58 research outputs found

    Revealing a third dissolved-phase Xenon-129 resonance in blood caused by hemoglobin glycation

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    Hyperpolarized (HP) xenon-129 (129^{129}Xe), when dissolved in blood, has two NMR resonances: one in red blood cells (RBC) and one in plasma. The impact of numerous blood components on these resonances, however, has not yet been investigated. This study evaluates the effects of elevated glucose levels on the chemical shift (CS) and T*2_{2} relaxation times of HP 129^{129}Xe dissolved in sterile citrated sheep blood for the first time. HP 129^{129}Xe was mixed with sheep blood samples premixed with a stock glucose solution using a liquid–gas exchange module. Magnetic resonance spectroscopy was performed on a 3T clinical MRI scanner using a custom-built quadrature dual-tuned 129^{129}Xe/1^{1}H coil. We observed an additional resonance for the RBCs (129^{129}Xe-RBC1) for the increased glucose levels. The CS of 129^{129}Xe-RBC1 and 129^{129}Xe-plasma peaks did not change with glucose levels, while the CS of 129^{129}Xe-RBC2 (original RBC resonance) increased linearly at a rate of 0.015 ± 0.002 ppm/mM with glucose level. 129^{129}Xe-RBC1 T*2_{2} values increased nonlinearly from 1.58 ± 0.24 ms to 2.67 ± 0.40 ms. As a result of the increased glucose levels in blood samples, the novel additional HP 129^{129}Xe dissolved phase resonance was observed in blood and attributed to the 129^{129}Xe bound to glycated hemoglobin (HbA1c_{1c})

    Cellular shear adhesion force measurement and simultaneous imaging by atomic force microscope

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    This paper presents a sensitive and fast cellular shear adhesion force measurement method using an atomic force microscope (AFM). In the work, the AFM was used both as a tool for the imaging of cells on the nano-scale and as a force sensor for the measurement of the shear adhesion force between the cell and the substrate. After the cell imaging, the measurement of cellular shear adhesion forces was made based on the different positions of the cell on the nano-scale. Moreover, different pushing speeds of probe and various locations of cells were used in experiments to study their influences. In this study, the measurement of the cell adhesion in the upper portion of the cell is different from that in the lower portion. It may reveal that the cancer cells have the metastasis tendency after cultured for 16 to 20 hours, which is significant for preventing metastasis in the patients diagnosed with early cancer lesions. Furthermore, the cellular shear adhesion forces of two types of living cancer cells were obtained based on the measurements of AFM cantilever deflections in the torsional and vertical directions. The results demonstrate that the shear adhesion force of cancer cells is twice as much as the same type of cancer cells with TRAIL. The method can also provide a way for the measurement of the cellular shear adhesion force between the cell and the substrate, and for the simultaneous exploration of cells using the AFM imaging and manipulatio

    Conception of vibroisolating system with magnetic elements

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    Celem pracy jest opracowanie koncepcji elementów układu wibroizolacji z wykorzystaniem pola magnetycznego magnesów stałych i określenie wpływu tego pola na parametry fizyko-mechaniczne wybranego typu elastomeru, który poddany był obciążeniu statycznemu i dynamicznemu w szerokim zakresie prędkości w temperaturze pokojowej.The aim of the work is development of the concept of the vibration isolation system with application of the magnetic field of solid magnets and determination of the influence of this field on the physico-mechanical parameters of the selected type of elastomer, which was subjected to static and dynamic load over a wide range of velocity at room temperature

    Medically unexplained symptoms, illness perception and childhood experience in neurology outpatients

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    AbstractObjectives: Up to one third of patients presenting to neurology outpatients clinics have medically unexplained symptoms, but the aetiology of such symptoms is not well understood. In the current study we sought to investigate the role of anxiety, depression, cognitive factors and early experience in the development of medically unexplained symptoms.Method: Fifty-seven new patients presenting to a neurology outpatients clinic were studied. Demographic details were recorded and a Hospital Anxiety and Depression Scale, an Illness Perception Questionnaire, and a Childhood Development Questionnaire were administered. An assessment was made by trained medical investigators as to whether the patients symptoms were medically unexplained or accounted for by organic pathology.Results: We found that 17 out of 56 patients (30%) had medically unexplained symptoms. Such patients complained of a greater number of symptoms, were more anxious, were more likely to have a past history of depression, and were more likely to attribute their illness to stress than patients with a presumed organic basis for their disease. They were also more likely to have been in foster care as children. High levels of depression and anxiety were strongly associated with the number of physical symptoms and the perceived negative consequences of the illness.Conclusions: The recognition and treatment of anxiety and depressive disorders may contribute to the management of patients with medically unexplained symptoms. Open discussion of beliefs regarding aetiology are also likely to be of benefit regardless of the presence or absence of organic pathology.</jats:p
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