62 research outputs found
Chemical composition and morphology of renal stones
Two issues related to nephrolithiasis are explored: (1) does the chemical composition and morphology of renal calculi in South Poland overlap with the studies from other countries? and (2) are there possibilities to evaluate in vivo chemical composition of stones using computed tomography? The study was conducted on 108 renal stones. X-ray fluorescence, X-ray diffraction and Fourier transformed infrared spectroscopy were used to determine the chemical composition. The morphology of the stones was examined using micro computed tomography. The stone chemical composition in South Poland indicate that calcium oxalate monohydrate was overwhelmingly dominant (84%) followed by hydroxyapatite (8%) and struvite (6%). The occurrence of uric acid stones was very low (2%). The relative frequency of various stone types is similar in South Poland to other industrialized countries. The studied renal stones were characterized by a large variability in the concentrations of both major and trace elements. The maximum/minimum concentration ratio exceeds two orders of magnitude. Significant morphological differences have been observed between different types of stones. The stones were composed of oxalate polyhedrons stuck together or had the phosphate core overlaid with layers oxalate and organic mater. The use of CT to identify stone type seems to be limited
Combining areal DXA bone mineral density and vertebrae postero-anterior width improves the prediction of vertebral strength
Objective - Areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) is an important determinant of bone strength (BS), despite the fact that the correlation between aBMD and BS is relatively weak. Parameters that describe BS more accurately are desired. The aim of this study was to determine whether the geometrical corrections applied to aBMD would improve its ability for BS prediction. We considered new parameters, estimated from a single DXA measurement, as well as BMAD (bone mineral apparent density) reported in the literature. Materials and methods - In vitro studies were performed with the L3 vertebrae from 20 cadavers, which were studied with DXA and quantitative computed tomography (QCT). A mechanical strength assessment was carried out. Two new parameters were introduced: vBMD_{min}=\frac{aBMD}{W_{PA}^{min}} and vBMD_{av}=\frac{aBMD}{W_{PA}^{av}} \left ( W^{min}_{PA}-minimal vertebral body width in postero-anterior \left ( PA \right ) view, {W_{PA}}^{av} — average PA vertebral body width\right ). Volumetric BMD measured by QCT (vBMD), aBMD, BMAD, vBMD _{min}, and vBMD_{av} were correlated to ultimate load and ultimate stress \left ( P_{max} \right ) to find the best predictor of vertebrae BS. Results - The coefficients of correlation between P_{max} and vBDM_{min} as well as BMAD, were r = 0.626 (p = 0.005), r = 0.610 (p = 0.006) and r = 0.567 (p = 0.012), respectively. Coefficients for vBMD and aBMD are r = 0.648 (p = 0.003) and r = 0.511 (p = 0.03), respectively. Conclusions. Our results showed that aBMD normalized by vertebrae dimensions describes vertebrae BS better than aBMD alone. The considered indices vBMD_{av}, vBMD_{min} and BMAD can be measured in routine PA DXA and considerably improve BS variability prediction. vBMD_{min} is superior compared to vBMD_{av} and BMAD
Thermographic assessment of skin prick tests in comparison with the routine evaluation methods
Introduction: The skin prick test is still the first and basic procedure in the diagnosis of allergic diseases. The possibility
of using a sensitive thermographic method supported by the mathematical model for the assessment of
skin test results will be highlighted in the studies.
Aim: To compare the proposed approach with routine planimetric and thermographic methods.
Material and methods: A mathematical model of allergic reaction was developed. Simplifying assumptions of the
IgE-mediated skin reaction is the essence of the model. Investigations were performed in a group of 40 patients.
Results: Using the spatio-temporal evolution of temperature distributions, the ratios of the histamine released from
mast cells to the control histamine were determined. The obtained values very well correlate with the standard
evaluation of skin prick tests (correlation coefficient = 0.98).
