected echoes, the RIS tries to estimate the motion parameters of the potential targets. In particular, to fulfill the goal of precise and timely target tracking, we adapt a particle filtering (PF) based and an extended Kalman filtering (EKF) based state estimation algorithms, where both the observations at RIS side and the inherent state evolution information are well exploited. Furthermore, numerical results are provided to validate the effectiveness of the proposed predictive phase design strategy in various scenarios. The performance of EKF scheme is superior to the PF about 15% averagely with lower computational complexity.

Compressive spectrum sensing (CSS) is regarded as one of the promising techniques to detect wideband spectrum holes. How to formulate an accurate prior knowledge in CSS is still an important and open topic. In this paper, we propose a novel CSS algorithm with cascade forward-backward propagation and prior knowledge refining. Firstly, the wideband signal reconstruction model is formulated as a $\ell _{p}$ -norm ( $0 < p < 1$ ) nonconvex optimization problem where the temporal correlation between continuous observed spectrum signals is exploited to improve the reconstruction accuracy of the current spectrum signal, and such nonconvex optimization problem is solved by iteratively reweighted least squares algorithm. Then, the multiple reconstructed versions of the current spectrum signal obtained by forward-backward propagation are fused into a prior. Finally, such fused prior is modified adaptively in each iteration, and thus significantly improves the accuracy of spectrum decision and speeds up the convergence. The simulation results show that compared with other CSS schemes based on weighted $\ell _{1}$ minimization, $\ell _{1}$ - $\ell _{1}$ minimization, $\ell _{1}$ - $\ell _{2}$ minimization, and maximizing correlation, the proposed scheme has more than 7% and 10% detection performance improvement when the probability of false alarm is 10%, under received signal-to-noise ratio as −10 dB and −5 dB, respectively.

For LOX/LCH4 variable thrust rocket engine, the propellant methane is traditionally selected as the coolant in regenerative cooling channel (RCC). With the decrease of engine thrust, the mass flow rate of coolant methane decreases gradually. At low engine thrust, the coolant methane is usually in a subcritical state. The heat transfer deterioration of subcritical methane occurs in RCC, which may cause thrust chamber wall ablation. The two-phase pressure drop data of methane are crucial parameters for the design and optimization of RCC. But it is rarely to find such measured frictional pressure drop data of methane in open published literature. The two-phase pressure drop of methane during flow boiling in the single mini channels with the diameters of 2.0 mm are investigated systematically. Effects of the mass flux (582.19~1755.48 kg/m2·s), inlet pressure (0.56~3.55 MPa), heat flux (53.25~318.68 kW/m2) on the frictional pressure drop of methane are discussed. The results show that the frictional pressure drop of methane during flow boiling increases with mass flux and inlet pressure at the experimental conditions, and heat flux shows weak effect on the frictional pressure drop. The comparisons of the experimental data with the predicted value by existing six correlations are analyzed. Contrary to the conventional channels, homogeneous model yields better prediction than five separated flow models. Present experimental results can provide reference for the design and optimization of RCC in LOX/LCH4 rocket engine.

LOX/LCH4 rocket engine has been recognized as the ideal power choice for future space vehicles due to the merits of low cost, non-toxic and pollution-free, convenient maintenance, suitable for reuse and high specific impulse. In the process of wide range variable thrust of LOX/LCH4 rocket engine, the coolant methane is in a subcritical state due to the low combustor pressure under low operation conditions. The instability of two-phase flow is easy to occur in regenerative cooling channel (RCC), and it is urgent to investigate the heat transfer performance of methane with phase change in RCC. Experiments have been conducted to investigate the flow boiling characteristics of liquid methane in the single mini channels with the diameters of 1.0, 1.5 and 2.0 mm. Effects of the mass flux (266.75~1781.26 kg/m2·s), inlet pressure (0.56~4.24 MPa), heat flux (53.25~800.07 kW/m2) and channel diameter (1.0~2.0 mm) on the flow boiling heat transfer coefficients are tested. Results show that there are two regions with different heat transfer mechanism, one is the nucleate boiling dominated region for low mass quality and the other is the convection evaporation dominated region for high mass quality. A new correlation expressed by Bo, We, Kp, X, Co, Ftg is proposed, which yields good fitting for 355 experimental data with a mean absolute error (MAE) of 10.9%. Present experimental results can provide reference for the thermal protection prediction and optimal design of RCC in LOX/LCH4 rocket engine.

To realize the recycling of magnesium sulfate wastewater in the hydrometallurgy and separation process of Baotou mixed rare earth (RE) concentrate, the research on preparation of magnesium bicarbonate (Mg(HCO3)2) solution from magnesium sulfate solution by CO2carbonation, extraction separation and transformation of RE sulfate solution by saponified HDEHP was investigated. The key influencing factors and carbonation mechanism in the preparation of Mg(HCO3)2, and the distribution of RE, calcium and magnesium elements in the saponification extraction were systematically studied. The results show that the conversion of Mg(HCO3)2during carbonation is inhibited by calcium sulfate, but promoted by increasing the concentration of magnesium sulfate and decreasing the carbonation temperature. Under the optimized conditions, Mg(HCO3)2solution with impurities (such as Fe, Al and Si) of less than 15 mg/L is prepared stably and efficiently, and the conversion rate of Mg(HCO3)2is more than 95%. After multi-stage cascade extraction of RE sulfate solution, the RE extraction recovery is greater than 99.5%. Calcium sulfate crystals do not precipitate during the process, and the raffinate phase is magnesium sulfate solution that is used for the preparation of Mg(HCO3)2solution.

