524 research outputs found
Análise Comparativa Da Tensão Limite De Escoamento De Argamassas Por Meio Da Técnica De Pashias E Reometria Rotacional
Studies about the rheological behavior of cementitious materials, especially mortars and concretes, have been developed to improve the quality and durability of these materials as well as prevent any future problems in the hardened state. The rotational rheometry is the classic test for the rheological characterization of cementitious materials, because it allows to infer about the level of yield stress and apparent viscosity of the material. The rotational rheometers are, however, costly equipments, which led to the development of alternative me-thods for low cost, as the Pashias technique. The Pashias technique is a modification of the slump-test proce-dure in order to characterize, rheologically, the materials by single determining of the yield stress. The work developed aimed to determine the yield stress of mortars from compositions of high performance concretes (HPC) dosed by the concepts of rheology and particles packing. For this, it was used the classic rheometric test and the Pashias technique (cylinder), in order to compare the results, and evaluate the capacity of alterna-tive technique in determining the yield stress of mortars. The comparison of the results obtained by different rheological test methods showed a good ability of the Pashias technique (alternative technique) to evaluate the of yield stress parameter of mortars (with errors ranging from 1% to 20%). In addition, was observed that the mortar obtained from HPC dosed by the concepts of particles packing appeared more fluid and workable, with less yield stress. © 2016, Universidade Federal do Rio de Janeiro. All rights reserved.21486687
Association between interpregnancy interval and pregnancy complications by history of complications: A population-based cohort study
Objective: To examine if the association between interpregnancy interval (IPI) and pregnancy complications varies by the presence or absence of previous complications. Design and setting Population-based longitudinally linked cohort study in Western Australia (WA). Participants: Mothers who had their first two (n=252 368) and three (n=96 315) consecutive singleton births in WA between 1980 and 2015. Outcome measures: We estimated absolute risks (AR) of preeclampsia (PE) and gestational diabetes (GDM) for 3–60 months of IPI according to history of each outcome. We modelled IPI using restricted cubic splines and reported adjusted relative risk (RRs) with 95% CI at 3, 6, 12, 24, 36, 48 and 60 months, with 18 months as reference. Results: Risks of PE and GDM were 9.5%, 2.6% in first pregnancies, with recurrence rates of 19.3% and 41.5% in second pregnancy for PE and GDM, respectively. The AR of GDM ranged from 30% to 43% across the IPI range for mothers with previous GDM compared with 2%–8% for mothers without previous GDM. For mothers with no previous PE, greater risks were observed for IPIs at 3 months (RR 1.24, 95% CI 1.07 to 1.43) and 60 months (RR 1.40, 95% CI 1.29 to 1.53) compared with 18 months. There was insufficient evidence for increased risk of PE at shorter IPIs of <18 months for mothers with previous PE. Shorter IPIs of <18 months were associated with lower risk than at IPIs of 18 months for mothers with no previous GDM. Conclusions: The associations between IPIs and risk of PE or GDM on subsequent pregnancies are modified by previous experience with these conditions. Mothers with previous complications had higher absolute, but lower RRs than mothers with no previous complications. However, IPI remains a potentially modifiable risk factor for mothers with previous complicated pregnancies.Amanuel Tesfay Gebremedhin, Gizachew Assefa Tessema, Annette K Regan, Gavin F Pereir
Hardware-efficient entangled measurements for variational quantum algorithms
Variational algorithms have received significant attention in recent years due to their potential to solve practical problems in noisy intermediate-scale quantum (NISQ) devices. A fundamental step of these algorithms is the evaluation of the expected value of Hamiltonians, and hence, efficient schemes to perform this task are required. The standard approach employs local measurements of Pauli operators and requires a large number of circuits. An alternative is to make use of entangled measurements, which significantly reduces the number of circuits but involves entangling gates between non-physically connected qubits, introducing intermediate entangling operations that increase the depth of the circuits. As a solution to this problem we propose hardware-efficient entangled measurements (HEEM), that is, measurements that only permit entanglement between physically connected qubits. We show that this strategy enhances the evaluation of molecular Hamiltonians in NISQ devices, reducing the number of circuits required without increasing their depth. We provide quantitative metrics of how this approach offers better results than only local measurements and arbitrarily entangled ones. We estimate with classical simulators and quantum hardware the ground state energy of the H2O molecule by the variational quantum eigensolver using HEEM
Cysteine as a Multifaceted Player in Kidney, the Cysteine-Related Thiolome and Its Implications for Precision Medicine
Funding Information: This research was supported by Fundação para a Ciência e Tecnologia (PTDC/MED-TOX/30418/2017) and iNOVA4Health (UID/Multi/04462/2013). M.J.C., D.G.F.F. and J.M. were supported by FCT (PhD grant SFRH/BD/131331/2017, PhD grant PD/BD/135484/2018 and postdoctoral contract PTDC/MED-TOX/30418/2017, respectively).In this review encouraged by original data, we first provided in vivo evidence that the kidney, comparative to the liver or brain, is an organ particularly rich in cysteine. In the kidney, the total availability of cysteine was higher in cortex tissue than in the medulla and distributed in free reduced, free oxidized and protein-bound fractions (in descending order). Next, we provided a comprehensive integrated review on the evidence that supports the reliance on cysteine of the kidney beyond cysteine antioxidant properties, highlighting the relevance of cysteine and its renal metabolism in the control of cysteine excess in the body as a pivotal source of metabolites to kidney biomass and bioenergetics and a promoter of adaptive responses to stressors. This view might translate into novel perspectives on the mechanisms of kidney function and blood pressure regulation and on clinical implications of the cysteine-related thiolome as a tool in precision medicine.publishersversionpublishe
Quem somos nós? Ou perfis da comunidade profissional arqueológica no Brasil: primeiras aproximações
WHO ARE WE? OR A PROFILE OF THE ARCHAEOLOGICAL PROFESSIONAL COMMUNITY IN BRAZIL: FIRST APPROACHESIn the last twenty years, archeological academic-scientific training has grown exponen-tially in Brazil, culminating in the recognition of the profession in 2018. However, little is known about the demographic profiles of people working in the area, as well as of students in the process of training, in undergraduate and graduate levels. By updating some data from previous studies, in this manuscript we present the results of an initial survey on the professional profile in Brazilian archeology, which includes information on the trajectory of education, gender, nationality and re-search themes. This initiative allows us to outline the challenges of inclusion and representativeness in the exercise of the profession, whose reflections will assist us in the conceiving of practical measures for a change in this situation in the future.Archaeology of the AmericasArchaeological Heritage Managemen
The conservation of native priority medicinal plants in a Caatinga area in Ceará, northeastern Brazil
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