100 research outputs found

    Operation Modes of Battery Chargers for Electric Vehicles in the Future Smart Grids

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    This paper presents an on-board bidirectional battery charger for Electric Vehicles (EVs), which operates in three different modes: Grid-to- Vehicle (G2V), Vehicle-to-Grid (V2G), and Vehicle-to-Home (V2H). Through these three operation modes, using bidirectional communications based on Information and Communication Technologies (ICT), it will be possible to exchange data between the EV driver and the future smart grids. This collaboration with the smart grids will strengthen the collective awareness systems, contributing to solve and organize issues related with energy resources and power grids. This paper presents the preliminary studies that results from a PhD work related with bidirectional battery chargers for EVs. Thus, in this paper is described the topology of the on-board bidirectional battery charger and the control algorithms for the three operation modes. To validate the topology it was developed a laboratory prototype, and were obtained experimental results for the three operation modes. FEDER Funds, through the Operational Programme for Competitiveness Factors COMPETE, and by National Funds through FCT Foundation for Science and Technology of Portugal, under the project FCOMP-01-0124- FEDER-022674, and QREN project AAC n.º36/SI/2009 13844 Document type: Part of book or chapter of boo

    Assessment of the role of transcript for GATA-4 as a marker of unfavorable outcome in human adrenocortical neoplasms

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    BACKGROUND: Malignant neoplasia of the adrenal cortex is usually associated with very poor prognosis. When adrenocortical neoplasms are diagnosed in the early stages, distinction between carcinoma and adenoma can be very difficult to accomplish, since there is yet no reliable marker to predict tumor recurrence or dissemination. GATA transcription factors play an essential role in the developmental control of cell fate, cell proliferation and differentiation, organ morphogenesis, and tissue-specific gene expression. Normal mouse adrenal cortex expresses GATA-6 while its malignant counterpart only expresses GATA-4. The goal of the present study was to assess whether this reciprocal change in the expression of GATA factors might be relevant for predicting the prognosis of human adrenocortical neoplasms. Since human adrenal cortices express luteinizing hormone (LH/hCG) receptor and the gonadotropins are known to up-regulate GATA-4 in gonadal tumor cell lines, we also studied the expression of LH/hCG receptor. METHODS: We conducted a study on 13 non-metastasizing (NM) and 10 metastasizing/recurrent (MR) tumors obtained from a group of twenty-two adult and pediatric patients. The expression of GATA-4, GATA-6, and LH/hCG receptor (LHR) in normal and tumoral human adrenal cortices was analysed using reverse transcriptase-polymerase chain reaction (RT-PCR) complemented by dot blot hybridization. RESULTS: Messenger RNA for GATA-6 was detected in normal adrenal tissue, as well as in the totality of NM and MR tumors. GATA-4, by its turn, was detected in normal adrenal tissue, in 11 out of 13 NM tumors, and in 9 of the 10 MR tumors, with larger amounts of mRNA found among those presenting aggressive clinical behavior. Transcripts for LH receptor were observed both in normal tissue and neoplasms. A more intense LHR transcript accumulation was observed on those tumors with better clinical outcome. CONCLUSION: Our data suggest that the expression of GATA-6 in human adrenal cortex is not affected by tumorigenesis. GATA-4 expression is more abundant in MR tumors, while NM tumors express more intensely LHR. Further studies with larger cohorts are needed to test whether relative expression levels of LHR or GATA-4 might be used as prognosis predictors

    A Chemical Analog of Curcumin as an Improved Inhibitor of Amyloid Abeta Oligomerization

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    Amyloid-like plaques are characteristic lesions defining the neuropathology of Alzheimer's disease (AD). The size and density of these plaques are closely associated with cognitive decline. To combat this disease, the few therapies that are available rely on drugs that increase neurotransmission; however, this approach has had limited success as it has simply slowed an imminent decline and failed to target the root cause of AD. Amyloid-like deposits result from aggregation of the Aβ peptide, and thus, reducing amyloid burden by preventing Aβ aggregation represents an attractive approach to improve the therapeutic arsenal for AD. Recent studies have shown that the natural product curcumin is capable of crossing the blood-brain barrier in the CNS in sufficient quantities so as to reduce amyloid plaque burden. Based upon this bioactivity, we hypothesized that curcumin presents molecular features that make it an excellent lead compound for the development of more effective inhibitors of Aβ aggregation. To explore this hypothesis, we screened a library of curcumin analogs and identified structural features that contribute to the anti-oligomerization activity of curcumin and its analogs. First, at least one enone group in the spacer between aryl rings is necessary for measureable anti-Aβ aggregation activity. Second, an unsaturated carbon spacer between aryl rings is essential for inhibitory activity, as none of the saturated carbon spacers showed any margin of improvement over that of native curcumin. Third, methoxyl and hydroxyl substitutions in the meta- and para-positions on the aryl rings appear necessary for some measure of improved inhibitory activity. The best lead inhibitors have either their meta- and para-substituted methoxyl and hydroxyl groups reversed from that of curcumin or methoxyl or hydroxyl groups placed in both positions. The simple substitution of the para-hydroxy group on curcumin with a methoxy substitution improved inhibitor function by 6-7-fold over that measured for curcumin