Unmanned aerial vehicle (UAV) can be combined with virtual reality (VR) to collect the rapidly changing physical environment by leveraging its high flexibility, so as to provide an immersive experience for metaverse users. In this letter, we study the UAV placement problem in UAV-assisted VR systems where UAVs are deployed to capture images of ground targets and then transmit them to ground users for virtual environment reconstruction. The goal is to minimize the transmission delay while satisfying the image resolution requirement. Firstly, the UAV placement problem is formulated into a non-convex optimization problem. Then, an efficient algorithm is proposed to obtain a high-quality solution by adopting the block coordinate descent and successive convex approximation techniques with low complexity. Finally, the numerical results are provided and show that considerable benefits can be obtained with a suboptimal UAV placement. Specifically, the proposed scheme can reduce the transmission delay by over 15 ms compared to the conventional scheme when the received signal-to-noise ratio at the reference distance is $10^{6}$ and the resolution requirement is 0.5.

In cognitive radios (CR), compressive spectrum sensing (CSS) is a promising technique to detect wideband spectrum holes with reduced sampling rate requirement of analog-to-digital converter (ADC). It is implied in compressive sensing (CS) that the minimum sampling rate is determined by the sparsity order of the observed wideband signal. Unfortunately, the sparsity order is previously unknown and dynamically varies. Meanwhile, CS technology fails to work efficiently for the nonsparse spectrum case. For example, the CSS performance degenerates significantly for low signal-to-noise ratio (SNR) scenarios since the observed signal becomes nonsparse in frequency domain. To overcome the above-mentioned challenges, we propose a novel CSS algorithm with temporally-correlated prior knowledge mining (TPKM-CSS) to detect spectrum holes without a prior sparsity order information. The proposed scheme can handle both the sparse and nonsparse spectrum cases. The proposed solution has three contributions: firstly, CR implements multiple parallel sampling simultaneously to acquire wireless spectrum signals, which have a low-rank spectrum matrix. Secondly, the temporal correlation between continuous CS data is further exploited to improve the estimation accuracy of the current spectrum. Finally, the theoretical performance of the proposed TPKM-CSS is evaluated, wherein the cumulative distribution function (CDF) of the spectrum reconstruction error is derived in the closed form. The simulation results show that the proposed scheme works well for both sparse and nonsparse spectrum scenarios. Compared with the CSS schemes that are based on low-rank matrix recovery (LMR-CSS), maximizing correlation (MC), iterative compressive filtering (ICF), or Bayesian CS (BCS), the proposed scheme yields the superior performance in terms of the probability of detection and the probability of false alarm, especially for nonsparse signals. Furthermore, the simulated statistical performance of the spectrum reconstruction error matches well the theoretical CDF curve.

Plant diseases caused by bacteria have become one of the serious problems that threaten human food security, which led to the remarkable reduction of agricultural yields and economic loss. Nitroreductase (NTR), as an important biomarker, is highly expressed in bacteria, and the level of NTR is closely related to the progression of pathogen infection. Therefore, the design of small-molecule fluorescent sensors targeting NTR is of great significance for the detection and diagnosis of plant pathogenic bacteria. In this study, a new fluorescent sensor targeting NTR was discovered and then successfully applied to the imaging of zebrafishand pathogenic bacteria. Most importantly, the developed sensor achieved the real-time diagnosis of Brassica napusL. infected with bacteria, which provides a promising tool for examining the temporal and spatial infection of plant pathogens in precision agriculture.

Metallic materials with unique surface structure have attracted much attention due to their unique physical and chemical properties. However, it is hard to prepare bulk metallic materials with special crystal faces, especially at the nanoscale. Herein, we report an efficient method to adjust the surface structure of a Cu plate which combines ion implantation technology with the oxidation–etching process. The large number of vacancies generated by ion implantation induced the electrochemical oxidation of several atomic layers in depth; after chemical etching, the Cu(100) planes were exposed on the surface of the Cu plate. As a catalyst for acid hydrogen evolution reaction, the Cu plate with (100) planes merely needs 273 mV to deliver a current density of 10 mA/cm2because the high-energy (100) surface has moderate hydrogen adsorption and desorption capability. This work provides an appealing strategy to engineer the surface structure of bulk metallic materials and improve their catalytic properties.

Supplemental Digital Content is available in the text.

