478 research outputs found

    Eficacia de la tierra de diatomeas y la cal sobre ariónidos y agriolimácidos

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    The aim of this research is to evaluate the effectof d iatomaceous earth (DE) and lime on Arion distinctus under laboratory conditions and on arionids and agriolimacids in the field. Dusting and spraying treatments were carried out to evaluate in the laboratory the effect by ingestion and by contact on the mobility and mortality of the specimens.In the laboratory, three doses of diatomaceous earth (1, 2 and 4 kg/ha), one of agricultural lime (2 kg/ha), and one control were used; and in the field, only the spraying method was evaluated with the same number of variants, but in all cases, doses were doubled. A random block design was used in a 5 x 4 arrangement, and the evaluation was carried out through the trap method, and 20 refuge traps per treatments were placed. Slug populations and the efficiency were established three and seven days after the applications. Tukey’s mean comparison test was used for the populations in thetreated plots and in the control. A higher effect was obtained by contact compared to ingestion. In both field and laboratory applications, the highest mortalities were observed after seven days, without significant differences between diatomaceou searth and lime. The results obtained show that DE is useful in the control of these mollusk species, and better results are obtained with two applications.El objetivo de la presente investigación fue evaluar el efecto de la tierra de diatomeas (TD) y la calsobre Arion distinctus en condiciones de laboratorio, y sobre ariónidos y agriolimácidos en campo. Se realizaron tratamientos por espolvoreo y aspersión para evaluar su efecto por ingestión y contacto en el laboratorio, y se registró la movilidad y la mortalidad de los ejemplares. En laboratorio se emplearon tres dosis de tierra de diatomeas: 1, 2 y 4 kg/ha, una de cal agrícola a 2 kg/ha, y un testigo; en campo solo se evaluó el método por aspersión con la misma cantidad de variantes, pero en todos los casos se duplicaron las dosis. Se utilizó un diseño de bloque azar en arreglo 5 × 4 y la evaluación se llevó a cabo a través del método de trampas; para ello, se colocaron 20 trampas de refugio por tratamientos. Se determinaron las poblaciones de babosas y la eficacia a los tres y siete días después las aplicaciones. Se aplicó una prueba de comparación de medias de Tukey para las poblaciones en las parcelas tratadas y el testigo. Se obtuvo mayor efecto por contacto que de ingestión. Tanto en las aplicaciones en campo como en laboratorio, las mayores mortalidades se observaron a los siete días, sin diferencias significativas entre la TD y la cal. Los resultados obtenidos muestran que la TD es útil en el control de estas especies de moluscos y su resultado es mejor con dos aplicaciones

    Switching the Spin State of Pentafluorophenylnitrene: Isolation of a Singlet Arylnitrene Complex

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    The chemistry of arylnitrenes is dominated by their triplet ground states and excited open-shell singlet states. This results in radical-type reactions and unwanted rearrangements, which diminish the use of arylnitrenes as intermediates in organic synthesis. While the closed-shell singlet states of arylnitrenes are expected to undergo useful chemical transformations (comparable to the closed-shell singlet states of carbenes), these states are too high in energy to be chemically accessible. When triplet pentafluorophenylnitrene is interacting with the Lewis acid BF<sub>3</sub> under the conditions of matrix isolation, a Lewis acid–base complex consisting of the closed-shell singlet state of the nitrene and two molecules of BF<sub>3</sub> is formed. Although the closed-shell singlet state of pentafluorophenylnitrene is calculated (CCSD­(T)) to lie more than 25 kcal/mol above its triplet ground state, the reaction with BF<sub>3</sub> results in switching the spin state from triplet to singlet. The formation of the singlet complex was monitored by IR, UV–vis, and EPR spectroscopy. DFT, CCSD­(T), and CASPT2 calculations confirm the experimental findings

    Tempol improves neuroinflammation and delays motor dysfunction in a mouse model (SOD1G93A) of ALS

