14 research outputs found

    Artificial Synthesis of Conserved Segment S Gene Fragment of Rift Valley Fever Virus and Preliminary Study of Its Reverse Transcription Loop-Mediated Isothermal Amplification Detection Method

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    Purpose: To develop a rapid detection method for Rift Valley fever virus (RVFV) diagnosis.Methods: According to the reference sequences of RVFV published in GenBank, nine overlapping polymerase chain reaction (PCR) primers and four specific reverse transcription loop-mediated isothermal amplification (RT-LAMP) primers were designed using DNAStar and LAMP primer design software, respectively. Based on the synthesis of a conserved part of the RVFV S segment gene sequence using overlapping PCR, RT-LAMP assay was first established and evaluated after a series of tests, including, optimization of reaction conditions, and sensitivity and specificity tests.Result: A target RVFV S segment gene fragment of 288 bp was synthesised. The optimal reaction conditions for RT-LAMP assay were 63 °C for 45 min: the assay has a specific ladder-like pattern of amplification bands from about 120 bp. The lowest target gene copy number of RT-LAMP for RVFV detection was 70 copies. The assay showed good specificity as only the synthesised target RVFV gene was amplified with no amplification for the detection of Peste des petits ruminants virus, Epidemic encephalitis B virus, E. coli, Pasteurella multocida, or Salmonella.Conclusion: This study provides a rapid, sensitive, specific RT-LAMP method for RVFV detection.Keywords: Rift valley fever virus, Overlapping polymerase chain reaction, Reverse transcription loopmediated isothermal amplification, Rapid diagnosis tes

    A Magnetometer-based Method for In-situ Syncing of Wearable Inertial Measurement Units

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    This paper presents a novel method to synchronize multiple wireless inertial measurement unit sensors (IMU) using their onboard magnetometers. The basic method uses an external electromagnetic pulse to create a known event measured by the magnetometer of multiple IMUs and in turn uses this to synchronize the devices. An initial evaluation using four commercial IMUs reveals a maximum error of 40 ms per hour as limited by a 25 Hz sample rate. Building on this we introduce a novel method to improve synchronization beyond the limitations imposed by the sample rate and evaluate this in a further study using 8 IMUs. We show that a sequence of electromagnetic pulses, in total lasting <3-s, can reduce the maximum synchronization error to 8 ms (for 25 Hz sample rate, and accounting for the transient response time of the magnetic field generator). An advantage of this method is that it can be applied to several devices, either simultaneously or individually, without the need to remove them from the context in which they are being used. This makes the approach particularly suited to synchronizing multi-person on-body sensors while they are being worn

    circNFATC3 sponges miR-548I acts as a ceRNA to protect NFATC3 itself and suppressed hepatocellular carcinoma progression

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    Circular RNAs (circRNA) have been reported as regulators involved in hepatocellular carcinoma (HCC), but their mechanism of activity remains unknown. This study performed quantitative reverse-transcription polymerase chain reaction to determine if circNFATC3 was downregulated in 46 paired HCC tissues and cell lines. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, apoptotic, and transwell assay proved that circNFATC3 can inhibit hepatoma cell proliferation, apoptosis, and migration/invasion in vitro. Mouse xenograft assay demonstrated that circNFATC3 suppressed tumor size and weight and reduced lung metastasis in vivo, and vice versa. The RNA-seq results showed that NFATC3 itself was the most significantly differentially expressed gene when circNFATC3 was manipulated, and bioinformatics and luciferase reporter assays verified circNFATC3 regulated the expression of NFATC3 by interacting with the hsa-miR-548I. Additionally, it was also indicated that the level of NFATC3 was downregulated in HCC patients also and was significantly correlated with the staging and prognosis of HCC. Moreover, both circNFATC3 and NFATC3 were shown to inhibit the phosphorylation of JNK, c-Jun, AKT, and mTOR signaling pathways. Overall, the circNFATC3 can sponge miR-548I to protect NFATC3 itself, then it regulates hepatoma cell function via the JNK, c-Jun, AKT, and mTOR signaling pathways, and the circNFATC3 can be a tumor-repressor on HCC.status: publishe

