35 research outputs found

    Development of an electrochemical immunosensor for Phakopsora pachyrhizi detection in the early diagnosis of soybean rust

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    Soybean rust is a disease that occurs on soybean leaves and is considered very aggressive, reducing product quality. Early identification of fungus in the plants prevents severe farming losses as well as spreading to neighboring cultures. In this paper, a label-free immunosensor was developed based on impedance measurements to detect Asian rust on soybean leaf extract at the early stages of the disease. The antibody anti-mycelium of Phakopsora pachyrhizi fungus (disease agent) was immobilized on a gold substrate via a self-assembled monolayer (SAM) of thiols using covalent cysteamine coupling. This immunosensor presents a limit of detection of 385 ng mL-1. The optimization of experimental conditions and surface blocking to minimize non-specific adsorption on the immunosensor response were evaluated. These studies, based on electrochemical impedance spectroscopy (EIS), provide new perspectives on using this method for early diagnosis of soybean rust

    Effect of certolizumab pegol over 96 weeks of treatment on inflammation of the spine and sacroiliac joints, as measured by MRI, and the association between clinical and MRI outcomes in patients with axial spondyloarthritis.

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    OBJECTIVE: To report MRI outcomes and explore the relationship between clinical remission and MRI inflammation in patients with axial spondyloarthritis (axSpA) from the RAPID-axSpA trial, including radiographic (r-)axSpA and non-radiographic (nr-)axSpA. METHODS: RAPID-axSpA (NCT01087762) was double-blind and placebo-controlled to week 24, dose-blind to week 48 and open-label to week 204. Patients were randomised to certolizumab pegol (CZP) or placebo. Placebo patients entering dose-blind were rerandomised to CZP. MRIs performed at baseline, weeks 12, 48 and 96 were scored by 2 reviewers independently: Spondyloarthritis Research Consortium of Canada (SPARCC) for sacroiliac (SI) joints; Berlin modification of the Ankylosing Spondylitis spine MRI scoring system for disease activity (Berlin) for spine. Inflammation thresholds: SPARCC≥2; Berlin>2. Remission thresholds: SPARCC<2 (SI joints); Berlin≤2 (spine); Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease (<1.3, clinical). RESULTS: Across 163 patients in the MRI set (109 CZP; 54 placebo), week 12 mean changes from baseline in MRI scores were greater for CZP versus placebo: SPARCC: -4.8 (SD 8.6) vs -1.6 (7.8; p<0.001); Berlin: -2.9 (4.2) vs 0.2 (4.8; p<0.001). Improvements were maintained to week 96. Week 12 MRI remission was achieved by 52.6% of patients with baseline MRI inflammation in SI joints, 62.0% in the spine and 37.9% of patients with both. MRI remission rates were sustained to week 96, with similar trends in r-axSpA and nr-axSpA. At week 96, 57.5% vs 65.9% of patients achieving versus not achieving clinical remission had MRI remission. CONCLUSIONS: CZP reduced inflammation in the spine and SI joints in patients with r-axSpA and nr-axSpA, with improvements maintained over 96 weeks. Substantial proportions of patients achieved MRI remission. Concordance between clinical remission and current definitions of absence of MRI inflammation was limited. TRIAL REGISTRATION NUMBER: NCT01087762; Post-results

    Genetic transformation of Citrus sinensis with Citrus tristeza virus (CTV) derived sequences and reaction of transgenic lines to CTV infection

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    Transgenic Citrus sinensis (L.) Osb. plants, cvs. Valencia and Hamlin, expressing Citrus tristeza virus (CTV) derived sequences were obtained by genetic transformation. The gene constructs were pCTV-CP containing the 25 kDa major capsid protein gene (CTV-CP), pCTV-dsCP containing the same CTV-CP gene in an intron-spliced hairpin construct, and pCTV-CS containing a 559 nt conserved region of the CTV genome. The transgenic lines were identified by PCR and the transgene integration was confirmed by Southern blot. Transgene mRNA could be detected in most transgenic lines containing pCTV-CP or pCTV-CS transgene. The mRNA of pCTV-dsCP transgene was almost undetectable, with very light bands in most analyzed plants. The transgene transcription appears to be closely linked to the type of gene construct. The virus challenge assays reveals that all transgenic lines were infected. However, it was possible to identify propagated clones of transgenic plants of both cultivars studied with a low virus titer, with values similar to the non-inoculated plants (negative control). These results suggested that the transgenic plants present some level of resistance to virus replication. The higher number of clones with low virus titer and where mRNA could not be detected or was presented in a very light band was found for pCTV-dsCP-derived transgenic lines561162166CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçã

    Nuclear astrophysics with radioactive ions at FAIR

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    The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes

    A disposable voltammetric immunosensor based on magnetic beads for early diagnosis of soybean rust

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Asian soybean rust is a fungal disease caused by Phakopsora pachyrhizi which is a virulent pathogen that can cause losses up to 80% in culture, reducing value and product quality. Early identification of fungus in the plant is the better way to prevent economic losses as well as spreading to neighboring farming, avoiding a rapid epidemic. In this paper, a disposable electrochemical immunosensor was developed to detect the presence of fungus mycelium, ensuring early identification of disease stages, allowing swift action to be taken. The antibody anti-mycelium of P. pachyrhizi was immobilized on magnetic microbeads, modified with a protein G, via Fc portion of antibody. The immunotest was the sandwich type, using a secondary antibody labeled with phosphatase alkaline enzyme. The optimization of experimental conditions and the analytical parameters were evaluated. The developed disposable immunosensor presented a detection limit of 90 ng mL(-1). These studies provide new perspectives on using screen-printed carbon electrodes based on magnetic beads, for early diagnosis of soybean rust for analysis in field. (C) 2012 Elsevier B.V. All rights reserved.166135140Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INCTBioFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Exhaustive exercise with different rest periods changes the collagen content and MMP-2 activation on the calcaneal tendon

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    Tendons adapt to different mechanical stimuli through a remodeling process involving metalloproteinases (MMPs) and collagen synthesis. The purpose of this study was to investigate the activities of MMP-2 and MMP-9 and the collagen content in tendons after exhaustive acute exercise sessions over the course of 1, 3, or 6 days, with 1-hr or 3-hr rest periods between each session. Wistar rats were grouped into control (C), trained with 1-hr (groups 1d1h, 3d1h, and 6d1h) and trained with 3-hr (groups 1d3h, 3d3h and 6d3h) groups with rest periods between the treadmill running sessions, for 1, 3, and 6 days. The analysis of MMP-2 showed a larger presence of the latent isoform in the 1d3h group and a larger presence of the active isoform in the 6d3h group compared to the control. No differences were detected for MMP-9. A lower concentration of hydroxyproline was found in the 6d3h group compared to the 6d1h group. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed more prominent collagen bands in the 6d3h group, which was confirmed by Western blotting for collagen type I. A higher concentration of glycosaminoglycans was observed in the 3d3h group compared to the 3d1h group, and the 6d3h group presented the highest value for non-collagenous proteins compared to other groups. In conclusion, different rest periods between exercise sessions had different effects on the composition of the calcaneal tendon because a greater activation of MMP-2 and a reduction of total collagen were observed on day 6 of exercise with 3-hr rest periods compared to 1-hr rest periods. Anat Rec, 297:281-288, 2014297228128
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