416 research outputs found

    Colloid-stabilized emulsions: behaviour as the interfacial tension is reduced

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    We present confocal microscopy studies of novel particle-stabilized emulsions. The novelty arises because the immiscible fluids have an accessible upper critical solution temperature. The emulsions have been created by beginning with particles dispersed in the single-fluid phase. On cooling, regions of the minority phase nucleate. While coarsening these nuclei become coated with particles due to the associated reduction in interfacial energy. The resulting emulsion is arrested, and the particle-coated interfaces have intriguing properties. Having made use of the binary-fluid phase diagram to create the emulsion we then make use of it to study the properties of the interfaces. As the emulsion is re-heated toward the single-fluid phase the interfacial tension falls and the volume of the dispersed phase drops. Crumpling, fracture or coalescence can follow. The results show that the elasticity of the interfaces has a controlling influence over the emulsion behaviour.Comment: Submitted for the proceedings of the 6th Liquid Matter Conference, held in Utrecht (NL) in July 200

    Excessive collagen turnover products are released during colorectal cancer progression and elevated in serum from metastatic colorectal cancer patients

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    During cancer progression, the homeostasis of the extracellular matrix becomes imbalanced with an excessive collagen remodeling by matrix metalloproteinases. As a consequence, small protein fragments of degraded collagens are released into the circulation. We have investigated the potential of protein fragments of collagen type I, III and IV as novel biomarkers for colorectal cancer. Specific fragments of degraded type I, III and IV collagen (C1M, C3M, C4M) and type III collagen formation (Pro-C3) were assessed in serum from colorectal cancer patients, subjects with adenomas and matched healthy controls using well-characterized and validated ELISAs. Serum levels of the biomarkers were significantly elevated in colorectal cancer patients compared to subjects with adenomas (C1M, Pro-C3, C3M) and controls (C1M, Pro-C3). When patients were stratified according to their tumour stage, all four biomarkers were able to differentiate stage IV metastatic patients from all other stages. Combination of all markers with age and gender in a logistic regression model discriminated between metastatic and non-metastatic patients with an AUROC of 0.80. The data suggest that the levels of these collagen remodeling biomarkers may be a measure of tumour activity and invasiveness and may provide new clinical tools for monitoring of patients with advanced stage colorectal cancer

    NETRA: Interactive Display for Estimating Refractive Errors and Focal Range

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    We introduce an interactive, portable, and inexpensive solution for estimating refractive errors in the human eye. While expensive optical devices for automatic estimation of refractive correction exist, our goal is to greatly simplify the mechanism by putting the human subject in the loop. Our solution is based on a high-resolution programmable display and combines inexpensive optical elements, interactive GUI, and computational reconstruction. The key idea is to interface a lenticular view-dependent display with the human eye in close range - a few millimeters apart. Via this platform, we create a new range of interactivity that is extremely sensitive to parameters of the human eye, like refractive errors, focal range, focusing speed, lens opacity, etc. We propose several simple optical setups, verify their accuracy, precision, and validate them in a user study.Alfred P. Sloan Foundation (Research Fellowship

    Influência da temperatura no comportamento alimentar e interação de filhotes de Kinosternon scorpioides em cativeiro.

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    O muçuã (Kinosternon scorpioides) é um cágado bastante apreciado em toda a região amazônica, sendo um quelônio com características zootécnicas promissoras na aquicultura. Contudo, há poucos estudos que abordem o comportamento alimentar desta espécie em cativeiro. Portanto, objetivou-se com o presente estudo avaliar a influencia da temperatura no comportamento alimentar e a interação de filhotes de muçuã (Kinosternon scopioides), mantidos em três diferentes temperaturas (29,5ºC, 31,5ºC e 33,5ºC). O experimento foi conduzido no Projeto Bio-Fauna/ISARH/UFRA, sediado em Belém, Pará. Um total de 84 filhotes de muçuãs foram subdivididos em seis lotes-berçário, distribuídos dois a dois em estufas mantidas sob diferentes temperaturas, 29,5ºC, 31,5ºC e 33,5ºC, durante os primeiros 90 dias de vida. Os animais foram alimentados com ração para peixe, na proporção de 2% do peso vivo/dia, distribuída em ofertas semanais. Quinzenalmente foram realizadas pesagens e medições individuais, para avaliação do desenvolvimento corpóreo e ajuste de alimentação. Constatou-se efeito significativo da temperatura em todos os parâmetros analisados. Durante o experimento foi notado uma diminuição na frequência alimentar em todos os tratamentos, porém os animais da temperatura mais alta do experimento (33,5ºC) apresentaram a maior diminuição no interesse pelo alimento durante o período de oferta/observação, portanto os mesmos tiveram o pior desempenho quando comparado aos demais lotes

    Impaired mitochondrial oxidative phosphorylation in the peroxisomal disease X-linked adrenoleukodystrophy

