905 resultados para New Generation Rollingstock Depot
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This paper describes a modular solid-state switching cell derived from the Marx generator concept to be used in topologies for generating multilevel unipolar and bipolar high-voltage (HV) pulses into resistive loads. The switching modular cell comprises two ON/OFF semiconductors, a diode, and a capacitor. This cell can be stacked, being the capacitors charged in series and their voltages balanced in parallel. To balance each capacitor voltage without needing any parameter measurement, a vector decision diode algorithm is used in each cell to drive the two switches. Simulation and experimental results, for generating multilevel unipolar and bipolar HV pulses into resistive loads are presented.
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Proceedings of the Scientific Meeting of the Portuguese Robotics Open 2004
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The gene SNRNP200 is composed of 45 exons and encodes a protein essential for pre-mRNA splicing, the 200 kDa helicase hBrr2. Two mutations in SNRNP200 have recently been associated with autosomal dominant retinitis pigmentosa (adRP), a retinal degenerative disease, in two families from China. In this work we analyzed the entire 35-Kb SNRNP200 genomic region in a cohort of 96 unrelated North American patients with adRP. To complete this large-scale sequencing project, we performed ultra high-throughput sequencing of pooled, untagged PCR products. We then validated the detected DNA changes by Sanger sequencing of individual samples from this cohort and from an additional one of 95 patients. One of the two previously known mutations (p.S1087L) was identified in 3 patients, while 4 new missense changes (p.R681C, p.R681H, p.V683L, p.Y689C) affecting highly conserved codons were identified in 6 unrelated individuals, indicating that the prevalence of SNRNP200-associated adRP is relatively high. We also took advantage of this research to evaluate the pool-and-sequence method, especially with respect to the generation of false positive and negative results. We conclude that, although this strategy can be adopted for rapid discovery of new disease-associated variants, it still requires extensive validation to be used in routine DNA screenings. © 2011 Wiley-Liss, Inc.
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Aspirin has always remained an enigmatic drug. Not only does it present with new benefits for treating an ever-expanding list of apparently unrelated diseases at an astounding rate but also because aspirin enhances our understanding of the nature of these diseases processe. Originally, the beneficial effects of aspirin were shown to stem from its inhibition of cyclooxygenase-derived prostaglandins, fatty acid metabolites that modulate host defense. However, in addition to inhibiting cyclooxygenase activity aspirin can also inhibit pro-inflammatory signaling pathways, gene expression and other factors distinct from eicosanoid biosynthesis that drive inflammation as well as enhance the synthesis of endogenous protective anti-inflammatory factors. Its true mechanism of action in anti-inflammation remains unclear. Here the data from a series of recent experiments proposing that one of aspirin's predominant roles in inflammation is the induction of nitric oxide, which potently inhibits leukocyte/endothelium interaction during acute inflammation, will be discussed. It will be argued that this nitric oxide-inducing effects are exclusive to aspirin due to its unique ability, among the family of traditional anti-inflammatory drugs, to acetylate the active site of inducible cyclooxygenase and generate a family of lipid mediators called the epi-lipoxins that are increasingly being shown to have profound roles in a range of host defense responses.
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The benzothiazinone lead compound, BTZ043, kills Mycobacterium tuberculosis by inhibiting the essential flavo-enzyme DprE1, decaprenylphosphoryl-beta-D-ribose 2-epimerase. Here, we synthesized a new series of piperazine-containing benzothiazinones (PBTZ) and show that, like BTZ043, the preclinical candidate PBTZ169 binds covalently to DprE1. The crystal structure of the DprE1-PBTZ169 complex reveals formation of a semimercaptal adduct with Cys387 in the active site and explains the irreversible inactivation of the enzyme. Compared to BTZ043, PBTZ169 has improved potency, safety and efficacy in zebrafish and mouse models of tuberculosis (TB). When combined with other TB drugs, PBTZ169 showed additive activity against M. tuberculosis in vitro except with bedaquiline (BDQ) where synergy was observed. A new regimen comprising PBTZ169, BDQ and pyrazinamide was found to be more efficacious than the standard three drug treatment in a murine model of chronic disease. PBTZ169 is thus an attractive drug candidate to treat TB in humans.
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Human embryonic stem (hES) cells represent a potential source for cell replacement therapy of many degenerative diseases. Most frequently, hES cell lines are derived from surplus embryos from assisted reproduction cycles, independent of their quality or morphology. Here, we show that hES cell lines can be obtained from poor-quality blastocysts with the same efficiency as that obtained from good- or intermediate-quality blastocysts. Furthermore, we show that the self-renewal, pluripotency, and differentiation ability of hES cell lines derived from either source are comparable. Finally, we present a simple and reproducible embryoid body-based protocol for the differentiation of hES cells into functional cardiomyocytes. The five new hES cell lines derived here should widen the spectrum of available resources for investigating the biology of hES cells and advancing toward efficient strategies of regenerative medicine.