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    The development of new therapeutic strategies to treat amyotrophic lateral sclerosis (ALS) is of utmost importance. The use of cyclic nitroxides such as tempol may provide neuroprotection and improve lifespan. We investigated whether tempol (50 mg/kg) presents therapeutic potential in SOD1G93A transgenic mice. Tempol treatment began at the asymptomatic phase of the disease (10th week) and was administered every other day until week 14, after which it was administered twice a week until the final stage of the disease. The animals were sacrificed at week 14 (initial stage of symptoms—ISS) and at the end stage (ES) of the disease. The lumbar spinal cord of the animals was dissected and processed for use in the following techniques: Nissl staining to evaluate neuronal survival; immunohistochemistry to evaluate astrogliosis and microgliosis (ISS and ES); qRT-PCR to evaluate the expression of neurotrophic factors and pro-inflammatory cytokines (ISS); and transmission electron microscopy to evaluate the alpha-motoneurons (ES). Behavioral analyses considering the survival of animals, bodyweight loss, and Rotarod motor performance test started on week 10 and were performed every 3 days until the end-stage of the disease. The results revealed that treatment with tempol promoted greater neuronal survival (23%) at ISS compared to untreated animals, which was maintained until ES. The intense reactivity of astrocytes and microglia observed in vehicle animals was reduced in the lumbar spinal cords of the animals treated with tempol. In addition, the groups treated with tempol showed reduced expression of proinflammatory cytokines (IL1β and TNFα) and a three-fold decrease in the expression of TGFβ1 at ISS compared with the group treated with vehicle. Altogether, our results indicate that treatment with tempol has beneficial effects, delaying the onset of the disease by enhancing neuronal survival and decreasing glial cell reactivity during ALS progression in SOD1G93A mice161CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP300553/2013-9; 303085/2017-72013/16168-8; 2014/06892-3; 2017/02895-6; 2018/05006-

    Correction: optimized labeling of bone marrow mesenchymal cells with superparamagnetic iron oxide nanoparticles and in vivo visualization by magnetic resonance imaging

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    Abstract Background Stem cell therapy has emerged as a promising addition to traditional treatments for a number of diseases. However, harnessing the therapeutic potential of stem cells requires an understanding of their fate in vivo. Non-invasive cell tracking can provide knowledge about mechanisms responsible for functional improvement of host tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) have been used to label and visualize various cell types with magnetic resonance imaging (MRI). In this study we performed experiments designed to investigate the biological properties, including proliferation, viability and differentiation capacity of mesenchymal cells (MSCs) labeled with clinically approved SPIONs. Results Rat and mouse MSCs were isolated, cultured, and incubated with dextran-covered SPIONs (ferumoxide) alone or with poly-L-lysine (PLL) or protamine chlorhydrate for 4 or 24 hrs. Labeling efficiency was evaluated by dextran immunocytochemistry and MRI. Cell proliferation and viability were evaluated in vitro with Ki67 immunocytochemistry and live/dead assays. Ferumoxide-labeled MSCs could be induced to differentiate to adipocytes, osteocytes and chondrocytes. We analyzed ferumoxide retention in MSCs with or without mitomycin C pretreatment. Approximately 95% MSCs were labeled when incubated with ferumoxide for 4 or 24 hrs in the presence of PLL or protamine, whereas labeling of MSCs incubated with ferumoxide alone was poor. Proliferative capacity was maintained in MSCs incubated with ferumoxide and PLL for 4 hrs, however, after 24 hrs it was reduced. MSCs incubated with ferumoxide and protamine were efficiently visualized by MRI; they maintained proliferation and viability for up to 7 days and remained competent to differentiate. After 21 days MSCs pretreated with mitomycin C still showed a large number of ferumoxide-labeled cells. Conclusions The efficient and long lasting uptake and retention of SPIONs by MSCs using a protocol employing ferumoxide and protamine may be applicable to patients, since both ferumoxides and protamine are approved for human use.</p

    Structure-Based Design and Optimization of Multitarget-Directed 2H-Chromen-2-one Derivatives as Potent Inhibitors of Monoamine Oxidase B and Cholinesterases

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    The multifactorial nature of Alzheimer’s disease calls for the development of multitarget agents addressing key pathogenic processes. To this end, by following a docking-assisted hybridization strategy, a number of aminocoumarins were designed, prepared, and tested as monoamine oxidases (MAOs) and acetyl- and butyryl-cholinesterase (AChE and BChE) inhibitors. Highly flexible N-benzyl-N-alkyloxy coumarins 2–12 showed good inhibitory activities at MAO-B, AChE, and BChE but low selectivity. More rigid inhibitors, bearing meta- and para-xylyl linkers, displayed good inhibitory activities and high MAO-B selectivity. Compounds 21, 24, 37, and 39, the last two featuring an improved hydrophilic/lipophilic balance, exhibited excellent activity profiles with nanomolar inhibitory potency toward hMAO-B, high hMAO-B over hMAO-A selectivity and submicromolar potency at hAChE. Cell-based assays of BBB permeation, neurotoxicity, and neuroprotection supported the potential of compound 37 as a BBB-permeant neuroprotective agent against H2O2-induced oxidative stress with poor interaction as P-gp substrate and very low cytotoxicity

