2,680 research outputs found

    Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats

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    NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers

    Using a hardware coprocessor for message scheduling in fieldbus-based distributed systems

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    “Copyright © [2001] IEEE. Reprinted from 8th IEEE International Conference on Electronics, Circuits and Systems. ISBN:0-7803-7057-0. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”Fieldbus based distributed embedded systems used in real-time applications tend to be inflexible in what concerns changing operational parameters on-line. Recent techniques such as the planning scheduler can avoid this problem but do not show adequate responsiveness f o r automatic negotiation of parameter values. In this paper the use of ASIC based coprocessors f o r message scheduling is proposed to solve the problem. Such coprocessors can be used in the arbiter nodes of systems based on widely used producer-consumer fieldbuses like WorldFIP and CAN. A prototype built with a Xilinx FPGA is presented. First performance results are shown and analyzed. They demonstrate that the device is able to achieve the expected performance and also point to the possibility of evolution to an almost dynamic scheduling approach

    An enhanced debugger for real-time fault injection

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    Chip debug infrastructures, present in most recentmicroprocessors, to execute real time fault injectioncampaigns. It is based on a debugger customized forfault injection and designed for maximum performanceand flexibility. The developed methodology can beapplied on the verification of dependable systems

    Integrating business, social, and environmental goals in open innovation through partner selection

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    Although collaborative networks (CN) are widespread in academia and have come to be even more used in corporations all over the world, they still face several challenges on behalf of the new product development (NPD) context, especially in regard to the selection of the CN’s right partner. This becomes even more evident when it comes to promoting sustainable development goals within a CN’s activities, by selecting the right partners with a wide consensus from a CN’s management board, avoiding, therefore, the subjectivity around managers’ perception of a CN’s partner selection. Therefore, this work attempts to answer this problem, by presenting a soft-com-puting-based framework, to support the managers’ board on partner search and selection. The method presented here is further assessed by using a case study, based on the development of a green product, where, according to the obtained results, it is demonstrated that the proposed approach is extremely effective for partner selection, by assessing and prioritizing each candidate involved. The most suitable candidate that fulfills the CN’s requirements is then selected to be integrated as a future partner.publishersversionpublishe

    Size also matters in biodegradable composite microfiber reinforced by chitosan nanofibers

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    Pioneer works on nanocomposites were focused in carbon nanofibers or nanotubes dispersed in epoxy matrix, a viscous liquid facilitating the compounding stage. The interest in developing new composites aimed for biomedical applications led us to design new nanocomposites based in biodegradable polymers with demonstrated biological performance. We report herein the development of micro-nano composites by extruding poly(butylene succinate) (PBS) microfibers with two different diameters, 200 and 500 m, reinforced with electrospun chitosan nanofibers. Analysis of the microfibers showed high levels of alignment of the reinforcing phase and excellent distribution of the nanofibers in the composite. Its geometry facilitates the development of orthotropy, maximizing the reinforcement in the axial fiber main axis. The biodegradable microfiber composites show an outstanding improvement of mechanical properties and of the kinetics of biodegradation, with very small fractions (0.05 and 0.1 wt.%) of electrospun chitosan nanofibers reinforcement. The high surface area-to-volume ratio of electrospun nanofibers combined with the increased water uptake capability of chitosan justify the accelerated kinetics of biodegradation of the composite as compared with the unfilled synthetic polymer.FCT -Fundação para a Ciência e a Tecnologi

    Renormalization group trajectories from resonance factorized S-matrices

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    We propose and investigate a large class of models possessing resonance factorized S-matrices. The associated Casimir energy describes a rich pattern of renormalization group trajectories related to flows in the coset models based on the simply laced Lie Algebras. From a simplest resonance S-matrix, satisfying the ``ϕ3\phi^3-property'', we predict new flows in non-unitary minimal models.Comment: (7 pages) (no figures included

    Klebsiella pneumoniae Invasive Syndrome

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    Klebsiella pneumoniae invasive syndrome (KPIS) is a rare clinical condition characterized by primary liver abscess associated with metastatic infection. Most case reports are from Southeast Asia, with only one case described in Portugal. The Authors present the case of a 44-year-old man with a history of fever, dry cough and cervicalgia. A thoracic computed tomography (CT) scan showed multiple pulmonary and hepatic nodules, suggestive of metastatic malignancy. Both blood cultures and bronchoalveolar lavage were positive for Klebsiella pneumoniae. Imaging studies were repeated during his hospital stay, showing a reduction in both number and volume of identified lesions, thus revealing their infectious nature. This case illustrates how much this entity can mimic other illnesses

    Effect of dietary conjugated linoleic acid isomers on water and glycerol permeability of kidney membranes

