33 research outputs found

    Humic substances-based polymer system

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    A system for use in forming polymer compositions, including as a replacement for phenolic based resin systems, for instance, in preparing foundry molds. In a preferred embodiment, the system includes the use of a) a polyermizable hydroxyl-containing component comprising a humic substance (as can be provided by lignite), b) an isocyanate component, and c) a catalyst, and preferably amine catalyst, component adapted to catalyze the polymerization of a) and b). The system is optionally used as binder system in the presence of a filler, such as, in combination with a foundry aggregate such as sand. A polymer system of this invention can be substantially free of formaldehyde or phenol, and preferably contains little or no aromatic solvents

    Effects of refrigeration and cryogenic treatments on austempered ductile iron

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    Low temperature treatment, as a method of improving mechanical properties of metals, has been studied and used for well over 60 years. Until recently these treatments have been limited to hardness and wear improvements of high alloy irons and steels. The purpose of this research is to determine the effects of refrigeration and cryogenic treatments on the mechanical properties, including hardness and tensile strength of austempered ductile iron. This research included the production of a high strength ductile iron of low alloy content capable of being used in either the as cast, conventionally heat treated or austempered condition. Refrigeration and cryogenic treatments were applied to the material at different points within the production cycles to determine the most effective order of treatment. After production of the base material at the university, representative specimens were treated by a series of sub-zero temperatures and austempering cycles at commercial treatment facilities. These specimens were then returned to the university and were subjected to a series of mechanical tests that included tensile and hardness property testing. After analysis of the data, it was determined that the greatest effects on the iron were in the increase in hardness and tensile strength of samples that had been cryogenically treated and after undergoing a commercial austempering cycle. Tensile and hardness properties of the material were increased approximately 16% over the nontreated samples. The study concluded that cryogenic treatment of austempered ductile iron is possible, and that it may have benefits over conventional hardening methods by preserving the surface _quality of machined components

    An A2A adenosine receptor agonist, ATL313, reduces inflammation and improves survival in murine sepsis models

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    <p>Abstract</p> <p>Background</p> <p>The pathophysiology of sepsis is due in part to early systemic inflammation. Here we describe molecular and cellular responses, as well as survival, in A<sub>2A </sub>adenosine receptor (AR) agonist treated and untreated animals during experimental sepsis.</p> <p>Methods</p> <p>Sepsis was induced in mice by intraperitoneal inoculation of live bacteria (<it>Escherichia coli </it>or <it>Staphylococcus aureus</it>) or lipopolysaccharide (LPS). Mice inoculated with live bacteria were treated with an A<sub>2A </sub>AR agonist (ATL313) or phosphate buffered saline (PBS), with or without the addition of a dose of ceftriaxone. LPS inoculated mice were treated with ATL313 or PBS. Serum cytokines and chemokines were measured sequentially at 1, 2, 4, 8, and 24 hours after LPS was administered. In survival studies, mice were followed until death or for 7 days.</p> <p>Results</p> <p>There was a significant survival benefit in mice infected with live <it>E. coli </it>(100% vs. 20%, <it>p </it>= 0.013) or <it>S. aureus </it>(60% vs. 20%, <it>p </it>= 0.02) when treated with ATL313 in conjunction with an antibiotic versus antibiotic alone. ATL313 also improved survival from endotoxic shock when compared to PBS treatment (90% vs. 40%, <it>p </it>= 0.005). The serum concentrations of TNF-α, MIP-1α, MCP-1, IFN-γ, and IL-17 were decreased by ATL313 after LPS injection (<it>p </it>< 0.05). Additionally, ATL313 increased the concentration of IL-10 under the same conditions (<it>p </it>< 0.05). Circulating white blood cell concentrations were higher in ATL313 treated animals (<it>p </it>< 0.01).</p> <p>Conclusion</p> <p>Further studies are warranted to determine the clinical utility of ATL313 as a novel treatment for sepsis.</p

    Temperature Effects on Gametophyte Life-History Traits and Geographic Distribution of Two Cryptic Kelp Species

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    A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors. In this study we emphasized the critical role of the haploid microscopic stage (gametophyte) of the life cycle to explain the difference of edge distribution of two related kelp species. Lessonia nigrescens was recently identified as two cryptic species occurring in parapatry along the Chilean coast: one located north and the other south of a biogeographic boundary at latitude 29–30°S. Six life history traits from microscopic stages were identified and estimated under five treatments of temperature in eight locations distributed along the Chilean coast in order to (1) estimate the role of temperature in the present distribution of the two cryptic L. nigrescens species, (2) compare marginal populations to central populations of the two cryptic species. In addition, we created a periodic matrix model to estimate the population growth rate (λ) at the five temperature treatments. Differential tolerance to temperature was demonstrated between the two species, with the gametophytes of the Northern species being more tolerant to higher temperatures than gametophytes from the south. Second, the two species exhibited different life history strategies with a shorter haploid phase in the Northern species contrasted with considerable vegetative growth in the Southern species haploid stage. These results provide strong ecological evidence for the differentiation process of the two cryptic species and show local adaptation of the life cycle at the range limits of the distribution. Ecological and evolutionary implications of these findings are discussed

    Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis

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    Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals
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