49 research outputs found
Atomic collisional data for neutral beam modeling in fusion plasmas
The injection of energetic neutral particles into the plasma of magnetic confinement fusion reactors is a widely-accepted method for heating such plasmas; various types of neutral beam are also used for diagnostic purposes. Accurate atomic data are required to properly model beam penetration into the plasma and to interpret photoemission spectra from both the beam particles themselves (e.g. beam emission spectroscopy) and from plasma impurities with which they interact (e.g. charge exchange recombination spectroscopy). This paper reviews and compares theoretical methods for calculating ionization, excitation and charge exchange cross sections applied to several important processes relevant to neutral hydrogen beams, including H + Be4+ and H + H+. In particular, a new cross section for the proton-impact ionization of H (1s) is recommended which is significantly larger than that previously accepted at fusion-relevant energies. Coefficients for an empirical fit function to this cross section and to that of the first excited states of H are provided and uncertainties estimated. The propagation of uncertainties in this cross section in modeling codes under JET-like conditions has been studied and the newly-recommended values determined to have a significant effect on the predicted beam attenuation. In addition to accurate calculations of collisional atomic data, the use of these data in codes modeling beam penetration and photoemission for fusion-relevant plasma density and temperature profiles is discussed. In particular, the discrepancies in the modeling of impurities are reported. The present paper originates from a Coordinated Research Project (CRP) on the topic of fundamental atomic data for neutral beam modeling that the International Atomic Energy Agency (IAEA) ran from 2017 to 2022; this project brought together ten research groups in the fields of fusion plasma modeling and collisional cross section calculations. Data calculated during the CRP is summarized in an appendix and is available online in the IAEA’s atomic database, CollisionDB
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Factors associated with variations in hospital expenditures for acute heart failure in the United States.
BackgroundRelatively little contemporary data are available that describe differences in acute heart failure (AHF) hospitalization expenditures as a function of patient and hospital characteristics, especially from a population-based investigation. This study aimed to evaluate factors associated with variations in hospital expenditures for AHF in the United States.MethodsA cross-sectional analysis using discharge data from the 2011 Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, was conducted. Discharges with primary International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis codes for AHF in adults were included. Costs were estimated by converting Nationwide Inpatient Sample charge data using the Healthcare Cost and Utilization Project Cost-to-Charge Ratio File. Discharges with highest (≥80th percentile) versus lowest (≤20th percentile) costs were compared for patient characteristics, hospital characteristics, utilization of procedures, and outcomes.ResultsOf the estimated 1 million AHF hospital discharges, the mean cost estimates were $10,775 per episode. Younger age, higher percentage of obesity, atrial fibrillation, pulmonary disease, fluid/electrolyte disturbances, renal insufficiency, and greater number of cardiac/noncardiac procedures were observed in stays with highest versus lowest costs. Highest-cost discharges were more likely to be observed in urban and teaching hospitals. Highest-cost AHF discharges also had 5 times longer length of stay, were 9 times more costly, and had higher in-hospital mortality (5.6% vs 3.5%) compared with discharges with lowest costs (all P < .001).ConclusionsAcute heart failure hospitalizations are costly. Expenditures vary markedly among AHF hospitalizations in the United States, with substantial differences in patient and hospital characteristics, procedures, and in-hospital outcomes among discharges with highest compared with lowest costs
American Heart Association’s Cholesterol CarePlan as a Smartphone-Delivered Web App for Patients Prescribed Cholesterol-Lowering Medication: Protocol for an Observational Feasibility Study
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Quality of discharge practices and patient understanding at an academic medical center.