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    NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. May 2009; 383(1): 108-112.Conjugated linoleic acid (CLA) refers to a group of positional and geometrical isomers of linoleic acid in which the double bonds are conjugated. Dietary CLA has been associated with various health benefits although details of its molecular mode of action remain elusive. The effect of CLA supplemented to palm oil-based diets in Wistar rats, as a mixture of both or isolated c9,t11 and t10,c12 isomers, was examined on water and glycerol membrane permeability of kidney proximal tubule. Although water permeability was unaltered, an increase in glycerol permeability was obtained for the group supplemented with CLA mixture, even though the activation energy for glycerol permeation remained high. This effect was correlated with an increased CLA isomeric membrane incorporation for the same dietary group. These results suggest that diet supplementation with CLA mixture, in contrast to its individual isomers, may enhance membrane fluidity subsequently raising kidney glycerol reabsorption

    Physiological and Metabolic Responses of Marine Mussels Exposed to Toxic Cyanobacteria Microcystis aeruginosa and Chrysosporum ovalisporum

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    Toxic cyanobacterial blooms are a major contaminant in inland aquatic ecosystems. Furthermore, toxic blooms are carried downstream by rivers and waterways to estuarine and coastal ecosystems. Concerning marine and estuarine animal species, very little is known about how these species are affected by the exposure to freshwater cyanobacteria and cyanotoxins. So far, most of the knowledge has been gathered from freshwater bivalve molluscs. This work aimed to infer the sensitivity of the marine mussel Mytilus galloprovincialis to single as well as mixed toxic cyanobacterial cultures and the underlying molecular responses mediated by toxic cyanobacteria. For this purpose, a mussel exposure experiment was outlined with two toxic cyanobacteria species, Microcystis aeruginosa and Chrysosporum ovalisporum at 1 × 105 cells/mL, resembling a natural cyanobacteria bloom. The estimated amount of toxins produced by M. aeruginosa and C. ovalisporum were respectively 0.023 pg/cell of microcystin-LR (MC-LR) and 7.854 pg/cell of cylindrospermopsin (CYN). After 15 days of exposure to single and mixed cyanobacteria, a depuration phase followed, during which mussels were fed only non-toxic microalga Parachlorella kessleri. The results showed that the marine mussel is able to filter toxic cyanobacteria at a rate equal or higher than the non-toxic microalga P. kessleri. Filtration rates observed after 15 days of feeding toxic microalgae were 1773.04 mL/ind.h (for M. aeruginosa), 2151.83 mL/ind.h (for C. ovalisporum), 1673.29 mL/ind.h (for the mixture of the 2 cyanobacteria) and 2539.25 mL/ind.h (for the non-toxic P. kessleri). Filtering toxic microalgae in combination resulted in the accumulation of 14.17 ng/g dw MC-LR and 92.08 ng/g dw CYN. Other physiological and biochemical endpoints (dry weight, byssus production, total protein and glycogen) measured in this work did not change significantly in the groups exposed to toxic cyanobacteria with regard to control group, suggesting that mussels were not affected with the toxic microalgae. Nevertheless, proteomics revealed changes in metabolism of mussels related to diet, specially evident in those fed on combined cyanobacteria. Changes in metabolic pathways related with protein folding and stabilization, cytoskeleton structure, and gene transcription/translation were observed after exposure and feeding toxic cyanobacteria. These changes occur in vital metabolic processes and may contribute to protect mussels from toxic effects of the toxins MC-LR and CYNPortuguese Science Foundation and under the Projects MOREBIVALVES (PTDC/ASP-PES/31762/2017) and UID/Multi/04423/2013NORTE 2020, Portugal 2020 and the European Union through the ERDF, and by FCT. Moreover, Project AGL2015-64558-RMINECO/FEDER, UE, and the grant FPI (BES-2016–078773

    Tuning branching in ceria nanocrystals

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    Branched nanocrystals (NCs) enable high atomic surface exposure within a crystalline network that provides avenues for charge transport. This combination of properties makes branched NCs particularly suitable for a range of applications where both interaction with the media and charge transport are involved. Herein we report on the colloidal synthesis of branched ceria NCs by means of a ligand-mediated overgrowth mechanism. In particular, the differential coverage of oleic acid as an X-type ligand at ceria facets with different atomic density, atomic coordination deficiency, and oxygen vacancy density resulted in a preferential growth in the [111] direction and thus in the formation of ceria octapods. Alcohols, through an esterification alcoholysis reaction, promoted faster growth rates that translated into nanostructures with higher geometrical complexity, increasing the branch aspect ratio and triggering the formation of side branches. On the other hand, the presence of water resulted in a significant reduction of the growth rate, decreasing the reaction yield and eliminating side branching, which we associate to a blocking of the surface reaction sites or a displacement of the alcoholysis reaction. Overall, adjusting the amounts of each chemical, well-defined branched ceria NCs with tuned number, thickness, and length of branches and with overall size ranging from 5 to 45 nm could be produced. We further demonstrate that such branched ceria NCs are able to provide higher surface areas and related oxygen storage capacities (OSC) than quasi-spherical NCs
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