849 research outputs found
Health Information Exchange Use in Primary Care
Indiana University-Purdue University Indianapolis (IUPUI)The United States has invested over $40 billion in digitizing the health care
system, yet the anticipated gains in improved care coordination, quality, and cost savings
remain largely unrealized. This is due in part to limited interoperability and low rates of
health information exchange (HIE) use, which can support care coordination and improve
provider decision-making. Primary care providers are central to the US health care
delivery system and frequently function as care coordinators, yet capability and HIE use
gaps among these providers limit the potential of these digital systems to achieve their
intended goals.
I study HIE use in the context of primary care to examine 1) factors associated
with provider HIE use, 2) the extent and nature of team-based HIE use, and 3) differences
in HIE system use patterns across discrete groups of system users. First, I use a national
sample of primary care providers to analyze market and practice factors related to HIE
use for patient referrals. Overall, I find that only 43% of primary care provider referrals
used HIE. Furthermore, I find substantial variation in HIE use rates across electronic
health record (EHR) vendors. Second, I use HIE system log data to understand the
breadth and depth of HIE use among teams, a care model underpinning primary care
delivery reform efforts. I find that although use of HIE systems remains low, in primary
care settings it overwhelmingly takes place in a manner consistent with team-based care
workflows. Furthermore, team-based use does not differ in breadth from single provider
HIE use, but illustrates less depth before and after visits. Third, I apply cluster analysis to
16 HIE use measures representing 7 use attributes, and identify 5 discrete user groups. I
then compare two of these user groups and find user-level variation in volume and
efficiency of use, both of which have implications for HIE system design and usability
improvements. Ultimately, these findings help to inform how HIE use can be increased
and improved in primary care, moving the US health care system closer to realizing the
coordination, quality, and cost savings made possible by a digitized delivery system
Development and Verification of the Charring, Ablating Thermal Protection Implicit System Simulator
The development and verification of the Charring Ablating Thermal Protection Implicit System Solver (CATPISS) is presented. This work concentrates on the derivation and verification of the stationary grid terms in the equations that govern three-dimensional heat and mass transfer for charring thermal protection systems including pyrolysis gas flow through the porous char layer. The governing equations are discretized according to the Galerkin finite element method (FEM) with first and second order fully implicit time integrators. The governing equations are fully coupled and are solved in parallel via Newton s method, while the linear system is solved via the Generalized Minimum Residual method (GMRES). Verification results from exact solutions and Method of Manufactured Solutions (MMS) are presented to show spatial and temporal orders of accuracy as well as nonlinear convergence rates
Development and Verification of the Charring Ablating Thermal Protection Implicit System Solver
The development and verification of the Charring Ablating Thermal Protection Implicit System Solver is presented. This work concentrates on the derivation and verification of the stationary grid terms in the equations that govern three-dimensional heat and mass transfer for charring thermal protection systems including pyrolysis gas flow through the porous char layer. The governing equations are discretized according to the Galerkin finite element method with first and second order implicit time integrators. The governing equations are fully coupled and are solved in parallel via Newton's method, while the fully implicit linear system is solved with the Generalized Minimal Residual method. Verification results from exact solutions and the Method of Manufactured Solutions are presented to show spatial and temporal orders of accuracy as well as nonlinear convergence rates
Three Component Velocity and Acceleration Measurement Using FLEET
The femtosecond laser electronic excitation and tagging (FLEET) method has been used to measure three components of velocity and acceleration for the first time. A jet of pure N2 issuing into atmospheric pressure air was probed by the FLEET system. The femtosecond laser was focused down to a point to create a small measurement volume in the flow. The long-lived lifetime of this fluorescence was used to measure the location of the tagged particles at different times. Simultaneous images of the flow were taken from two orthogonal views using a mirror assembly and a single intensified CCD camera, allowing two components of velocity to be measured in each view. These different velocity components were combined to determine three orthogonal velocity components. The differences between subsequent velocity components could be used to measure the acceleration. Velocity accuracy and precision were roughly estimated to be +/-4 m/s and +/-10 m/s respectively. These errors were small compared to the approx. 100 m/s velocity of the subsonic jet studied
Precision of FLEET Velocimetry Using High-Speed CMOS Camera Systems
