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Wyszukujesz frazę "Kwiatek, W." wg kryterium: Autor


Tytuł:
Synchrotron Radiation Induced X-Ray Emission - SRIXE
Autorzy:
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1920883.pdf
Data publikacji:
1992-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.En
87.15.Mi
Opis:
The synchrotron radiation induced X-ray emission (SRIXE) technique was found very useful and sensitive for determination of trace elements content and distribution in different types of materials. Due to properties of synchrotron radiation the SRIXE technique became very unique and powerful for trace elements analysis. This paper describes the phenomena related to production of characteristic X-rays and principles of the method. The properties of SRIXE such as minimum detectable limit, spatial resolution, radiation damage, and depth sensitivity are also discussed. Selected applications are given to emphasize the usefulness of the technique.
Źródło:
Acta Physica Polonica A; 1992, 82, 2; 263-271
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomedical Applications of Synchrotron X-Ray Fluorescence
Autorzy:
Kwiatek, W. M.
Powiązania:
https://bibliotekanauki.pl/articles/1931695.pdf
Data publikacji:
1994-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.85.+n
87.59.-e
32.30.Rj
Opis:
Since the exact role of trace elements in living organisms is still not very well known, it is a need of a careful analysis and study on trace element distributions in various biomedical materials. The conventional techniques such as X-ray fluorescence, proton-induced X-ray emission, atomic absorption spectrophotometry do not always give precise determination, especially in microstructures areas. Since synchrotron radiation is very powerful and gives the opportunity to work with micro-beams the synchrotron radiation induced X-ray emission technique has been recently developed. Due to many properties of synchrotron radiation it becomes a very useful tool in science. In this paper a characterization of different apparatus for a trace element analysis as well as several applications are described to show the usefulness of the synchrotron radiation induced X-ray emission.
Źródło:
Acta Physica Polonica A; 1994, 86, 5; 695-703
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FTIR Study of Multifunctional Coatings
Autorzy:
Paluszkiewicz, C.
Długoń, E.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1490258.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.80.Gk
81.15.Pq
68.37.Yz
82.80.Dx
78.30.Er
Opis:
Nanoparticles of hydroxyapatite (HAp) or tricalcium phosphates (TCP) connected with fibrous phase create biomimetic system between the natural fibrous and ceramic materials building a bone. Chemical bonding between the implant and host tissue takes place through the phosphate layer, which is created on the bioactive implant surface when in contact with the body fluids environment. The Fourier transform infrared spectroscopy can yield microstructural information on the segment level complementary to the morphological information acquired from X-ray scattering as well as electron microscopy. The Fourier transform infrared method is applied to study thin films on different substrates. Moreover, the Fourier transform infrared microscope technique allows to obtain surface and cross-section maps in reflection and transmission modes. This leads to visualization of chemical imaging between substrates and films. In this work, the coatings with different addition of nanohydroxyapatite were deposited by electrodeposition method on titanium and Ti6Al4V alloys. Additionally, sublayers, such as $TiO_2$, were used to increase hydroxyapatite coating adhesion. The selection of suspension composition, depositing time and layer heat treatment conditions have the conclusive influence on the films parameters. All these experimental parameters were monitored during the sample preparation procedure. Changes in phase composition of biomaterials were determined by the Fourier transform infrared reflection technique based on focal plane array detection system. It has been found that results obtained by the Fourier transform infrared spectroscopy show the differences between the studied samples as well as that optimum time of HAp deposition was 90 s.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 551-554
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Trace Element Concentration in Diabetic Rats Tissues
Autorzy:
Kowalska, J.
Krośniak, M.