    Molecular Evidence for a Functional Ecdysone Signaling System in Brugia malayi

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    Filarial parasites such as Brugia malayi and Onchocerca volvulus are the causative agents of the tropical diseases lymphatic filariasis and onchocerciasis, which infect 150 million people, mainly in Africa and Southeast Asia. Filarial nematodes have a complex life cycle that involves transmission and development within both mammalian and insect hosts. The successful completion of the life cycle includes four molts, two of which are triggered upon transmission from one host to the other, human and mosquito, respectively. Elucidation of the molecular mechanisms involved in the molting processes in filarial nematodes may yield a new set of targets for drug intervention. In insects and other arthropods molting transitions are regulated by the steroid hormone ecdysone that interacts with a specialized hormone receptor composed of two different proteins belonging to the family of nuclear receptors. We have cloned from B. malayi two members of the nuclear receptor family that show many sequence and biochemical properties consistent with the ecdysone receptor of insects. This finding represents the first report of a functional ecdysone receptor homolog in nematodes. We have also established a transgenic hormone induction assay in B. malayi that can be used to discover ecdysone responsive genes and potentially lead to screening assays for active compounds for pharmaceutical development

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Upregulation of the vascular endothelial growth factor, Flt-1, in rat hippocampal neurons after envenoming by Phoneutria nigriventer; age-related modulation

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)This study characterizes the distribution and quantifies the expression of the tyrosine kinase receptor for the vascular endothelial growth factor (VEGF), Flt-1, in the rat hippocampus following intra-peritoneal injection of Phoneutria nigriventer venom (PNV). Postnatal day 14 (P14) and 8-10 weeks (adult) old rats were used and analyses were done at 1, 2, 5 and 24 h after venom exposure and compared with saline-injected counterparts. PNV-injected animals showed hippocampal venules with perivascular edema indicating blood-brain barrier (BBB) dysfunction. This was accompanied by significant overexpression of Flt-1 which though was not the same for CA1, CA2, CA3 and dentate gyrus (DG) hippocampal regions, neither for P14 and adult rats. Regional analysis using GIMP methodology showed that Flt-1 was constitutively distributed more densely in neurons of DG, followed by CA1/CA2 and CA3 of both control P14 and adult animals, without variation over time, but significantly more expressed in P14 than in adults. A time-course analysis showed that Flt-1 upregulation was progressive and that neurons VEGFR1/Flt-1+ of PNV-exposed animals are timely and regionally modulated depending on the hippocampal region, being CA2 the least responsive region regardless animal's age, whilst DG was the most susceptible with adult animals having higher upregulation than neonates. Since VEGF has been reported to confer protection in several pathological processes we suggest that VEGF may be involved in hippocampal neurons response via Flt-1 mediation following PNV envenoming; its higher upregulation in adult envenomed rats may be an indication that Flt-1 neuroprotective mediation is more efficient with age. The Flt-1 upregulation and the incidence of perivascular edema in young animals may indicate a pro-inflammatory role of the receptor. (c) 2012 Elsevier Ltd. All rights reserved.604SI656664Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [2008/55748-1]CNPq [302206/2008-6, 481316/2008-6

    Expression of matrix metalloproteases-2 and-9 in horse hoof laminae after intestinal obstruction, with or without Hydrocortisone treatment

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Twenty horses were used in the experiment, for composed control group, (Cg) instrumented group, (Ig; without intestinal obstruction), treated group (Tg; submitted to intestinal obstruction and hydrocortisone treatment) and non-treated group (Ntg; submitted to intestinal obstruction without treatment). Immunohistochemistry and zymography techniques were used for researches on MMPs 2 and 9 in horse hoof laminae. There was an increase in the expression of MMP-2 in animals of Tg and Ntg. MMP-9 increased on animals from groups Ntg and Ig, however there was no rise of this MMP on the Tg when compared to the other groups in the immunohistochemistry analysis. Based on the results, it was observed that the intestinal injury caused by enterotomy and intestinal obstruction raise the quantities of MMPs in the hoof laminae.4316672Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
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