253 research outputs found
Corrigendum: Ultra-High Field NMR and MRI–The Role of Magnet Technology to Increase Sensitivity and Specificity
State of ions copper(II) and cobalt(II) in phase carboxyl cation resin according to the methods ESDR and EPR
The properties of the Tokheim-250 carboxylic cation exchange resin and its selectivity to Co2 + and Ni2+ ions are studied. The values of the sorption capacity for the Co2+ and Ni2+ ions, the effective ionization constant of the functional groups (pKa = 6,59), and the values of the ion distribution coefficients (~ 103) are calculated. Founded that the selectivity of the sorption of Co2+ increased to Ni2 +. In this regard, carboxylic cation exchanger Tokem-250 samples with nickel ion was used to create spherical catalysts. The developed spherical materials have catalytic activity in the reactions of deep and partial oxidation of n-heptane
Phosphocreatine line with changes in localised 31P MRS of exercising muscle at 7T
The aim was to investigate changes in the line width of high-energy phosphates solely originating from the intramyocellular compartment by temporally resolved localised 31P-MRS after aerobic calf muscle exercise. Semi-Laser [2] localised 31P-MRS of gastrocnemius muscle and pulse-acquire-MRS (10cm-surface coil) were performed alternatingley in three exercise bouts separated by >20min inactivity. PCr and Pi were quantified in AMARES from single acquitsitions, with TR=6s. While Pi line width is known to change due to pH, to our knowledge this is the first observation of an exercise induced line width increase of intra-myocellular PCr, which may be associated with myoglobin deoxygenation
Re-establishment of normal blood flow is mandatory to restore intramuscular high energy phosphate levels after transient ischemia
General and specific responsiveness of the amygdala during explicit emotion recognition in females and males
<p>Abstract</p> <p>Background</p> <p>The ability to recognize emotions in facial expressions relies on an extensive neural network with the amygdala as the key node as has typically been demonstrated for the processing of fearful stimuli. A sufficient characterization of the factors influencing and modulating amygdala function, however, has not been reached now. Due to lacking or diverging results on its involvement in recognizing all or only certain negative emotions, the influence of gender or ethnicity is still under debate.</p> <p>This high-resolution fMRI study addresses some of the relevant parameters, such as emotional valence, gender and poser ethnicity on amygdala activation during facial emotion recognition in 50 Caucasian subjects. Stimuli were color photographs of emotional Caucasian and African American faces.</p> <p>Results</p> <p>Bilateral amygdala activation was obtained to all emotional expressions (anger, disgust, fear, happy, and sad) and neutral faces across all subjects. However, only in males a significant correlation of amygdala activation and behavioral response to fearful stimuli was observed, indicating higher amygdala responses with better fear recognition, thus pointing to subtle gender differences. No significant influence of poser ethnicity on amygdala activation occurred, but analysis of recognition accuracy revealed a significant impact of poser ethnicity that was emotion-dependent.</p> <p>Conclusion</p> <p>Applying high-resolution fMRI while subjects were performing an explicit emotion recognition task revealed bilateral amygdala activation to all emotions presented and neutral expressions. This mechanism seems to operate similarly in healthy females and males and for both in-group and out-group ethnicities. Our results support the assumption that an intact amygdala response is fundamental in the processing of these salient stimuli due to its relevance detecting function.</p
Секрет влажных салфеток
Converging evidence has accumulated that menstrual cycle and thus hormonal levels can affect emotional behavior, in particular facial emotion recognition. Here we explored the association of ovarian hormone levels and amygdala activation during an explicit emotion recognition task in two groups of healthy young females: one group was measured while in their follicular phase (n = 11) and the other during their luteal phase (n = 11). Using a 3T scanner in combination with a protocol specifically optimized to reliably detect amygdala activation we found significantly stronger amygdala activation in females during their follicular phase. Also, emotion recognition performance was significantly better in the follicular phase. We observed significant negative correlations between progesterone levels and amygdala response to fearful, sad and neutral faces, further supporting a significant modulation of behavior and neural response by hormonal changes during the menstrual cycle. From an evolutionary point of view this significant influence of ovarian hormone level on emotion processing and an important neural correlate, the amygdala, may enable a higher social sensitivity in females during their follicular phase, thus facilitating socio-emotional behavior (and social interaction) which may possibly facilitate mating behavior as well
A Quantitative Comparison of Clinically Employed Parameters in the Assessment of Acute Cerebral Ischemia Using Dynamic Susceptibility Contrast Magnetic Resonance Imaging
Purpose: Perfusion magnetic resonance imaging (P-MRI) is part of the mismatch concept employed for therapy decisions in acute ischemic stroke. Using dynamic susceptibility contrast (DSC) MRI the time-to-maximum (Tmax) parameter is quite popular, but its inconsistently defined computation, arterial input function (AIF) selection, and the applied deconvolution method may introduce bias into the assessment. Alternatively, parameter free methods, namely, standardized time-to-peak (stdTTP), zf-score, and standardized-zf (stdZ) are also available, offering consistent calculation procedures without the need of an AIF or deconvolution.Methods: Tmax was compared to stdTTP, zf-, and stdZ to evaluate robustness of infarct volume estimation in 66 patients, using data from two different sites and MR systems (i.e., 1.5T vs. 3T; short TR (= 689 ms) vs. medium TR (= 1,390 ms); bolus dose 0.1 or 0.2 ml/kgBW, respectively).Results: Quality factors (QF) for Tmax were 0.54 ± 0.18 (sensitivity), 0.90 ± 0.06 (specificity), and 0.87 ± 0.05 (accuracy). Though not significantly different, best specificity (0.93 ± 0.05) and accuracy (0.90 ± 0.04) were found for stdTTP with a sensitivity of 0.56 ± 0.17. Other tested parameters performed not significantly worse than Tmax and stdTTP, but absolute values of QFs were slightly lower, except for zf showing the highest sensitivity (0.72 ± 0.16). Accordingly, in ROC-analysis testing the parameter performance to predict the final infarct volume, stdTTP and zf showed the best performance. The odds for stdTTP to obtain the best prediction of the final infarct size, was 6.42 times higher compared to all other parameters (odds-ratio test; p = 2.2*10–16).Conclusion: Based on our results, we suggest to reanalyze data from large cohort studies using the parameters presented here, particularly stdTTP and zf-score, to further increase consistency of perfusion assessment in acute ischemic stroke
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