2,891 research outputs found

    Oxidation of Long Chain Fatty Acids by Rat Liver Mitochondria

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    Abstract Long chain fatty acids are oxidized by rat liver mitochondria provided that endogenous adenosine triphosphate is not depleted. If endogenous ATP is depleted, e.g. by 2,4-dinitrophenol, external ATP as well as carnitine is required for fatty acid oxidation. Atractyloside does not block this reaction in media containing orthophosphate buffer. Oligomycin can substitute for carnitine, but the oligomycin-dependent route is inhibited by atractyloside. These experimental situations localize two ATP-dependent fatty acid-activating systems, one of which is linked to carnitine. The dinitrophenol-insensitive, GTP-specific fatty acyl coenzyme A synthetase is active only in the absence of orthophosphate. Inhibition of oxidation of fatty acids by atractylate in phosphate-free media is not relieved with oligomycin or carnitine

    A Guanosine Triphosphate-dependent Acyl Coenzyme A Synthetase from Rat Liver Mitochondria

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    A guanosine triphosphate-specific acyl coenzyme A synthetase has been purified from extracts of sonically disrupted rat liver mitochondria. This enzyme, which is free of adenosine triphosphate-dependent activating systems and from succinyl-CoA synthetase activity, catalyzes the formation of CoA esters of both long and short chain fatty acids. GTP-specific fatty acid activation is inhibited by orthophosphate and fluoride

    Microscopic theory of quantum-transport phenomena in mesoscopic systems: A Monte Carlo approach

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    A theoretical investigation of quantum-transport phenomena in mesoscopic systems is presented. In particular, a generalization to ``open systems'' of the well-known semiconductor Bloch equations is proposed. The presence of spatial boundary conditions manifest itself through self-energy corrections and additional source terms in the kinetic equations, whose form is suitable for a solution via a generalized Monte Carlo simulation. The proposed approach is applied to the study of quantum-transport phenomena in double-barrier structures as well as in superlattices, showing a strong interplay between phase coherence and relaxation.Comment: to appear in Phys. Rev. Let

    Electron-hole correlation effects in the emission of light from quantum wires

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    We present a self-consistent treatment of the electron-hole correlations in optically excited quantum wires within the ladder approximation, and using a contact potential interaction. The limitations of the ladder approximation to the excitonic low-density region are largely overcome by the introduction of higher order correlations through self consistency. We show relevance of these correlations in the low-temperature emission, even for high density relevant in lasing, when large gain replaces excitonic absorption.Comment: 4 paes 3 figure

    Local treatment with electrochemotherapy of superficial angiosarcomas: Efficacy and safety results from a multi-institutional retrospective study

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    Background: Angiosarcoma is an aggressive vascular neoplasm with a high propensity for local recurrence. Electrochemotherapy is an emerging skin-directed therapy, exerting prominent cytotoxic activity, and antivascular effects. Its efficacy in angiosarcoma has not been investigated. Methods: This multicenter retrospective analysis reviewed patients who underwent electrochemotherapy from 2007 to 2014 for superficial advanced angiosarcomas. Bleomycin was administered intravenously and delivered within tumors by means of percutaneously applied electric pulses, according to the European Standard Operating Procedures for Electrochemotherapy. Tumor assessment was performed using RECIST (version 1.1). Toxicity (CTCAE, v4.0) and local progression-free survival (LPFS) were also evaluated. Results: Nineteen patients (13 with locally advanced and 6 with metastatic angiosarcomas) were treated. Tumor sites were: scalp (nÂĽ5), breast(nÂĽ8), other skin sites (nÂĽ3), and soft tissue (nÂĽ3). Target lesions (nÂĽ54) ranged in size from 1.5 to 2.5 cm (median, 2 cm). Treatment was well tolerated. After 2 months, an objective response was observed in 12/19 (63%) patients, complete in 8 (42%). One-year LPFS within treatment field was 68%. Local symptom improvement included palliation of bleeding (5/19 patients) and pain relief (6/19 patients). Conclusions: Electrochemotherapy may represent a new locoregional treatment for selected patients with superficial angiosarcomas

    Gene expression profiling of peripheral blood in patients with abdominal aortic aneurysm

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    AbstractObjectAbdominal aortic aneurysm (AAA) pathogenesis remains poorly understood. This study investigated the gene expression profile of peripheral blood from patients with AAA using microarray technology.Methods and resultsWe determined gene expression profiles in pooled RNA from 10 AAA patients and 10 matched controls with arrays representing 14,000 transcripts. Microarray data for selected genes were confirmed by real-time PCR in two different AAA (n=36) and control (n=36) populations and integrated with biochemical data. We identified 91 genes which were differentially expressed in AAA patients. Gene Ontology analysis indicated a significant alteration of oxygen transport (increased hemoglobin gene expression) and lipid metabolism [including monoglyceride lipase and low density lipoprotein receptor-related protein 5 (LRP5) gene]. LRP5 expression was associated inversely with serum lipoprotein(a) [Lp(a)] concentration.ConclusionsIncreased expression of hemoglobin chain genes as well as of genes involved in erythrocyte mechanical stability were observed in the AAA RNA pools. The association between low levels of LRP5 gene expression and increased levels of Lp(a) in AAA patients suggests a potential role of LRP5 in Lp(a) catabolism. Our data underline the power of microarrays in identifying further molecular perturbations associated with AAA

