741 research outputs found

    New Pathophysiological Aspects of Growth and Prevention of Kidney Stones

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    Kidney stones probably grow during crystalluria by crystal sedimentation and aggregation (AGN) on stone surfaces. This process has to occur within urinary transit time (UT) through the kidney before crystals are washed out by diuresis. To get more information, we studied by spectrophotometry the formation and AGN of Ca oxalate (Ca Ox) crystals which were directly produced in urine of 30 stone patients and 30 controls by an oxalate (Ox) titration. Some tests were also performed after removing urinary macromolecules (UMs) by ultrafiltration. To induce rapid crystallization, high Ox additions (0.5–0.8 mM) were necessary. The most important finding was retardation of crystal AGN by UM. In urine of 63% of controls but only 33% of patients, no AGN was observed during an observation of 60 minutes (P < 0.05). Also growth and sedimentation rate of crystals were significantly reduced by UM. For stone metaphylaxis, especially for posttreatment residuals, avoiding dietary Ox excesses to prevent crystal formation in the kidney and increasing diuresis to wash out crystals before they aggregate are recommended

    Adaptives Grundwassermanagement in urbanen Gebieten: Einfluss der OberflĂ€chengewĂ€sser-Grundwasser-Interaktion am Beispiel kĂŒnstlicher Grundwasseranreicherung sowie variabler In-/Exfiltration der Birs (Schweiz)

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    Zusammenfassung: Der Nutzungsdruck auf Grundwasserressourcen in intensiv genutzten Flussebenen wird zunehmend grĂ¶ĂŸer. Ziel dieses Beitrages ist, anhand eines reprĂ€sentativen, instationĂ€ren Datensatzes eines urbanen Grundwassersystems (Unteres Birstal CH) aufzuzeigen, wie mit AnsĂ€tzen des adaptiven Grundwassermanagements die Voraussetzungen fĂŒr die nachhaltige Nutzung von Grundwasserressourcen geschaffen werden können. Mithilfe eines instationĂ€ren Grundwassermodells können spezifische Fragen der Fluss-Grundwasser-Interaktion und dem Betrieb kĂŒnstlicher Grundwasseranreicherung beantwortet werden. Die InstationaritĂ€t der Fluss-Grundwasser-Interaktion und eine damit zusammenhĂ€ngende Änderung von In - und ExfiltrationsverhĂ€ltnissen konnte fĂŒr verschiedene Flussabschnitte ermittelt werden. Die Datenauswertung eines Jahrhunderthochwassers trug wesentlich zum VerstĂ€ndnis dieser Prozesse bei. Durch ein Experiment mit der lĂ€ngerfristigen Außerbetriebnahme einer kĂŒnstlichen Grundwasseranreicherung im Untersuchungsgebiet konnten die Auswirkungen von geplanten NutzungsĂ€nderungen abgeschĂ€tzt werden. Die Untersuchungen tragen zum ProzessverstĂ€ndnis des Grundwassersystems bei und liefern die Grundlage fĂŒr eine Diskussion ĂŒber lang-, mittel- und kurzfristige Ziele hinsichtlich der regionalen Bewirtschaftung urbaner Wasserressource

    Observation of Ising-like critical fluctuations in frustrated Josephson junction arrays with modulated coupling energies

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    We report the results of ac sheet conductance measurements performed on fully frustrated square arrays of Josephson junctions whose coupling energy is periodically modulated in one of the principal lattice directions. Such systems are predicted to exhibit two distinct transitions: a low-temperature Ising-like transition triggered by the proliferation of domain walls and a high-temperature transition driven by the vortex unbinding mechanism of the Beresinskii-Kosterlitz-Thouless (BKT) theory. Both the superfluid and dissipative components of the conductance are found to exhibit features which unambiguously demonstrate the existence of a double transition whose properties are consistent with the Ising-BKT scenario.Comment: To be published in Physica C (Proceedings of the 2nd European Conference in School Format 'Vortex Matter in Superconductors'

    Laser annealing of silicon on sapphire

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    Silicon-implanted silicon-on-sapphire wafers have been annealed by 50-ns pulses from a Q-switched Nd : YAG laser. The samples have been analyzed by channeling and by omega-scan x-ray double diffraction. After irradiation with pulses of a fluence of about 5 J cm^–2 the crystalline quality of the silicon layer is found to be better than in the as-grown state

    From awareness raising to sustainable behaviour change in school: the WASH in school road map

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    Development organisations working in the WASH sector tend to focus on their preferred methodologies for Hygiene and Sanitation (H&S) promotion, while the sustainability of an intervention depends much more on how the methodology is implemented and whether an enabling environment is in place. In 2014, Caritas Switzerland in Kenya started a learning and critical review process on how to improve its WASH in school interventions to finally make the step from raising students’ awareness on good H&S practices to sustainable behaviour change. As a result of this process, a number of lessons on how to foster the enabling environment were learned, based on which the WASH in school road map was developed. This article presents, for each phase of the WASH in school road map, the main lessons learned and how they have been implemented in Kenya

    Moisture and Seasonality Shifts Recorded in Holocene and Pleistocene Speleothems From Southeastern Arabia

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    The source and seasonality of rainfall in southern Arabia during the early- to mid-Holocene and preceding humid periods are controversial because fossil lacustrine sediments provide solely indirect information on the amount of rainfall. Hydrogen and oxygen isotope measurements on fluid inclusion water trapped in Holocene and Pleistocene stalagmites from Hoti Cave in Northern Oman are direct indicators of the isotopic composition of paleoprecipitation. Isotope values of fluid inclusions formed during peak interglacial periods plot along monsoonal water lines and are indicative of a southern monsoonal moisture source. The last monsoon-dominated period lasting from ∌10,100 to 6,300 years before present was terminated within a few decades in southeastern Arabia. The subsequent reduction in rainfall amount and change from predominantly summer to predominantly winter rainfall had a profound impact on human communities living in this area and triggered migration from inland to coastal areas where resources were more abundant

    Murine cytomegalovirus protein pM79 is a key regulator for viral late transcription

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    Herpesvirus genes are temporally expressed during permissive infections, but how their expression is regulated at late times is poorly understood. Previous studies indicate that the human cytomegalovirus (CMV) gene, UL79, is required for late gene expression. However, the mechanism remains to be fully elucidated, and UL79 homologues in other CMVs have not been studied. Here, we characterized the role of the conserved murine CMV (MCMV) gene M79. We showed that M79 encoded a protein (pM79) which was expressed with early-late kinetics and localized to nuclear viral replication compartments. M79 transcription was significantly decreased in the absence of viral DNA synthesis but markedly stimulated by pM79. To investigate its role, we created the recombinant virus SMin79, in which pM79 expression was disrupted. While marker-rescued virus grew efficiently in fibroblasts, SMin79 failed to produce infectious progeny but was rescued by pM79 expression in trans. During SMin79 infection, representative viral immediate-early and early gene products as well as viral DNA accumulated sufficiently. Formation of viral replication compartments also appeared normal. Pulsed-field gel electrophoresis analysis indicated that the overall structure of replicating viral DNA was indistinguishable between wild-type and SMin79 infection. Viral tiled array and quantitative PCR analysis revealed that many late transcripts sensitive to a viral DNA synthesis inhibitor (phosphonoacetic acid) were markedly reduced by pM79 mutation. This study indicates that cytomegaloviruses use a conserved mechanism to promote transcription at late stages of infection and that pM79 is a critical regulator for at least a subset of viral DNA synthesis-dependent transcripts
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