An application of functional magnetic resonance in medicine : optimization of fMRI and rsfMRI studies

Novel functional magnetic resonance techniques based on variation of the blood-oxygenated-level-dependent (BOLD) signal during the performance of a task or in response to a stimulus (fMRI) as well as at the rest (rsfMRI) are compared. These techniques play a significant role in the investigation of functional architecture of the brain. There is a good overlap between the areas of fMRI activation elicited by motor, language, visual or other task studies and the corresponding rsfMRI networks (RSNs). Progress in statistical approaches for processing is presented particularly for rsfMRI data. Both fMRI techniques as completely non-invasive can be successfully used in medical diagnostics and neurosurgery. In recent years, research has focused on the rsfMRI technique since it represents a promising and cost-effective alternative to task-based fMRI for scientific needs as well as for medical applications

Prenatal Zidovudine Treatment Modifies Early Development of Rat Osteoid – Confocal Microspectroscopy Analysis

Autofluorescence of the bone extracellular matrix (ECM) has not been widely explored although the ECMplays a very important role in bone development. In our research we focused on examining the bone matrix of very young animals due to the intense growth process during the first month of life. Structure images and fluorescence spectra of the bone surface were carried out using confocal fluorescence microscope Eclipse Ti-S inverted CLSM (NIKON, Japan) for compact tibia of healthy 7-, 14- and 28-dayold rat newborns after prenatal zidovudine administration in comparison with control. Spectral features of ECM autofluorescence were analyzed statistically by taking into consideration p < 0.05. The CLSM technique allows for simultaneous examination of the structure and autofluorescence from selected areas of the bone surface. Excessive autofluorescence of ECM after prenatal zidovudine administration influences bone growth incommensurably to the newborns’ age. Therefore the possibility of an additional non-enzymatic mechanism of collagen cross-linking in the first two weeks of life of newborn rats prenatally treated with zidovudine has been considered. Our results suggest that ECMautofluorescence can be an indicator of bone development in the normal and pathological state

Using rsfMRI and ICA in analysis of visual cortex area in healthy and multiple sclerosis patients

The aim of this study is to apply the independent component analysis in a GIFT toolbox in a restingstate functional MRI analysis of the visual cortex. The measurements were performed during rest in normal subjects (20) and patients with multiple sclerosis (14) on a 3 T scanner. A number of independent components influencing the visual network in the MS group in comparison with the healthy group is discussed taking into consideration some spectral parameters such as: dynamic range and low frequency fluctuation and value of kurtosis of time courses and spatial maps. Our analyses have shown that healthy patients are characterized by higher and more numerous activations in the visual areas than MS patients. It should be noted that spectral factors such as kurtosis of spatial maps is markedly higher in the healthy group than in the MS one. The number of activations in the visual area of the brain depends on model order ICA as well as on the kind of the group. The majority of activations in the healthy group were found for ICA100 while in MS high model order (80,100) they were not seen

Structural and magnetic properties of Dy(Fe,V,Si)12 compounds

An influence of Si on the structural and magnetic properties of Dy(Fe,V,Si)12 compounds is studied. X-ray diffraction shows that these materials crystallise in the tetragonal ThΜn12-typae structure. An increase in the saturation magnetization, the Curie temperatures and magnetocrystalline anisotropy in the Si substitutional systems is observed when compared with DyFeι2-xVx . The magnetic properties depend on the preferential site occupation and concentration of Si and V atoms in these compounds

Breakdown of the de Gennes scaling in Y1-xDyxNi2B2C

Single crystals of Y1-xDyxΝi2B2C (1 ≤ x≤ 0.7) were examined by X-ray diffraction and stoichiometry was attested by XPS measurements. The superconducting transition temperature T^ and Neel temperature TN were determined by means of magnetisation measurements. A dramatic breakdown of the de Gennes scaling in the Dy-rich compounds was found when < TN

Comparison between ERP (sLORETA) and fMRI of somatosensory cortex for healthy group

The purpose of this paper is to present event-related potential (ERP) measurements during visual language processing experiment and comparison with functional magnetic resonance imaging as well as compare brain activity and estimate the diagnostic value. sLORETA (standardized Low Resolution Electromagnetic Tomography) was chosen to compute current source densities because it can lead to the same type of mapping activity as fMRI, which was used as a reference method for imaging of somatosensory areas. Research focused on selected paradigms which was finger movement for healthy group. Exogenous potentials and associated endogenous potentials were analyzed, taking into account the phenomenon of lateralization and showing the impact of parameters in SPM in the area of somatosensory cortex of fMRI study

Anomalous reversible torque in layered superconducting Bi2Sr2CaCu2x single crystal

Magnetic anisotropy of layered superconducting Bi2Sr2CaCu2O x single crystal was investigated by the torque metlod in the reversible regime. The torque was analyzed in the model taking into account 2D layered structure. Considered model gives the better fit to the data wlen the magnetic fieJd is applied near (a, b) plane. Obtained results establish to 6 x 10 3 value of the superconducting effective mass anisotropy coefficient ε

Effects of low-dose ionizing radiation on α,β-globulins solutions studied by DSC

An attempt has been made to detect the effect of a small dose of ionizing radiation on the course of a,b-globulin thermal denaturation in aqueous solutions. Doses of 0.1 and 1.8 Gy have been delivered using c-rays emitted by 60Co isotope while doses of 10 and 100 Gy have been supplied by X-rays produced by linear accelerator. The highest dose has visibly changed DSC curve of protein solution while the changes due to lower doses are hardly detectable. Although very weak, the irradiation effect found has been dose dependent. The results suggest that the influence of ionizing radiation on globulins solution is bigger when the dose rate is lower at given dose. The opposite direction of differences between irradiated and control samples for fresh and stored protein solutions suggests various characters of changes in initial and later period of sample aging. This may be an important reason for difficulties in an investigation of the effect of ionizing radiation on protein solution, especially for low doses delivered very slowly

Calorimetric monitoring of the effect of endurance training and testosterone treatment on rat serum denaturation transition

Differential scanning calorimetry (DSC) was applied to evaluate whether endurance training and/or testosterone treatment affect thermal behavior of rat serum. Thirty-six adolescent male Wistar rats were divided into six groups: three untrained and three trained groups, receiving weekly 0, 8, or 80 mg kgBM -1 of testosterone enanthate (TE) each. Total testosterone was significantly higher in both groups treated with the higher TE dose. The rats’ body mass and the levels of serum glucose, uric acid, and free fatty acids were additionally determined. The effect of TE treatment was clearly visible in DSC curves for sedentary rats and much less for trained rats. The differences between averaged endothermic denaturation transitions of serum from sedentary and physically active untreated groups were within an experimental error. A statistically significant increase of the width of peak at its half height and the ratio of excess heat capacity at 75 C and in the temperature of peak maximum (Cp75/Cpmax) were observed due to TE treatment. The same two parameters were significantly lower for physically active rats. Significantly lower values of the enthalpy of serum denaturation (DH) and the first moment of the transition with respect to the temperature axis (M1) were observed for endurance-trained than for sedentary rats