BackgroundCancer cachexia is a complex metabolic syndrome characterised by a loss of muscle with or without loss of fat mass, and is associated with high morbidity and mortality. Despite its clinical importance, there is a lack of simple tools to screen patients for cancer cachexia. The aim of this study was to evaluate and validate the patient-generated subjective global assessment (PG-SGA) as a screening tool for cancer cachexia.MethodsThis is a secondary analysis of a multicentre, cross-sectional, observational study. Cancer cachexia was diagnosed when there was weight loss ≥5% during the past 12 months and at least three of the five following conditions were present: decreased muscle strength, fatigue, anorexia, low Fat-Free Mass Index (FFMI) and abnormal laboratory findings. A quadratic discriminant analysis was conducted for the ability of PG-SGA to predict cachexia.ResultsA total of 4231 patients with cancer were included in this analysis, and 351 patients (8.3%) were diagnosed as having cachexia. The highest incidence of cachexia was found among patients with pancreatic cancer (32.5%), oesophageal cancer (21.5%) and gastric cancer (17.9%). Compared with patients without cachexia, patients with cachexia had a lower body mass index, FFMI, hand grip strength, total protein, prealbumin, albumin, haemoglobin and Karnofsky performance status (p<0.05), while they had a higher C reactive protein level and PG-SGA Score (4.71±3.71 vs 10.87±4.84, p<0.05). The best cut-off value for PG-SGA was 6.5, with 79.8% of sensitivity and 72.3% specificity for cachexia, and the area under the receiver operating characteristic curve was 0.846 (95% CI 0.826 to 0.866, p<0.001).ConclusionsPG-SGA is a highly specific tool that can be used to screen patients for cancer cachexia.

The temperature-dependent absorption coefficient and thermal conductivity of a quartz window are obtained through experimental tests at a wide range of temperatures. A Fourier transform infrared spectrometer with a heated cavity is used for performing the transmittance measurements. The spectral absorption coefficient of the quartz window is inverted by the transmittance information at different temperatures using a genetic algorithm. Then, a quartz window-graphite plate-quartz window multilayer structure is designed, and the transient response of the structure subjected to high-temperature heating is recorded by a self-designed setup. Cooperating with the above absorption coefficient, a non-gray radiative-conductive heat transfer model is built for the multilayer structure, and the intrinsic thermal conductivity of the quartz window is identified. Finally, the effects of the temperature-dependent absorption coefficient and spectral selective features of the medium on the heat transfer characteristics are discussed. The results show that the absorption coefficient gradually increases with temperature. The intrinsic thermal conductivity of the quartz window varies from 1.35 to 2.52 W/(m·K) as the temperature rises, while the effective thermal conductivity is higher than the intrinsic thermal conductivity due to thermal radiation, specifically 26.4% higher at 1100 K. In addition, it is found that the influence of the temperature-dependent absorption coefficient on temperature of unheated side shows a trend of first increasing and then decreasing. When the absorption coefficient varies greatly with wavelength, a non-gray radiative-conductive heat transfer model should be built for the semitransparent materials.

Soil salinization is a vital factor limiting crop yield in dryland oasis cropland. A film‐mulched drip irrigation and subsurface pipe drainage (MDI‐SPD) system has been proved to be highly efficient at mitigating salination globally. However, the soil salt balance in time and spatial dimension is unclear in this system. A MDI‐SPD experiment was conducted for 4 yr (2015–2019) in a field in Manas River Basin, western China. The subsurface drainage pipes were installed at a depth of 1 m with a space of 15 m. Three long‐term observation points were set at 0, 5, and 7.5 m horizontal from the subsurface pipe and served as long‐term observation points in 0‐to‐20‐, 60‐to‐80‐, and 180‐to‐200‐cm soil layers. Results after 4 yr indicated that the total salt output in the irrigated area was 260 t, with 103 t of salt drained by the subsurface pipe (40% of the total salt output in the irrigation area), and the seed cotton yield increased by 52%. Soil salt balance indicated desalination. The electrical conductivity (EC) of subsurface pipe drainage was positively correlated with drainage flow and salt discharge and negatively correlated with drainage discharge and time (P< .05). If salt leaching stops, soil EC at the 0‐to‐200‐cm depth could reach 15 dS m–1in 8 yr. Thus, two or three uses of MDI‐SPD measures in the next 8 yr should suffice to maintain the soil salt at a low concentration. An increase in shaft drainage would also reduce the deep seepage of salt. Results from a 4‐yr study showed that using drip irrigation with subsurface pipe systems improved cotton yield.Subsurface pipe systems drained 103 t salt, 40% of the total salt discharge over 4 yr.We quantified salt accumulation due to shallow groundwater recharge in the tillage layer.Subsurface pipe systems increased cotton yield by 52% in saline alkali land.Soil salt should be leached once every 3 yr without changing the leaching measures.

