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Increasing Fraction (increasing + fraction)
Selected AbstractsExciton,Exciton Annihilation in Mixed-Phase Polyfluorene FilmsADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Paul E. Shaw Abstract Singlet,singlet annihilation is studied in polyfluorene (PFO) films containing different fractions of , -phase chains using time-resolved fluorescence. On a timescale of >15,ps after excitation, the results are fitted well by a time-independent annihilation rate, which indicates that annihilation is controlled by 3D exciton diffusion. A time-dependent annihilation rate is observed during the first 15,ps in the glassy phase and in the , -phase rich films, which can be explained by the slowdown of exciton diffusion after excitons reach low-energy sites. The annihilation rate in the mixed-phase films increases with increasing fraction of , -phase present, indicating enhanced exciton diffusion. The observed trend agrees well with a model of fully dispersed, -phase chromophores in the surrounding glassy phase with the exciton diffusion described using the line-dipole approximation for an exciton wavefunction extending over 2.5,nm. The results indicate that glassy and, -phase chromophores are intimately mixed rather than clustered or phase-separated. [source] Trends in Inpatient Treatment Intensity among Medicare Beneficiaries at the End of LifeHEALTH SERVICES RESEARCH, Issue 2 2004Amber E. Barnato Objective. Although an increasing fraction of Medicare beneficiaries die outside the hospital, the proportion of total Medicare expenditures attributable to care in the last year of life has not dropped. We sought to determine whether disproportionate increases in hospital treatment intensity over time among decedents are responsible for the persistent growth in end-of-life expenditures. Data Source. The 1985,1999 Medicare Medical Provider Analysis and Review (MedPAR) and Denominator files. Study Design. We sampled inpatient claims for 20 percent of all elderly fee-for-service Medicare decedents and 5 percent of all survivors between 1985 and 1999 and calculated age-, race-, and gender-adjusted per-capita inpatient expenditures and rates of intensive care unit (ICU) and intensive procedure use. We used the decedent-to-survivor expenditure ratio to determine whether growth rates among decedents outpaced growth relative to survivors, using the growth rate among survivors to control for secular trends in treatment intensity. Data Collection. The data were collected by the Centers for Medicare and Medicaid Services. Principal Findings. Real inpatient expenditures for the Medicare fee-for-service population increased by 60 percent, from $58 billion in 1985 to $90 billion in 1999, one-quarter of which were accrued by decedents. Between 1985 and 1999 the proportion of beneficiaries with one or more intensive care unit (ICU) admission increased from 30.5 percent to 35.0 percent among decedents and from 5.0 percent to 7.1 percent among survivors; those undergoing one or more intensive procedure increased from 20.9 percent to 31.0 percent among decedents and from 5.8 percent to 8.5 percent among survivors. The majority of intensive procedures in the United States were performed in the more numerous survivors, although in 1999 50 percent of feeding tube placements, 60 percent of intubations/tracheostomies, and 75 percent of cardiopulmonary resuscitations were in decedents. The proportion of beneficiaries dying in a hospital decreased from 44.4 percent to 39.3 percent, but the likelihood of being admitted to an ICU or undergoing an intensive procedure during the terminal hospitalization increased from 38.0 percent to 39.8 percent and from 17.8 percent to 30.3 percent, respectively. One in five Medicare beneficiaries who died in the hospital in 1999 received mechanical ventilation during their terminal admission. Conclusions. Inpatient treatment intensity for all fee-for-service beneficiaries increased between 1985 and 1999 regardless of survivorship status. Absolute changes in per-capita hospital expenditures, ICU admissions, and intensive inpatient procedure use were much higher among decedents. Relative changes were similar except for ICU admissions, which grew faster among survivors. The secular decline in in-hospital deaths has not resulted in decreased per capita utilization of expensive inpatient services in the last year of life. This could imply that net hospital expenditures for the dying might have been even higher over this time period if the shift toward hospice had not occurred. [source] Cubic-Formation and Grain-Growth Mechanisms in Tetragonal Zirconia PolycrystalJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2003Koji Matsui The microstructure in Y2O3 -stabilized tetragonal zirconia polycrystal (Y-TZP) sintered at 1300°,1500°C was examined to clarify the role of Y3+ ions on grain growth and the formation of cubic phase. The grain size and the fraction of the cubic phase in Y-TZP increased as the sintering temperature increased. Both the fraction of the tetragonal phase and the Y2O3 concentration within the tetragonal phase decreased with increasing fraction of the cubic phase. Scanning transmission electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS) measurements revealed that cubic phase regions in grain interiors in Y-TZP generated as the sintering temperature increased. High-resolution electron microscopy and nanoprobe EDS measurements revealed that no amorphous layer or second phase existed along the grain-boundary faces in Y-TZP and Y3+ ions segregated at their grain boundaries over a width of ,10 nm. Taking into account these results, it was clarified that cubic phase regions in grain interiors started to form from grain boundaries and the triple junctions in which Y3+ ions segregated. The cubic-formation and grain-growth mechanisms in Y-TZP can be explained using the grain boundary segregation-induced phase transformation model and the solute drag effect of Y3+ ions segregating along the grain boundary, respectively. [source] Information resources in High-Energy Physics: Surveying the present landscape and charting the future courseJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 1 2009Anne Gentil-Beccot Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally "early adopters" of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities. [source] Mental Health and Emergency Medicine: A Research AgendaACADEMIC EMERGENCY MEDICINE, Issue 11 2009Gregory Luke Larkin MD Abstract The burden of mental illness is profound and growing. Coupled with large gaps in extant psychiatric services, this mental health burden has often forced emergency departments (EDs) to become the de facto primary and acute care provider of mental health care in the United States. An expanded emergency medical and mental health research agenda is required to meet the need for improved education, screening, surveillance, and ED-initiated interventions for mental health problems. As an increasing fraction of undiagnosed and untreated psychiatric patients passes through the revolving doors of U.S. EDs, the opportunities for improving the art and science of acute mental health care have never been greater. These opportunities span macroepidemiologic surveillance research to intervention studies with individual patients. Feasible screening, intervention, and referral programs for mental health patients presenting to general EDs are needed. Additional research is needed to improve the quality of care, including the attitudes, abilities, interests, and virtues of ED providers. Research that optimizes provider education and training can help academic settings validate psychosocial issues as core components and responsibilities of emergency medicine. Transdisciplinary research with federal partners and investigators in neuropsychiatry and related fields can improve the mechanistic understanding of acute mental health problems. To have lasting impact, however, advances in ED mental health care must be translated into real-world policies and sustainable program enhancements to assure the uptake of best practices for ED screening, treatment, and management of mental disorders and psychosocial problems. [source] | |||||||||||||