Dual Band-Notched Microstrip-Fed Vivaldi Antenna Utilizing Compact EBG Structures

We propose an ultra-wideband (UWB) antipodal Vivaldi antenna (AVA) with high-Q stopband characteristics based on compact electromagnetic bandgap (EBG) structures. First, an AVA is designed and optimized to operate over an UWB spectrum. Then, two pairs of EBG cells are introduced along the antenna feed line to suppress the frequency components at 3.6–3.9 and 5.6–5.8 GHz (i.e., WiMAX and ISM bands, resp.). Simulated and measured results show a voltage standing wave ratio (VSWR) below 2 for the entire 3.1–10.6 GHz band with high attenuation at the two selected subbands. This simple yet effective approach eliminates the need to deform the antenna radiators with slots/parasitic elements or comprise multilayer substrates. Furthermore, the flexibility it offers in terms of controlling both the number and locations of the band-reject frequencies is advantageous for antennas with nonuniform flares as in the AVA

Glycosylated fibronectin positivity in the spectrum of hypertensive disorders of pregnancy in relation to the severity and adverse outcomes

Background: The aim of the study was to estimate the levels of glycosylated fibronectin (GlyFn) in preeclampsia (PE), and hypertensive disorders of pregnancy (HDP) and to correlate with the severity of the disease, adverse outcomes and complications. The study included 77 cases of HDP that were managed in the Institute of Obstetrics and Gynaecology, Modern Government Maternity Hospital (MGMH), Osmania Medical College, Hyderabad.Methods: This study was a prospective non-interventional analytical investigative study. To ascertain the performance of this biomarker, GlyFn, we evaluated the LumellaTM GlyFn POC test.Results: GlyFn positivity percentage was found to be highest in eclampsia (78.57%), next in PE with severe features 74.07%, in HELLP syndrome and gestational hypertension (HTN) (71.42%). In PE without severe features (66.66%) and in chronic HTN with PE superimposed (55.55%). Maternal complications include: abruption 5 (6.57%), thrombocytopenia 3 (3.94%), acute kidney injury (AKI) 3 (3.94%), post-partum hemorrhage (PPH) 3 (3.94%), and ascites 3 (3.94%). Perinatal outcome in 77 cases include: fetal growth restriction in 18 (23.37%) and total perinatal mortality was 14 (18.18%).Conclusions: GlyFn positivity was found to be highest in eclampsia and the severe forms of PE. The positivity declined in the less severe disease. The birth weight in the severe forms of PE group was significantly lower (p<0.0006). The differences in the birth weight among the GlyFn positive and normal groups was not significant for this population size (p=0.38).

Autoimmune Parkinsonism: A Newer Manifestation of Contactin-Associated Protein-Like 2 Autoimmunity: A Case Report

Contactin-associated protein-like 2 (CASPR2) antibodies are part of an expanding spectrum of disorders. Although they were initially associated with Morvan’s syndrome and peripheral nerve hyperexcitability, their clinical manifestations are more varied than previously recognized. In this report, we present a rare case of a middle-aged woman who experienced gait disturbances, sleep disturbances, behavioral changes, and postural abnormalities over a period of five months. A thorough examination revealed a Parkinsonian phenotype. Considering the timeline and symptomatology, an autoimmune work-up was conducted, which detected CASPR2 antibodies in the patient’s serum. Treatment with high-dose intravenous Methylprednisolone followed by rituximab effectively reversed her clinical manifestations without residual neurological deficits

Jamming Detection and Classification in OFDM-based UAVs via Feature- and Spectrogram-tailored Machine Learning

In this paper, a machine learning (ML) approach is proposed to detect and classify jamming attacks against orthogonal frequency division multiplexing (OFDM) receivers with applications to unmanned aerial vehicles (UAVs). Using software-defined radio (SDR), four types of jamming attacks; namely, barrage, protocol-aware, single-tone, and successive-pulse are launched and investigated. Each type is qualitatively evaluated considering jamming range, launch complexity, and attack severity. Then, a systematic testing procedure is established by placing an SDR in the vicinity of a UAV (i.e., drone) to extract radiometric features before and after a jamming attack is launched. Numeric features that include signal-to-noise ratio (SNR), energy threshold, and key OFDM parameters are used to develop a feature-based classification model via conventional ML algorithms. Furthermore, spectrogram images collected following the same testing procedure are exploited to build a spectrogram-based classification model via state-of-the-art deep learning algorithms (i.e., convolutional neural networks). The performance of both types of algorithms is analyzed quantitatively with metrics including detection and false alarm rates. Results show that the spectrogram-based model classifies jamming with an accuracy of 99.79% and a false-alarm of 0.03%, in comparison to 92.20% and 1.35%, respectively, with the feature-based counterpart

Using Noun Phrases for Navigating Biomedical Literature on Pubmed: How Many Updates Are We Losing Track of?

Author-supplied citations are a fraction of the related literature for a paper. The “related citations” on PubMed is typically dozens or hundreds of results long, and does not offer hints why these results are related. Using noun phrases derived from the sentences of the paper, we show it is possible to more transparently navigate to PubMed updates through search terms that can associate a paper with its citations. The algorithm to generate these search terms involved automatically extracting noun phrases from the paper using natural language processing tools, and ranking them by the number of occurrences in the paper compared to the number of occurrences on the web. We define search queries having at least one instance of overlap between the author-supplied citations of the paper and the top 20 search results as citation validated (CV). When the overlapping citations were written by same authors as the paper itself, we define it as CV-S and different authors is defined as CV-D. For a systematic sample of 883 papers on PubMed Central, at least one of the search terms for 86% of the papers is CV-D versus 65% for the top 20 PubMed “related citations.” We hypothesize these quantities computed for the 20 million papers on PubMed to differ within 5% of these percentages. Averaged across all 883 papers, 5 search terms are CV-D, and 10 search terms are CV-S, and 6 unique citations validate these searches. Potentially related literature uncovered by citation-validated searches (either CV-S or CV-D) are on the order of ten per paper – many more if the remaining searches that are not citation-validated are taken into account. The significance and relationship of each search result to the paper can only be vetted and explained by a researcher with knowledge of or interest in that paper

The effect of perfluorocarbon vapour on the measurement of respiratory tidal volume during partial liquid ventilation

During partial liquid ventilation perfluorocarbon vapour is present in the exhaled gases. The volumes of these gases are measured by pneumotachometers. Error in measuring tidal volumes will give erroneous measurement of lung compliance during partial liquid ventilation. We aim to compare measured tidal volumes with and without perfluorocarbon vapour using tidal volumes suitable for use in neonates. Tidal volumes were produced with a 100 ml calibration syringe from 20 to 100 ml and with a calibrated Harvard rodent ventilator from 2.5 to 20 ml. Control tidal volumes were drawn from a humidifier chamber containing water vapour and the PFC tidal volumes were drawn from a humidifier chamber containing water and perfluorocarbon (FC-77) vapour. Tidal volumes were measured by a fixed orifice, target, differential pressure flowmeter (VenTrak) or a hot-wire anenometer (Bear Cub) placed between the calibration syringe or ventilator and the humidifier chamber. All tidal volumes measured with perfluorocarbon vapour were increased compared with control (ANOVA p < 0.001 and post t-test p < 0.0001). Measured tidal volume increased from 7 to 16% with the fixed orifice type flow-meter, and from 35 to 41% with the hot-wire type. In conclusion, perfluorocarbon vapour flowing through pneumotachometers gives falsely high tidal volume measurements. Calculation of lung compliance must take into account the effect of perfluorocarbon vapour on the measurement of tidal volume