Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Swimming and flying animals generate unsteady locomotive forces by delivering net momentum into the fluid wake. Hence, swimming and flying forces can be quantified by measuring the momentum of animal wakes. A recently developed model provides an approach to empirically deduce swimming and flying forces based on the measurement of velocity and vortex added-mass in the animal wake. The model is contingent on the identification of the vortex boundary in the wake. This paper demonstrates the application of that method to a case study quantifying the instantaneous locomotive forces generated by the pectoral fins of the bluegill sunfish (Lepomis macrochirus Rafinesque), measured using digital particle image velocimetry (DPIV). The finite-time Lyapunov exponent (FTLE) field calculated from the DPIV data was used to determine the wake vortex boundary, according to recently developed fluid dynamics theory. Momentum of the vortex wake and its added-mass were determined and the corresponding instantaneous locomotive forces were quantified at discrete time points during the fin stroke. The instantaneous forces estimated in this study agree in magnitude with the time-averaged forces quantified for the pectoral fin of the same species swimming in similar conditions and are consistent with the observed global motion of the animals. A key result of this study is its suggestion that the dynamical effect of the vortex wake on locomotion is to replace the real animal fin with an ;effective appendage', whose geometry is dictated by the FTLE field and whose interaction with the surrounding fluid is wholly dictated by inviscid concepts from potential flow theory. Benefits and limitations of this new framework for non-invasive instantaneous force measurement are discussed, and its application to comparative biomechanics and engineering studies is suggested.
 ...
PMID:Non-invasive measurement of instantaneous forces during aquatic locomotion: a case study of the bluegill sunfish pectoral fin. 1726 54

Atrial fibrillation (AF) is an independent risk factor for thromboembolism and stroke. Women with AF are at a higher overall risk for thromboembolic stroke when compared to men with AF. Recent evidence suggests that female sex, after adjusting for stroke risk profile and sex differences in utilisation of anticoagulation, is an independent stroke risk factor in AF. The inclusion of female sex has improved the accuracy of the CHADS2 stroke risk stratification schema (Congestive heart failure, Hypertension, Age 75 years or greater, Diabetes mellitus, and prior Stroke or TIA). The newly revised and validated schema, CHA2DS2-VASc, dichotomises age and incorporates female sex and vascular disease history. The pathophysiological mechanisms to explain this increased risk in women are not well understood. According to Virchow's triad, thrombosis that leads to stroke in AF should arise from three co-existing phenomena: structural abnormalities, blood stasis, and a hypercoagulable state. Herein, we explore the sex differences in the biological processes that lead to thrombus formation as applied to Virchow's Triad. The objective of this review is to describe the potential mechanisms behind the increased risk of stroke in AF associated with female sex.
...
PMID:Female sex as an independent risk factor for stroke in atrial fibrillation: possible mechanisms. 2430 74

Atrial fibrillation (AF) is said to be a pre-thrombotic state. In patients with AF, the left atrium is usually dilated and blood flow is sluggish, which enables the formation of a thrombus within the left atrium. This is consistent with two of Virchow's Triad, stasis of blood flow and endothelial injury, but the last of the Triad, hypercoagulability of blood, is difficult to explain in AF. There are reports that von Willebrand Factor (vWF), FVIII, fibrinogen, D-dimer, and Fragment 1+2 are elevated in AF patients. The important thing in the daily clinical setting is to identify high-risk AF patients who are prone to stroke and treat them with oral anticoagulants. Over the last 15 years, two well known criteria to predict the risk have been proposed. The first one is called CHADS2 and the second one is the CHA2DS2-VASc score. The CHADS2 score is a clinical prediction rule for estimating the risk of stroke in patients with non-valvular atrial fibrillation (NVAF). A high CHADS2 score corresponds to a greater risk of stroke, while a low CHADS2 score corresponds to a lower risk. The CHA2DS2-VASc score was proposed to complement the CHADS2 score by the inclusion of additional risk factors. These prediction rules are important because not all NVAF patients require oral anticoagulant therapy. There are disadvantages to taking oral anticoagulants, primarily bleeding complications. Therefore, even prediction rules of bleeding risks have been proposed to screen NVAF patients. In conclusion, it is difficult to predict a high-risk pre-thrombotic state among NVAF patients based only on laboratory findings. Practically, prediction rules will play a major role in the decision to start oral anticoagulant therapy.
 ...
PMID:[Is Atrial Fibrillation a Pre-Thrombotic State?]. 2708 60

In EU-funded BALANCE project, developing a stability index which can be employed to estimate actual state of balance of both healthy and neurologically impaired humans' walking in exoskeleton was one of scientific tasks. In the task, Centroidal Momentum (CM), referring to linear and angular momenta at Center of Mass (CoM), has raised as a potential index for such purpose. While our past studies have presented analysis results of CM in offline and online (real time) manners for walking of healthy human and stroke patients, in this study, we present real time computation of CM in exoskeleton-supported walking, specifically with healthy subjects. Experimental setup consists of LOPES II, a treadmill-based robotic gait training exoskeleton for lower limbs rehabilitation developed by Twente University, and commercially available IMUs (Inertial Measurement Units)-based full body motion capture suits from Xsens. CM was computed and demonstrated in two walking conditions: unperturbed walking and walking with unexpected pelvic perturbations in lateral direction. While electromagnetic fields (EMF) from LOPES II exoskeleton affected signals of IMUs in the motion capture suit, the results show the potential applicability of the CM as a sort of stability index for human walking in the exoskeleton.
 ...
PMID:Real time computation of Centroidal Momentum while human walking in the lower limbs rehabilitation exoskeleton: Preliminary trials. 3137 16

Race/ethnic minorities face significant inequities in stroke incidence, prevalence, care, and outcomes. The Health Equity and Actionable Disparities in Stroke: Understanding and Problem-solving symposium, a collaborative initiative of the American Heart Association and National Institute of Neurological Disorders and Stroke, was the first-ever annual multidisciplinary scientific forum focused on race/ethnic inequities in cerebrovascular disease, with the overarching goal of reducing inequities in stroke and accelerating the translation of research findings to improve outcomes for race/ethnic minorities. The symposium featured esteemed invited plenary speakers, lecturing on determinants of race/ethnic inequities in stroke and interventions aimed at redressing the inequities. The Edgar J. Kenton III Award recognized Ralph Sacco, MD, MS, for his lifetime contributions to investigation, management, mentorship, and community service in the field of stroke inequities. Early career investigators were provided with travel awards to attend the symposium; presented their research at moderated poster and Think Tank sessions; received career development advice at the Building Momentum session; and networked with experienced stroke inequities researchers. Future conferences-The Health Equity and Actionable Disparities in Stroke: Understanding and Problem-solving 2021 to 2024-will broaden the focus to include 5 major persistent inequities (race/ethnic, sex, geographic, socioeconomic, and global). Each year will focus on a different theme (community and stakeholder engagement; clinical trials; implementation science; and policy and dissemination). By fostering a community of stroke inequities researchers, we hope to highlight promising work, illuminate research gaps, facilitate networking, inform policy makers, recognize achievement, inspire greater interest among junior investigators to pursue careers in this field, and provide networking opportunities for underrepresented minority scientists.
Stroke 2020 Nov
PMID:Inaugural Health Equity and Actionable Disparities in Stroke: Understanding and Problem-Solving Symposium. 3310 74