764 research outputs found

    Droplets on Inclined Plates: Local and Global Hysteresis of Pinned Capillary Surfaces

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    Local contact line pinning prevents droplets from rearranging to minimal global energy, and models for droplets without pinning cannot predict their shape. We show that experiments are much better described by a theory, developed herein, that does account for the constrained contact line motion, using as example droplets on tilted plates. We map out their shapes in suitable phase spaces. For 2D droplets, the critical point of maximum tilt depends on the hysteresis range and Bond number. In 3D, it also depends on the initial width, highlighting the importance of the deposition history.Comment: 5 pages, 5 figures, accepted for publication in Phys. Rev. Let

    Candidate hypervelocity stars of spectral type G and K revisited

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    Hypervelocity stars (HVS) move so fast that they are unbound to the Galaxy. When they were first discovered in 2005, dynamical ejection from the supermassive black hole (SMBH) in the Galactic Centre (GC) was suggested as their origin. The two dozen HVSs known today are young massive B stars, mostly of 3-4 solar masses. Recently, 20 HVS candidates of low mass were discovered in the Segue G and K dwarf sample, but none of them originates from the GC. We embarked on a kinematic analysis of the Segue HVS candidate sample using the full 6D phase space information based on new proper motion measurements. Their orbital properties can then be derived by tracing back their trajectories in different mass models of our Galaxy. We present the results for 14 candidate HVSs, for which proper motion measurements were possible. Significantly lower proper motions than found in the previous study were derived. Considering three different Galactic mass models we find that all stars are bound to the Galaxy. We confirm that the stars do not originate from the GC. The distribution of their proper motions and radial velocities is consistent with predictions for runaway stars ejected from the Galactic disk by the binary supernova mechanism. However, their kinematics are also consistent with old disk membership. Moreover, most stars have rather low metallicities and strong α\alpha-element enrichment as typical for thick disk and halo stars, whereas the metallicity of the three most metal-rich stars could possibly indicate that they are runaway stars from the thin disk. One star shows halo kinematics.Comment: A&A letter accepte

    DNA double strand breaks but not interstrand crosslinks prevent progress through meiosis in fully grown mouse oocytes

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    There is some interest in how mammalian oocytes respond to different types of DNA damage because of the increasing expectation of fertility preservation in women undergoing chemotherapy. Double strand breaks (DSBs) induced by ionizing radiation and agents such as neocarzinostatin (NCS), and interstrand crosslinks (ICLs) induced by alkylating agents such as mitomycin C (MMC), are toxic DNA lesions that need to be repaired for cell survival. Here we examined the effects of NCS and MMC treatment on oocytes collected from antral follicles in mice, because potentially such oocytes are readily collected from ovaries and do not need to be in vitro grown to achieve meiotic competency. We found that oocytes were sensitive to NCS, such that this ionizing radiation mimetic blocked meiosis I and caused fragmented DNA. In contrast, MMC had no impact on the completion of either meiosis I or II, even at extremely high doses. However, oocytes treated with MMC did show ?-H2AX foci and following their in vitro maturation and parthenogenetic activation the development of the subsequent embryos was severely compromised. Addition of MMC to 1-cell embryos caused a similarly poor level of development, demonstrating oocytes have eventual sensitivity to this ICL-inducing agent but this does not occur during their meiotic division. In oocytes, the association of Fanconi Anemia protein, FANCD2, with sites of ICL lesions was not apparent until entry into the embryonic cell cycle. In conclusion, meiotic maturation of oocytes is sensitive to DSBs but not ICLs. The ability of oocytes to tolerate severe ICL damage and yet complete meiosis, means that this type of DNA lesion goes unrepaired in oocytes but impacts on subsequent embryo quality

    Introduction to Mentalization-Based Approaches for Parents, Children, Youths, and Families

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    Family members mentalize when they try to understand each other's behavior on the basis of intentional mental states. This article aims to introduce and briefly describe how the concept of mentalization can provide a useful framework for clinicians to understand psychopathology of children, youths, and families. The authors further outline how mentalization-based techniques and interventions can be applied to build epistemic trust and to reestablish mentalizing in families by presenting clinical vignettes of initial sessions from various clinical settings in the United Kingdom and Germany. The article concludes with a brief summary about the current evidence for mentalization-based interventions with children, adolescents, and families and provides an outlook for future clinical and research work

