72 research outputs found

    Timed circuit verification using TEL structures

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    Journal ArticleAbstract-Recent design examples have shown that significant performance gains are realized when circuit designers are allowed to make aggressive timing assumptions. Circuit correctness in these aggressive styles is highly timing dependent and, in industry, they are typically designed by hand. In order to automate the process of designing and verifying timed circuits, algorithms for their synthesis and verification are necessary. This paper presents timed event/level (TEL) structures, a specification formalism for timed circuits that corresponds directly to gate-level circuits. It also presents an algorithm based on partially ordered sets to make the state-space exploration o f TEL structures more tractable. The combination of the new specification method and algorithm significantly improves efficiency for gate-level timing verification. Results on a number of circuits, including many from the recently published gigahertz unit Test Site (guTS) processor from IBM indicate that modules of significant size can be verified using a level of abstraction that preserves the interesting timing properties of the circuit. Accurate circuit level verification allows the designer to include less margin in the design, which can lead to increased performance

    Timed circuits: a new paradigm for high-speed design

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    Journal ArticleAbstract| In order to continue to produce circuits of increasing speeds, designers must consider aggressive circuit design styles such as self-resetting or delayed-reset domino circuits used in IBM's gigahertz processor (GUTS) and asynchronous circuits used in Intel's RAPPID instruction length decoder. These new timed circuit styles, however, cannot be efficiently and accurately analyzed using traditional static timing analysis methods. This lack of efficient analysis tools is one of the reasons for the lack of mainstream acceptance of these design styles. This paper discusses several industrial timed circuits and gives an overview of our timed circuit design methodology

    Verification of delayed-reset domino circuits using ATACS

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    Journal ArticleThis paper discusses the application of the timing analysis tool ATACS to the high performance, self-resetting and delayed-reset domino circuits being designed at IBM's Austin Research Laboratory. The tool, which was originally developed to deal with asynchronous circuits, is well suited to the self-resetting style since internally, a block of selfresetting or delayed-reset domino logic is asynchronous. The circuits are represented using timed event/level structures. These structures correspond very directly to gate level circuits, making the translation from a transistor schematic to a TEL structure straightforward. The statespace explosion problem is mitigated using an algorithm based on partially ordered sets (POSETs). Results on a number of circuits from the recently published guTS (gigahertz unit Test Site) processor from IBM indicate that modules of significant size can be verified with ATACS using a level of abstraction that preserves the interesting timing properties of the circuit. Accurate circuit level verification allows the designer to include less margin in the design, which can lead to increased performance

    Exploring the role of respiratory microbiome in lung cancer: A systematic review

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    Giving the potential contribute in cancer initiation and progression, lung microbiota represents a promising topic in cancer research, although still unexplored. We performed a systematic literature search to identify clinical studies evaluating lung microbiota composition, its correlation with lung cancer patients’ clinico-pathological features and prognosis. Of the identified 370 studies, 21 were eligible and included. Although studies were heterogeneous, lung cancer resulted to be enriched in peculiar microbial communities, with differences in composition and diversity according to clinico-pathological parameters. Few studies explored how lung microbiota influences cancer outcome. In light of these findings and borrowing the suggestions coming from gut microbiota, we speculate that respiratory microbiome may influence pathogenesis, progression and outcome of lung cancer. Taking advantage of the experience of chronical lung diseases, prospective studies should be designed to evaluate lung microbiota changes throughout any phase of lung cancer course, particularly with the advent of immunotherapy as pivotal treatment

    Lipoxin A4 and interleukin-8 levels in cystic fibrosis sputum after antibiotherapy

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    AbstractAntibiotics are largely prescribed for cystic fibrosis (CF) respiratory exacerbations. Effects of antibiotics on the inflammatory profile of the patients have been shown but remain controversial. Lipoxin A4 (LXA4) is a lipid mediator, reported to play a central role in resolving airway inflammation. The aim of the study was to investigate the consequences of antibiotherapy on LXA4 and IL-8 levels in CF patients' airways.MethodsEighteen CF patients (7 females, median age 20, range 8 to 47 years) consecutively admitted at the CF center of Montpellier for antibiotics during pulmonary exacerbation, were enrolled. Before and after antibiotics, all patients underwent spirometry (FEV1 and FVC), bacterial cultures and cell counts in sputa. IL-8 and LXA4 concentrations were determined in sputum samples by the median of immunometric assays.ResultsAs previously reported, after antibiotics therapy, FEV1 and FVC significantly improved. While neutrophil cell counts and IL-8 levels decreased, the LXA4 levels significantly increased after antibiotics therapy and were inversely correlated with IL-8 levels.In conclusion, we reported a correlation between antibiotics treatments and inflammatory markers in CF sputum. Our data provide evidences for a novel effect of antibiotics increasing the concentration of the anti-inflammatory lipid mediator LXA4
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