52 research outputs found
A Novel Design of a Miniature Metamaterial Antenna for RFID Reader Applications
In this article, we propose a novel design of a dual band antenna based metamaterial for RFID applications. The proposed antenna consists of a rectangular patch using inverted u-slot in radiating element and two split ring resonators loaded in the ground plane. The antenna is printed on an FR4 substrate having athickness of 1.6 mm, permitivitty of 4.4 and loss tanget of 0.025. this antenna is feed by a micostrip line having caracteristique of 50 Ohms. The designed antenna resonates at the UHF band around 900Mz with an input impedance of 87MHz and also, resonates at the ISM band around 2.45GHz with a large bandwidth about 516MHz. The designed antenna is simulated bys using CST and the results is validated by HFSS. After simulation, a prototype of the proposed antenna is fabricated, and the measured results show a good agreement with the simulated one
A new configuration of patch antenna array for rectenna array applications
The performance and advantages of microstrip patch antennas made them a field of interest for wireless power transmission applications, especially for rectenna systems where the choice of the antenna is a crucial step. In this paper, a 5.8 GHz circularly polarized patch antenna has been designed and fabricated, then mounted by using 4 elements to achieve an antenna array to enhance the captured power to be converted by the rectifier circuit. The antenna array is well matched at 5.8 GHz in terms of reflection coefficient and has a directivity of 11dB and a gain of 6 dB. Results have been confirmed by fabrication
A New Configuration of A High Output Voltage 2.45 GHz Rectifier For Wireless Power Transmission Applications
This work deals with the design, simulation, fabrication and experimentation of a novel 2.45 GHz rectifier for wireless power transmission applications. We have designed a voltage multiplier topology rectifier including 5 Schottky diodes known by their low threshold. This rectifier could perform a wireless power supply for many cases where the use of batteries or wires is impossible due to many limitations. The circuit was analyzed and optimized with the Harmonic Balance method provided by the Advanced Design System (ADS). Good performances are observed through the simulated results and confirmed by the fabrication tests in terms of RF-DC conversion efficiency, DC output voltage level and matching input impedance
Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19
Background: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15–20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. Methods: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5–528.7, P = 1.1 × 10−4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3–8.2], P = 2.1 × 10−4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1–2635.4], P = 3.4 × 10−3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3–8.4], P = 7.7 × 10−8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10−5). Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old
RNA sequencing of identical twins discordant for autism reveals blood-based signatures implicating immune and transcriptional dysregulation
Background: A gap exists in our mechanistic understanding of how genetic and environmental risk factors converge at the molecular level to result in the emergence of autism symptoms. We compared blood-based gene expression signatures in identical twins concordant and discordant for autism spectrum condition (ASC) to differentiate genetic and environmentally driven transcription differences, and establish convergent evidence for biological mechanisms involved in ASC.
Methods: Genome-wide gene expression data were generated using RNA-seq on whole blood samples taken from 16 pairs of monozygotic (MZ) twins and seven twin pair members (39 individuals in total), who had been assessed for ASC and autism traits at age 12. Differential expression (DE) analyses were performed between (a) affected and unaffected subjects (N = 36) and (b) within discordant ASC MZ twin pairs (total N = 11) to identify environmental-driven DE. Gene set enrichment and pathway testing was performed on DE gene lists. Finally, an integrative analysis using DNA methylation data aimed to identify genes with consistent evidence for altered regulation in cis.
Results: In the discordant twin analysis, three genes showed evidence for DE at FDR < 10%: IGHG4, EVI2A and SNORD15B. In the case-control analysis, four DE genes were identified at FDR<10% including IGHG4, PRR13P5, DEPDC1B, and ZNF501. We find enrichment for DE of genes curated in the SFARI human gene database. Pathways showing evidence of enrichment included those related to immune cell signalling and immune response, transcriptional control and cell cycle/proliferation. Integrative methylomic and transcriptomic analysis identified a number of genes showing suggestive evidence for cis dysregulation.
Limitations: Identical twins stably discordant for ASC are rare, and as such the sample size was limited and constrained to the use of peripheral blood tissue for transcriptomic and methylomic profiling. Given these primary limitations, we focused on transcript-level analysis.
Conclusions: Using a cohort of ASC discordant and concordant MZ twins, we add to the growing body of transcriptomic-based evidence for an immune-based component in the molecular aetiology of ASC. Whilst the sample size was limited, the study demonstrates the utility of the discordant MZ twin design combined with multi-omics integration for maximising the potential to identify disease-associated molecular signals
Compact CPW-fed dual-band uniplanar antenna for RFID applications
International audienceThis paper presents a novel dual-band uniplanar monopole antenna fed by Coplanar Waveguide (CPW) line suitable for Radio Frequency Identification (RFID) applications especially designed for RFID readers and it operates at 2.45 GHZ and 5.8 GHZ. This antenna is designed with reasonable gain, low profile and low cost achievement. The proposed antenna benefits from the advantages of the CPW line to simplify the structure of the antenna into a single metallic level, hence making it easier for integration with integrated microwave circuits. The simulation results carried out by ADS from Agilent technologies and CST Microwave Studio electromagnetic solvers, demonstrate that we have good performances in term of return loss, gain, radiation pattern and efficiency for the desired frequency bands. This antenna has a total area of 30×45mm 2 and mounted on an FR4 substrate with constant dielectric permittivity 4.4 and thickness of 1.6mm and loss tangent of 0.025. The simulated return loss less than -10 dB at the lower band is about 200 MHz and for the upper band reaches about 400 MHz, which covers the RFID standards. The gain obtained into simulation of this antenna is 1,9 dB at 2.45GHz and 2,8 dB at 5.8 GHz
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