11,556 research outputs found
Strategic Shift to a Diagnostic Model of Care in a Multi-Site Group Dental Practice.
BackgroundDocumenting standardized dental diagnostic terms represents an emerging change for how dentistry is practiced. We focused on a mid-sized dental group practice as it shifted to a policy of documenting patients' diagnoses using standardized terms in the electronic health record.MethodsKotter's change framework was translated into interview questions posed to the senior leadership in a mid-size dental group practice. In addition, quantitative content analyses were conducted on the written policies and forms before and after the implementation of standardized diagnosis documentation to assess the extent to which the forms and policies reflected the shift. Three reviewers analyzed the data individually and reached consensuses where needed.ResultsKotter's guiding change framework explained the steps taken to 97 percent utilization rate of the Electronic Health Record and Dental Diagnostic Code. Of the 96 documents included in the forms and policy analysis, 31 documents were officially updated but only two added a diagnostic element.ConclusionChange strategies established in the business literature hold utility for dental practices seeking diagnosis-centered care.Practical implicationsA practice that shifts to a diagnosis-driven care philosophy would be best served by ensuring that the change process follows a leadership framework that is calibrated to the organization's culture
QCD axion and quintessential axion
The axion solution of the strong CP problem is reviewed together with the
other strong CP solutions. We also point out the quintessential
axion(quintaxion) whose potential can be extremely flat due to the tiny ratio
of the hidden sector quark mass and the intermediate hidden sector scale. The
quintaxion candidates are supposed to be the string theory axions, the model
independent or the model dependent axions.Comment: 15 pages. Talk presented at Castle Ringberg, June 9-14, 200
Generating and Adding Flows on Locally Complete Metric Spaces
As a generalization of a vector field on a manifold, the notion of an arc
field on a locally complete metric space was introduced in \cite{BC}. In that
paper, the authors proved an analogue of the Cauchy-Lipschitz Theorem i.e they
showed the existence and uniqueness of solution curves for a time independent
arc field. In this paper, we extend the result to the time dependent case,
namely we show the existence and uniqueness of solution curves for a time
dependent arc field. We also introduce the notion of the sum of two time
dependent arc fields and show existence and uniqueness of solution curves for
this sum.Comment: 29 pages,6 figure
Anomalous material-dependent transport of focused, laser-driven proton beams.
Intense lasers can accelerate protons in sufficient numbers and energy that the resulting beam can heat materials to exotic warm (10 s of eV temperature) states. Here we show with experimental data that a laser-driven proton beam focused onto a target heated it in a localized spot with size strongly dependent upon material and as small as 35 μm radius. Simulations indicate that cold stopping power values cannot model the intense proton beam transport in solid targets well enough to match the large differences observed. In the experiment a 74 J, 670 fs laser drove a focusing proton beam that transported through different thicknesses of solid Mylar, Al, Cu or Au, eventually heating a rear, thin, Au witness layer. The XUV emission seen from the rear of the Au indicated a clear dependence of proton beam transport upon atomic number, Z, of the transport layer: a larger and brighter emission spot was measured after proton transport through the lower Z foils even with equal mass density for supposed equivalent proton stopping range. Beam transport dynamics pertaining to the observed heated spot were investigated numerically with a particle-in-cell (PIC) code. In simulations protons moving through an Al transport layer result in higher Au temperature responsible for higher Au radiant emittance compared to a Cu transport case. The inferred finding that proton stopping varies with temperature in different materials, considerably changing the beam heating profile, can guide applications seeking to controllably heat targets with intense proton beams
Properties of the Broad-Range Nematic Phase of a Laterally Linked H-Shaped Liquid Crystal Dimer
In search for novel nematic materials, a laterally linked H-shaped liquid
crystal dimer have been synthesized and characterized. The distinct feature of
the material is a very broad temperature range (about 50 oC) of the nematic
phase, which is in contrast with other reported H-dimers that show
predominantly smectic phases. The material exhibits interesting textural
features at the scale of nanometers (presence of smectic clusters) and at the
macroscopic scales. Namely, at a certain temperature, the flat samples of the
material show occurrence of domain walls. These domain walls are caused by the
surface anchoring transition and separate regions with differently tilted
director. Both above and below this transition temperature the material
represents a uniaxial nematic, as confirmed by the studies of defects in flat
samples and samples with colloidal inclusions, freely suspended drops, X-ray
diffraction and transmission electron microscopy.Comment: 30 pages (including Supplementary Information), 7 Figure
Seroprevalence of Hepatitis B, C and D in Vietnam: A systematic review and meta-analysis.