    Progress in strength, toughness and lifetime methods for ceramics

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    Fortschritte auf dem Gebiet der Festigkeit, Risszähigkeit und Lebensdauer von Keramik Zur Charakterisierung des Versagensverhaltens keramischer Werkstoffe sind Festigkeits- und Risszähigkeitsmessungen erforderlich. Weist eine Keramik noch den Effekt des unterkritischen Risswachstums auf, sind auch Lebensdauermessungen unter statischer Belastung von großer Wichtigkeit. Neuere Beiträge der Autoren zur Untersuchungs-Methodik sind in diesem Bericht zusammengefasst. Teil A befasst sich mit der Berechnung der maximalen Spannungen in runden Scheiben unter Kugelbelastung. Hierbei werden der “ball-on-ring test”, der “ball-on-3-balls test” und der kürzlich von den Verfassern entwickelte „3-balls-on-3-balls test“ betrachtet. Als praktische Anwendung der ermittelten Spannungen im “ball-on-3-balls test” wird das bei grobkörnigem Aluminiumoxid gefundene stabile Bruchverhalten als Effekt einer stark ansteigenden Risswiderstandskurve diskutiert. In Teil B wird auf eine von den Verfassern entwickelte Methode eingegangen, die es gestattet, sehr kurze Kerben mit extrem kleinen Kerbradien zu erzeugen. Bei einer ZrO2-Keramik konnten Kerbradien von unter 0.1 μm bei einer Kerbtiefe von nur 40μm erzeugt werden. Derartig kurze und scharfe Kerben sollten geeignet sein, das Verhalten natürlicher Risse in Keramiken anzunähern. Schließlich wird in Teil C über eine Prozedur berichtet, die sich dafür eignet, eine vorhandene Anzahl an Lebensdauer-Versuchsproben optimal auszunutzen. Hierbei kann aus der erneuten Verwendung von auf niederem Lastniveau angefallenen „Durchläufern“ zusätzliche Information über das Risswachstumsgesetz gewonnen werden. Die Methode wird an Lebensdauermessungen von SIALON in destilliertem Wasser von 20°C demonstriert

    Towards developing a Core Outcome Set for malnutrition intervention studies in older adults: a scoping review to identify frequently used research outcomes

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    Purpose: To conduct a scoping review to provide a systematic overview of outcomes used in nutritional intervention studies focused on the treatment of protein-energy malnutrition in older adults. // Methods: A systematic search of four electronic databases (Medline, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials (CENTRAL) was performed to retrieve randomized controlled trials (RCTs), published until March 9, 2020, that evaluated the effect of nutritional interventions to treat protein-energy malnutrition in older adults and those at risk for malnutrition. Two authors screened titles, abstracts and full texts independently. One author extracted data that were cross-checked by another author. // Results: Sixty-three articles reporting 60 RCTs were identified. Most frequently used outcomes included body weight/body mass index (75.0% of RCTs), dietary intake (61.7%), functional limitations (48.3%), handgrip strength (46.7%), and body circumference (40.0%). The frequencies differed by setting (community, hospital and long-term care). For some outcomes there was a preferred assessment method (e.g., Barthel index for functional limitations), while for other outcomes (e.g., functional performance) a much greater variation was observed. // Conclusion: A large variation in outcomes, not only across but also within settings, was identified in nutritional intervention studies in malnourished older adults and those at risk. Furthermore, for many outcomes there was a large variation in the used assessment method. These results highlight the need for developing a Core Outcome Set for malnutrition intervention studies in older adults to facilitate future meta-analyses that may enhance our understanding on the effectiveness of treatment

    a scoping review to identify frequently used research outcomes

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    © 2022. The Author(s).PURPOSE: To conduct a scoping review to provide a systematic overview of outcomes used in nutritional intervention studies focused on the treatment of protein-energy malnutrition in older adults. METHODS: A systematic search of four electronic databases (Medline, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials (CENTRAL) was performed to retrieve randomized controlled trials (RCTs), published until March 9, 2020, that evaluated the effect of nutritional interventions to treat protein-energy malnutrition in older adults and those at risk for malnutrition. Two authors screened titles, abstracts and full texts independently. One author extracted data that were cross-checked by another author. RESULTS: Sixty-three articles reporting 60 RCTs were identified. Most frequently used outcomes included body weight/body mass index (75.0% of RCTs), dietary intake (61.7%), functional limitations (48.3%), handgrip strength (46.7%), and body circumference (40.0%). The frequencies differed by setting (community, hospital and long-term care). For some outcomes there was a preferred assessment method (e.g., Barthel index for functional limitations), while for other outcomes (e.g., functional performance) a much greater variation was observed. CONCLUSION: A large variation in outcomes, not only across but also within settings, was identified in nutritional intervention studies in malnourished older adults and those at risk. Furthermore, for many outcomes there was a large variation in the used assessment method. These results highlight the need for developing a Core Outcome Set for malnutrition intervention studies in older adults to facilitate future meta-analyses that may enhance our understanding on the effectiveness of treatment.publishersversionepub_ahead_of_prin
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