60 research outputs found

    VEGFR1 signaling in retinal angiogenesis and microinflammation

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    Five vascular endothelial growth factor receptor (VEGFR) ligands (VEGF-A, -B, –C, -D, and placental growth factor [PlGF]) constitute the VEGF family. VEGF-A binds to VEGF receptors 1 and 2 (VEGFR1/2), whereas VEGF-B and PlGF only bind VEGFR1. Although much research has been conducted on VEGFR2 to elucidate its key role in retinal diseases, recent efforts have shown the importance and involvement of VEGFR1 and its family of ligands in angiogenesis, vascular permeability, and microinflammatory cascades within the retina. Expression of VEGFR1 depends on the microenvironment, is differentially regulated under hypoxic and inflammatory conditions, and it has been detected in retinal and choroidal endothelial cells, pericytes, retinal and choroidal mononuclear phagocytes (including microglia), MĂŒller cells, photoreceptor cells, and the retinal pigment epithelium. Whilst the VEGF-A decoy function of VEGFR1 is well established, consequences of its direct signaling are less clear. VEGFR1 activation can affect vascular permeability and induce macrophage and microglia production of proinflammatory and proangiogenic mediators. However the ability of the VEGFR1 ligands (VEGF-A, PlGF, and VEGF-B) to compete against each other for receptor binding and to heterodimerize complicates our understanding of the relative contribution of VEGFR1 signaling alone toward the pathologic processes seen in diabetic retinopathy, retinal vascular occlusions, retinopathy of prematurity, and age-related macular degeneration. Clinically, anti-VEGF drugs have proven transformational in these pathologies and their impact on modulation of VEGFR1 signaling is still an opportunity-rich field for further research

    Low rank approximation of multidimensional data

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    In the last decades, numerical simulation has experienced tremendous improvements driven by massive growth of computing power. Exascale computing has been achieved this year and will allow solving ever more complex problems. But such large systems produce colossal amounts of data which leads to its own difficulties. Moreover, many engineering problems such as multiphysics or optimisation and control, require far more power that any computer architecture could achieve within the current scientific computing paradigm. In this chapter, we propose to shift the paradigm in order to break the curse of dimensionality by introducing decomposition to reduced data. We present an extended review of data reduction techniques and intends to bridge between applied mathematics community and the computational mechanics one. The chapter is organized into two parts. In the first one bivariate separation is studied, including discussions on the equivalence of proper orthogonal decomposition (POD, continuous framework) and singular value decomposition (SVD, discrete matrices). Then, in the second part, a wide review of tensor formats and their approximation is proposed. Such work has already been provided in the literature but either on separate papers or into a pure applied mathematics framework. Here, we offer to the data enthusiast scientist a description of Canonical, Tucker, Hierarchical and Tensor train formats including their approximation algorithms. When it is possible, a careful analysis of the link between continuous and discrete methods will be performed.IV Research and Transfer Plan of the University of SevillaInstitut CarnotJunta de AndalucĂ­aIDEX program of the University of Bordeau

    The Cosmological Constant

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    This is a review of the physics and cosmology of the cosmological constant. Focusing on recent developments, I present a pedagogical overview of cosmology in the presence of a cosmological constant, observational constraints on its magnitude, and the physics of a small (and potentially nonzero) vacuum energy.Comment: 50 pages. Submitted to Living Reviews in Relativity (http://www.livingreviews.org/), December 199

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    Purification of alpha-galactosidase from seeds of Sesbania marginata

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    Alpha-galactosidase taken from a raw extract of Sesbania marginata legume seeds was purified by partitioning in aqueous two-phase systems (ATPS). Initially, galactomannan/dextran 2,000,000 systems were used for the purification, and the partition coefficients of alpha -galactosidase varied from 1.5 to 4.0. However, mass transport in these systems was poor due to the high viscosity of the employed polymers. Therefore, partitioning in polyethyleneglycol (PEG)/ sodium phosphate systems and the effect of sodium chloride upon the enzyme purification and the yield of a-galactosidase were also investigated. The purification achieved in a single-step was 5.7 with a recovery of 144% of a-galactosidase, possibly due to the removal of materials which inhibited a-galactosidase activity before the purification. The removal of the main protein contaminants and the highest yields were achieved in PEG 4,000/ sodium phosphate + 6% NaCl system at pH 5.0. Further purification by preparative on-exchange chromatography was also developed.174182481982

