57 research outputs found

    Gigahertz-rate-switchable wavefront shaping through integration of metasurfaces with photonic integrated circuit

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    Achieving spatiotemporal control of light at high-speeds presents immense possibilities for various applications in communication, computation, metrology, and sensing. The integration of subwavelength metasurfaces and optical waveguides offers a promising approach to manipulate light across multiple degrees of freedom at high-speed in compact photonic integrated circuit (PICs) devices. Here, we demonstrate a gigahertz-rate-switchable wavefront shaping by integrating metasurface, lithium niobite on insulator (LNOI) photonic waveguide and electrodes within a PIC device. As proofs of concept, we showcase the generation of a focus beam with reconfigurable arbitrary polarizations, switchable focusing with lateral focal positions and focal length, orbital angular momentum light beams (OAMs) as well as Bessel beams. Our measurements indicate modulation speeds of up to gigahertz rate. This integrated platform offers a versatile and efficient means of controlling light field at high-speed within a compact system, paving the way for potential applications in optical communication, computation, sensing, and imaging

    A network access control framework for 6LoWPAN networks

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    Low power over wireless personal area networks (LoWPAN), in particular wireless sensor networks, represent an emerging technology with high potential to be employed in critical situations like security surveillance, battlefields, smart-grids, and in e-health applications. The support of security services in LoWPAN is considered a challenge. First, this type of networks is usually deployed in unattended environments, making them vulnerable to security attacks. Second, the constraints inherent to LoWPAN, such as scarce resources and limited battery capacity, impose a careful planning on how and where the security services should be deployed. Besides protecting the network from some well-known threats, it is important that security mechanisms be able to withstand attacks that have not been identified before. One way of reaching this goal is to control, at the network access level, which nodes can be attached to the network and to enforce their security compliance. This paper presents a network access security framework that can be used to control the nodes that have access to the network, based on administrative approval, and to enforce security compliance to the authorized nodes

    Synthesis and Application of Carbon–Iron Oxide Microspheres’ Black Pigments in Electrophoretic Displays

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    Carbon–iron oxide microspheres’ black pigments (CIOMBs) had been prepared via ultrasonic spray pyrolysis of aqueous solutions containing ferrous chloride and glucose. Due to the presence of carbon, CIOMBs not only exhibited remarkably acid resistance, but also could be well dispersed in both polar solvents and nonpolar solvent. Finally, dispersions of hollow CIOMBs in tetrachloroethylene had successfully been applied in electrophoretic displays

    17β-Estradiol and estrogen receptor α protect right ventricular function in pulmonary hypertension via BMPR2 and apelin

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    Women with pulmonary arterial hypertension (PAH) exhibit better right ventricular (RV) function and survival than men; however, the underlying mechanisms are unknown. We hypothesized that 17β-estradiol (E2), through estrogen receptor α (ER-α), attenuates PAH-induced RV failure (RVF) by upregulating the procontractile and prosurvival peptide apelin via a BMPR2-dependent mechanism. We found that ER-α and apelin expression were decreased in RV homogenates from patients with RVF and from rats with maladaptive (but not adaptive) RV remodeling. RV cardiomyocyte apelin abundance increased in vivo or in vitro after treatment with E2 or ER-α agonist. Studies employing ER-α–null or ER-β–null mice, ER-α loss-of-function mutant rats, or siRNA demonstrated that ER-α is necessary for E2 to upregulate RV apelin. E2 and ER-α increased BMPR2 in pulmonary hypertension RVs and in isolated RV cardiomyocytes, associated with ER-α binding to the Bmpr2 promoter. BMPR2 is required for E2-mediated increases in apelin abundance, and both BMPR2 and apelin are necessary for E2 to exert RV-protective effects. E2 or ER-α agonist rescued monocrotaline pulmonary hypertension and restored RV apelin and BMPR2. We identified what we believe to be a novel cardioprotective E2/ER-α/BMPR2/apelin axis in the RV. Harnessing this axis may lead to novel RV-targeted therapies for PAH patients of either sex

    A Survey on Moving Target Defense: Intelligently Affordable, Optimized and Self-Adaptive

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    Represented by reactive security defense mechanisms, cyber defense possesses a static, reactive, and deterministic nature, with overwhelmingly high costs to defend against ever-changing attackers. To change this situation, researchers have proposed moving target defense (MTD), which introduces the concept of an attack surface to define cyber defense in a brand-new manner, aiming to provide a dynamic, continuous, and proactive defense mechanism. With the increasing use of machine learning in networking, researchers have discovered that MTD techniques based on machine learning can provide omni-bearing defense capabilities and reduce defense costs at multiple levels. However, research in this area remains incomplete and fragmented, and significant progress is yet to be made in constructing a defense mechanism that is both robust and available. Therefore, we conducted a comprehensive survey on MTD research, summarizing the background, design mechanisms, and shortcomings of MTD, as well as relevant features of intelligent MTD that are designed to overcome these limitations. We aim to provide researchers seeking the future development of MTD with insight into building an intelligently affordable, optimized, and self-adaptive defense mechanism

    Characterization of the Miiuy Croaker (<i>Miichthys miiuy</i>) Transcriptome and Development of Immune-Relevant Genes and Molecular Markers

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    <div><p>Background</p><p>The miiuy croaker (<i>Miichthys miiuy</i>) is an important species of marine fish that supports capture fisheries and aquaculture. At present commercial scale aquaculture of this species is limited due to diseases caused by pathogens and parasites which restrict production and limit commercial value. The lack of transcriptomic and genomic information for the miiuy croaker limits the ability of researchers to study the pathogenesis and immune system of this species. In this study we constructed a cDNA library from liver, spleen and kidney which was sequenced using Illumina paired-end sequencing to enable gene discovery and molecular marker development.</p><p>Principal Findings</p><p>In our study, a total of 69,071 unigenes with an average length of 572 bp were obtained. Of these, 45,676 (66.13%) were successfully annotated in public databases. The unigenes were also annotated with Gene Ontology, Clusters of Orthologous Groups and KEGG pathways. Additionally, 498 immune-relevant genes were identified and classified. Furthermore, 14,885 putative simple sequence repeats (cSSRs) and 8,510 putative single nucleotide polymorphisms (SNPs) were identified from the 69,071 unigenes.</p><p>Conclusion</p><p>The miiuy croaker (<i>Miichthys miiuy</i>) transcriptome data provides a large resource to identify new genes involved in many processes including those involved in the response to pathogens and diseases. Furthermore, the thousands of potential cSSR and SNP markers found in this study are important resources with respect to future development of molecular marker assisted breeding programs for the miiuy croaker.</p></div

    Frequency distribution of SNPs based on different types.

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    <p>A total of 8,510 putative single nucleotide polymorphisms (SNPs) included 2,328 transversions and 6,182 transitions.</p

    Gradient of the temperature function at the voxel (i, j, k) for heterogeneous bio-thermal model

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    Determination of the relationship between electromagnetic power absorption and temperature distributions inside highly heterogeneous biological samples based on numerical methods is essential in biomedical engineering (e.g. microwave thermal ablation in clinic). In this paper, the gradient expression is examined and analyzed in detail, as how the gradient operators can be discretized is the only real difficulty to the solution of bio-heat equation for highly inhomogeneous model utilizing implicit scheme
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