654 research outputs found

    Einfluss chronisch-struktureller Veränderungen der Muskelsehneneinheit auf Indikation und Technik der Rotatorenmanschettenrekonstruktion

    Get PDF
    Zusammenfassung: Rotatorenmanschettenläsionen sind häufig und die Inzidenz steigt mit zunehmendem Alter. Nach einer Sehnenruptur der Rotatorenmanschette kommt es zu einer Retraktion der muskulotendinösen Einheit, was mit einer Muskelverfettung (fettige Infiltration), einer Atrophie sowie einer interstitiellen Fibrose der Muskulatur einhergeht und die Muskelarchitektur grundlegend verändert. Diese Umgestaltungen gelten als wichtige prognostische Faktoren für das Ergebnis einer operativen Rotatorenmanschettenrekonstruktion. Die Wahl des richtigen Zeitpunkts der Rekonstruktion sowie eine optimale mechanische Fixation sind mitentscheidend für das erfolgreiche Einheilen der Sehne an der Knocheninsertion. Hierbei spielt die Kenntnis pathophysiologischer Vorgänge eine wichtige Rolle. Ziel dieses Artikels ist es, die bis heute existierende Evidenz bezüglich der präoperativ bestehenden Veränderungen der muskulotendinösen Einheit mit der Wahl des Operationszeitpunkts und der Operationstechnik in Beziehung zu setze

    Are spectroscopic factors from transfer reactions consistent with asymptotic normalisation coefficients?

    Full text link
    It is extremely important to devise a reliable method to extract spectroscopic factors from transfer cross sections. We analyse the standard DWBA procedure and combine it with the asymptotic normalisation coefficient, extracted from an independent data set. We find that the single particle parameters used in the past generate inconsistent asymptotic normalization coefficients. In order to obtain a consistent spectroscopic factor, non-standard parameters for the single particle overlap functions can be used but, as a consequence, often reduced spectroscopic strengths emerge. Different choices of optical potentials and higher order effects in the reaction model are also studied. Our test cases consist of: 14^{14}C(d,p)15^{15}C(g.s.) at Edlab=14E_d^{lab}=14 MeV, 16^{16}O(d,p)17^{17}O(g.s.) at Edlab=15E_d^{lab}=15 MeV and 40^{40}Ca(d,p)41^{41}Ca(g.s.) at Edlab=11E_d^{lab}=11 MeV. We underline the importance of performing experiments specifically designed to extract ANCs for these systems.Comment: 15 pages, 12 figures, Phys. Rev. C (in press

    Global precipitation response to changing forcings since 1870

    Get PDF
    Predicting and adapting to changes in the hydrological cycle is one of the major challenges for the 21st century. To better estimate how it will respond to future changes in climate forcings, it is crucial to understand how the hydrological cycle has evolved in the past and why. In our study, we use an atmospheric global climate model with prescribed sea surface temperatures (SSTs) to investigate how, in the period 1870–2005, changing climate forcings have affected the global land temperature and precipitation. We show that between 1870 and 2005, prescribed SSTs (encapsulating other forcings and internal variability) determine the decadal and interannual variabilities of the global land temperature and precipitation, mostly via their influence in the tropics (25° S–25° N). In addition, using simulations with prescribed SSTs and considering the atmospheric response alone, we find that between 1930 and 2005 increasing aerosol emissions have reduced the global land temperature and precipitation by up to 0.4 °C and 30 mm yr<sup>−1</sup>, respectively, and that between about 1950 and 2005 increasing greenhouse gas concentrations have increased them by up to 0.25 °C and 10 mm yr<sup>−1</sup>, respectively. Finally, we suggest that between about 1950 and 1970, increasing aerosol emissions had a larger impact on the hydrological cycle than increasing greenhouse gas concentrations

    Self-assembly and two-dimensional spontaneous resolution of cyano-functionalized [7]helicenes on Cu111

    Get PDF
    Birds of a feather flock together: STM and DFT studies provide the first example of spontaneous chiral resolution of a helicene on a surface. Racemic 6,13-dicyano[7]helicene forms fully segregated domains of pure enantiomers (2D conglomerate) on Cu(111). The propensity of the system to optimize intermolecular CN⋅⋅⋅HC(Ar) hydrogen bonding and CN⋅⋅⋅CN dipolar interactions translates into chiral recognition with preferential assembly of homochiral molecules

    Temperature-dependent benefits of bacterial exposure in embryonic development of Daphnia magna resting eggs

