342 research outputs found

    Theory of the optical properties of non-absorbing compensated cholesteric liquid crystals

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    A theory is developed of the optical properties of a non-absorbing compensated cholesteric liquid crystal. It is shown that the Mauguin-de Vries equation fails when the pitch becomes very large. Theoretical curves are presented of the dependence of the rotatory power on pitch for different values of the sample thickness. The results are in agreement with the observed variation of the rotatory power of a compensated cholesteric mixture with temperature

    Thermomechanical effect in cholesteric liquid crystals

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    We discuss some possible experimental geometries for studying Leslie's thermomechanical effect in cholesteric liquid crystals. The discussion includes the effect of a temperature gradient (i) along and (ii) perpendicular to the helical axis. The feasibility of observing the effect and of extracting the thermomechanical coefficients is examined

    Flow of cholesteric liquid crystals-I: Flow along the helical axis

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    It is shown that the essential features of Helfrich's penneation model for flow along the helical axis of a cholesteric liquid crystal can be derived approximately on the basis of the Ericksen-Leslie theory

    White Blood Cell Count and Major Adverse Cardiovascular Events After Percutaneous Coronary Intervention in the Contemporary Era: Insights From the PARIS Study (Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients Registry).

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    Elevated white blood cell (WBC) count is associated with increased major adverse cardiovascular events (MACE) in the setting of acute coronary syndrome. The aim of this study was to evaluate whether similar associations persist in an all-comers population of patients undergoing percutaneous coronary intervention in the contemporary era. In the multicenter, prospective, observational PARIS study (Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients Registry), 4222 patients who underwent percutaneous coronary intervention in the United States and Europe between July 1, 2009, and December 2, 2010, were evaluated. The associations between baseline WBC and MACE (composite of cardiac death, stent thrombosis, spontaneous myocardial infarction, or target lesion revascularization) at 24-month follow-up were analyzed using multivariable Cox regression. Patients with higher WBC were more often younger, smokers, and with less comorbid risk factors compared with those with lower WBC. After adjustment for baseline and procedural characteristics, WBC remained independently associated with MACE (hazard ratio [HR] per 10(3) cells/μL increase, 1.05 [95% confidence intervals (CI), 1.02-1.09]; P=0.001), cardiac death (HR, 1.10 [95% CI, 1.05-1.17]; P<0.001), and clinically indicated target revascularization (HR, 1.04 [95% CI, 1.00-1.09]; P=0.03) but not stent thrombosis (HR, 1.07 [95% CI, 0.99-1.16]; P=0.10) or spontaneous myocardial infarction (HR, 1.03 [95% CI, 0.97-1.09]; P=0.29). The association between WBC and MACE was consistent in acute coronary syndrome and non-acute coronary syndrome presentations (interaction P=0.15). Increased WBC is an independent predictor of MACE after percutaneous coronary intervention in a contemporary all-comers cohort. Further studies to delineate the underlying pathophysiologic role of elevated WBC across a spectrum of coronary artery disease presentations are warranted. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00998127

    Use of prasugrel vs clopidogrel and outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention in contemporary clinical practice: Results from the PROMETHEUS study

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    Background and objectivesWe sought to determine the frequency of use and association between prasugrel and outcomes in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) in clinical practice
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