Femtosecond laser electronic excitation tagging (FLEET) is an optical measurement technique that permits quantitative velocimetry of unseeded air or nitrogen using a single laser and a single camera. In this paper, we seek to determine the fundamental precision of the FLEET technique using high-speed complementary metal-oxide semiconductor (CMOS) cameras. Also, we compare the performance of several different high-speed CMOS camera systems for acquiring FLEET velocimetry data in air and nitrogen free-jet flows. The precision was defined as the standard deviation of a set of several hundred single-shot velocity measurements. Methods of enhancing the precision of the measurement were explored such as digital binning (similar in concept to on-sensor binning, but done in post-processing), row-wise digital binning of the signal in adjacent pixels and increasing the time delay between successive exposures. These techniques generally improved precision; however, binning provided the greatest improvement to the un-intensified camera systems which had low signal-to-noise ratio. When binning row-wise by 8 pixels (about the thickness of the tagged region) and using an inter-frame delay of 65 microseconds, precisions of 0.5 meters per second in air and 0.2 meters per second in nitrogen were achieved. The camera comparison included a pco.dimax HD, a LaVision Imager scientific CMOS (sCMOS) and a Photron FASTCAM SA-X2, along with a two-stage LaVision HighSpeed IRO intensifier. Excluding the LaVision Imager sCMOS, the cameras were tested with and without intensification and with both short and long inter-frame delays. Use of intensification and longer inter-frame delay generally improved precision. Overall, the Photron FASTCAM SA-X2 exhibited the best performance in terms of greatest precision and highest signal-to-noise ratio primarily because it had the largest pixels
Precision of FLEET Velocimetry Using High-speed CMOS Camera Systems
Femtosecond laser electronic excitation tagging (FLEET) is an optical measurement technique that permits quantitative velocimetry of unseeded air or nitrogen using a single laser and a single camera. In this paper, we seek to determine the fundamental precision of the FLEET technique using high-speed complementary metal-oxide semiconductor (CMOS) cameras. Also, we compare the performance of several different high-speed CMOS camera systems for acquiring FLEET velocimetry data in air and nitrogen free-jet flows. The precision was defined as the standard deviation of a set of several hundred single-shot velocity measurements. Methods of enhancing the precision of the measurement were explored such as digital binning (similar in concept to on-sensor binning, but done in post-processing), row-wise digital binning of the signal in adjacent pixels and increasing the time delay between successive exposures. These techniques generally improved precision; however, binning provided the greatest improvement to the un-intensified camera systems which had low signal-to-noise ratio. When binning row-wise by 8 pixels (about the thickness of the tagged region) and using an inter-frame delay of 65 micro sec, precisions of 0.5 m/s in air and 0.2 m/s in nitrogen were achieved. The camera comparison included a pco.dimax HD, a LaVision Imager scientific CMOS (sCMOS) and a Photron FASTCAM SA-X2, along with a two-stage LaVision High Speed IRO intensifier. Excluding the LaVision Imager sCMOS, the cameras were tested with and without intensification and with both short and long inter-frame delays. Use of intensification and longer inter-frame delay generally improved precision. Overall, the Photron FASTCAM SA-X2 exhibited the best performance in terms of greatest precision and highest signal-to-noise ratio primarily because it had the largest pixels
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A phospholipid mimetic targeting LRH-1 ameliorates colitis.
Phospholipids are ligands for nuclear hormone receptors (NRs) that regulate transcriptional programs relevant to normal physiology and disease. Here, we demonstrate that mimicking phospholipid-NR interactions is a robust strategy to improve agonists of liver receptor homolog-1 (LRH-1), a therapeutic target for colitis. Conventional LRH-1 modulators only partially occupy the binding pocket, leaving vacant a region important for phospholipid binding and allostery. Therefore, we constructed a set of molecules with elements of natural phospholipids appended to a synthetic LRH-1 agonist. We show that the phospholipid-mimicking groups interact with the targeted residues in crystal structures and improve binding affinity, LRH-1 transcriptional activity, and conformational changes at a key allosteric site. The best phospholipid mimetic markedly improves colonic histopathology and disease-related weight loss in a murine T cell transfer model of colitis. This evidence of in vivo efficacy for an LRH-1 modulator in colitis represents a leap forward in agonist development
On the dynamics of nitrite, nitrate and other biomarkers of nitric oxide production in inflammatory bowel disease