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    This is a pre-copyedited, author-produced PDF of an article accepted for publication in Human Molecular Genetics following peer review. The version of record Human Molecular Genetics 22.16 (2013): 3296-3305 is available online at http://hmg.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=23604518X-linked adrenoleukodystrophy (X-ALD) is an inherited metabolic disorder of the nervous system characterized by axonopathy in spinal cords and/or cerebral demyelination, adrenal insufficiency and accumulation of very long-chain fatty acids (VLCFAs) in plasma and tissues. The disease is caused by malfunction of the ABCD1 gene, which encodes a peroxisomal transporter of VLCFAs or VLCFA-CoA. In the mouse, Abcd1 loss causes late onset axonal degeneration in the spinal cord, associated with locomotor disability resembling the most common phenotype in patients, adrenomyeloneuropathy. We have formerly shown that an excess of the VLCFA C26:0 induces oxidative damage, which underlies the axonal degeneration exhibited by the Abcd1(-) mice. In the present study, we sought to investigate the noxious effects of C26:0 on mitochondria function. Our data indicate that in X-ALD patients' fibroblasts, excess of C26:0 generates mtDNA oxidation and specifically impairs oxidative phosphorylation (OXPHOS) triggering mitochondrial ROS production from electron transport chain complexes. This correlates with impaired complex V phosphorylative activity, as visualized by high-resolution respirometry on spinal cord slices of Abcd1(-) mice. Further, we identified a marked oxidation of key OXPHOS system subunits in Abcd1(-) mouse spinal cords at presymptomatic stages. Altogether, our results illustrate some of the mechanistic intricacies by which the excess of a fatty acid targeted to peroxisomes activates a deleterious process of oxidative damage to mitochondria, leading to a multifaceted dysfunction of this organelle. These findings may be of relevance for patient management while unveiling novel therapeutic targets for X-ALDThis study was supported by grants from the European Commission (FP7-241622), the European Leukodystrophy Association (ELA2009-036C5; ELA2008-040C4), the Spanish Institute for Health Carlos III (FIS PI080991 and FIS PI11/01043), the Autonomous Government of Catalonia (2009SGR85) to A.P. and the Spanish Institute for Health Carlos III (Miguel Servet program CP11/00080) to S.F. The CIBER on Rare Diseases (CIBERER) is an initiative of the ISCIII. The study was developed under the COST action BM0604 (to A.P.). J.L.-E. was a fellow of the Department of Education, Universities and Research of the Basque Country Government (BFI07.126). S.F. was a fellow of the European Leukodystrophy Association (ELA 2010-020F1). The studies conducted at the Department of Experimental Medicine were supported in part by R&D grants from the Spanish Ministry of Science and Innovation (BFU2009-11879/BFI), the Spanish Ministry of Health (PI11/1532), the Autonomous Government of Catalonia (2009SGR735), the ‘La Caixa’ Foundation and COST B35 Action of the European Union. D.C. is a fellow from the Spanish Ministry of Health (FI08-00707). The studies conducted at the Department of Biochemistry and Molecular Biology, University of Barcelona, were supported by grants SAF2008-01896 and SAF2011-23636 from the Spanish Ministry of Science and Innovatio

    Antifungal activity of the isolated from caatinga actinobacteria in control of Pythium aphanidermatum.

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    The Caatinga is a biome located in a semiarid region of northeastern Brazil. It consists of various ecosystems, presented a unique environmental system of this country. Because it is an environment with unique characteristics, recent studies have revealed the private wealth of this biome in terms of microbial biodiversity. Microorganisms found in this habitat may present specific mechanisms to ensure their survival in this environment that provides extreme conditions, such as temperature changes, intense solar radiation and hydrous stress. Because of these different mechanisms used by different microorganisms, becomes an enabling environment to search for new enzymes and bioactive substances produced by these organisms can present different biotechnological applications. Among all microbial diversity, the group of actinobacteria is of great importance, because they are responsible for producing most of the known antibiotics and present as great producers of enzymes with various industrial applications. One possible application of compounds produced by this organism is the phytogenic fungi combat, such as rot caused in roots of plants by the fungus Pythium aphanidermatum. This study aimed to search actinobacteria from Caatinga biome with metabolic potential to work in the biological control of Pythium aphanidermatum fungus. With Caatinga soil samples, they were isolated actinomycetes differences in morphologies and subjected to extraction metabolites produced from solid culture medium. The extracts were tested on the P. aphanidermatum fungus diffused by drive test. From the isolation were recovered a total of 272 strains of actinomycetes, of this total 47% of the isolates showed in vitro activity against the pathogen Pythium aphanidermatum. The results showing the great potential that actinobacteria may present as control agents against root rot. However, more detailed studies are needed to prove such results

    Apolipoprotein E4 influences growth and cognitive responses to micronutrient supplementation in shantytown children from northeast Brazil