Stray radiation analysis coupled with a temperature field is performed for a semitransparent window, focusing on the temperature-dependent optical properties. The transient temperature response of the optical window-based encapsulation structure is first investigated under an external transient high-heat flux loading. The spectral selectivity of the window to thermal radiation is involved. Subsequently, several typical cases for stray radiation are conducted, considering the inhomogeneous optical properties caused by the temperature heterogeneity. It is found that the stray radiation distribution is more chaotic compared to the results with optical properties independent of temperature. In addition, the stray radiation power has a large deviation (150%) if one neglects the temperature dependence. Meanwhile, the difference in wave band power decreases with the wavelength rising. Additionally, the stray radiation power generated by the window is far less in the visible wave band than that in the near-infrared wave band. The results reveal that the temperature dependence in optical properties of a semitransparent window should be seriously considered when calculating the stray radiation, especially in high-precision detection devices.

•Spherical volume elements scheme to calculate the van der Waals force is proposed.•By defining effective zones, the computational time is reduced from hours to minutes.•The spherical volume elements can fill in the bodies with arbitrary complex shapes.•The calculated force distributions is good agreement with the exist experimental data.

ABSTRACTIn order to explore new prediction methods and key genes for gastric cancer. Firstly, we downloaded the 6 original sequencing data of gastric cancer on the Illumina HumanHT-12 platform from Array Expression and Gene Expression Omnibus, and used bioinformatics methods to identify 109 up-regulated genes and 271 down-regulated genes. Further, we performed univariate Cox regression analysis of prognostic-related genes, then used Lasso regression to remove collinearity, and finally used multivariate Cox regression to analyze independent prognostic genes (MT1M, AKR1C2, HEYL, KLK11, EEF1A2, MMP7, THBS1, KRT17, RPESP, CMTM4, UGT2B17, CGNL1, TNFRSF17, REG1A). Based on these, we constructed a prognostic risk proportion signature, and found that patients with high-risk gastric cancer have a high degree of malignancy. Subsequently, we used the GSE15459 data set to verify the signature. By calculating the area under the recipient operator characteristic curve of 5-year survival rate, the test set and verification set are 0.739 and 0.681, respectively, suggesting that the prognostic signature has a moderate prognostic ability. The nomogram is used to visualize the prognostic sig-nature, and the calibration curve verification showed that the prediction accuracy is higher. Finally, we verified the expression and prognosis of the hub gene, and suggested that HEYL, MMP7, THBS1, and KRT17 may be potential prognostic biomarkers.

Based on the structures of isoxaflutole (IFT) and N-isobutyl-N-(4-chloro-benzyl)-4-chloro-2-pentenamide, a series of N-benzyl-5-cyclopropyl-isoxazole-4-carboxamides was designed by connecting their pharmacophores (i.e., a multitarget drug design strategy). A total of 27 N-benzyl-5-cyclopropyl-isoxazole-4-carboxamides were prepared from 5-cyclopropylisoxazole-4-carboxylic acid and substituted benzylamines, and their structures were confirmed by NMR and MS. Laboratory bioassays indicated that I-26showed 100% inhibition against Portulaca oleraceaand Abutilon theophrastiat a concentration of 10 mg/L, better than the positive control butachlor (50% inhibition for both weeds). A strong growth inhibition was observed, but a typical bleaching phenomenon of IFT could not be observed in the Petri dish assay. I-05displayed excellent postemergence herbicidal activity against Echinochloa crusgalliand A. theophrastiat a rate of 150 g/ha, and bleaching symptoms were observed in the leaves of treated weeds. The bleaching effect of Chlamydomonas reinhardtiitreated by I-05could be reversed by adding homogentisate. Enzymatic bioassays indicated that I-05could not inhibit 4-hydroxyphenylpyruvate dioxygenase (HPPD) activity, but II-05, an isoxazole ring-opening product of I-05, could inhibit HPPD activity with an EC50value of 1.05 μM, similar to that of mesotrione (with an EC50value of 1.35 μM). Detailed discussion about observed herbicidal symptoms is provided in the Results and Discussion section. This investigation provided a proof-of-concept foundation that a multitarget drug design strategy could be applied in agrochemical research.

Plasmonic Fano resonance (FR) that contributes to multitudinous potential applications in subwavelength nanostructures can facilitate the realization of tunable wavelength selectivity for controlling light–matter interactions in metasurfaces. However, the plasmonic FR can be generated in metasurfaces with simple or complex geometries, and few of them can support flexible amplitude modulation and multiwavelength information transfer and processing. Here, we study the near-infrared plasmonic FR in a hybrid metasurface composed of concentrically hybridized parabolic-hole and circular-ring-aperture unit cells, which can induce polarization-dependent dual-wavelength passive plasmonic switching (PPS) and digital metasurface (DM). It is shown that the designable plasmonic FR can be realized by changing the geometric configurations of the unit cells. In particular, owing to the polarization-dependent characteristic of FR, it is possible to fulfill a compact dual-wavelength PPS with high ON/OFF ratios in the related optical communication bands. Moreover, such PPS that manipulates the amplitude response of the transmitted spectrum is an efficient way to reveal a 1-bit DM, which can also be rationally extended to a 2-bit DM or more. Our results suggest a pathway for studying polarization-dependent PPS and programmable metasurface devices, yielding possibilities for subwavelength nanostructures in optical communication and information processing.

