367 research outputs found
Development of Indiana\u27s SPS9-A Site
The Superpave system for hot mix asphalt (HMA) design was introduced in 1995 and adopted throughout most of the USA by 2000. This system uses performance-oriented approach to materials selection and mix design, and takes into account the local environmental and traffic conditions. It recognizes that the behavior of HMA depends on the temperature, loading and aging conditions and provides tools (in the form of materials selection and performance-related tests) that should help to protect pavements against low-temperature cracking, rutting and fatigue cracking. This report summarizes the field and laboratory studies conducted to investigate the influence of asphalt binder grade on the field performance of HMA pavements. In particular, the effect of binder grade on low temperature cracking and on permanent deformation (rutting) of pavement was investigated. In addition, the validity of some of the existing low-temperature models for assessing the susceptibility of a given binder to low temperature cracking is also analyzed. The study involved construction and field evaluation of six test sections on the interstate I-70, east of Indianapolis, Indiana. Four of the six sections contained various SUPERPAVE binder grades, one of the sections was constructed using traditional Marshal mix design, and one of the sections contained 15% of recycled asphalt concrete (RAP). The monitoring of performance of the test sections involved periodical distress surveys and collection of field cores for laboratory testing of volumetric, binder and aggregate properties. In addition, the original binders and plant mix samples were also evaluated. The results of this test program indicate that, in general, the binder grade does influence the field performance of HMA and that susceptibility to failure of a given material can (in many cases) be predicted from the laboratory test results. Particularly good correlation between the laboratory-based data and field performance was observed for low-temperature binder tests, indicating that these tests can reliably predict the critical cracking temperature of the pavement. On the other hand, the test results also confirmed that low-temperature prediction algorithms proposed in the original Superpave specifications were too conservative, for the environmental conditions present at the test site
DNA methylation profiling of the human major histocompatibility complex: A pilot study for the Human Epigenome Project
The Human Epigenome Project aims to identify, catalogue, and interpret genome-wide DNA methylation phenomena. Occurring naturally on cytosine bases at cytosine-guanine dinucleotides, DNA methylation is intimately involved in diverse biological processes and the aetiology of many diseases. Differentially methylated cytosines give rise to distinct profiles, thought to be specific for gene activity, tissue type, and disease state. The identification of such methylation variable positions will significantly improve our understanding of genome biology and our ability to diagnose disease. Here, we report the results of the pilot study for the Human Epigenome Project entailing the methylation analysis of the human major histocompatibility complex. This study involved the development of an integrated pipeline for high-throughput methylation analysis using bisulphite DNA sequencing, discovery of methylation variable positions, epigenotyping by matrix-assisted laser desorption/ionisation mass spectrometry, and development of an integrated public database available at http://www.epigenome.org. Our analysis of DNA methylation levels within the major histocompatibility complex, including regulatory exonic and intronic regions associated with 90 genes in multiple tissues and individuals, reveals a bimodal distribution of methylation profiles (i.e., the vast majority of the analysed regions were either hypo- or hypermethylated), tissue specificity, inter-individual variation, and correlation with independent gene expression data
Carbon supported CdSe nanocrystals
Insights to the mechanism of CdSe nanoparticle attachment to carbon nanotubes
following the hot injection method are discussed. It was observed that the
presence of water improves the nanotube coverage while Cl containing media are
responsible for the shape transformation of the nanoparticles and further
attachment to the carbon lattice. The experiments also show that the mechanism
taking place involves the right balance of several factors, namely, low
passivated nanoparticle surface, particles with well-defined crystallographic
facets, and interaction with an organics-free sp2 carbon lattice. Furthermore,
this procedure can be extended to cover graphene by quantum dots.Comment: 5 pages, 5 figure
Automatic System for the D.C. High Voltage Qualification of the Superconducting Electrical Circuits of the LHC Machine
A d.c. high voltage test system has been developed to verify automatically the insulation resistance of the powering circuits of the LHC. In the most complex case, up to 72 circuits share the same volume inside cryogenic lines. Each circuit can have an insulation fault versus any other circuit or versus ground. The system is able to connect up to 80 circuits and apply a voltage up to 2 kV D.C. The leakage current flowing through each circuit is measured within a range of 1 nA to 1.6 mA. The matrix of measurements allows characterizing the paths taken by the currents and locating weak points of the insulation between circuits. The system is composed of a D.C. voltage source and a data acquisition card. The card is able to measure with precision currents and voltages and to drive up to 5 high voltage switching modules offering 16 channels each. A LabVIEW application controls the system for an automatic and safe operation. This paper describes the hardware and software design, the testing methodology and the results obtained during the qualification of the LHC superconducting circuits
Statins increase the frequency of circulating CD4+ FOXP3+ regulatory T cells in healthy individuals
RESUMEN: Las estatinas se han demostrado para modular el número y la función supresora de células T CD4 + FOXP3 (Treg) en condiciones inflamatorias. Sin embargo, no está bien establecido si estatinas también podría afectar Treg en ausencia de inflamación. Para abordar esta cuestión, dieciocho sujetos masculinos normocolesterolémicos fueron tratados con lovastatina o atorvastatina al día durante 45 días. La frecuencia y el fenotipo de circulación Treg se evaluaron en los días 0, 7, 30, y 45. Los niveles de ARNm de FOXP3, IDO, TGF-β, e IL-10 se midieron en las células T CD4 +. Se encontró que tanto los que aumenta significativamente los niveles de ARNm y de frecuencia de Treg FOXP3 en el día 30. En el día 45, los números de Treg volvieron a los valores basales; Sin embargo, el TGF-β y los niveles de ARNm de FOXP3 se mantuvo alta, acompañada por el aumento de los porcentajes de CTLA-4 y GITR que expresan Treg. Treg expresión de Ki-67 se redujo tras el tratamiento con estatinas. la frecuencia de Treg correlacionó positivamente con los niveles plasmáticos de colesterol de lipoproteínas de alta densidad (HDL-C), lo que sugiere un papel para el HDL-C en la homeostasis de Treg. Por lo tanto, las estatinas parecen tener efectos inmunomoduladores inflamación independiente. Por lo tanto, el aumento de la frecuencia de Treg células probablemente contribuye a inmunomoduladores efecto de las estatinas, incluso en individuos sanos.ABSTRACT: Statins have been shown to modulate the number and the suppressive function of CD4+FOXP3+ T cells (Treg) in inflammatory conditions. However, it is not well established whether statin could also affect Treg in absence of inflammation. To address this question, eighteen normocholesterolemic male subjects were treated with lovastatin or atorvastatin daily for 45 days. The frequency and phenotype of circulating Treg were evaluated at days 0, 7, 30, and 45. mRNA levels of FOXP3, IDO, TGF-β, and IL-10 were measured in CD4+ T cells. We found that both statins significantly increased Treg frequency and FOXP3 mRNA levels at day 30. At day 45, Treg numbers returned to baseline values; however, TGF-β and FOXP3 mRNA levels remained high, accompanied by increased percentages of CTLA-4- and GITR-expressing Treg. Treg Ki-67 expression was decreased upon statin treatment. Treg frequency positively correlated with plasma levels of high-density lipoprotein cholesterol (HDL-c), suggesting a role for HDL-c in Treg homeostasis. Therefore, statins appear to have inflammation-independent immune-modulatory effects. Thus, the increase in Treg cells frequency likely contributes to immunomodulatory effect of statins, even in healthy individual
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