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71.
Joan Ubach Antxon Martínez de Ilarduya Robert Quintana Abdelilah Alla Elisabet Rudé Sebastián Muñoz‐Guerra 《应用聚合物科学杂志》2010,115(3):1823-1830
A series of poly(ethylene terephthalate‐co‐isophthalate) copolyesters containing upto 50%‐mole of isophthalic units were prepared by polycondensation from ethylene terephthalate and ethylene isophthalate fractions of linear oligomers containing from 5 to 6 repeating units in average. The polyesters were obtained in good yields and with high‐molecular‐weights. The microstructure of the copolyesters was studied as a function of reaction time by 13C‐NMR showing that a random distribution of the comonomers was achieved since the earlier stages of polycondensation. The melting temperature and enthalpy of the copolyesters decreased with the content of isophthalic units so that copolyesters containing more than 25% of these units were amorphous. Isothermal crystallization studies made on crystalline copolyesters revealed that the crystallization rate of copolyesters decreased with the content in isophthalic units. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
72.
Elaine Armelin Mireia Martí Elisabet Rudé Jordi Labanda Joan Llorens Carlos Alemán 《Progress in Organic Coatings》2006
A simple rheological model is proposed to describe the thixotropic behavior of paints since the classical hysteresis area, which is usually employed, is not enough to evaluate thixotropy. The model, which is based on the assumption that viscosity is a direct measure of the structural level of the paint, depends on two equations: the Cross–Carreau equation to describe the equilibrium viscosity and a second order kinetic equation to express the time dependence of viscosity. Two characteristic thixotropic times are distinguished: one for the net structure breakdown, which is defined as a power law function of shear rate, and another for the net structure buildup, which does not depend on the shear rate. The useful information provided by these two kinetic processes can be potentially used to improve both the quality and applicability of paints. 相似文献
73.
74.
Fitó M Gimeno E Covas MI Miró E López-Sabater Mdel C Farré M de lT Marrugat J 《Lipids》2002,37(3):245-251
It is generally believed that virgin olive oil consumption has beneficial effects, but little is known about its effects postprandially
on oxidant/antioxidant status. The aim of this study was to determine changes in oxidative stress biomarkers and lipid profile
after a single dose of virgin olive oil and after 1 wk of daily consumption. Sixteen subjects (9 men, 7 women) ingested 50
mL of virgin olive oil in a single dose. Blood samples were collected from 0 to 24 h. Thereafter, 14 participants (8 men,
6 women) followed a 1-wk 25 mg/d virgin olive oil dietary intervention. Blood samples were collected at the end of this period.
Serum TAG (P=0.016), plasma FA (P<0.001) and lipid peroxidation products in plasma (P<0.001) and VLDL (P=0.007) increased, reaching a peak at 4–6 h, and returning to baseline values at 24 h after oil ingestion. The opposite changes
were observed in plasma glutathione peroxidase (P=0.001) and glutathione reductase (GR) (P=0.042). No changes in LDL lipid peroxidation or resistance to oxidation were observed postprandially. At 24 h, plasma oleic
acid remained increased (P<0.05) and resistance of LDL to oxidation improved (P<0.05). After 1 wk of virgin olive oil consumption, plasma oleic acid (P=0.031), resistance of LDL to oxidation (P<0.05), and plasma GR activity (P=0.005) increased. These results indicate that changes in oxidant/antioxidant status occur after oral virgin olive oil. Virgin
olive oil consumption could provide short-term benefits for LDL resistance to oxidation and in glutathione-related enzyme
activities. 相似文献
75.