Background: Vietnam has one of the greatest disease burdens from chronic viral hepatitis. Comprehensive prevalence data are essential to support its elimination as a public health threat. Methods: We searched Medline and Embase from 1990 to 2021 for seroprevalence data relating to Hepatitis B (HBV), C (HCV) and D (HDV) in Vietnam. We estimated pooled prevalence with a DerSimonian-Laird random-effects model and stratified study populations into i) low-risk ii) high-risk exposure and iii) liver disease. We further estimated prevalence by decade and region and rates of HIV-coinfection. Findings: We analysed 72 studies, including 120 HBV, 114 HCV and 23 HDV study populations. Pooled HBV prevalence was low in blood donors (1.86% [1.82-1.90]) but high in antenatal populations (10.8% [10.1-11.6]) and adults in the general population (10.5% [10.0-11.0]). It was similar or modestly increased in groups at highest risk of exposure, suggesting the epidemic is largely driven by chronic infections acquired in childhood. HCV pooled prevalence in the general population was lower than historical estimates: 0.26% (0.09-0.51) have active infection defined by detectable antigen or HCV RNA. In contrast, there is an extremely high prevalence of active HCV infection in people who inject drugs (PWID) (57.8% [56.5-59.1]), which has persisted through the decades despite harm-reduction interventions. HDV appears mainly confined to high-risk groups. Interpretation: Blood safety has improved, but renewed focus on HBV vaccination at birth and targeted HCV screening and treatment of PWID are urgently required to meet elimination targets. Large cross-sectional studies are needed to better characterize HDV prevalence, but mass screening may not be warranted. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
Unwinding of a cholesteric liquid crystal and bidirectional surface anchoring
We examine the influence of bidirectional anchoring on the unwinding of a planar cholesteric liquid crystal induced by the application of a magnetic field. We consider a liquid crystal layer confined between two plates with the helical axis perpendicular to the substrates. We fixed the director twist on one boundary and allow for bidirectional anchoring on the other by introducing a high-order surface potential. By minimizing the total free energy for the system, we investigate the untwisting of the cholesteric helix as the liquid crystal attempts to align with the magnetic field. The transitions between metastable states occur as a series of pitchjumps as the helix expels quarter or half-turn twists, depending on the relative sizes of the strength of the surface potential and the bidirectional anchoring. We show that secondary easy axis directions can play a significant role in the unwinding of the cholesteric in its transition towards a nematic, especially when the surface anchoring strength is large
Advanced perception, navigation and planning for autonomous in-water ship hull inspection
Inspection of ship hulls and marine structures using autonomous underwater vehicles has emerged as a unique and challenging application of robotics. The problem poses rich questions in physical design and operation, perception and navigation, and planning, driven by difficulties arising from the acoustic environment, poor water quality and the highly complex structures to be inspected. In this paper, we develop and apply algorithms for the central navigation and planning problems on ship hulls. These divide into two classes, suitable for the open, forward parts of a typical monohull, and for the complex areas around the shafting, propellers and rudders. On the open hull, we have integrated acoustic and visual mapping processes to achieve closed-loop control relative to features such as weld-lines and biofouling. In the complex area, we implemented new large-scale planning routines so as to achieve full imaging coverage of all the structures, at a high resolution. We demonstrate our approaches in recent operations on naval ships.United States. Office of Naval Research (Grant N00014-06-10043)United States. Office of Naval Research (Grant N00014-07-1-0791
Influence of severe plastic deformation on the precipitation hardening of a FeSiTi steel
The combined strengthening effects of grain refinement and high precipitated
volume fraction (~6at.%) on the mechanical properties of FeSiTi alloy subjected
to SPD processing prior to aging treatment were investigated by atom probe
tomography and scanning transmission electron microscopy. It was shown that the
refinement of the microstructure affects the precipitation kinetics and the
spatial distribution of the secondary hardening intermetallic phase, which was
observed to nucleate heterogeneously on dislocations and sub-grain boundaries.
It was revealed that alloys successively subjected to these two strengthening
mechanisms exhibit a lower increase in mechanical strength than a simple
estimation based on the summation of the two individual strengthening
mechanisms
Emergent excitations in a geometrically frustrated magnet
Frustrated systems are ubiquitous and interesting because their behavior is
difficult to predict. Magnetism offers extreme examples in the form of spin
lattices where all interactions between spins cannot be simultaneously
satisfied. Such geometrical frustration leads to macroscopic degeneracies, and
offers the possibility of qualitatively new states of matter whose nature has
yet to be fully understood. Here we have discovered how novel composite spin
degrees of freedom can emerge from frustrated interactions in the cubic spinel
ZnCr2O4. Upon cooling, groups of six spins self-organize into weakly
interacting antiferromagnetic loops whose directors, defined as the unique
direction along which the spins are aligned parallel or antiparallel, govern
all low temperature dynamics. The experimental evidence comes from a
measurement of the magnetic form factor by inelastic neutron scattering. While
the data bears no resemblance to the atomic form factor for chromium, they are
perfectly consistent with the form factor for hexagonal spin loop directors.
The hexagon directors are to a first approximation decoupled from each other
and hence their reorientations embody the long-sought local zero energy modes
for the pyrochlore lattice.Comment: 10 pages, 4 figures upon reques
- …