Nitrite and nitrate are frequently used surrogate markers of nitric oxide (NO) production. Using rat models of acute and chronic DSS-induced colitis we examined the applicability of these and other NO-related metabolites, in tissues and blood, for the characterization of inflammatory bowel disease. Global NO dynamics were assessed by simultaneous quantification of nitrite, nitrate, nitroso and nitrosyl species over time in multiple compartments. NO metabolite levels were compared to a composite disease activity index (DAI) and contrasted with measurements of platelet aggregability, ascorbate redox status and the effects of 5-aminosalicylic acid (5-ASA). Nitroso products in the colon and in other organs responded in a manner consistent with the DAI. In contrast, nitrite and nitrate, in both intra- and extravascular compartments, exhibited variations that were not always in step with the DAI. Extravascular nitrite, in particular, demonstrated significant temporal instabilities, ranging from systemic drops to marked increases. The latter was particularly evident after cessation of the inflammatory stimulus and accompanied by profound ascorbate oxidation. Treatment with 5-ASA effectively reversed these fluctuations and the associated oxidative and nitrosative stress. Platelet activation was enhanced in both the acute and chronic model. Our results offer a first glimpse into the systemic nature of DSS-induced inflammation and reveal a greater complexity of NO metabolism than previously envisioned, with a clear dissociation of nitrite from other markers of NO production. The remarkable effectiveness of 5-ASA to abrogate the observed pattern of nitrite instability suggests a hitherto unrecognized role of this molecule in either development or resolution of inflammation. Its possible link to tissue oxygen consumption and the hypoxia that tends to accompany the inflammatory process warrants further investigation
Management of type 2 diabetes: the current situation and key opportunities to improve care in the UK
In common with global trends, the number of individuals with type 2 diabetes in the UK is rising, driven largely by obesity. The increasing prevalence of younger individuals with type 2 diabetes is of particular concern because of the accelerated course of diabetes-related complications that is observed in this population. The importance of good glycaemic control in the prevention of microvascular complications of diabetes is widely accepted, and there is a growing body of evidence to support a benefit in the reduction of cardiovascular events in the long term. Despite the importance of maintaining a healthy weight for the prevention of type 2 diabetes, the results from trials of lifestyle intervention strategies to reduce body weight have been disappointing. New glucose-lowering agents offer some promise in this regard, offering an opportunity to combat the dual burden of hyperglycaemia and obesity simultaneously. The timing and appropriate choice of glucose-lowering therapy has never been more complex as a result of rising prevalence of obesity in the young, concomitant obesity in some 90% of adults with type 2 diabetes and an ever-increasing range of therapeutic options. The present review evaluates performance measures specific to weight and glycaemic control in type 2 diabetes in the UK using data from the Quality and Outcomes Framework in England and Wales, and the Scottish Diabetes Survey. Potential barriers to improvement in standards of care for people with type 2 diabetes are considered, including patient factors, clinical inertia and the difficulties in translating therapeutic guidelines into everyday clinical practice
The consequences of delaying insulin initiation in UK type 2 diabetes patients failing oral hyperglycaemic agents: a modelling study
<p>Abstract</p> <p>Background</p> <p>Recent data have shown that type 2 diabetes patients in the UK delay initiating insulin on average for over 11 years after first being prescribed an oral medication. Using a published computer simulation model of diabetes we used UK-specific data to estimate the clinical consequences of immediately initiating insulin versus delaying initiation for periods in line with published estimates.</p> <p>Methods</p> <p>In the base case scenario simulated patients, with characteristics based on published UK data, were modelled as either initiating insulin immediately or delaying for 8 years. Clinical outcomes in terms of both life expectancy and quality-adjusted life expectancy and also diabetes-related complications (cumulative incidence and time to onset) were projected over a 35 year time horizon. Treatment effects associated with insulin use were taken from published studies and sensitivity analyses were performed around time to initiation of insulin, insulin efficacies and hypoglycaemia utilities.</p> <p>Results</p> <p>For patients immediately initiating insulin there were increases in (undiscounted) life expectancy of 0.61 years and quality-adjusted life expectancy of 0.34 quality-adjusted life years versus delaying initiation for 8 years. There were also substantial reductions in cumulative incidence and time to onset of all diabetes-related complications with immediate versus delayed insulin initiation. Sensitivity analyses showed that a reduced delay in insulin initiation or change in insulin efficacy still demonstrated clinical benefits for immediate versus delayed initiation.</p> <p>Conclusion</p> <p>UK type 2 diabetes patients are at increased risk of a large number of diabetes-related complications due to an unnecessary delay in insulin initiation. Despite clear guidelines recommending tight glycaemic control this failure to begin insulin therapy promptly is likely to result in needlessly reduced life expectancy and compromised quality of life.</p
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