    A Theory of Sampling for Continuous-time Metric Temporal Logic

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    This paper revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of Metric Temporal Logic (MTL) formulas over continuous-time models and over discrete-time models is studied. It is shown to what extent discrete-time sequences obtained by sampling continuous-time signals capture the semantics of MTL formulas over the two time domains. The main results apply to "flat" formulas that do not nest temporal operators and can be applied to the problem of reducing the verification problem for MTL over continuous-time models to the same problem over discrete-time, resulting in an automated partial practically-efficient discretization technique.Comment: Revised version, 43 pages

    Recommendations for improving the quality of reporting clinical electrochemotherapy studies based on qualitative systematic review

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    Background: Electrochemotherapy is becoming a well-established treatment for malignancies of skin and non-skin origin and its use is widening across Europe. The technique was developed and optimized from solid experimental and clinical evidence. A consensus document is now warranted to formalize reporting results, which should strengthen evidence-based practice recommendations. This consensus should be derived from high quality clinical data collection, clinical expertise and summarizing patient feedback. The first step, which is addressed in this paper, aims to critically analyze the quality of published studies and to provide the recommendations for reporting clinical trials on electrochemotherapy. Methods: The quality of reporting in published studies on electrochemotherapy was analyzed in order to produce procedure specific reporting recommendations. A comprehensive literature search of studies published from 2006 to 2015 was performed followed by qualitative analysis of manuscripts assessing for 47 quality criteria grouped into four major clusters: (1) trial design, (2) description of patient population, (3) description of treatment delivery and patient outcome, (4) analysis of results and their interpretation. The summary measure during literature assessment was the proportion of studies fulfilling each manuscript quality criteria. Results: A total of 56 studies were screened, from the period 2006 to 2015, of which 33 were included in the qualitative analysis, with a total of 1215 patients. Overall, the quality of reporting was highly variable. Twenty-four reports (73%) were single-center, non-comparative studies, and only 15 (45%) were prospective in nature (only 2 of them were entered into a clinical trials registry). Electrochemotherapy technique was consistently reported, with most studies (31/33) adhering closely to published standard operating procedures. The quality of reporting the patient population was variable among the analyzed studies, with only between 45% and 100% achieving dedicated quality criteria. Reporting of treatment delivery and patient outcome was also highly variable with studies only fulfilling between 3% and 100%. Finally, reporting study results critically varied, fulfilling from 27% to 100% of the quality criteria. Based on the critical issues emerging from this analysis, recommendations and minimal requirements for reporting clinical data on electrochemotherapy were prepared and summarized into a checklist. Conclusions: There is an increasing body of published clinical data on electrochemotherapy, but more high quality clinical data are needed. Published papers often lack accurate description of study population, treatment delivery as well as patient outcome. Our recommendations, provided in the form of a summary checklist, are intended to ameliorate data reporting in future studies on electrochemotherapy and help researchers to provide a solid evidence basis for clinical practice

    The one-dimensional contact process: duality and renormalisation

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    We study the one-dimensional contact process in its quantum version using a recently proposed real space renormalisation technique for stochastic many-particle systems. Exploiting the duality and other properties of the model, we can apply the method for cells with up to 37 sites. After suitable extrapolation, we obtain exponent estimates which are comparable in accuracy with the best known in the literature.Comment: 15 page

    Literature search on risk factors for sarcoma: PubMed and Google Scholar may be complementary sources

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    <p>Abstract</p> <p>Background</p> <p>Within the context of a European network dedicated to the study of sarcoma the relevant literature on sarcoma risk factors was collected by searching PubMed and Google Scholar, the two information storage and retrieval databases which can be accessed without charge. The present study aims to appraise the relative proficiency of PubMed and Google Scholar.</p> <p>Findings</p> <p>Unlike PubMed, Google Scholar does not allow a choice between "Human" and "Animal" studies, nor between "Classical" and other types of studies. As a result, searches with Google Scholar produced high numbers of citations that have to be filtered. Google Scholar resulted in a higher sensitivity (proportion of relevant articles, meeting the search criteria), while PubMed in a higher specificity (proportion of lower quality articles not meeting the criteria, that are not retrieved). Concordance between Google Scholar and PubMed was as low as 8%.</p> <p>Conclusions</p> <p>This study focused just on one topic. Although further studies are warranted, PM and GS appear to be complementary and their integration could greatly improve the search of references in medical research.</p
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