Articles: human.
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Comparative Study
Prehospital emergency care: evaluation of the junctional emergency tourniquet tool with a perfused cadaver model.
Junctional bleeding from the groin is a leading cause of potentially preventable death on the battlefield. To address this problem, a novel device called the Junctional Emergency Treatment Tool (JETT™) was developed. The JETT was designed to stabilize pelvic ring fractures while controlling lower extremity bleeding sustained during high-energy traumatic events on the battlefield and in the civilian environment. Our purpose was to assess the effectiveness of the JETT in the control of simulated life threatening hemorrhage from proximal injuries in the groin of a perfused cadaver. ⋯ The JETT is a single device capable of effectively and quickly controlling bilateral lower extremity junctional hemorrhage at normal physiological blood pressures.
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Comparative Study
Color-detection thresholds in rhesus macaque monkeys and humans.
Macaque monkeys are a model of human color vision. To facilitate linking physiology in monkeys with psychophysics in humans, we directly compared color-detection thresholds in humans and rhesus monkeys. Colors were defined by an equiluminant plane of cone-opponent color space. ⋯ These asymmetries may reflect differences in retinal circuitry for S-ON and S-OFF. At plateau performance, the two species also had similar detection thresholds for all colors, although monkeys had shorter reaction times than humans and slightly lower thresholds for colors that modulated L/M cones. We discuss whether these observations, together with previous work showing that monkeys have lower spatial acuity than humans, could be accounted for by selective pressures driving higher chromatic sensitivity at the cost of spatial acuity amongst monkeys, specifically for the more recently evolved L − M mechanism.
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Understanding the neural basis of consciousness is fundamental to neuroscience research. Disruptions in cortico-cortical connectivity have been suggested as a primary mechanism of unconsciousness. By using a novel combination of positron emission tomography and functional magnetic resonance imaging, we studied anesthesia-induced unconsciousness and recovery using the α₂-agonist dexmedetomidine. ⋯ However, DMN thalamo-cortical functional connectivity was disrupted. Recovery from this state was associated with sustained reduction in cerebral blood flow and restored DMN thalamo-cortical functional connectivity. We report that loss of thalamo-cortical functional connectivity is sufficient to produce unconsciousness.
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Restor. Neurol. Neurosci. · Jan 2014
Comparative StudyIncreasing human leg motor cortex excitability by transcranial high frequency random noise stimulation.
Transcranial random noise stimulation (tRNS) can increase the excitability of hand area of the primary motor cortex (M1). The aim of this study was to compare the efficacy of tRNS and transcranial direct current stimulation (tDCS) on the leg motor cortex. ⋯ Our results suggest that although the leg area has a deeper position in the cortex compared to the hand area, it can be reached by weak transcranial currents. Both anodal tDCS and tRNS had comparable effect on cortical excitability.
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Stud Health Technol Inform · Jan 2014
Validation of a computerized technique for automatically tracking and measuring the inferior vena cava in ultrasound imagery.
Accurate resuscitation of the critically-ill patient using intravenous fluids and blood products is a challenging, time sensitive task. Ultrasound of the inferior vena cava (IVC) is a non-invasive technique currently used to guide fluid administration, though multiple factors such as variable image quality, time, and operator skill challenge mainstream acceptance. ⋯ Addressing problems such as gaps in the vessel wall and intra-lumen speckle should result in improved performance in average and poor quality videos. Semi-automated measurement of the IVC for the purposes of non-invasive estimation of circulating blood volume poses challenges however is feasible.