ABSTRACTThis study focused on the role of methionine (MET) in the autophagy of gastric cancer stem cells (GCSCs) and aims to elaborate its regulatory mechanism.In the present study, the GCSCs were isolated from human gastric cancer cell lines using an anti-CD44 antibody, and then cultured in MET+homocysteine (HCY)−or MET−HCY+medium.In MET+HCY–treated GCSCs, autophagy was suppressed, the methylation and phosphorylation of RAB37 were elevated, and miR-200b expression was down-regulated. Lentiviral vector (LV-) carrying methionine-γ lyase (an enzyme that could specifically lyse MET; Metase) promoted autophagy, reduced the methylation and phosphorylation of RAB37, and up-regulated miR-200b expression in MET+HCY–-treated GCSCs. Then, we found that miR-200b suppressed the expression of protein kinase C α (PKCα), a protein that could inactivate RAB37 through promoting its phosphorylation. LV-Metase down-regulated RAB37 phosphorylation via miR-200b/PKCα, thus promoting the RAB37-mediated autophagy and suppressing cell viability in MET+HCY–treated GCSCs. Finally, the in vivostudy proved that LV-Metase treatment inhibited tumor growth through up-regulating RAB37 expression.In conclusion, MET suppressed RAB37 expression via enhancing its methylation and suppressed RAB37 activity via miR-200b/PKCα axis, thus repressing RAB37-mediated autophagy in GCSCs. The supplementation of Metase lysed MET, thus inducing the autophagy of GCSCs and inhibiting tumor growth.

(±)-Melipatulinones A–C (1–3), three unique enantiomeric pairs of lignan–phloroglucinol hybrids along with the biogenetically related compound melipatulignan A (4), were isolated from the leaves of Melicope patulinervia. Melipatulinones A (1) and B (2) share a novel spiro[hydrobenzofuran-2,3′-furan] 5/5/6 tricyclic ring system, while melipatulinone C (3) features an unprecedented spiro[cyclopenta[b]hydrofuran-2,3′-furan] 5/5/5 tricyclic framework. Their structures were determined by spectroscopic methods, electronic circular dichroism (ECD) calculations, and X-ray diffraction. Compounds 1–3exhibited a pancreatic lipase inhibitory effect.

Timosaponin AIII (Timo AIII) is a natural steroidal saponin isolated from the traditional Chinese herb Anemarrhena asphodeloidesBge with proved effectiveness in the treatment of numerous cancers. However, whether Timo AIII suppresses tumor angiogenesis remains unclear. In the present study, we investigated the antiangiogenesis effects of Timo AIII and the underlying mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and zebrafish embryos in vivo. We showed that treatment with Timo AIII (0.5–2 µM) partially disrupted the intersegmental vessels (ISVs) and subintestinal vessels (SIVs) growth in transgenic zebrafish Tg(fli-1a: EGFP)y1. Timo AIII (0.5–4 µM) dose-dependently inhibited VEGF-induced proliferation, migration, invasion, and tube formation of HUVECs, but these inhibitory effects were not due to its cytotoxicity. We further demonstrated that Timo AIII treatment significantly suppressed the expression of VEGF receptor (VEGFR) and the phosphorylation of Akt, MEK1/2, and ERK1/2 in HUVECs. Timo AIII treatment also significantly inhibited VEGF-triggered phosphorylation of VEGFR2, Akt, and ERK1/2 in HUVECs. Moreover, we conducted RNA-Seq and analyzed the transcriptome changes in both HUVECs and zebrafish embryos following Timo AIII treatment. The coexpression network analysis results showed that various biological processes and signaling pathways were enriched including angiogenesis, cell motility, cell adhesion, protein serine/threonine kinase activity, transmembrane signaling receptor activity, growth factor activity, etc., which was consistent with the antiangiogenesis effects of Timo AIII in HUVECs and zebrafish embryos. We conclude that the antiangiogenesis effect of Timo AIII is mediated through VEGF/PI3K/Akt/MAPK signaling cascade; Timo AIII potentially exerts antiangiogenesis effect in cancer treatment.

Multidimensional critical regulation of water resources in a typical arid area, such as in the Manas River Watershed in China, is an important way to solve the contradiction between water supply and demand and realize sustainable development. Typically, water managers do not take into account the coordinated development of various water sources and water sectors. To solve this problem, we used a system dynamics model to analyze the supply and demand of water resources in the planning year, and establish a critical control model with four dimensions (water resources, economy, society and ecology) to optimally regulate water resources. The results show that (1) the water resources system entropy was reduced to 0.1506 after several iterations in the planning year; (2) the water resources subsystem, economic subsystem and social subsystem were negatively correlated with system entropy, while the ecosystem subsystem was positively correlated with it; and (3) the reduced water shortage will increase from 2.27×108m3in 2020 to 3.76×108m3in 2030, which indicates that the water resources system will develop in an orderly and coordinated way.

•A double-sided asymmetric cooling device was designed for thermophotovoltaic cells (TPVC).•A three-dimension model for the thermal management of TPVC under high-flux irradiation was developed.•A double-sided asymmetric cooling scheme has a better cooling effect and energy conversion efficiency.•The temperature uniformity of TPVC is significantly improved under high-flux irradiation.

