275 research outputs found

    Applications of the Cracow X-ray microprobe in tomography

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    A nuclear microprobe at the IFJ PAN in Cracow has found numerous applications in different fields of research, mostly in biophysics, medical sciences, geology, and material research. In order to extend the research possibilities, a new X-ray microprobe was constructed. This new microprobe consists of three experimental lines dedicated to: (i) X-ray irradiation of biological specimens, (ii) elemental analysis of samples by micro X-ray fluorescence or total reflection X-ray fluorescence methods and (iii) computer microtomography. In this paper the computer microtomography line was described. The line consists of an open type Hamamatsu L9191 X-ray tube with microfocusing to about 2 μm, a high resolution X-ray sensitive CCD camera, and a precise goniometer composed of six piezoelectric motors. Depending on the required X-ray energy, the Hamamatsu tube is used with Ti, Mo, Ag, or W targets. A small focus size and short focus-to-object distance enable to obtain images of samples with a magnification of more than 1000× and resolution of the order of 2 μm. The computer microtomography measurements are carried out using home developed codes combined with commercial software. Details of the microprobe construction and preliminary results of the computer microtomography experiments are presented

    EXAFS studies of prostate cancer cell lines

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    Sulphur plays a vital role in every human organism. It is known, that sulphur-bearing compounds, such as for example cysteine and glutathione, play critical roles in development and progression of many diseases. Any alteration in sulphur's biochemistry could become a precursor of serious pathological conditions. One of such condition is prostate cancer, the most frequently diagnosed malignancy in the western world and the second leading cause of cancer related death in men. The purpose of presented studies was to examine what changes occur in the nearest chemical environment of sulphur in prostate cancer cell lines in comparison to healthy cells. The Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy was used, followed by theoretical calculations. The results of preliminary analysis is presented

    First approach to studies of sulphur electron DOS in prostate cancer cell lines and tissues studied by XANES

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    Abstract Urological cancers comprise approximately one-third of all cancers diagnosed in men worldwide and out of these, prostate cancer is the most common one ( WHO World Cancer Report, 2008 ). Several risk factors such as age, hormone levels, environmental conditions and family history are suspected to play a role in the onset of this disease of otherwise obscure aetiology. It is therefore the medical need that drives multidisciplinary research in this field, carried out by means of various experimental and theoretical techniques. Out of many relevant factors, it is believed that sulphur can take an important part in cancer transformations. We have investigated the prostate cancer cell lines and tissues, along with selected organic and inorganic compounds used as references, by the X-ray absorption fine structure spectroscopy near the sulphur edge energy region. Particularly, the comparison of the experimental results collected during XANES measurements and theoretical calculations of electron density of states with use of the FEFF8 code and LAPW (linearised augmented plane-wave) method has been performed and in this work the first results of our studies are presented

    Chemical composition of atherosclerotic plaques of apoE/LDLR-double knockout mice by synchrotron radiation FTIR microspectroscopy

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    Atherosclerosis is a multietiological inflammatory disease of large and medium-sized arteries of increasing incidence in westernized countries. The aim of this study was to identify the biochemical changes during the progression of atherosclerosis by synchrotron radiation Fourier transform infrared microspectroscopy in atheromas of apoE/LDLR//LDLR^{-//-} mice fed egg-rich diet supplemented or not with angiotensin converting enzyme inhibitor perindopril. Synchrotron radiation Fourier transform infrared microspectroscopy technique was used to obtain information at high spatial resolution about the distribution of proteins (C-N, N-H, CO for amide I and amide II bands), lipids (CH2CH_2, CH3CH_3 bands) as well as mineral deposits (calcium carbonates and phosphates). Total contents of lipids and proteins were found to be significantly lower in animals treated with the diet and perindopril. An increase in saturation level of lipids was observed in animals fed with egg-rich diet when compared to the normal diet and perindopril treatment, which did not inhibit this effect. Moreover, a significant change in the secondary structure of proteins (ratio between absorption bands 1634 cm1cm^{-1}/1656 cm1cm^{-1} attributed to β-type and α-type, respectively) was observed in both experimental groups in comparison with the control. Principal component analysis was used to analyse the recorded spectra. It has revealed that higher content of phosphates (wavenumber range 950-1020 cm1cm^{-1}) was observed between egg-rich diet fed animals and the control group

    Preliminary investigations of elemental content, microporosity, and specific surface area of porous rocks using PIXE and X-ray microtomography techniques

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    Determination of physical properties of porous geological materials is of great importance for oil industry. The knowledge of rocks properties is usually obtained from porosity studies such as pore size distribution, specific surface area determination, and hydrodynamic permeability calculations. This study describes determination of elemental composition and measurements of the particular physical properties of geological samples (porous sandstone rocks) by means of the nuclear and X-ray microprobes at the Institute of Nuclear Physics, Polish Academy of Sciences in Kraków, Poland. The special emphasis has been put on the computed microtomography method. Measurements have been carried out in close cooperation with Department of Geophysics, FGGEP AGH in Kraków, Poland. Chemical composition of the Rotliegend sandstone rock samples (few millimeters diameter), extracted from a borehole at 2679.6 m, 2741.4 m and 2742.4 m depth have been investigated using the 2.2 MeV proton beam (proton induced X-ray emission technique). Next, measurements of the porosity and the specific surface area of the pore space have been carried out using the X-ray microtomography technique. Basing on microtomographic data obtained with the high spatial resolution, simulations of the fluid dynamic in the void space of porous media have been carried out. Lattice Boltzmann method in the 3DQ19 geometrical model has been used in order to predict the hydraulic permeability of the media. In order to avoid viscosity-permeability dependence the multiple-relaxation-time model with half-way bounce back boundary conditions has been used. Computing power-consuming processing has been performed with the use of modern grid infrastructure