    Phase change plasmonic metasurface for dynamic thermal emission modulation

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    Plasmonic metasurfaces with adjustable optical responses can be achieved through phase change materials (PCMs) with high optical contrast. However, the on–off behavior of the phase change process results in the binary response of photonic devices, limiting the applications to the two-stage modulation. In this work, we propose a reconfigurable metasurface emitter based on a gold nanorod array on a VO2 thin film for achieving continuously tunable narrowband thermal emission. The electrode line connecting the center of each nanorod not only enables emission excitation electrically but also activates the phase transition of VO2 beneath the array layer due to Joule heating. The change in the dielectric environment due to the VO2 phase transition results in the modulation of emissivity from the plasmonic metasurfaces. The device performances regarding critical geometrical parameters are analyzed based on a fully coupled electro-thermo-optical finite element model. This new metasurface structure extends the binary nature of PCM based modulations to continuous reconfigurability and provides new possibilities toward smart metasurface emitters, reflectors, and other nanophotonic devices

    Validation efficiency of coupling of beads and probes for detection by Bio-Plex suspension array system, used in high-throughput multiplexed nucleic acid detection of respiratory and reproductive pathogens in swine

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    <div>The data and figures in this file set show the correlation between median fluorescence intensity (MFI) and biotinylated RCS concentration. </div><div><br></div><div>Magnetic carboxylic beads were coupled to different virus probes as follows: PRV (no. 26), PRRSV (no. 29), CSFV (no. 34), JEV (no. 36), PCV-2 (no. 46), ASFV (no. 62) and PPV (no. 65). </div><div><br></div><div>Validation of coupling was performed with different amounts of biotin-modified RCS. The curve was drawn with 0, 5, 10, 20, 50, 100 and 200 fmol RCS, respectively.</div><div><br></div><div>Article abstract:</div><div><br></div><div>Background: The aim of this study was to develop a multiple PCR assay based on the suspension array system for the simultaneous detection of respiratory and reproductive pathogens in swine. Pseudorabies virus (PRV), Japanese encephalitis virus (JEV), classic swine fever virus (CFSV), African swine fever virus (ASFV), porcine circovirus type 2 (PCV-2), porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) are the major respiratory and reproductive viral pathogens in pig farms. </div><div><br></div><div>Results: Seven pairs of specific primers and probes were designed, and multiple PCR was performed, with the PCR products hybridized to beads coupled to probes, which were then detected by Bio-Plex suspension array system. The limit of detection, specificity and repeatability of this method was determined. The assay was further tested using 137 clinical samples, and the results were compared with conventional PCR to evaluate the ability of the method to diagnose porcine viruses. The results showed that the assay had a high degree of specificity and repeatability, and the simultaneous detection limit for the seven viruses reached 103 copies/ÎĽL. The detection of viruses in clinical samples using the Bio-Plex method was high and comparable to conventional PCR (> 90%).<br></div

    Validation efficiency of coupling of beads and probes, used in high-throughput multiplexed nucleic acid detection of respiratory and reproductive pathogens in swine

