15 research outputs found
Recent Trends and Considerations for High Speed Data in Chips and System Interconnects
This paper discusses key issues related to the design of large processing volume chip architectures and high speed system interconnects. Design methodologies and techniques are discussed, where recent trends and considerations are highlighted
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.
BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK
Background
A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.
Methods
This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674.
Findings
Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation.
Interpretation
ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials
Integrated Instantaneous Frequency Measurement Subsystem Based on Multi-Band-Stop Filters
A 4-bit instantaneous frequency measurement (IFM) subsystem operating in the 1.5–4.66 GHz frequency band has been developed based on multi-band-stop filters. The design instantaneously detects the incoming signal which is then associated to one of the 16 sub-bands. Design, simulation and measurement of the device are presented in this paper, where a good agreement between simulations and measurements was obtained
Multi-band Microwave Sensor based on Hilbert`s Fractal for Dielectric Solid Material Characterization
A planar sensor designed using the fourth Hilbert fractal curve iteration for solid material characterization at multiple frequencies is reported in this paper. The fractal curve is self-similar with space filling properties. The Hilbert fractal geometry is used to form a compact resonator, with a multiband frequency response where miniaturization is achieved, since a large transmission line length is effectively confined in a limited area. The sensor provides five resonances in the frequency range from 0 to 5 GHz. The resonant frequencies are 0.56, 1.68, 2.72, 3.69 and 4.72 GHz, all used to measure the real permittivity of known samples with a sensitivity of 7, 20, 27, 43 and 50 MHz/permittivity, respectively. The sensor is used to measure dielectric samples with 20 x 20 mm2 areas with several thicknesses. Simulations and measurements demonstrate that the Hilbert fractal geometry can be used to design a multiband planar sensor for solid dielectric material characterization.Grant numbers : 5G-TRIDENT - 5G Technologies for ReconfIgurable and efficient raDio accEss iNfrastrucTure and mobile devices (RTI2018-099841-B-I00)
Regeneração de espécies arbóreas e relações com componente adulto em uma floresta estacional no vale do rio Uruguai, Brasil Tree regeneration and relationships with adult trees in a seasonal forest in the Uruguai river valley, Brazil
O estudo de fenômenos relacionados às variações na estrutura das comunidades vegetais tem cada vez mais envolvido a avaliação do potencial de regeneração das espécies arbóreas, uma vez que a regeneração torna as florestas capazes de se restaurarem após distúrbios naturais ou antrópicos. Neste sentido, objetivou-se avaliar o componente arbóreo regenerante, identificando composição e abundância, grupos funcionais de dispersão, estratificação vertical e necessidades de luz para germinação, além de estimativas de riqueza e diversidade e comparar estes valores com o respectivo componente adulto. O levantamento foi realizado em 20 unidades amostrais de 10 x 10 m, sendo amostrados todos os indivíduos com altura > 0,30 m e diâmetro a altura do solo < 4,7 cm. O levantamento do componente adulto, avaliado em estudo anterior, foi estabelecido em unidades amostrais de 20 x 20 metros, sendo amostrados todos os indivíduos com diâmetro à altura do peito > 4,7 cm. Foram amostrados 1.649 indivíduos em regeneração, pertencentes a 64 espécies, com densidade total estimada em 8.245 ind.ha-1. As espécies com maior densidade absoluta foram Gymnanthes concolor Spreng., Trichilia elegans A.Juss. e Calyptranthes tricona D.Legrand. Uma análise de coordenadas principais indicou nítida separação das unidades amostrais amostradas e um teste de Mantel revelou haver independência entre as matrizes de composição e abundância dos componentes adulto e regenerante (r = 0,19; p = 0,1). Dentre os grupos funcionais, verificou-se que o componente regenerante está mantendo as mesmas proporções observadas para o componente adulto, com maior proporção de espécies zoocóricas, dependentes de luz para germinação e formadoras do dossel florestal. Ao contrário do esperado, houve diminuição da riqueza no componente regenerante (p < 0,001) e manutenção da equabilidade ao longo da área.<br>Studies related to variation in plant communities have been involved the analysis of regenerative potential of tree species, because saplings may enable forests to restore themselves after natural or human disturbances. The goal of this study was to analyze tree regeneration by identifying composition and abundance, the ecological groups of dispersion, vertical stratification and light requirements for germination and to look for changes in expected richness, diversity and relationships with structure of adult trees. A sapling survey was conducted in 20 sample units of 10 x 10 m where all individual living trees were sampled that had a height > 0.30 m and diameter at soil height < 4.7 cm. Adult trees with a diameter at breast height > 4.7 cm were surveyed in 20 x 20 m sampling units, according to a previous study. We sampled 1,649 living trees (64 species), which generated a total density of 8,245 ind.ha-1. The species with higher absolute density were Gymnanthes concolor Spreng., Trichilia elegans A.Juss. and Calyptranthes tricona D.Legrand. A principal coordinates analysis indicated sharp differences among sampled units and a Mantel test showed no dependence among composition and abundance matrices from adult and regenerative surveys (r = 0.19; p = 0.1). According to the ecological groups, we found that the regenerative component has kept the same proportions of adults, with a higher proportion of zoochorous, light demanding, canopy covering species. Contrary to our initial hypothesis, we found lower expected richness in the regenerative component (p < 0.001) with the same equability in the entire area