    Representing human motion with FADE and U-FADE: an efficient frequency-domain approach

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    In this work, we present FADE, a frequency-based descriptor to encode human motion. FADE is simple, and provides high compression rate and low computational complexity. In order to reduce space and time complexity, we exploit the biomechanical property that human motion is bounded in frequency. FADE and U-FADE can be used in combination with both supervised and unsupervised learning approaches in order to classify and cluster human actions, respectively. We present also a branch of FADE, called Uncompressed FADE (U-FADE). U-FADE performs well in combination with some unsupervised algorithms such as spectral clustering, paying the price of a reduced compression rate. Also, U-FADE performs in general better than FADE well with small datasets. We tested our descriptors with well-known, public motion databases, such as HDM05, Berkeley MHAD, and MSR. Moreover, we compared FADE and U-FADE with diverse state of the art approaches

    Carpal tunnel syndrome in the elderly: nerve conduction parameters SĂ­ndrome do tĂșnel do carpo em idosos: parĂąmetros de condução nervosa

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    OBJECTIVE: To establish nerve conduction parameters for carpal tunnel syndrome (CTS) electrodiagnosis in the elderly. METHOD: Thirty healthy subjects (65-86 years), 9 male and 21 female, were studied. Routine median and ulnar sensory and motor nerve conduction studies, median mixed palmar latency, comparative latency techniques median to ulnar (sensory, mixed and motor lumbrical-interossei), median to radial (sensory), and combined sensory index (CSI) were performed in both hands. RESULTS: The upper limits of normality (97.5%) were: median sensory distal latency 3.80 ms (14 cm); median motor distal latency 4.30 ms (8 cm); median palmar latency 2.45 ms (8 cm); lumbrical-interossei latency difference 0.60 ms (8 cm); comparative median to radial 0.95 ms (10 cm); comparative median to ulnar 0.95 ms (14 cm); comparative palmar median to ulnar 0.50 ms (8 cm); and CSI 2.20 ms. Sensory and mixed latencies were measured at peak. CONCLUSION: Our results establish new nerve conduction parameters for mild CTS electrodiagnosis in the elderly and will be helpful to reduce the number of false positive cases in this age.<br>OBJETIVO: Estabelecer parĂąmetros de condução nervosa para o eletrodiagnĂłstico da sĂ­ndrome do tĂșnel do carpo (STC) em idosos. MÉTODO: Foram estudadas 30 pessoas idosas (65-86 anos) saudĂĄveis. Foi realizado estudo de condução nervosa sensitiva e motora rotineira dos nervos mediano e ulnar, latĂȘncia palmar mista do mediano, tĂ©cnicas de comparação de latĂȘncias mediano-ulnar (sensitivo, misto e motor lumbrical-interĂłsseo) e mediano-radial (sensitivo) e Ă­ndice sensitivo combinado (ISC) em ambas as mĂŁos. RESULTADOS: Os limites superiores de normalidade, 97,5% foram: latĂȘncia distal sensitiva do mediano 3,80 ms (14 cm); latĂȘncia distal motora do mediano 4,30 ms (8 cm), latĂȘncia palmar do mediano 2,45 ms (8 cm), diferença de latĂȘncia lumbrical-interĂłsseo 0,60 ms (8 cm), comparação mediano-radial 0,95 ms (10 cm), comparação mediano-ulnar 0,95 ms (14 cm), comparação mediano-ulnar palmar 0,50 ms (8 cm) e ISC 2,20 ms. As latĂȘncias sensitivas e mistas foram medidas no pico. CONCLUSÃO: Nossos resultados estabelecem novos valores de condução nervosa para o eletrodiagnĂłstico da STC leve em idosos
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