4,237 research outputs found
OFT ascent/descent ancillary data requirements document
Requirements are presented for the ascent/descent (A/D) navigation and attitude-dependent ancillary data products to be generated for the space shuttle orbiter in support of orbital flight test requirements, MPAD guidance and navigation performance assessment, and the mission evaluation team. It was intended that this document serve as the sole requirements control instrument between MPB/MPAD and the A/D ancillary data users. The requirements are primarily functional in nature, but some detail level requirements are also included
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Approaches to decision-making among late-stage melanoma patients: a multifactorial investigation.
PurposeThe treatment decisions of melanoma patients are poorly understood. Most research on cancer patient decision-making focuses on limited components of specific treatment decisions. This study aimed to holistically characterize late-stage melanoma patients' approaches to treatment decision-making in order to advance understanding of patient influences and supports.Methods(1) Exploratory analysis of longitudinal qualitative data to identify themes that characterize patient decision-making. (2) Pattern analysis of decision-making themes using an innovative method for visualizing qualitative data: a hierarchically-clustered heatmap. Participants were 13 advanced melanoma patients at a large academic medical center.ResultsExploratory analysis revealed eight themes. Heatmap analysis indicated two broad types of patient decision-makers. "Reliant outsiders" relied on providers for medical information, demonstrated low involvement in decision-making, showed a low or later-in-care interest in clinical trials, and expressed altruistic motives. "Active insiders" accessed substantial medical information and expertise in their networks, consulted with other doctors, showed early and substantial interest in trials, demonstrated high involvement in decision-making, and employed multiple decision-making strategies.ConclusionWe identified and characterized two distinct approaches to decision-making among patients with late-stage melanoma. These differences spanned a wide range of factors (e.g., behaviors, resources, motivations). Enhanced understanding of patients as decision-makers and the factors that shape their decision-making may help providers to better support patient understanding, improve patient-provider communication, and support shared decision-making
Defect-induced modification of low-lying excitons and valley selectivity in monolayer transition metal dichalcogenides
We study the effect of point-defect chalcogen vacancies on the optical
properties of monolayer transition metal dichalcogenides using ab initio GW and
Bethe-Salpeter equation calculations. We find that chalcogen vacancies
introduce unoccupied in-gap states and occupied resonant defect states within
the quasiparticle continuum of the valence band. These defect states give rise
to a number of strongly-bound defect excitons and hybridize with excitons of
the pristine system, reducing the valley-selective circular dichroism. Our
results suggest a pathway to tune spin-valley polarization and other optical
properties through defect engineering
Developments in the scientific understanding of osteoarthritis
Osteoarthritis is often a progressive and disabling disease, which occurs in the setting of a variety of risk factors – such as advancing age, obesity, and trauma – that conspire to incite a cascade of pathophysiologic events within joint tissues. An important emerging theme in osteoarthritis is a broadening of focus from a disease of cartilage to one of the 'whole joint'. The synovium, bone, and cartilage are each involved in pathologic processes that lead to progressive joint degeneration. Additional themes that have emerged over the past decade are novel mechanisms of cartilage degradation and repair, the relationship between biomechanics and biochemical pathways, the importance of inflammation, and the role played by genetics. In this review we summarize current scientific understanding of osteoarthritis and examine the pathobiologic mechanisms that contribute to progressive disease
ELECTROKINETIC PHENOMENA : VII. RELATIONSHIP BETWEEN ELECTRIC MOBILITY, CHARGE, TITRATION CURVE, AND OPTICAL ROTATION OF PROTEIN
The specific rotation of egg albumin, gliadin, and gelatin (40°C.) is discussed in connection with available data on (a) mobility, (b) titration curve, and (c) osmotic pressure. It seems likely that the change in specific rotation with pH of protein solutions is proportional to the change in net charge
Energy Level Alignment at Molecule-Metal Interfaces from an Optimally-Tuned Range-Separated Hybrid Functional
The alignment of the frontier orbital energies of an adsorbed molecule with
the substrate Fermi level at metal-organic interfaces is a fundamental
observable of significant practical importance in nanoscience and beyond.
Typical density functional theory calculations, especially those using local
and semi-local functionals, often underestimate level alignment leading to
inaccurate electronic structure and charge transport properties. In this work,
we develop a new fully self-consistent predictive scheme to accurately compute
level alignment at certain classes of complex heterogeneous molecule-metal
interfaces based on optimally-tuned range-separated hybrid functionals.
Starting from a highly accurate description of the gas-phase electronic
structure, our method by construction captures important nonlocal surface
polarization effects via tuning of the long-range screened exchange in a
range-separated hybrid in a non-empirical and system-specific manner. We
implement this functional in a plane-wave code and apply it to several
physisorbed and chemisorbed molecule-metal interface systems. Our results are
in quantitative agreement with experiments, both the level alignment and work
function changes. Our approach constitutes a new practical scheme for accurate
and efficient calculations of the electronic structure of molecule-metal
interfaces.Comment: 15 pages, 8 figure
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