    Subacute AMD3100 treatment is not efficient in neonatal hypoxic-schemic rats

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    Background and Purpose: Despite the advances in treating neonatal hypoxic-ischemic encephalopathy (HIE) with induced hypothermia, the rates of severe disability are still high among survivors. Preclinical studies have indicated that cell therapies with hematopoietic stem/progenitor cells could improve neurological outcomes in HIE. In this study, we investigated whether the administration of AMD3100, a CXCR4 antagonist that mobilizes hematopoietic stem/progenitor cells into the circulation, has therapeutic effects in HIE. Methods: P10 Wistar rats of both sexes were subjected to right common carotid artery occlusion or sham procedure, and then were exposed to hypoxia for 120 minutes. Two subcutaneous injections of AMD3100 or vehicle were given on the third and fourth day after HIE. We first assessed the interindividual variability in brain atrophy after experimental HIE and vehicle treatment in a small cohort of rats. Based on this exploratory analysis, we designed and conducted an experiment to test the efficacy of AMD3100. Brain atrophy on day 21 after HIE was defined as the primary end point. Secondary efficacy end points were cognitive (T-water maze) and motor function (rotarod) on days 17 and 18 after HIE, respectively. Results: AMD3100 did not decrease the brain atrophy in animals of either sex. Cognitive impairments were not observed in the T-water maze, but male hypoxic-ischemic animals exhibited motor coordination deficits on the rotarod, which were not improved by AMD3100. A separate analysis combining data from animals of both sexes also revealed no evidence of the effectiveness of AMD3100 treatment. Conclusions: These results indicate that the subacute treatment with AMD3100 does not improve structural and functional outcomes in a rat HIE model

    NeuroBoricuas: a novel approach for incorporating neuroscience education in schools of Puerto Rico

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    [EN] Puerto Rico is in dire need of transforming its education system to counter the current economic recession and ensure a future with talented Puerto Ricans at the forefront of scientific research and technology development.  Here we present a group of neuroscientists and educators, the NeuroBoricuas, committed to revolutionize the scientific culture of Puerto Rico by incorporating neuroscience research training and inquiry-based activities in public and private schools. We carry out our vision through diverse methods, such as community outreach activities, where we promote neuroscience literacy using diverse learning activities. In parallel, we are designing a neuroscience course and textbook with educators to be implemented in schools. We also established neuroscience laboratories in K-12 schools and trained science teachers to manage such laboratories, using equipment from the company “Backyard Brains”. These laboratory experiences are integrated into the academic curriculum in high schools and the equipment is also available for students interested in designing their independent research projects. Lastly, we are expanding a network of committed scientists who partner with educators to help nurture future neuroscientists early in their academic endeavors. Here, we describe our trajectory and our approach to transform scientific education in Puerto Rico.We thank Dr. Gregory J. Quirk, Dr. Daniel Colon-Ramos and Dr. Mark Miller for their support. We thank Tim Marzullo, from Backyard Brains, for supporting NeuroBoricuas. We also thank Palabreria, Digi-Serv and Puerto Rico 4.0 for their constant support. We thank all the NeuroBoricuas that selflessly work hard for a better Puerto Rico. This work has been supported by generous donations from the Puerto Rican people, a grant from the University of Puerto Rico Medical Sciences Campus’ Chancellor’s office, and the Grass Foundation.http://ocs.editorial.upv.es/index.php/HEAD/HEAD18Bravo-Rivera, C.; Díaz-Ríos, M.; Aldarondo-Hernández, A.; Santos-Vera, B.; Ramos-Medina, L.; De Jesús-Burgos, M.; Bravo-Rivera, H.... (2018). NeuroBoricuas: a novel approach for incorporating neuroscience education in schools of Puerto Rico. Editorial Universitat Politècnica de València. 1447-1455. https://doi.org/10.4995/HEAD18.2018.8223OCS1447145
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