Matteo Bocci Clara Oudenaarden Xavier Senz-Sard Joel Simrn Arvid Edn Jonas Sjlund Christina Mller Magnus Gissln Henrik Zetterberg Elisabet Englund Kristian Pietras 《International journal of molecular sciences》2021,22(21)
A wide range of neurological manifestations have been associated with the development of COVID-19 following SARS-CoV-2 infection. However, the etiology of the neurological symptomatology is still largely unexplored. Here, we used state-of-the-art multiplexed immunostaining of human brains (n = 6 COVID-19, median age = 69.5 years; n = 7 control, median age = 68 years) and demonstrated that expression of the SARS-CoV-2 receptor ACE2 is restricted to a subset of neurovascular pericytes. Strikingly, neurological symptoms were exclusive to, and ubiquitous in, patients that exhibited moderate to high ACE2 expression in perivascular cells. Viral dsRNA was identified in the vascular wall and paralleled by perivascular inflammation, as signified by T cell and macrophage infiltration. Furthermore, fibrinogen leakage indicated compromised integrity of the blood–brain barrier. Notably, cerebrospinal fluid from additional 16 individuals (n = 8 COVID-19, median age = 67 years; n = 8 control, median age = 69.5 years) exhibited significantly lower levels of the pericyte marker PDGFRβ in SARS-CoV-2-infected cases, indicative of disrupted pericyte homeostasis. We conclude that pericyte infection by SARS-CoV-2 underlies virus entry into the privileged central nervous system space, as well as neurological symptomatology due to perivascular inflammation and a locally compromised blood–brain barrier. 相似文献
76.
Elisabet Estévez Marga Marcos Darío Orive 《The International Journal of Advanced Manufacturing Technology》2007,35(5-6):527-540
Industrial process measurement and control systems (IPMCS) are used in most of the industrial sectors to achieve production
improvement, process optimization and time and cost reduction. Integration, reuse, flexibility and optimization are demanded
to adapt to a rapidly changing and competitive market. In order to achieve these goals, the use of standards in the application
field, methodologies for defining the application design and tools for supporting the development cycle are needed. This paper
proposes a component-based model of the implementation of the control system under design (the hardware and software architectures).
The software architecture is defined to follow the software model of the IEC 61131-3 standard for programming programmable
logic controllers and the hardware architecture is composed by equipment characterised by vendor and range of product. The
proposed modelling is implemented as a markup language that allows to describe models of industrial control systems (icsML). From the application model, described in the markup language, the automation project for every programmable logic controller
(PLC) present in the application is automatically generated. 相似文献
77.
By varying cooking temperature, alkali charge, ionic strength, and cooking time in Kraft pulping of spruce chips, pulps ranging between kappa numbers 20–80 were obtained. The unbleached Kraft pulp fibers were subjected to mechanical peeling in order to separate the surface material from the bulk of the fibers and the carbohydrate composition and lignin content of the two fractions were analyzed. As expected, the lignin and xylan contents were higher on the fiber surface than in the fiber wall. The percentage of xylan on the fiber surface was fairly constant, independent of different pulping conditions or degree of delignification. The lignin proportion on the fiber surface gradually decreased with decreasing kappa number. At a given kappa number, pulping at a higher temperature resulted in less lignin on the fiber surface, probably because of the higher solubility of lignin at higher temperature. Cooking at lower alkali charge also resulted in lower lignin content on the fiber surface at a given kappa number. In this case, there was more time available for degradation of the surface lignin since the lower alkali charge resulted in longer cooking time needed to reach a certain kappa number. 相似文献
78.
Elisabet Kaa 《Lipids》1976,11(9):693-696
Weanling rats were fed either a semi-synthetic diet with no fat, with 28% by wt partially hydrogenated fish oil, or with 28%
by wt arachis oil (control diet) for 6 or 71/2 months. The in vitro conversion of arachidonic acid to prostaglandin E2 by homogenates of the rat kidney medulla was measured by gaschromatography with electron capture detection. The kidney medulla
of essential fatty acid deficient animals showed increased activity for the in vitro conversion of exogenous arachidonic acid
to prostaglandin E2 when compared to the controls. The change of the enzymatic activity in the essential fatty acid deficient animals was reversible,
as shown by refeeding. Inhibition of the prostaglandin synthetase was found at exogenous substrate concentrations higher than
50–100 μM. 相似文献
79.
