Thin Film Multilayer Conductor/Ferroelectric Tunable Microwave Components for Communication Applications

High Temperature Superconductor/Ferroelectric (HTS/FE ) thin film multilayered structures deposited onto dielectric substrates are currently being investigated for use in low loss, tunable microwave components for satellite and ground based communications. The main goal for this technology is to achieve maximum tunability while keeping the microwave losses as low as possible, so as to avoid performance degradation when replacing conventional technology (e.g., filters and oscillators) with HTS/FE components. Therefore, for HTS/FE components to be successfully integrated into current working systems, full optimization of the material and electrical properties of the ferroelectric films, without degrading those of the HTS film; is required. Hence, aspects such as the appropriate type of ferroelectric and optimization of the deposition conditions (e.g., deposition temperature) should be carefully considered. The tunability range as well as the microwave losses of the desired varactor (i.e., tunable component) are also dependent on the geometry chosen (e.g., parallel plate capacitor, interdigital capacitor, coplanar waveguide, etc.). In addition, the performance of the circuit is dependent on the location of the varactor in the circuit and the biasing circuitry. In this paper, we will present our results on the study of the SrTiO3/YBa2Cu3O(7-delta)/LaAl03 (STO/YBCO/LAO) and the Ba(x)Sr(1-x)TiO3/YBa2Cu3O(7-delta)/LaAl03(BSTO/YBCO/ILAO) HTS/FE multilayered structures. We have observed that the amount of variation of the dielectric constant upon the application of a dc electric field is closely related to the microstructure of the film. The largest tuning of the STO/YBCO/LAO structure corresponded to single-phased, epitaxial STO films deposited at 800 C and with a thickness of 500 nm. Higher temperatures resulted in interfacial degradation and poor film quality, while lower deposition temperatures resulted in films with lower dielectric constants, lower tunabilities, and higher losses. For STO/LAO multilayer structures having STO film of similar quality we have observed that interdigital capacitor configurations allow for higher tunabilities and lower losses than parallel plate configurations, but required higher dc voltage. Results on the use of these geometries in working microwave components such as filters and stabilizing resonators for local oscillators (LO) will be discussed

Ohio Economic Insects and Related Anthropods

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Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Rapid Response to SARS-CoV-2 in Aotearoa New Zealand: Implementation of a Diagnostic Test and Characterization of the First COVID-19 Cases in the South Island

It has been 20 months since we first heard of SARS-CoV-2, the novel coronavirus detected in the Hubei province, China, in December 2019, responsible for the ongoing COVID-19 pandemic. Since then, a myriad of studies aimed at understanding and controlling SARS-CoV-2 have been published at a pace that has outshined the original effort to combat HIV during the beginning of the AIDS epidemic. This massive response started by developing strategies to not only diagnose individual SARS-CoV-2 infections but to monitor the transmission, evolution, and global spread of this new virus. We currently have hundreds of commercial diagnostic tests; however, that was not the case in early 2020, when just a handful of protocols were available, and few whole-genome SARS-CoV-2 sequences had been described. It was mid-January 2020 when several District Health Boards across New Zealand started planning the implementation of diagnostic testing for this emerging virus. Here, we describe our experience implementing a molecular test to detect SARS-CoV-2 infection, adapting the RT-qPCR assay to be used in a random-access platform (Hologic Panther Fusion® System) in a clinical laboratory, and characterizing the first whole-genome SARS-CoV-2 sequences obtained in the South Island, right at the beginning of the SARS-CoV-2 outbreak in New Zealand. We expect that this work will help us and others prepare for the unequivocal risk of similar viral outbreaks in the future

Characterization of the First SARS-CoV-2 Isolates from Aotearoa New Zealand as Part of a Rapid Response to the COVID-19 Pandemic

SARS-CoV-2, the virus responsible for the COVID-19 pandemic, has wreaked havoc across the globe for the last two years. More than 300 million cases and over 5 million deaths later, we continue battling the first real pandemic of the 21st century. SARS-CoV-2 spread quickly, reaching most countries within the first half of 2020, and New Zealand was not an exception. Here, we describe the first isolation and characterization of SARS-CoV-2 variants during the initial virus outbreak in New Zealand. Patient-derived nasopharyngeal samples were used to inoculate Vero cells and, three to four days later, a cytopathic effect was observed in seven viral cultures. Viral growth kinetics was characterized using Vero and VeroE6/TMPRSS2 cells. The identity of the viruses was verified by RT-qPCR, Western blot, indirect immunofluorescence assays, and electron microscopy. Whole-genome sequences were analyzed using two different yet complementary deep sequencing platforms (MiSeq/Illumina and Ion PGM™/Ion Torrent™), classifying the viruses as SARS-CoV-2 B.55, B.31, B.1, or B.1.369 based on the Pango Lineage nomenclature. All seven SARS-CoV-2 isolates were susceptible to remdesivir (EC50 values from 0.83 to 2.42 µM) and β-D-N4-hydroxycytidine (molnupiravir, EC50 values from 0.96 to 1.15 µM) but not to favipiravir (>10 µM). Interestingly, four SARS-CoV-2 isolates, carrying the D614G substitution originally associated with increased transmissibility, were more susceptible (2.4-fold) to a commercial monoclonal antibody targeting the spike glycoprotein than the wild-type viruses. Altogether, this seminal work allowed for early access to SARS-CoV-2 isolates in New Zealand, paving the way for numerous clinical and scientific research projects in the country, including the development and validation of diagnostic assays, antiviral strategies, and a national COVID-19 vaccine development program