244 research outputs found
Cellulose nanowhisker obtained from cotton rejected by textile industry
This study aimed to characterize cellulose nanowhiskers (NWs) extracted from discarded cotton fibers. The nanocellulose was characterized by dynamic light scattering, zeta potential, Scanning Transmission Electron Microscopy (STEM), Atomic force microscopy (AFM) and X-ray powder diffraction (XRD). The nanocrystals are characterized by a rod-like morphology with sizes between 100 nm and 300 nm. The acidic hydrolyses applied to the extract nanocrystals increased the crystallinity index from 72 to 86%. The average length and diameter obtained were 98.1±4.7 and 8.0±3.4 nm, respectively. The aspect ratio of the fibers, around 12.3, was lower than the values usually reported in the literature. The dynamic light scattering results were in accordance with the nano crystal dimensions showing an average size of 235 nm. Cellulose NWs obtained from cotton rejected by textile industry due to their abundance, low cost, high crystallinity, strength, low weight and biodegradability, are the ideal candidates for the processing of polymer nanocomposites
Genetic variation in the Solanaceae fruit bearing species lulo and tree tomato revealed by Conserved Ortholog (COSII) markers
The Lulo or naranjilla (Solanum quitoense Lam.) and the tree tomato or tamarillo (Solanum betaceum Cav. Sendt.) are both Andean tropical fruit species with high nutritional value and the potential for becoming premium products in local and export markets. Herein, we present a report on the genetic characterization of 62 accessions of lulos (n = 32) and tree tomatoes (n = 30) through the use of PCR-based markers developed from single-copy conserved orthologous genes (COSII) in other Solanaceae (Asterid) species. We successfully PCR amplified a set of these markers for lulos (34 out of 46 initially tested) and tree tomatoes (26 out of 41) for molecular studies. Six polymorphic COSII markers were found in lulo with a total of 47 alleles and five polymorphic markers in tree tomato with a total of 39 alleles in the two populations. Further genetic analyses indicated a high population structure (with FST > 0.90), which may be a result of low migration between populations, adaptation to various niches and the number of markers evaluated. We propose COSII markers as sound tools for molecular studies, conservation and the breeding of these two fruit species
Country-level gender inequality is associated with structural differences in the brains of women and men
Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining womenÂŽs worse outcomes in gender-unequal countries. We examined this through a random-effects meta-analysis on cortical thickness and surface area differences between adult healthy men and women, including a meta-regression in which country-level gender inequality acted as an explanatory variable for the observed differences. A total of 139 samples from 29 different countries, totaling 7,876 MRI scans, were included. Thickness of the right hemisphere, and particularly the right caudal anterior cingulate, right medial orbitofrontal, and left lateral occipital cortex, presented no differences or even thicker regional cortices in women compared to men in gender-equal countries, reversing to thinner cortices in countries with greater gender inequality. These results point to the potentially hazardous effect of gender inequality on womenÂŽs brains and provide initial evidence for neuroscience-informed policies for gender equality.Fil: Zugman, AndrĂ©. National Institutes of Health; Estados UnidosFil: Alliende, Luz MarĂa. Pontificia Universidad CatĂłlica de Chile; Chile. Universidad CatĂłlica de Chile; Chile. Northwestern University; Estados UnidosFil: Medel, Vicente. Universidad Adolfo Ibañez; ChileFil: Bethlehem, Richard A.I.. University of Cambridge; Estados UnidosFil: Seidlitz, Jakob. University of Pennsylvania; Estados UnidosFil: Ringlein, Grace. National Institutes of Health; Estados UnidosFil: Arango, Celso. Universidad Complutense de Madrid; EspañaFil: ArnatkeviÄiĆ«tÄ, Aurina. Monash University; AustraliaFil: Asmal, Laila. Stellenbosch University; SudĂĄfricaFil: Bellgrove, Mark. Monash University; AustraliaFil: Benegal, Vivek. National Institute Of Mental Health And Neuro Sciences; IndiaFil: Bernardo, Miquel. Universidad de Barcelona; EspañaFil: Billeke, Pablo. Universidad del Desarrollo; ChileFil: Bosch Bayard, Jorge. McGill University. Montreal Neurological Institute and Hospital; CanadĂĄ. UniversitĂ© Mcgill; CanadĂĄFil: Bressan, Rodrigo. Universidade Federal de Sao Paulo; BrasilFil: Busatto, Geraldo F.. Universidade de Sao Paulo; BrasilFil: Castro, Mariana Nair. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad de Buenos Aires; Argentina. FundaciĂłn para la Lucha contra las Enfermedades NeurolĂłgicas de la Infancia; ArgentinaFil: Chaim Avancini, Tiffany. Universidade de Sao Paulo; BrasilFil: Compte, Albert. Institut dâInvestigacions BiomĂšdiques August Pi i Sunyer; EspañaFil: Costanzi, Monise. Hospital de Clinicas de Porto Alegre; BrasilFil: Czepielewski, Leticia. Hospital de Clinicas de Porto Alegre; Brasil. Universidade Federal do Rio Grande do Sul; BrasilFil: Dazzan, Paola. Kings College London (kcl);Fil: de la Fuente-Sandoval, Camilo. Instituto Nacional de NeurologĂa y NeurocirugĂa; MĂ©xicoFil: Gonzalez Campo, Cecilia. Universidad de San AndrĂ©s; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Zamorano, Francisco. Universidad del Desarrollo; Chile. Universidad San SebastiĂĄn; ChileFil: Zanetti, Marcus V.. Universidade de Sao Paulo; BrasilFil: Winkler, Anderson M.. University of Texas; Estados UnidosFil: Pine, Daniel S.. National Institutes of Health; Estados UnidosFil: Evans Lacko, Sara. School of Economics and Political Science; Reino UnidoFil: Crossley, Nicolas A.. Pontificia Universidad CatĂłlica de Chile; Chile. Universidad CatĂłlica de Chile; Chile. University of Oxford; Reino Unid
An Image-Based High-Content Screening Assay for Compounds Targeting Intracellular Leishmania donovani Amastigotes in Human Macrophages
Leishmaniasis is a tropical disease threatening 350 million people from endemic regions. The available drugs for treatment are inadequate, with limitations such as serious side effects, parasite resistance or high cost. Driven by this need for new drugs, we developed a high-content, high-throughput image-based screening assay targeting the intracellular amastigote stage of different species of Leishmania in infected human macrophages. The in vitro infection protocol was adapted to a 384-well-plate format, enabling acquisition of a large amount of readouts by automated confocal microscopy. The reading method was based on DNA staining and required the development of a customized algorithm to analyze the images, which enabled the use of non-modified parasites. The automated analysis generated parameters used to quantify compound activity, including infection ratio as well as the number of intracellular amastigote parasites and yielded cytotoxicity information based on the number of host cells. Comparison of this assay with one that used the promastigote form to screen 26,500 compounds showed that 50% of the hits selected against the intracellular amastigote were not selected in the promastigote screening. These data corroborate the idea that the intracellular amastigote form of the parasite is the most appropriate to be used in primary screening assay for Leishmania
Astrocytic αVÎČ3 Integrin Inhibits Neurite Outgrowth and Promotes Retraction of Neuronal Processes by Clustering Thy-1
Thy-1 is a membrane glycoprotein suggested to stabilize or inhibit growth of neuronal processes. However, its precise function has remained obscure, because its endogenous ligand is unknown. We previously showed that Thy-1 binds directly to αVÎČ3 integrin in trans eliciting responses in astrocytes. Nonetheless, whether αVÎČ3 integrin might also serve as a Thy-1-ligand triggering a neuronal response has not been explored. Thus, utilizing primary neurons and a neuron-derived cell line CAD, Thy-1-mediated effects of αVÎČ3 integrin on growth and retraction of neuronal processes were tested. In astrocyte-neuron co-cultures, endogenous αVÎČ3 integrin restricted neurite outgrowth. Likewise, αVÎČ3-Fc was sufficient to suppress neurite extension in Thy-1(+), but not in Thy-1(â) CAD cells. In differentiating primary neurons exposed to αVÎČ3-Fc, fewer and shorter dendrites were detected. This effect was abolished by cleavage of Thy-1 from the neuronal surface using phosphoinositide-specific phospholipase C (PI-PLC). Moreover, αVÎČ3-Fc also induced retraction of already extended Thy-1(+)-axon-like neurites in differentiated CAD cells as well as of axonal terminals in differentiated primary neurons. Axonal retraction occurred when redistribution and clustering of Thy-1 molecules in the plasma membrane was induced by αVÎČ3 integrin. Binding of αVÎČ3-Fc was detected in Thy-1 clusters during axon retraction of primary neurons. Moreover, αVÎČ3-Fc-induced Thy-1 clustering correlated in time and space with redistribution and inactivation of Src kinase. Thus, our data indicates that αVÎČ3 integrin is a ligand for Thy-1 that upon binding not only restricts the growth of neurites, but also induces retraction of already existing processes by inducing Thy-1 clustering. We propose that these events participate in bi-directional astrocyte-neuron communication relevant to axonal repair after neuronal damage
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