443 research outputs found

    Il primo esercizio italiano di valutazione della ricerca: una prima valutazione

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    Market organization and propagation of shocks: the furniture industry in Germany and Italy

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    In this paper we study the furniture industry in two European countries, Germany and Italy. Although the two industries are characterized by very similar output and technology, they differ widely in terms of market organization, most notably the distribution of firms by size, and the organization of retail. We find some evidences that these differences have an influence on the dynamic behavior of industry output, prices and exports in the two countries

    Il primo esercizio italiano di valutazione della ricerca: una prima valutazione

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    QuantiFERON-TB performs better in children, including infants, than in adults with active tuberculosis: A multicenter study

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    Immunological tests, including the QuantiFERON-TB Gold In-Tube (QFT-IT) assay, represent an important aid for diagnosing active tuberculosis (TB) and latent TB infections in children, but concerns about their use in children <5 years of age persist. This is a multicenter retrospective study comparing a population of 226 children to 521 adults with pulmonary or extrapulmonary TB. The aim was to evaluate the QFT-IT performance, analyzing both qualitative and quantitative results, according to age, birthplace, and disease localization. Compared to culture, QFT-IT sensitivity was 93.9%, 100%, and 94.4% in children <= 2, 2 to 5, and 5 to 16 years of age, respectively, and was significantly higher than that in adults (81.0%) (P < 0.0001). The rate of indeterminate test results for children (2.2%) was significantly lower than that for adults (5.2%) (P < 0.0001). In children, QFT-IT sensitivity was not affected by disease localization or birthplace (Italy born versus foreign born). Interferon gamma (IFN-gamma) values in response to TB antigen and mitogen were significantly higher in children than in adults (TB antigen, median of 10 versus 1.66 IU IFN-gamma/ml; mitogen, median of 10 versus 6.70 IU IFN-gamma/ml; P < 0.0001). In summary, this study supports the use of QFT-IT as a complementary test for the diagnosis of pediatric TB even under 2 years of age. Our observations could be applicable to the new version of the test, QuantiFERON-TB Gold Plus, which has recently been shown to have similar sensitivity in active TB, although data in children are still lacking

    Stimulatory effects of ghrelin on circulating somatostatin and pancreatic polypeptide levels

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    Ghrelin, the recently identified endogenous ligand of the GH secretagogue receptor, is a gut-brain peptide with endocrine, orexigenic, and gastrointestinal effects. In rodents it increases circulating gastrin and insulin levels, whereas in man it appears to decrease insulin secretion despite a rise in blood glucose levels. The aim of the present study was to evaluate the effects of ghrelin administration on total circulating somatostatin (SS), pancreatic polypeptide (PP), and gastrin levels compared with those elicited on insulin, glucose, and GH. Eight healthy volunteers of normal weight (four women and four men) were injected with 3.3 \u3bcg/kg ghrelin or saline after an overnight fast on 2 different days. Blood was taken every 15 min for 1 h and then every 30 min for 2 h. As expected, ghrelin injection elicited a prompt GH and glucose increase with a peak at 30 min and an insulin decrease with a nadir at 60 min. Gastrin concentrations were not modified, whereas significant rises were observed in both SS (in a biphasic pattern with peaks at 15 and 120 min) and PP (which increased promptly with a peak at 15 min). A significant negative correlation was found between SS (first peak) and insulin changes (r = -0.86; P < 0.01). In conclusion, this study clearly demonstrates that ghrelin stimulates SS and PP release in man. Although the underlying mechanisms and biological significance of these pharmacological effects remain to be elucidated, a causal relationship between the SS increase and the insulin changes may be hypothesized. Finally, these findings strongly support ghrelin's postulated role in linking the endocrine control of energy balance and growth with the regulation of gastrointestinal functions

    The metalloprotein YhcH is an anomerase providing N-acetylneuraminate aldolase with the open form of its substrate

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    N-acetylneuraminate (Neu5Ac), an abundant sugar present in glycans in vertebrates and some bacteria, can be used as an energy source by several prokaryotes, including Escherichia coli. In solution, more than 99% of Neu5Ac is in cyclic form (≈92% beta-anomer and ≈7% alpha-anomer), whereas &lt;0.5% is in the open form. The aldolase that initiates Neu5Ac metabolism in E. coli, NanA, has been reported to act on the alphaanomer. Surprisingly, when we performed this reaction at pH 6 to minimize spontaneous anomerization, we found NanA and its human homolog NPL preferentially metabolize the open form of this substrate. We tested whether the E. coli Neu5Ac anomerase NanM could promote turnover, finding it stimulated the utilization of both beta and alpha-anomers by NanA in vitro. However, NanM is localized in the periplasmic space and cannot facilitate Neu5Ac metabolism by NanA in the cytoplasm in vivo. We discovered that YhcH, a cytoplasmic protein encoded by many Neu5Ac catabolic operons and belonging to a protein family of unknown function (DUF386), also facilitated Neu5Ac utilization by NanA and NPL and displayed Neu5Ac anomerase activity in vitro. YhcH contains Zn, and its accelerating effect on the aldolase reaction was inhibited by metal chelators. Remarkably, several transition metals accelerated Neu5Ac anomerization in the absence of enzyme. Experiments with E. coli mutants indicated that YhcH expression provides a selective advantage for growth on Neu5Ac. In conclusion, YhcH plays the unprecedented role of providing an aldolase with the preferred unstable open form of its substrate

    Grass lignin: biosynthesis, biological roles, and industrial applications

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    Lignin is a phenolic heteropolymer found in most terrestrial plants that contributes an essential role in plant growth, abiotic stress tolerance, and biotic stress resistance. Recent research in grass lignin biosynthesis has found differences compared to dicots such as Arabidopsis thaliana. For example, the prolific incorporation of hydroxycinnamic acids into grass secondary cell walls improve the structural integrity of vascular and structural elements via covalent crosslinking. Conversely, fundamental monolignol chemistry conserves the mechanisms of monolignol translocation and polymerization across the plant phylum. Emerging evidence suggests grass lignin compositions contribute to abiotic stress tolerance, and periods of biotic stress often alter cereal lignin compositions to hinder pathogenesis. This same recalcitrance also inhibits industrial valorization of plant biomass, making lignin alterations and reductions a prolific field of research. This review presents an update of grass lignin biosynthesis, translocation, and polymerization, highlights how lignified grass cell walls contribute to plant development and stress responses, and briefly addresses genetic engineering strategies that may benefit industrial applications
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