    Get PDF
    The environments in which animals develop and evolve are profoundly shaped by bacteria, which affect animals both indirectly through their role in biogeochemical processes and directly through antagonistic or beneficial interactions. The outcomes of these activities can differ according to environmental context. In a series of laboratory experiments with diapausing eggs of the water flea Daphnia magna, we manipulated two environmental parameters, temperature and presence of bacteria, and examined their effect on development. At elevated temperatures (≥ 26 °C), resting eggs developing without live bacteria had reduced hatching success and correspondingly higher rates of severe morphological abnormalities compared with eggs with bacteria in their environment. The beneficial effect of bacteria was strongly reduced at 20 °C. Neither temperature nor the presence of bacteria affected directly developing parthenogenetic eggs. The mechanistic basis of this effect of bacteria on development is unclear, but these results highlight the complex interplay of biotic and abiotic factors influencing animal development after diapause

    7,8-dihydro-8-oxoadenine, a highly mutagenic adduct, is repaired by Escherichia coli and human mismatch-specific uracil/thymine-DNA glycosylases

    Get PDF
    Hydroxyl radicals predominantly react with the C8 of purines forming 7,8-dihydro-8-oxoguanine (8oxoG) and 7,8-dihydro-8-oxoadenine (8oxoA) adducts, which are highly mutagenic in mammalian cells. The majority of oxidized DNA bases are removed by DNA glycosylases in the base excision repair pathway. Here, we report for the first time that human thymine-DNA glycosylase (hTDG) and Escherichia coli mismatch-specific uracil-DNA glycosylase (MUG) can remove 8oxoA from 8oxoA•T, 8oxoA•G and 8oxoA•C pairs. Comparison of the kinetic parameters of the reaction indicates that full-length hTDG excises 8oxoA, 3,N4-ethenocytosine (εC) and T with similar efficiency (kmax = 0.35, 0.36 and 0.16 min−1, respectively) and is more proficient as compared with its bacterial homologue MUG. The N-terminal domain of the hTDG protein is essential for 8oxoA-DNA glycosylase activity, but not for εC repair. Interestingly, the TDG status had little or no effect on the proliferation rate of mouse embryonic fibroblasts after exposure to γ-irradiation. Nevertheless, using whole cell-free extracts from the DNA glycosylase-deficient murine embryonic fibroblasts and E. coli, we demonstrate that the excision of 8oxoA from 8oxoA•T and 8oxoA•G has an absolute requirement for TDG and MUG, respectively. The data establish that MUG and TDG can counteract the genotoxic effects of 8oxoA residues in viv

    7,8-Dihydro-8-oxoadenine, a highly mutagenic adduct, is repaired by Escherichia coli and human mismatch-specific uracil/thymine-DNA glycosylases

    Get PDF
    Hydroxyl radicals predominantly react with the C(8) of purines forming 7,8-dihydro-8-oxoguanine (8oxoG) and 7,8-dihydro-8-oxoadenine (8oxoA) adducts, which are highly mutagenic in mammalian cells. The majority of oxidized DNA bases are removed by DNA glycosylases in the base excision repair pathway. Here, we report for the first time that human thymine-DNA glycosylase (hTDG) and Escherichia coli mismatch-specific uracil-DNA glycosylase (MUG) can remove 8oxoA from 8oxoA*T, 8oxoA*G and 8oxoA*C pairs. Comparison of the kinetic parameters of the reaction indicates that full-length hTDG excises 8oxoA, 3,N(4)-ethenocytosine (epsilonC) and T with similar efficiency (k(max) = 0.35, 0.36 and 0.16 min(-1), respectively) and is more proficient as compared with its bacterial homologue MUG. The N-terminal domain of the hTDG protein is essential for 8oxoA-DNA glycosylase activity, but not for epsilonC repair. Interestingly, the TDG status had little or no effect on the proliferation rate of mouse embryonic fibroblasts after exposure to gamma-irradiation. Nevertheless, using whole cell-free extracts from the DNA glycosylase-deficient murine embryonic fibroblasts and E. coli, we demonstrate that the excision of 8oxoA from 8oxoA*T and 8oxoA*G has an absolute requirement for TDG and MUG, respectively. The data establish that MUG and TDG can counteract the genotoxic effects of 8oxoA residues in vivo

    PROBABILISTIC RUNOFF FORECASTING USING A COUPLED ATMOSPHERIC-HYDROLOGIC ENSEMBLE PREDICTION SYSTEM

    Get PDF
    A high-resolution atmospheric ensemble forecasting system, based on 51 runs of the Local Model (LM), has been used to make probabilistic runoff forecasts for a 5 day forecasting period in the alpine tributaries of the Rhine basin. The investigated cases are the spring 1999 flood, when a combination of snowmelt and heavy precipitation caused severe floods in Central Europe and the November 2002 flash flood in the Alpine Rhine area. This study focuses on the feasibility of ensemble prediction system (EPS) for runoff forecasting. Runoff predictions from the deterministic forecast are compared with those obtained from probabilistic atmospheric forecasts. For both cases, the deterministic simulations yield large forecast failures, while the hydrometeorologic EPS provides appropriate forecast guidance with proper uncertainty intervals. The use of clustering techniques showed that the clustering methodology does not reduce ensemble spread
    corecore