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Education and diagnostic tests capable of early detection represent our most effective means of preventing transmission of human immunodeficiency virus (HIV). The importance of early detection is underlined by studies demonstrating increased life expectancy following early initiation of antiviral treatment. The Elecsys(®) HIV combi PT assay is a fourth-generation antigen-antibody combination assay developed to allow earlier detection of seroconversion, and to have increased sensitivity and improved specificity. We aimed to determine how early the assay could detect infection compared with existing assays; whether all HIV variants could be detected; and the assay's specificity using samples from blood donors, routine specimens, and patients with potential cross-reacting factors. Samples were identified as positive by the Elecsys(®) assay 4.9 days after a positive polymerase chain reaction result (as determined by the panel supplier), which was earlier than the 5.3-7.1 days observed with comparators. The analytical sensitivity of the Elecsys(®) HIV combi PT assay for the HIV-1 p24 antigen was 1.05 IU/mL, which compares favorably with the comparator assays. In addition, the Elecsys(®) assay identified all screened HIV subtypes and displayed greater sensitivity to HIV-2 homologous antigen and antibodies to HIV-1 E and O and HIV-2 than the other assays. Overall, the specificity of the Elecsys(®) assay was 99.88 % using samples from blood donors and 99.81 % when analyzing unselected samples. Potential cross-reacting factors did not interfere with assay performance. The Elecsys(®) HIV combi PT assay is a sensitive and specific assay that has been granted the CE mark according to Directive 2009/886/EC.
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The aim of this work was to design a novel strategy to detect new targets for anticancer treatments. The rationale was to build Biological Association Networks from differentially expressed genes in drug-resistant cells to identify important nodes within the Networks. These nodes may represent putative targets to attack in cancer therapy, as a way to destabilize the gene network developed by the resistant cells to escape from the drug pressure. As a model we used cells resistant to methotrexate (MTX), an inhibitor of DHFR. Selected node-genes were analyzed at the transcriptional level and from a genotypic point of view. In colon cancer cells, DHFR, the AKR1 family, PKC¿, S100A4, DKK1, and CAV1 were overexpressed while E-cadherin was lost. In breast cancer cells, the UGT1A family was overexpressed, whereas EEF1A1 was overexpressed in pancreatic cells. Interference RNAs directed against these targets sensitized cells towards MTX.
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In the past 5 years "Next-generation" Sequencing (NGS) technologies have transformed genomics by delivering fast, inexpensive and accurate genomeinformation changing the way we think about scientific approaches in basic,applied and clinical research. The inexpensive production of large volumes ofsequence data is the main advantage over the automated Sanger method,making this new technology useful for many applications. In this chapter, a brieftechnical review of NGS technologies is given, along with the keys to NGSsuccess and a broad range of applications for NGS technologies.
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Our main aim in this report is to use Next generation SDH to solve the problem associated with the new telecom services. We have tried to analyze the different services and in this way identified some drawbacks which can be seen as hindrances in supporting these services. In this thesis we will first try to have idea of the past SDH technology and how the next generation SDH came into effect overriding the drawbacks of the past SDH technology. Our main concern throughout the report will be the way we can use next generation SDH to provide quality telecommunication services. In the section dealing with the telecommunication services through next generation SDH we will consider how we can transport Ethernet services through the Next generation SDH and what are the benefits to the customer and the service provider in using next generation SDH as a carrier. We will also see to improve to the ATM services through Next generation SDH. And finally towards the end I have identified some possible future work can be done in this area.
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Kristiina Hormia-Poutasen esitys CBUC-konferenssissa Barcelonassa 12.4.2013.
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Embryonic stem cells are totipotent cells derived from the inner cell mass of blastocysts. Recently, the development of appropriate culture conditions for the differentiation of these cells into specific cell types has permitted their use as potential therapeutic agents for several diseases. In addition, manipulation of their genome in vitro allows the creation of animal models of human genetic diseases and for the study of gene function in vivo. We report the establishment of new lines of murine embryonic stem cells from preimplantation stage embryos of 129/Sv mice. Most of these cells had a normal karyotype and an XY sex chromosome composition. The pluripotent properties of the cell lines obtained were analyzed on the basis of their alkaline phosphatase activity and their capacity to form complex embryoid bodies with rhythmically contracting cardiomyocytes. Two lines, USP-1 and USP-3, with the best in vitro characteristics of pluripotency were used in chimera-generating experiments. The capacity to contribute to the germ line was demonstrated by the USP-1 cell line. This cell line is currently being used to generate mouse models of human diseases.
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A class of twenty-two grade one children was tested to determine their reading levels using the Stanford Diagnostic Reading Achievement Test. Based on these results and teacher input the students were paired according to reading ability. The students ages ranged from six years four months to seven years four months at the commencement of the study. Eleven children were assigned to the language experience group and their partners became the text group. Each member of the language experience group generated a list of eight to be learned words. The treatment consisted of exposing the student to a given word three times per session for ten sessions, over a period of five days. The dependent variables consisted of word identification speed, word identification accuracy, and word recognition accuracy. Each member of the text group followed the same procedure using his/her partner's list of words. Upon completion of this training, the entire process was repeated with members of the text group from the first part becoming members of the language experience group and vice versa. The results suggest that generally speaking language experience words are identified faster than text words but that there is no difference in the rate at which these words are learned. Language experience words may be identified faster because the auditory-semantic information is more readily available in them than in text words. The rate of learning in both types of words, however, may be dictated by the orthography of the to be learned word.