337 research outputs found

    Association between gender and receipt of magnetic resonance imaging (MRI) in stroke patients from Puerto Rico

    Get PDF
    Introduction: Stroke is the fifth principal cause of death in the United States and Puerto Rico and a prime cause of adult disability. Women tend to have worse outcomes post-stroke. Initial diagnoses and management of stroke include the use of computed tomography (CT) and magnetic resonance image (MRI) scans. MRI scans are more sensitive and more specific than CT scans. Still, CT scans are used more commonly. Whether differences in the choice of imaging techniques exists for gender and whether that can be a potential reason for gender differences in post-stroke outcomes it is yet unknown. The study is directed to evaluate the association between gender and receipt of a MRI in stroke patients in the Puerto Rico population. Methods: We did a secondary analysis of data collected from patients who suffered from a stroke and who participated in the Puerto Rican Cardiovascular Surveillance System (PRCSS) in 2007, 2009 and 2011. The main independent variable was gender (male and female). The dependent variable will be receipt of a MRI (alone or in combination with any other imaging modality as recorded in the medical charts). Multivariate logistic regression was used to assess for the independent associations. P-value < 0.05 for a two tailed test was considered to be statistically significant. SPSS software was used for analysis. Results: A total of 1,950 patients suffered from an ischemic stroke and participated at the PRCSS. We excluded 595 patients due to BMI ≥35 (n=135) or no recorded BMI (n=460). MRI was used for 50% of participants. Women were 85% less likely to receive a MRI compared to men in both the unadjusted (OR-0.85, 95% CI=0.11-0.20, p-value <0.001) and after adjusting for BMI, age, marital status, hypertension, and transient ischemic attacks (TIA) (OR=0.15; 95%CI: 0.11-0.20). No other variables assessed had significant independent association with the receipt of a MRI. Conclusions: We found evidence of gender disparities in the receipt of MRI during hospitalization for stroke in patients in the Puerto Rico. Women were less likely to receive MRI compared to men. Further research on potential reasons for such dispairites, increasing awareness, and testing intervention as to decrease these potential disparities are needed

    Recent advances in the application of the Schwinger multichannel method with pseudopotentials to electron-molecule collisions

    Get PDF
    The Schwinger multichannel method [K. Takatsuka and V. McKoy, Phys. Rev. A 30, 1734 (1984)], which is based on the Schwinger variational principle for the scattering amplitude [J. Schwinger, Phys. Rev. 72, 742 (1947)], was designed to account for exchange, polarization and electronically multichannel coupling effects in the low-energy region of electron scattering from molecules with arbitrary geometry. The applications of the method became more ambitious with the availability of computer power combined with parallel processing, use of norm-conserving pseudopotentials and improvement of the description of target excited states (minimal orbital basis for single configuration interaction). The most recent applications involving 33 and 45 electronically open channels for phenol and ethylene molecules, represent good examples of the present status of the method. In this colloquium, we review the strategy and point out new directions to apply the method in its full extension

    E-cigarette use and respiratory symptoms in residents of the United States : A BRFSS report

    Get PDF
    Publisher Copyright: Copyright: © 2022 Varella et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Purpose E-cigarettes are the most common type of electronic nicotine delivery system in the United States. E-cigarettes contain numerous toxic compounds that has been shown to induce severe structural damage to the airways. The objective of this study is to assess if there is an association between e-cigarette use and respiratory symptoms in adults in the US as reported in the BRFSS. Methods We analyzed data from 18,079 adults, 18–44 years, who participated at the Behavioral Risk Factor Surveillance System (BRFSS) in the year 2017. E-cigarette smoking status was categorized as current everyday user, current some days user, former smoker, and never smoker. The frequency of any respiratory symptoms (cough, phlegm, or shortness of breath) was compared. Unadjusted and adjusted logistic regression analysis were used to calculate odds ratios (OR) and 95% confidence intervals (CI). Results The BRFSS reported prevalence of smoking e-cigarettes was 6%. About 28% of the participants reported any of the respiratory symptoms assessed. The frequency of reported respiratory symptoms was highest among current some days e-cigarette users (45%). After adjusting for selected participant’s demographic, socio-economic, and behavioral characteristics, and asthma and COPD status, the odds of reporting respiratory symptoms increased by 49% among those who use e-cigarettes some days (OR 1.49; 95% CI: 1.06–2.11), and by 29% among those who were former users (OR 1.29; 95% CI: 1.07–1.55) compared with those who never used e-cigarettes. No statistically significant association was found for those who used e-cigarettes every day (OR 1.41; 95% CI 0.96–2.08). Conclusion E-cigarettes cannot be considered as a safe alternative to aid quitting use of combustible traditional cigarettes. Cohort studies may shed more evidence on the association between e-cigarette use and respiratory diseases.Peer reviewe