ApUGT, a diterpene glycosyltransferase from Andrographis paniculata, could transfer a glucose to the C-19 hydroxyl moiety of andrograpanin to form neoandrographolide. This glycosyltransferase has a broad substrate scope, and it can glycosylate 26 natural and unnatural compounds of different structural types. This study provides a basis for exploring the glycosylation mechanism of ent-labdane-type diterpenes and plays an important role in diversifying the structures used in drug discovery.

The biomedical co-continuous (β-TCP+MgO)/Zn-Mg composite was fabricated by infiltrating Zn-Mg alloy into porous β-TCP+MgO using suction exsorption technique. The microstructure, mechanical properties and corrosion behaviors of the composite were evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, electrochemical and immersion test. It was found that the molten Zn-Mg alloy had infiltrated not only into the pores but also into the struts of the porous β-TCP+MgO scaffold to form a compact composite. The Zn-Mg alloy contacted to the β-TCP+MgO scaffold closely, and no reaction layer can be found between the alloy and the scaffold. The compressive strength of the composite was as high as 244 MPa, which was about 1000 times higher than that of the original porous β-TCP+MgO scaffold and 2/3 of the strength of the Zn-Mg bulk alloy. The electrochemical and immersion tests in simulated body fluid (SBF) solution indicated that the corrosion resistance of the composite was better than that of the Zn-Mg bulk alloy. The corrosion products on the composite surface were mainly Zn(OH)2. Appropriate mechanical and corrosion properties indicated that the (β-TCP+MgO)/Zn-Mg composite fabricated by suction exsorption would be a very promising candidate for bone substitute.

Type-I clathrates have been considered as very promising thermoelectric (TE) materials thus attracting attention widely. Here we report new clathrates Ba8CuxSiyGe46-x-y (4≤ x ≤ 6.5, y = 0 and 5.15 ≤ x ≤ 6.425, 2.05≤ y ≤ 36.9), focusing on their phase purity and TE properties. Our results show that samples prepared by arc melting followed by annealing are multi-phases alloys. The composition of the clathrate phase is also inhomogeneous. This indicates that the kinetic factor dominates the reaction of forming the clathrate phase during element-melting and sample-annealing. We select three compositions in these two series of samples, which have less impurity and better composition homogeneity for the clathrate phase, and the annealed alloys are furthered processed by ball milling (BM) and powder-solidification (either by hot pressing (HP) or by spark plasma sintering (SPS)) for TE properties investigations. The BM and HP/SPS processes can improve the phase purity and homogeneity. The TE measurements show that the Si-substituted samples have better performance than the Ge-based sample, mainly by decreasing the electrical resistivity. This indicates that the elemental substitution may be still an effective way to improve the TE performance of clathrates.

Olfaction plays an instrumental role in host plant selection by phytophagous insects. Helicoverpa assultaand Helicoverpa armigeraare two closely related moth species with different host plant ranges. In this study, we first comparatively analyzed the function of 11 female-biased odorant receptors (ORs) and their orthologs in the two species by the DrosophilaT1 neuron expression system and then examined the electroantennography responses of the two species to the most effective OR ligands. Behavioral assays using a Y-tube olfactometer indicate that guaiene, the primary ligand of HassOR21–2 and HarmOR21–2, only attracts the females, while benzyl acetone, the main ligand of HassOR35 and HarmOR35, attracts both sexes of the two species. Oviposition preference experiments further confirm that guaiene and benzyl acetone are potent oviposition attractants for the mated females of both species. These findings deepen our understanding of the olfactory coding mechanisms of host plant selection in herbivorous insects and provide valuable attractants for managing pest populations.

ObjectiveCatheter ablation is commonly performed for ventricular tachycardia (VT) in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The success rate of VT ablation, either conventional endocardial strategy or recent combined endocardial and epicardial approach, in ARVD/C patients still remains to be determined because of the relatively small sample sizes and various outcomes of previous studies.MethodsPubMed, EMBASE and Cochrane Library were comprehensively searched from their inception until September 2015. All studies have to report acute and long-term efficacy of VT ablation in ARVD/C patients. Data was extracted and analysed according to pre-defined criterions.ResultsEight eligible studies were identified. The mean follow-up duration ranged from 13 to 41 months (median 20 months). The acute efficacy of VT ablation in ARVD/C patients was high, regardless of the ablation strategy. Pooled estimate of acute efficacy was 96% (95% CI: 87%–100%) for endocardial ablation strategy and 98% (95% CI: 91%–100%) for endo-epicardial ablation strategy. Pooled estimate for long-term efficacy with endo-epicardial ablation strategy (82%, 95% CI: 72%–90%) was numerically higher than individual endocardial ablation strategy (63%, 95% CI: 51%–74%).ConclusionsThe current evidence suggests that VT ablation in ARVD/C patients is feasible with a high acute and long-term efficacy. Combined endocardial and epicardial ablation strategy is associated with a numerically better outcome of long-term efficacy than individual endocardial ablation strategy.