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    <div>This file set contains results files from the Bio-Plex integrated biomolecular assay system, each containing the data from a reading, the Protocol parameters used to collect that data and analysis tools for interpreting the data. The .rbx format data files must be opened by the Bio-Plex Manager integrated software. Please see the references link below for .xls format data related to this study.<br></div><div><br></div><div><div>Magnetic carboxylic beads were coupled to different virus probes as follows: PRV (no. 26), PRRSV (no. 29), CSFV (no. 34), JEV (no. 36), PCV-2 (no. 46), ASFV (no. 62) and PPV (no. 65). </div></div><div><br></div><div>Validation of coupling was performed with different amounts of biotin-modified RCS. The curve was drawn with 0, 5, 10, 20, 50, 100 and 200 fmol RCS, respectively.</div><div><br></div><div>Article abstract:</div><div><br></div><div>Background: The aim of this study was to develop a multiple PCR assay based on the suspension array system for the simultaneous detection of respiratory and reproductive pathogens in swine. Pseudorabies virus (PRV), Japanese encephalitis virus (JEV), classic swine fever virus (CFSV), African swine fever virus (ASFV), porcine circovirus type 2 (PCV-2), porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) are the major respiratory and reproductive viral pathogens in pig farms.</div><div><br></div><div>Results: Seven pairs of specific primers and probes were designed, and multiple PCR was performed, with the PCR products hybridized to beads coupled to probes, which were then detected by Bio-Plex suspension array system. The limit of detection, specificity and repeatability of this method was determined. The assay was further tested using 137 clinical samples, and the results were compared with conventional PCR to evaluate the ability of the method to diagnose porcine viruses. The results showed that the assay had a high degree of specificity and repeatability, and the simultaneous detection limit for the seven viruses reached 103 copies/ÎĽL. The detection of viruses in clinical samples using the Bio-Plex method was high and comparable to conventional PCR (> 90%).</div

    Evaluation of the detection limit of Bio-Plex, part of suspension array system used in high-throughput multiplexed nucleic acid detection of respiratory and reproductive pathogens in swine

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    Evaluation of the detection limit of Bio-Plex. The assay detected as few as 100 copies/ÎĽL of PRV, CSFV, JEV and PCV-2, and 1000 copies/ÎĽL of PRRSV, ASFV and PPV. The detection limit of assay achieved an approximate 1000 copies/ÎĽL when all seven templates were present.<div><br></div><div><div>Article abstract:</div><div><br></div><div>Background: The aim of this study was to develop a multiple PCR assay based on the suspension array system for the simultaneous detection of respiratory and reproductive pathogens in swine. Pseudorabies virus (PRV), Japanese encephalitis virus (JEV), classic swine fever virus (CFSV), African swine fever virus (ASFV), porcine circovirus type 2 (PCV-2), porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) are the major respiratory and reproductive viral pathogens in pig farms.</div><div><br></div><div>Results: Seven pairs of specific primers and probes were designed, and multiple PCR was performed, with the PCR products hybridized to beads coupled to probes, which were then detected by Bio-Plex suspension array system. The limit of detection, specificity and repeatability of this method was determined. The assay was further tested using 137 clinical samples, and the results were compared with conventional PCR to evaluate the ability of the method to diagnose porcine viruses. The results showed that the assay had a high degree of specificity and repeatability, and the simultaneous detection limit for the seven viruses reached 103 copies/ÎĽL. The detection of viruses in clinical samples using the Bio-Plex method was high and comparable to conventional PCR (> 90%).</div></div

    Electrically Programmable Pixelated Graphene-Integrated Plasmonic Metasurfaces for Coherent Mid-Infrared Emission

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    Active metasurfaces have recently emerged as compact, lightweight, and efficient platforms for dynamic control of electromagnetic fields and optical responses. However, the complexities associated with their post-fabrication tunability significantly hinder their widespread applications, especially for the mid-infrared range due to material scarcity and design intricacy. Here, we experimentally demonstrate highly dynamic, pixelated modulations of coherent mid-infrared emission based on an electrically programmable plasmonic metasurface integrated with graphene field effect transistors (Gr-FETs). The ultrabroad infrared transparency of graphene allows for free-form control over plasmonic meta-atoms, thus achieving coherent mid-infrared states across a broad range of wavelengths and polarizations. The spatial temperature modulation generated by Gr-FETs is effectively synergized with the emissivity control by the localized surface plasmon polaritons from gold nanoantennas. This integrated temperature-emissivity modulation of metasurfaces is systematically extended to form a pixelated 2D array, envisioning new approaches toward scalable 2D electrical wiring for densely packed, independently controlled pixels.Comment: Needs more updates for the experiment
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