50 research outputs found

    Decrease in shunt volume in patients with cryptogenic stroke and patent foramen ovale

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    <p>Abstract</p> <p>Background</p> <p>In patients with patent foramen ovale (PFO) there is evidence supporting the hypothesis of a change in right-to-left shunt (RLS) over time. Proven, this could have implications for the care of patients with PFO and a history of stroke. The following study addressed this hypothesis in a cohort of patients with stroke and PFO.</p> <p>Methods</p> <p>The RLS volume assessed during hospitalisation for stroke (index event/T0) was compared with the RLS volume on follow-up (T1) (median time between T0 and T1 was 10 months). In 102 patients with a history of stroke and PFO the RLS volume was re-assessed on follow-up using contrast-enhanced transcranial Doppler/duplex (ce-TCD) ultrasound. A change in RLS volume was defined as a difference of ≥20 microembolic signals (MES) or no evidence of RLS during ce-TCD ultrasound on follow-up.</p> <p>Results</p> <p>There was evidence of a marked reduction in RLS volume in 31/102 patients; in 14/31 patients a PFO was no longer detectable. An index event classified as cryptogenic stroke (P < 0.001; OD = 39.2, 95% confidence interval 6.0 to 258.2) and the time interval to the follow-up visit (P = 0.03) were independently associated with a change in RLS volume over time.</p> <p>Conclusions</p> <p>RLS volume across a PFO decreases over time, especially in patients with cryptogenic stroke. These may determine the development of new strategies for the management in the secondary stroke prevention.</p

    Optical Detection of Long Electron Spin Transport Lengths in a Monolayer Semiconductor

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    International audienceUsing a spatially-resolved optical pump-probe experiment, we measure the lateral transport of spin/valley polarized electrons over very long distances (tens of micrometers) in a single WSe2 monolayer. By locally pumping the Fermi sea of 2D electrons to a high degree of spin/valley polarization (up to 75%) using circularly-polarized light, the lateral diffusion of the electron polarization can be mapped out via the photoluminescence induced by a spatially-separated and linearly-polarized probe laser. Up to 25% spin-valley polarization is observed at pump-probe separations up to 20 microns. Characteristic spin/valley diffusion lengths of 18 +/- 3 um are revealed at low temperatures. The dependence on temperature, pump helicity, pump intensity, and electron density highlight the key roles played by spin relaxation time and pumping efficiency on polarized electron transport in monolayer semiconductors possessing spin-valley locking

    Needs Assessment for Weight Management: The Learning Health System Network Experience

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    Objective: To assess patients’ weight management needs and experiences across multiple sites within the Learning Health System Network. Patients and Methods: A total of 19,964 surveys were sent to patients identified with overweight or obesity through medical record query at 5 health care systems throughout 11 states. The survey collected patients’ experiences with and opinions about weight management in clinical care from October 27, 2017, through March 1, 2018. Results: Among the 2380 responders, being younger, female, nonwhite, and single and having some college education or less were all significantly associated with higher body mass index (BMI). The most frequent weight loss barriers included food cravings (30.7%-49.9%) and having a medical condition limiting physical activity (17.7%-47.1%) (P<.001). Higher BMI was associated with a higher frequency of comorbidities and lower health status (P<.001). Higher BMI was also associated with a higher belief that primary care providers (PCPs) should be involved in weight loss management (P=.01) but lower belief that the PCP had the necessary skills and knowledge to help (P<.001). Responders with a higher BMI were more likely to feel judged (P<.001) and not always respected (P<.001) by their PCP. In addition, those with a higher BMI more frequently reported avoiding health care visits because of weight gain, not wanting to undress or be weighed, and not wanting to discuss their weight with their PCP (P<.001). Conclusion: Physician involvement in weight management is important to patients whose needs and experiences differ by BMI. These data may inform clinical weight management efforts and create greater alignment with patient expectations
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