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    OBJECTIVE: Apolipoprotein E4 may benefit children during early periods of life when the body is challenged by infection and nutritional decline. We examined whether apolipoprotein E4 affects intestinal barrier function, improving short-term growth and long-term cognitive outcomes in Brazilian shantytown children. METHODS: A total of 213 Brazilian shantytown children with below-median height-for-age z-scores (HAZ) received 200,000 IU of retinol (every four months), zinc (40 mg twice weekly), or both for one year, with half of each group receiving glutamine supplementation for 10 days. Height-for-age z-scores, weight-for-age z-scores, weight-forheight z-scores, and lactulose:mannitol ratios were assessed during the initial four months of treatment. An average of four years (range 1.4-6.6) later, the children underwent cognitive testing to evaluate non-verbal intelligence, coding, verbal fluency, verbal learning, and delayed verbal learning. Apolipoprotein E4 carriage was determined by PCR analysis for 144 children. RESULTS: Thirty-seven children were apolipoprotein E4(+), with an allele frequency of 13.9%. Significant associations were found for vitamin A and glutamine with intestinal barrier function. Apolipoprotein E4(+) children receiving glutamine presented significant positive Pearson correlations between the change in height-for-age z-scores over four months and delayed verbal learning, along with correlated changes over the same period in weight-for-age z-scores and weight-for-height z-scores associated with non-verbal intelligence quotients. There was a significant correlation between vitamin A supplementation of apolipoprotein E4(+) children and improved delta lactulose/mannitol. Apolipoprotein E4(-) children, regardless of intervention, exhibited negative Pearson correlations between the change in lactulose-to-mannitol ratio over four months and verbal learning and non-verbal intelligence. CONCLUSIONS: During development, apolipoprotein E4 may function concomitantly with gut-tropic nutrients to benefit immediate nutritional status, which can translate into better long-term cognitive outcomes

    Apolipoprotein E4 influences growth and cognitive responses to micronutrient supplementation in shantytown children from northeast Brazil

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    OBJECTIVE: Apolipoprotein E4 may benefit children during early periods of life when the body is challenged by infection and nutritional decline. We examined whether apolipoprotein E4 affects intestinal barrier function, improving short-term growth and long-term cognitive outcomes in Brazilian shantytown children. METHODS: A total of 213 Brazilian shantytown children with below-median height-for-age z-scores (HAZ) received 200,000 IU of retinol (every four months), zinc (40 mg twice weekly), or both for one year, with half of each group receiving glutamine supplementation for 10 days. Height-for-age z-scores, weight-for-age z-scores, weight-forheight z-scores, and lactulose:mannitol ratios were assessed during the initial four months of treatment. An average of four years (range 1.4-6.6) later, the children underwent cognitive testing to evaluate non-verbal intelligence, coding, verbal fluency, verbal learning, and delayed verbal learning. Apolipoprotein E4 carriage was determined by PCR analysis for 144 children. RESULTS: Thirty-seven children were apolipoprotein E4(+), with an allele frequency of 13.9%. Significant associations were found for vitamin A and glutamine with intestinal barrier function. Apolipoprotein E4(+) children receiving glutamine presented significant positive Pearson correlations between the change in height-for-age z-scores over four months and delayed verbal learning, along with correlated changes over the same period in weight-for-age z-scores and weight-for-height z-scores associated with non-verbal intelligence quotients. There was a significant correlation between vitamin A supplementation of apolipoprotein E4(+) children and improved delta lactulose/mannitol. Apolipoprotein E4(-) children, regardless of intervention, exhibited negative Pearson correlations between the change in lactulose-to-mannitol ratio over four months and verbal learning and non-verbal intelligence. CONCLUSIONS: During development, apolipoprotein E4 may function concomitantly with gut-tropic nutrients to benefit immediate nutritional status, which can translate into better long-term cognitive outcomes

    A cultura do cupuaçu: mudas.

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    Propagação. Viveiro. Transporte das mudas. Plantas-matrizes. Coeficientes técnicos.bitstream/item/128298/1/PLANTAR-Cupuacu-mudas-ed01-2008.pd

    Ocorrência de um surto de anel vermelho do dendê no Estado do Amazonas.

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    A cultura do dendê no Brasil é afetada por importantes doenças, com destaque para anel-vermelho (Rhadinaphelenchus cocophilus). No estado do Amazonas, os plantios de dendê são recentes, e, normalmente, estabelecidos em áreas próximas de floresta. A intensificação das práticas de poda e colheita, por ocasião do início da produção, tende a expor as plantas ao ataque do inseto vetor Rhynchophorus palmarum. Na estação experimental do CPAA, onde existe um banco de germoplasma de dendê plantado em 412ha, foi constatado recentemente um surto dessa doença. Estudos estão sendo conduzidos visando determinar a população anual do inseto vetor e os níveis de contaminação deste com os nematóides.Edição dos resumos do XXVIII Congresso Brasileiro de Fitopatologia. Resumo 421
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