    Applications of the Schwinger Multichannel method with pseudopotentials to electron scattering from polyatomic molecules II: rotational excitation cross sections

    Get PDF
    This paper reports results for rotational excitation of H2O and H2S molecules by electron impact. It is also a databasis including tables of previously published rotationally resolved cross sections for CH4, SiH4, GeH4, SnH4, PbH4, NH3, PH3, AsH3, SbH3, CF4, CCl4, SiCl4 SiBr4, and SiI4. Our scattering amplitudes were calculated using the Schwinger multichannel method with norm-conserving pseudopotentials and the rotational resolved cross sections were obtained with the help of the adiabatic nuclei rotation approximation. Our results are in good agreement with other theoretical data and experimental results when available.2129Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Time-resolved photoelectron spectroscopy of proton transfer in the ground state of chloromalonaldehyde: Wave-packet dynamics on effective potential surfaces of reduced dimensionality

    Get PDF
    We report on a simple but widely useful method for obtaining time-independent potential surfaces of reduced dimensionality wherein the coupling between reaction and substrate modes is embedded by averaging over an ensemble of classical trajectories. While these classically averaged potentials with their reduced dimensionality should be useful whenever a separation between reaction and substrate modes is meaningful, their use brings about significant simplification in studies of time-resolved photoelectron spectra in polyatomic systems where full-dimensional studies of skeletal and photoelectron dynamics can be prohibitive. Here we report on the use of these effective potentials in the studies of dump-probe photoelectron spectra of intramolecular proton transfer in chloromalonaldehyde. In these applications the effective potentials should provide a more realistic description of proton-substrate couplings than the sudden or adiabatic approximations commonly employed in studies of proton transfer. The resulting time-dependent photoelectron signals, obtained here assuming a constant value of the photoelectron matrix element for ionization of the wave packet, are seen to track the proton transfer. (c) 2006 American Institute of Physics.1241

    Low-energy electron scattering by CH3F, CH2F2, CHF3, and CF4

    Get PDF
    We present measured and calculated differential cross sections, as well as calculated integral cross sections, for elastic electron collisions with CH3F, CHF2F2, CHF3, and CF4. The calculated cross sections were obtained with the Schwinger multichannel method, and a Born-closure procedure was used to improve the differential cross sections for polar systems. Polarization effects were found to be relevant even for systems with moderately large permanent dipole moments, such as CH3F and CHF3. In general, there is good agreement between theory and experiment.65

    Recomendações para a escolha e manejo de plantas forrageiras em sistemas silvipastoris no Sul do Brasil.

    Get PDF
    Fundamentos eco-fisiológicos de forrageiras adaptadas ao sistema silvipastoril; Definição dos espaçamentos e arranjos arbóreos; A escolha de espécies forrageiras para a integração floresta-pecuária; Manejo de forrageiras em SSP.bitstream/item/63860/1/DT76.pdfDisponível no formato online

    Positron collisions with ethene

    Get PDF
    We present experimental and theoretical cross sections for positron collisions with ethene molecules. The experimental total cross sections (TCSs) were obtained with a linear transmission technique, for energies from 0.1 eV up to 70 eV. The calculations employed the Schwinger multichannel method and were performed in the static plus polarization approximation for energies up to 10 eV. Our calculated elastic cross sections indicate a Ramsauer-Townsend minimum around 2.8 eV and a virtual state, in agreement with previous calculations by da Silva et al. [ Phys. Rev. Lett. 77 1028 (1996)]. We found reasonable agreement between the calculated elastic integral cross section and the measured total cross section below the positronium formation threshold. The present results are also in quite good agreement with available theoretical and experimental data, although for the experiments this is only true for TCSs above about 7 eV
    corecore