ImportanceWith growing national focus on reducing readmissions, there is a need to comprehensively assess the quality of transitional care, including discharge practices, patient perspectives, and patient understanding.ObjectiveTo conduct a multifaceted evaluation of transitional care from a patient-centered perspective.DesignProspective observational cohort study, May 2009 through April 2010.SettingUrban, academic medical center.ParticipantsPatients 65 years and older discharged home after hospitalization for acute coronary syndrome, heart failure, or pneumonia.Main outcomes and measuresDischarge practices, including presence of follow-up appointment and patient-friendly discharge instructions; patient understanding of diagnosis and follow-up appointment; and patient perceptions of and satisfaction with discharge care.ResultsThe 395 enrolled patients (66.7% of those eligible) had a mean age of 77.2 years. Although 349 patients (95.6%) reported understanding the reason they had been in the hospital, only 218 patients (59.6%) were able to accurately describe their diagnosis in postdischarge interviews. Discharge instructions routinely included symptoms to watch out for (98.4%), activity instructions (97.3%), and diet advice (89.7%) in lay language; however, 99 written reasons for hospitalization (26.3%) did not use language likely to be intelligible to patients. Of the 123 patients (32.6%) discharged with a scheduled primary care or cardiology appointment, 54 (43.9%) accurately recalled details of either appointment. During postdischarge interviews, 118 patients (30.0%) reported receiving less than 1 day’s advance notice of discharge, and 246 (66.1%) reported that staff asked whether they would have the support they needed at home before discharge.Conclusions and relevancePatient perceptions of discharge care quality and self-rated understanding were high, and written discharge instructions were generally comprehensive although not consistently clear. However, follow-up appointments and advance discharge planning were deficient, and patient understanding of key aspects of postdischarge care was poor. Patient perceptions and written documentation do not adequately reflect patient understanding of discharge care
Quality of discharge practices and patient understanding at an academic medical center.
ImportanceWith growing national focus on reducing readmissions, there is a need to comprehensively assess the quality of transitional care, including discharge practices, patient perspectives, and patient understanding.ObjectiveTo conduct a multifaceted evaluation of transitional care from a patient-centered perspective.DesignProspective observational cohort study, May 2009 through April 2010.SettingUrban, academic medical center.ParticipantsPatients 65 years and older discharged home after hospitalization for acute coronary syndrome, heart failure, or pneumonia.Main outcomes and measuresDischarge practices, including presence of follow-up appointment and patient-friendly discharge instructions; patient understanding of diagnosis and follow-up appointment; and patient perceptions of and satisfaction with discharge care.ResultsThe 395 enrolled patients (66.7% of those eligible) had a mean age of 77.2 years. Although 349 patients (95.6%) reported understanding the reason they had been in the hospital, only 218 patients (59.6%) were able to accurately describe their diagnosis in postdischarge interviews. Discharge instructions routinely included symptoms to watch out for (98.4%), activity instructions (97.3%), and diet advice (89.7%) in lay language; however, 99 written reasons for hospitalization (26.3%) did not use language likely to be intelligible to patients. Of the 123 patients (32.6%) discharged with a scheduled primary care or cardiology appointment, 54 (43.9%) accurately recalled details of either appointment. During postdischarge interviews, 118 patients (30.0%) reported receiving less than 1 day’s advance notice of discharge, and 246 (66.1%) reported that staff asked whether they would have the support they needed at home before discharge.Conclusions and relevancePatient perceptions of discharge care quality and self-rated understanding were high, and written discharge instructions were generally comprehensive although not consistently clear. However, follow-up appointments and advance discharge planning were deficient, and patient understanding of key aspects of postdischarge care was poor. Patient perceptions and written documentation do not adequately reflect patient understanding of discharge care
The 2013 ACC/AHA Cholesterol Treatment Guidelines: Applicability to Patients with Diabetes
Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide and the management of blood cholesterol is a cornerstone of medical therapy for the primary and secondary prevention of cardiovascular disease. Patients with diabetes represent an important high-risk group in whom clinicians should advocate the use of statins and lifestyle modification for the reduction of ASCVD. The recent 2013 ACC/AHA guidelines on managing blood cholesterol provide an important framework for the effective implementation of this important risk reduction strategy. The guidelines identify four groups of individuals who have been shown to benefit from statin therapy and update the dosing and monitoring recommendations based on evidence from published, large-scale randomized controlled trials (RCTs) with clinical hard endpoints. Primary care physicians and specialists play key roles in identifying populations at elevated ASCVD risk and providing effective care for patients, especially those with diabetes. This article will summarize the 2013 ACC/AHA guidelines on managing blood cholesterol and provide a practical management overview in order to facilitate implementation of these guidelines for patients with diabetes