Conclusions: The proposed method of skin test evaluation presents several advantages. The continuous acquisition
of data provides the monitoring of time course of the allergic response. The transport of mediator and its concentration
were distinctly discriminated, which may be diagnostically useful, especially for abnormal cases. The high
sensitivity of the method enables studying patients regardless of age and skin sensitivity
Repeated transcranial direct current stimulation induces behavioral, metabolic and neurochemical effects in rats on high-calorie diet
Due to its high prevalence, obesity is considered an epidemic, which stimulated research on non-invasive methods to reduce excess body fat. Transcranial direct current stimulation (tDCS) is a non-invasive technique used to modulate the activity of cerebral cortex, which has already found increasing interest in medicine as a promising methodology. The aim of this study was to analyze the impact of tDCS on feeding behavior, metabolic abnormalities and neurotransmitters in certain brain areas involved in appetite control of obese rats. The male Wistar rats were divided into five subgroups depending on consumed diet effect (lean, obese) and tDCS type (anodal, cathodal, sham, and no stimulation). Two 10-min daily sessions of tDCS for 8 consecutive days of the study were applied. Rats subjected to active tDCS (anodal right or cathodal left of the prefrontal cortex) had reduced appetite and showed lesser body weight gain than the animals subjected to sham procedure or those receiving no stimulation at all. Furthermore, tDCS contributed to reduction of epididymal fat pads and to a decrease in blood concentration of leptin. Neurochemical examination revealed that tDCS modulated serotonin pathways of the reward-related brain areas and contributed to a significant decrease in the density of D2 but not D1 dopamine receptors in the dorsal striatum, recorded 5 h after the last stimulation. No significant effect of tDCS on dopamine and it's metabolites in examined brain regions was observed. It seems that the hypothalamus was not affected by tDCS application as no changes in measured neurotransmitters were detected at any examined time point. However, these results do not exclude the possibility of the delayed response of the monoamines in the examined brain areas to tDCS application. Altogether, these findings imply that repeated tDCS of the prefrontal cortex may change feeding behavior of obese rats. Either right anodal or left cathodal tDCS were sufficient to decrease food intake, to reduce body adiposity and to normalize other metabolic anomalies. These beneficial effects can be at least partially explained by changes in serotoninergic and in lesser extent dopaminergic system activity within some brain areas belonging to reward system
The influence of electromagnetic wave originating from WiFi router on water viscosity
Celem prezentowanej pracy było sprawdzenie, czy mikrofale generowane przez typowy router WiFi wpływają na lepkość wody, jak
sugerują niektórzy autorzy. Pomysł bazuje na obserwacji ruchu magnetycznych nanocząstek pod mikroskopem w obecności mikrofal i bez nich.
Ruch nanocząstek w polu widzenia mikroskopu był wymuszony przez zastosowanie stałego pola magnetycznego. Porównywano prędkości
nanocząstek w obecności pola elektromagnetycznego i bez niego.The aim of the study was to investigate if microwaves generated by a typical WiFi router influence the viscosity of water, as suggested by
some authors. The idea relies on the microscopic observation of magnetic nano-beads motion with and without microwave irradiation. A static
magnetic field was applied to force the nano-beds movements in the microscope field of view (FOV). The nano-beds velocities under microwave
irradiation were compared to their velocities without the electromagnetic stimulation (Wpływ fali elektromagnetycznej generowanej przez router
WiFi na lepkość wody)
Symptoms related to idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) : a questionnaire study
Badanie miało na celu analizę objawów związanych ze zjawiskiem idiopatycznej nietolerancji środowiskowej przypisywanej działaniu
pola elektromagnetycznego. Zostało ono przeprowadzone z zastosowaniem metody ankietowej. Objawy zgłaszane przez 408 potencjalnie
elektrowrażliwych respondentów zostały przeanalizowane i porównane w odniesieniu do danych demograficznych. Zgłaszane objawy były zwykle
niespecyficzne i trudne do obiektywnej oceny, co potwierdza wyniki wcześniej przeprowadzonych badań.The aim of the study was to analyse the symptoms reported by self-reported IEI-EMF subjects with the use of web-based questionnaire. 408 potentially electrosensitive individuals were identified and symptoms reported by them were analysed and compared depending on demographic characteristics. Declared symptoms were usually not specific and difficult for an objective medical assessment, what is in line with results of previous studies
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