The last few decades have witnessed an increasing emphasis on the development of strain-based approach for predicting the creep life or damage of components operating at elevated temperatures. Creep ductility, as a key parameter in this approach, may vary with a number of factors including strain rate, state of stress, operating temperature, material microstructure, etc. The present paper, however, is focused on reviewing the state-of-the-art understanding of the effects of stress level and stress state on the creep ductility. Mechanisms involving the void growth and coalescence are presented to describe the role of stress level in the variation of uniaxial creep ductility. The prediction capacity of existing empirical ductility models is also assessed in light of uniaxial test data. On the other hand, a vast body of multiaxial creep test data, collected from open literature, is utilized to examine the influence of the state of stress on the creep ductility. Then, a variety of multiaxial ductility factor models are introduced and evaluated with the available experimental data. Finally, a brief discussion on the dependence of creep ductility on the stress triaxiality and Lode parameter, predicted by numerical methods, is provided. [ABSTRACT FROM AUTHOR]

In vehicular ad-hoc network (VANET), the reliability of communication is associated with driving safety. However, research shows that the safety-message transmission in VANET may be congested under some urgent communication cases. More spectrum resource is an effective way to solve transmission congestion. Hence, we introduce cognitive radio (CR) enabled VANET (CR-VANET), where CR device can detect possible idle spectrum for VANET communications and assist to timely broadcast safety-message. Given high-speed mobility of vehicles and dynamically-changing availability of channels, a novel prediction algorithm is proposed to pick out the channel with the greatest probability of availability, which can meet the quality of service (QoS) requirement of urgent communications and effectively avoid conflict with licensed users. Specifically, the spatiotemporal correlations among historical spectrum sensing data are exploited to form prior knowledge of channel availability probability, and Bayesian inference is used to derive posterior probability of channel availability. Comparing with other spectrum detection methods, the proposed algorithm has more than 8 percent detection performance improvement at false alarm probability 0.2, and thus can avoid access conflict with licensed users dramatically. Furthermore, the proposed algorithm always has larger packet reception probability (PRP) and lower transmission delay compared with conventional VANET broadcasting. Hence, the proposed algorithm can improve reliability of safety-message transmission and enhance driving safety significantly.

In the thermophotovoltaic (TPV) system, thermophotovoltaic cells can produce a high output power density. According to existing research results, concentrated irradiance is adopted to achieve high‐level thermophotovoltaic cell output. However, irradiance nonuniformity on the surface of the thermophotovoltaic cell can occur when the energy is concentrated. Such nonuniformity will destroy the balance of temperature and cause a spectrum mismatch of the cell, which will also reduce the reusability. To address these problems, a single spectral TPV optical path with spectral selectivity is proposed. Between the filter and the thermophotovoltaic cell module, a four‐prismatic straight funnel is designed and added. The Monte Carlo ray‐tracing method is used to examine the irradiance intensity and uniformity of the cell surface. The current–voltage characteristics of the cell module are computed using a single‐diode model. The results indicate that the uniformity of the TPV cell module can be maintained above 90% and the average cell module power density is 0.0861 W cm−2with the addition of a four‐prismatic straight funnel. Meanwhile, the network efficiency and the system efficiency are 82.76% and 4.56%, respectively. A single spectral thermophotovoltaic (TPV) optical path with spectral selectivity is proposed. Between the filter and the TPV cell module, a four‐prismatic straight funnel is designed and added. This novel design is significant in achieving high irradiance intensity in a single spectrum.

The sliding electrical contact behavior of AuAgCu brush on Au plating was investigated at various normal loads and sliding speeds. The contact voltage drop and electrical noise between the two brushes were measured and the resistance waveforms were recorded. The morphologies of the worn surfaces and wear debris of the brush and plating were observed. The results show that the contact voltage drop and electrical noise decrease with the addition of load whereas increase drastically with increasing sliding speed. With the electrical current in vacuum, the wear process of AuAgCu brush on Au plating involves adhesion, transfer of gold from the plating to the brush, rolling of wear debris between contact surfaces and arc-induced melt at the contact edge, and this gold-on-gold sliding electrical contact system is reliable within experiment period.

Composites are getting more and more attention in the usage of major structures on ships owing to many advantages such as high specific strength and rigidity. However, composites are sensitive to impact, which indicates that the load-carrying capacity and stability of composite structures will decrease dramatically even for an invisible impact damage. Hence, a real-time impact monitoring system which has already been applied in aviation industry is important for reliability of ships, which inevitably encounter impacts during their lifetime due to different sources. This paper deals with the realization of an operational processing scheme to monitor the impact on composite structures, and estimate the impact location and load history by power distribution approach and system identification method. A PZT (piezoelectric lead zirconate titanate) sensor network was designed and employed to collect sensing signals for monitoring the impact. In the monitoring process, stress wave signals caused by impact were captured, and used to determine the impacted location and load history. Results demonstrate that the proposed method can be successfully applied in identifying the location and load history of impact on composite structures. The impact identification approach is of great significance for marine applications.