    Preliminary studies of sediments from the Dobczyce drinking water reservoir

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    The analysis of river and lake sediments indicates that the physical, chemical, biochemical and geochemical processes that influence the fate of toxic compounds and elements in sediments are numerous and complex (for example: sorption - desorption, oxidation - reduction, ion-exchange, biological activity). Due to the above-mentioned general statement, only a long term and complex research programme can lead to satisfactory answers to the questions relating to possible changes of water and environmental quality in the future. The aim of our study consisted in physical and chemical characterisation of sediments in in-depth profiles taken from the Dobczyce reservoir in southern Poland that is a main source of drinking water for the city of Kraków. Due to morphological reasons, 7 layers of sediment samples were distinguished from the ground level to about 90 cm below (total thickness of the sediments in the sampling site). Analysis of grain size distribution and application of x-ray diffraction method, enabled mineralogical description of sediments. The use of proton-induced x-ray emission (PIXE) and atomic absorption spectrometry (AAS) revealed elemental composition of the samples (Al, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn). Concentrations of natural 40K and artificial 137Cs radionuclides were determined by the use of gamma spectrometry. The following facts were established: 1) the oldest (deepest) and newest, recently deposited layers of sediments are similar in their physical and chemical properties. It means that the inflow of contaminants and biogenic compounds to the reservoir has changed little since it was constructed and filled with water; 2) the severe flood in 1997 changed significantly sediment composition and, in fact, led to purification of sediments in the Dobczyce reservoir

    Concentrations of 137Cs^{137}Cs, 40K^{40}K radionuclides and some heavy metals in soil samples of Chochołowska Valley from Tatra National Park

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    This paper presents the results of determination of artificial 137Cs^{137}Cs and natural 40K^{40}K activity concentrations and some heavy metals in soil samples from the region of one of the main valleys of Tatra National Park (Chochołowska). Our investigation concentrated on 137Cs^{137}Cs and heavy metal levels in mountain soil taken from Chochołowska Valley, which revealed great variability in their concentration. The results show considerably small amounts of radionuclides 137Cs^{137}Cs and 40K^{40}K in the soils. Larger amounts of those elements can be found in the organic surface horizons of the soils. The evaluation of the content of those elements must be based on the bulk density analysis of the soil

    Using markers and field evaluation to identify the source of eyespot resistance gene Pch1 in the collection of wheat breeding lines

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    Pch1 gene translocated from Aegilops ventricosa provides effective resistance to eyespot in wheat. To track the Pch1 gene introgression, we investigated 372 genotypes obtained from various breeding programs using endopeptidase EpD1b marker, sequence-tagged-site (STS) marker XustSSR2001-7DL, and the score of infection index (K-index) evaluated after in vivo inoculation test. These genotypes were divided into three groups with 136, 124 and 112 genotypes for the field test lasting three years. In 2011, the mean K-index was 0.81, while 2012 and 2013 the mean K-indexes were 1.60 and 1.46, respectively. Both marker results indicated that 18 genotypes possessed Pch1 gene. Statistical analysis of the level of K-index showed that these 18 genotypes were resistant to eyespot, which verified the proper assignment of wheat genotypes with Pch1 gene based on the marker data. Thus, the endopeptidase and XustSSR2001-7DL are useful for identifying sources of eyespot resistance gene Pch1 in wheat breeding program

    Optimization and evaluation of a non-invasive tool for peste des petits ruminants surveillance and control

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    Peste des petits ruminants (PPR) is a highly contagious and devastating viral disease affecting mainly sheep and goats, but also a large number of wild species within the order Artiodactyla. A better understanding of PPR transmission dynamics in multi-host systems is necessary to efficiently control the disease, in particular where wildlife and livestock co-occur. Notably, the role of wildlife in PPR epidemiology is still not clearly understood. Non-invasive strategies to detect PPR infection without the need for animal handling could greatly facilitate research on PPR epidemiology and management of the disease in atypical hosts and in complex field situations. Here, we describe optimized methods for the direct detection of PPR virus genetic material and antigen in fecal samples. We use these methods to determine the detection window of PPR in fecal samples, and compare the sensitivity of these methods to standard invasive sampling and PPR diagnostic methods using field samples collected at a wildlife-livestock interface in Africa. Our results show that quantitative reverse transcription PCR (RT-QPCR) amplification of PPRV from fecal swabs has good sensitivity in comparison to ocular swabs. Animals infected by PPRV could be identified relatively early on and during the whole course of infection based on fecal samples using RT-QPCR. Partial gene sequences could also be retrieved in some cases, from both fecal and ocular samples, providing important information about virus origin and relatedness to other PPRV strains. Non-invasive strategies for PPRV surveillance could provide important data to fill major gaps in our knowledge of the multi-host PPR epidemiology
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