Julia Hernandez-Baixauli Nerea Abasolo Hector Palacios-Jordan Elisabet Foguet-Romero David Suol Mar Galofr Antoni Caimari Laura Baselga-Escudero Josep M Del Bas Miquel Mulero 《International journal of molecular sciences》2022,23(5)
Chronic inflammation is an important risk factor in a broad variety of physical and mental disorders leading to highly prevalent non-communicable diseases (NCDs). However, there is a need for a deeper understanding of this condition and its progression to the disease state. For this reason, it is important to define metabolic pathways and complementary biomarkers associated with homeostatic disruption in chronic inflammation. To achieve that, male Wistar rats were subjected to intraperitoneal and intermittent injections with saline solution or increasing lipopolysaccharide (LPS) concentrations (0.5, 5 and 7.5 mg/kg) thrice a week for 31 days. Biochemical and inflammatory parameters were measured at the end of the study. To assess the omics profile, GC-qTOF and UHPLC-qTOF were performed to evaluate plasma metabolome; 1H-NMR was used to evaluate urine metabolome; additionally, shotgun metagenomics sequencing was carried out to characterize the cecum microbiome. The chronicity of inflammation in the study was evaluated by the monitoring of monocyte chemoattractant protein-1 (MCP-1) during the different weeks of the experimental process. At the end of the study, together with the increased levels of MCP-1, levels of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α) and prostaglandin E2 (PGE2) along with 8-isoprostanes (an indicative of oxidative stress) were significantly increased (p-value < 0.05). The leading features implicated in the current model were tricarboxylic acid (TCA) cycle intermediates (i.e., alpha-ketoglutarate, aconitic acid, malic acid, fumaric acid and succinic acid); lipids such as specific cholesterol esters (ChoEs), lysophospholipids (LPCs) and phosphatidylcholines (PCs); and glycine, as well as N, N-dimethylglycine, which are related to one-carbon (1C) metabolism. These metabolites point towards mitochondrial metabolism through TCA cycle, β-oxidation of fatty acids and 1C metabolism as interconnected pathways that could reveal the metabolic effects of chronic inflammation induced by LPS administration. These results provide deeper knowledge concerning the impact of chronic inflammation on the disruption of metabolic homeostasis. 相似文献
80.
Julia Hernandez-Baixauli Pere Puigb Nerea Abasolo Hector Palacios-Jordan Elisabet Foguet-Romero David Suol Mar Galofr Antoni Caimari Laura Baselga-Escudero Josep M. Del Bas Miquel Mulero 《International journal of molecular sciences》2021,22(23)
Stress disorders have dramatically increased in recent decades becoming the most prevalent psychiatric disorder in the United States and Europe. However, the diagnosis of stress disorders is currently based on symptom checklist and psychological questionnaires, thus making the identification of candidate biomarkers necessary to gain better insights into this pathology and its related metabolic alterations. Regarding the identification of potential biomarkers, omic profiling and metabolic footprint arise as promising approaches to recognize early biochemical changes in such disease and provide opportunities for the development of integrative candidate biomarkers. Here, we studied plasma and urine metabolites together with metagenomics in a 3 days Chronic Unpredictable Mild Stress (3d CUMS) animal approach that aims to focus on the early stress period of a well-established depression model. The multi-omics integration showed a profile composed by a signature of eight plasma metabolites, six urine metabolites and five microbes. Specifically, threonic acid, malic acid, alpha-ketoglutarate, succinic acid and cholesterol were proposed as key metabolites that could serve as key potential biomarkers in plasma metabolome of early stages of stress. Such findings targeted the threonic acid metabolism and the tricarboxylic acid (TCA) cycle as important pathways in early stress. Additionally, an increase in opportunistic microbes as virus of the Herpesvirales was observed in the microbiota as an effect of the primary stress stages. Our results provide an experimental biochemical characterization of the early stage of CUMS accompanied by a subsequent omic profiling and a metabolic footprinting that provide potential candidate biomarkers. 相似文献