265 research outputs found

    Gender Differences in Response to a School-Based Mindfulness Training Intervention for Early Adolescents

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    Mindfulness training has been used to improve emotional wellbeing in early adolescents. However, little is known about treatment outcome moderators, or individual differences that may differentially impact responses to treatment. The current study focused on gender as a potential moderator for affective outcomes in response to school-based mindfulness training. Sixth grade students (N = 100) were randomly assigned to either the six weeks of mindfulness meditation or the active control group as part of a history class curriculum. Participants in the mindfulness meditation group completed short mindfulness meditation sessions four to five times per week, in addition to didactic instruction (Asian history). The control group received matched experiential activity in addition to didactic instruction (African history) from the same teacher with no meditation component. Self-reported measures of emotional wellbeing/affect, mindfulness, and self-compassion were obtained at pre and post intervention. Meditators reported greater improvement in emotional wellbeing compared to those in the control group. Importantly, gender differences were detected, such that female meditators reported greater increases in positive affect compared to females in the control group, whereas male meditators and control males displayed equivalent gains. Uniquely among females but not males, increases in self-reported self-compassion were associated with improvements in affect. These findings support the efficacy of school-based mindfulness interventions, and interventions tailored to accommodate distinct developmental needs of female and male adolescents

    The nature of iron-oxygen vacancy defect centers in PbTiO3

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    The iron(III) center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c-axis. Its microscopic structure has been analyzed in detail comparing results from a semi-empirical Newman superposition model analysis based on finestructure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B-site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12 K, exhibiting a c/a-ratio of 1.0721.Comment: 11 pages, 5 figures, accepted in Phys. Rev.

    Sr Surface Enrichment in Solid Oxide Cells – Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations

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    In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX), and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion surface. This hints at a mechanism originating at the complexion and requires in-depth studies at the atomistic level, where the developed routine can be beneficial for analyzing large hyperspectral EDX datasets

    Lithium deposition in single ion conducting polymer electrolytes

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    Lithium Li metal is considered as promising anode material for high energy density rechargeable batteries, although its application is hampered by inhomogeneous Li deposition and dendritic Li morphologies that could eventually result in contact losses of bulk and deposited Li as well as cell short circuits. Based on theoretical investigations, recent works on polymer electrolytes particularly focus on the design of single ion conducting electrolytes and improvement of bulk Li transport properties, including enhanced Li transference numbers, ionic conductivity, and mechanical stability, thereby affording safer and potentially dendrite free cycling of Li metal batteries. In the present work, it is revealed that the spatial microstructures, localized chemistry, and corresponding distributions of properties within the electrolyte are also decisive for achieving superior cell performances. Thus, targeted modification of the electrolyte microstructures should be considered as further critical design parameters for future electrolyte development and to actually control Li deposition behavior and longevity of Li metal batterie

    Robot-assisted laparoscopic transperitoneal pelvic lymphadenectomy and metastasectomy for melanoma: initial report of two cases

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    Robotic pelvic lymphadenectomy is a well established procedure in the urologic and gynecologic literature. To our knowledge robotic pelvic lymphadectomy for metastatic melanoma has yet to be described. Herein we present the first report of robot-assisted pelvic lymphadenectomy in malignant melanoma. After placement of six laparoscopic ports (12 mm camera, three 8-mm robotic ports, 12-mm and 5-mm assistant ports) the DaVinci S robot (Intuitive Surgical, CA, USA) was docked in standard fashion with the patient in low lithotomy. In both cases the patients had enlarged pelvic lymph nodes on computed tomography and complete excision of these masses was accomplished along with complete lymphadenectomy extending from Cooper’s ligament to just below the hypogastric artery in case 1 and to level of the bifurcation of aorta in case 2. A PK Maryland Dissector and monopolar scissors were used for dissection. Both patients were discharged on postoperative day #1. Robotic pelvic lymphadenectomy can be safely used for management of patients with metastatic melanoma involving the pelvic lymph nodes. Compared with the standard open procedure, pelvic lymphadenectomy with robotic assistance is associated with excellent vision and minimum morbidity

    Progressive axonopathy when oligodendrocytes lack the myelin protein CMTM5

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    Oligodendrocytes facilitate rapid impulse propagation along the axons they myelinate and support their long-term integrity. However, the functional relevance of many myelin proteins has remained unknown. Here, we find that expression of the tetraspan-transmembrane protein CMTM5 (chemokine-like factor-like MARVEL-transmembrane domain containing protein 5) is highly enriched in oligodendrocytes and central nervous system (CNS) myelin. Genetic disruption of the Cmtm5 gene in oligodendrocytes of mice does not impair the development or ultrastructure of CNS myelin. However, oligodendroglial Cmtm5 deficiency causes an early-onset progressive axonopathy, which we also observe in global and tamoxifen-induced oligodendroglial Cmtm5 mutants. Presence of the WldS mutation ameliorates the axonopathy, implying a Wallerian degeneration-like pathomechanism. These results indicate that CMTM5 is involved in the function of oligodendrocytes to maintain axonal integrity rather than myelin biogenesis

    Экспериментальное определение тепловых потерь теплопроводов при применении сверхтонкой тепловой изоляции.

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    Объектом исследования является тонкопленочный теплоизоляционный материал торговой марки – «Корунд», Цель работы – Анализ тепловых потерь и исследование теплотехнических характеристик тонкопленочного теплоизоляционного материала торговой марки «Корунд». В результате исследования были найдены коэффициенты теплопроводности тонкопленочного теплоизоляционного материала при различных температурах поверхности ТЭНа.The object of study is the thin-film insulating material of the trademark "Emery", The work purpose – the Analysis of thermal losses and investigation of thermal characteristics of thin film insulating material of the trademark "Emery". The study was found the thermal conductivity of thin film insulating material at different temperatures the heating element surface

    Overpotential analysis of graphite-based Li-ion batteries seen from a porous electrode modeling perspective

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    The overpotential of Li-ion batteries is one of the most relevant characteristics influencing the power and energy densities of these battery systems. However, the intrinsic complexity and multi-influencing factors make it challenging to analyze the overpotential precisely. To decompose the total overpotential of a battery into various individual components, a pseudo-two-dimensional (P2D) model has been adopted and used for electrochemical simulations of a graphite-based porous electrode/Li battery. Analytical expressions for the total overpotential have been mathematically derived and split up into four terms, associated with the electrolyte concentration overpotential, the Li concentration overpotential in the solid, the kinetic overpotential, and the ohmic overpotential. All these four terms have been separately analyzed and are found to be strongly dependent on the physical/chemical battery parameters and the reaction-rate distribution inside the porous electrode. The reaction-rate distribution of the porous electrode is generally non-uniform and shows dynamic changes during (dis)charging, resulting in fluctuations in the four overpotential components. In addition, the disappearance of the phase-change information in the voltage curve of the graphite-based porous electrode/Li battery under moderate and high C-rates is ascribed to the Li concentration overpotential among solid particles, resulting from the non-uniform reaction-rate distribution
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