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Wyświetlanie 1-4 z 4
Tytuł:
Applications of the Cracow X-Ray Microprobe in Tomography
Autorzy:
Bielecki, J.
Bożek, S.
Lekki, J.
Stachura, Z.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1809463.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.59.-e
87.57.Q-
Opis:
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.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 537-541
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Changes in Sulphur Oxidation States in Prostate Cancer Cells
Autorzy:
Czapla, J.
Kwiatek, W.
Lekki, J.
Steininger, R.
Göttlicher, J.
Powiązania:
https://bibliotekanauki.pl/articles/1490177.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.64.kd
87.19.xj
Opis:
Prostate cancer cell lines along with selected organic and inorganic compounds used as references were studied with sulphur K-edge X-ray absorption near edge structure spectroscopy. The experiment was performed at the SUL-X beamline of the synchrotron radiation source ANKA, Karlsruhe (Germany). The sulphur was chosen for the studies because it is an essential biological element and out of many relevant factors, it is believed that it can take an important part in cancer transformations. The main goal was to determine which sulphur forms occur in prostate cancer cells and to compare these results with the ones obtained for non-cancerous cells. Therefore oxidation state of this element was analysed with S K-edge X-ray absorption near edge structure spectroscopy. The analysis of K-edge structure was done in order to investigate also the chemical structure of the elements neighbouring the central atom. The preliminary results from sulphur X-ray absorption near edge structure in prostate cancer cell line PC-3 and prostatic epithelial cell line PZ-HPV-7 (which was used as a control) show that there are various oxidation states of sulphur occurring in cells. The set of reference compounds with various sulphur oxidation states was used to establish the relation between the energy of the white line maximum and the oxidation state of sulphur. The equation of linear fit was used to compute the unknown oxidation state. In order to obtain a more detailed information the method of deconvolution of X-ray absorption near edge structure spectra was used. Experimental spectra were fitted with two Gaussian peaks and one arctangent step function. Fitting procedure was performed in Athena code and the deconvolution was used to assign the fraction of each sulphur form. The next step was to compare the results calculated for cancerous and non-cancerous cells. In this work, the first results of these studies are presented.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 497-501
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FTIR Microspectroscopy in Studies of DNA Damage Induced by Proton Microbeam in Single PC-3 Cells
Autorzy:
Lipiec, E.
Kowalska, J.
Lekki, J.
Wiecheć, A.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1490193.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.14.gk
87.64.km
78.30.Jw
87.53.Bn
Opis:
In recent years, the Fourier transformed infrared spectroscopy is often applied in studies of biological materials on cellular level. Undoubted advantage of this method is high sensitivity. In presented research the FTIR microspectroscopy was used to analyse the DNA damage in single PC-3 cells (prostate cancer cell line derived from bone metastases) irradiated by counted number of protons. Focused proton microbeam 2 MeV from the Van de Graaff accelerator at the Institute of Nuclear Physics, Polish Academy of Sciences, was used as an irradiation source. Four groups of single cells were irradiated with 1000, 2000, 4000, and 8000 protons per cell, respectively. Following irradiation cells were fixed in 70% ethanol and then analyzed by IR microspectroscopy. Bond analysis of IR spectra served as a base for result analysis. This research has focused on the detection of changes in DNA backbone spectral range (950-1240 $cm^{-1}$), which could be related to damages such as single and double strand breaks, DNA-DNA, and DNA-protein cross links. Switches and differences in intensity of DNA backbone bands (980-1149 $cm^{-1}$, 1151-1350 $cm^{-1}$ - symmetric and asymmetric $PO^{2-}$ stretching vibrations, as well as in 1110 $cm^{-1}$ - symmetric stretching of P-O-C band) were observed. Experimental spectra of irradiated and control cells were compared with simulated spectra generated by HyperChem software. The multivariate statistical methods of principal component analysis and hierarchical cluster analysis (Ward's method) were also performed and are discussed.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 506-509
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary Investigations of Elemental Content, Microporosity, and Specific Surface Area of Porous Rocks Using PIXE and X-ray Microtomography Techniques
Autorzy:
Bielecki, J.
Bożek, S.
Dutkiewicz, E.
Hajduk, R.
Jarzyna, J.
Lekki, J.
Pieprzyca, T.
Stachura, Z.
Szklarz, Z.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1490118.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.70.Tx
91.65.-n
47.56.+r
Opis:
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.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 474-479
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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