Low price of wheat starch as a wide range of sources of edible film substrate, glycerol as a plasticizer, pullulan as a film-forming agent, prepared by solution casting of wheat starch-based edible green packaging materials. Tests were run on wheat starch-based edible films to determine mechanical properties, transparency and color evaluation. It was observed that the increase of the glycerol content in the wheat starch films increased the macromolecular mobility, the wheat starch films became less stiff and more flexible. Meanwhile the transparency and yellow index are both increased, obviously.

Metal packaging waste accounts for about 10% of total packaging waste and possesses the quality of high resource-consumption and high environmental pollution. This paper presents: 1) the design of the production process, based on the core of easy recycling in the metal packaging life cycle; 2) improve the legal framework, strengthen publicity and management, further refine metal packaging waste classification, encourage people participate in recycling through interest, set up model demonstrations; 3) through scientific and technological innovation, advance recycling level to improve the current situation of low recovery, low utilization level.

Low price of potato starch as a wide range of sources of edible film substrate, glycerol as a plasticizer, pullulan as a film-forming agent, prepared by solution casting of potato starch-based edible environment-friendly packaging materials. Tests were run on potato starch-based edible films to determine mechanical properties, transparency and color evaluation. It was observed that the increase of the glycerol content in the films increased the macromolecular mobility, the potato starch films became less stiff and more flexible. Meanwhile the transparency and yellow index are both increased, obviously.

A novel bisbenzimidazolylpyridine-functionalized fluorescent epoxy resin was synthesized for organophosphate pesticide detection.

The emergence of visual big data is a doubleedged sword to mobile communications. On one hand, the massive scale of visual data transmission brings a huge challenge to the RAN. On the other, the abundant information in visual big data may improve the spectrum efficiency and robustness of visual communications. In this article, we propose a DaC-RAN architecture for visual communications, which integrates the ideas of SDN and C-RAN. We propose to separate the control and data planes in the conventional infrastructure, and integrate a new data plane specifically designed for visual communications into the virtual base station. We demonstrate the proposed DaC-RAN architecture through a practical visual communication system based on pseudo-analog transmission and CSbased data sampling and reconstruction. The correlation information retrieved from visual big data is utilized as prior knowledge in CS decoding. Preliminary simulation evaluations show that significant gain is achieved in spectrum efficiency over the conventional method.

Nanostructured Ba-Cu-Si clathrate powders were synthesized by mechanical milling using different amounts of process control agent (PCA). We investigated systematically the effects of PCA on the phase constitution and crystallite size of nanopowders using X-ray diffraction (XRD) as well as the particle size and morphology by scanning electron microscopy (SEM). The PCA increases the powder yield by reducing the powder agglomeration. No detectable reaction occurred between the PCA and the clathrate phase, and thus the composition of the clathrate phase is unchanged after milling. Compared to the powders milled without PCA, the crystalline size of powders with PCA is reduced from about 70 to about 50 nm.

The power energy storage in battery transfers to capacitors through thyristor in hybrid energy storage, which makes the instantaneous power amplified. As the switch in Hybrid energy storage, the thyristor must satisfy its opening requirements , besides, the characteristics of the hybrid energy storage system is considered to design the width of trigger pulse, otherwise the thyristor can’t be opened that leads to failure of energy transfer. In this paper, the model of the system is established, the function of current to time is derived from the model, and then the minimum width of trigger pulse is calculated out. The simulation and experiment results are presented, which match with the designation well.

In this paper, a kind of Linear Synchronous Motor (LSM) with Permanent Magnet (PM) arranged in Halbach array and IronLess Coil (PMH&ILC) is presented for Magnetic Levitation Vehicles (Maglev). First, the propulsion force of this kind of LSM is deduced analytically. Then, the influences of pole spacing, the current in the coil, the width of the motor and the size of the Halbach array on the propulsion force are analyzed mathematically in detail. Based on the results, the design method and basic principle of PMH&ILC-typed LSM are proposed, which shows a better performance with small pole spacing, higher permanent magnet array, optimal value of the width of the permanent magnet Halbach and so on. Finally, a sample LSM system is designed according to the requirements of Maglev propulsion system.

To estimate the influences of uncertain factors on the modeling error of maglev vehicles, the single electro-magnet is taken as the object in this paper. Researches on the model-building error are carried out, including factors of the uncertainty of the inductor, the elasticity of the guideway and the coupling between Modules. Also, the model-building errors are analyzed numerically from the view of L∞ norm. And the calculation results are presented, which shows severe model-building severe error with the simplified model. The results are revelatory to comprehend the phenomena of the vehicle’s vibration, and to search after new methods of levitation control for EMS maglev vehicles.

In this paper, the sensing principle of a B-dot probe to measure the armature position was analyzed. The output waveforms of the probe for two different orientations were given after mathematical deduction. An electromagnetic launching experiment was conducted, and the result shows that the output waveforms of the probes can present the velocity trend of the armature. After data fitting, the velocity of the armature moving in the bore was given, and combined with the waveform of the muzzle voltage, the muzzle velocity was obtained, which matched the measurement result by a high speed camera well.