Gryboś, R.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1809705.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
29.30.Ep
78.70.En
87.19.X-
Opis:
Diabetes is one of the most frequent diseases in developing countries and thus there is a significant interest in diabetes related studies. It was found that vanadium compounds have glucose-lowering properties in diabetes and therefore it is very important to estimate the vanadium dose in diabetes treatment. On the other hand, the proper estimation of vanadium concentration is important due to side effects that occur in vanadium supplementation. In this study the influence of V(IV) and V(V) compounds with different ligands on the concentration of K, Ca, Mn, Fe, Cu, and Zn in selected rat's tissues was investigated by means of proton induced X-ray emission technique. As a result of the measurements it was found that the concentration of vanadium depends on the organ. The highest value was determined in spleen while the lowest in pancreas. It was also found that the concentration of other elements depends on the presence of vanadium and its concentration. The most meaningful influence of vanadium presence was on iron concentration in spleen, on copper and zinc in kidney, and on manganese in pancreas.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 556-560
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of magnetite composite on the amount of double strand breaks induced with X-rays
Autorzy:
Wiecheć, A.
Nowicka, K.
Błażewicz, M.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1065182.pdf
Data publikacji:
2016-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.-a
87.53.-j
81.05.Mh
81.05.Ni
81.05.Pj
81.05.Qk
75.50.Bb
Opis:
The aim of this study was to find out if polylactide (PLA) modified with magnetite might affect the amount of DNA double strand breaks induced with X-rays. The human osteosarcoma cells (MG63) were seeded on the polystyrene cell culture dishes (PS), PLA and PLA modified with magnetite substrates. The double strand breaks were analyzed after X-ray irradiation (dose rate 2 Gy/min), in the first day of culturing. The number of double strand breaks increased in the PLA modified with magnetite, for example after 1 Gy of X-rays irradiation, double strand breaks/cell equaled: 24.5 vs. 17.5 and 17.3, for PLA modified with magnetite vs. PLA and PS, p < 0.0003. We conclude that PLA modified with magnetite changed the number of double strand breaks induced with X-rays. However, more research is needed to confirm that such composite might be considered as radiosensitizer in radiotherapy.
Źródło:
Acta Physica Polonica A; 2016, 129, 2; 174-175
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy Dissipation in the AFM Elasticity Measurements
Autorzy:
Klymenko, O.
Wiltowska-Zuber, J.
Lekka, M.
Kwiatek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1809585.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.37.Ps
87.10.Vg
87.15.La
Opis:
Nowadays, it is well established that changes of cell stiffness observed by atomic force microscopy are linked with the cell cytoskeleton. Its structural and functional alterations are underlying major diseases such as cancer, inflammation or neurodegenerative disorders. So far, the use of atomic force microscopy is mostly focused on the determination of the Young modulus using the modified Hertz model. It can quantitatively describe the elastic properties of living cells, however, its value is burdened by the fact that cells are neither isotropic nor homogeneous material. Often, during the atomic force microscopy measurements, the hysteresis between the loading and unloading curves are observed which indicates the dissipation of an energy. In our studies, the index of plasticity was introduced to enumerate such effect during a single loading-unloading cycle. As the results show, such approach delivers an additional parameter describing the mechanical state of cell cytoskeleton. The analysis was performed on test samples where the mechanical properties of the melanoma cells were changed by glutaraldehyde and cytochalasin D treatments. The non-treated cells were compared with fibroblasts.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 548-551
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sulphur XANES Analysis of Cultured Human Prostate Cancer Cells
Autorzy:
Kwiatek, W.
Podgórczyk, M.
Paluszkiewicz, Cz.
Balerna, A.
Kisiel, A.
Powiązania:
https://bibliotekanauki.pl/articles/1812260.pdf
Data publikacji:
2008-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.64.kd
87.19.xj
Opis:
Prostate cancer is one of the most commonly diagnosed cancers in men throughout the world. It is believed that changes to the structure of protein binding sites, altering its metabolism, may play an important role in carcinogenesis. Sulphur, often present in binding sites, can influence such changes through its chemical speciation. Hence there is a need for precise investigation of coordination environment of sulphur. X-ray absorption near edge structure spectroscopy offers such possibility. Cell culture samples offer histologically well defined areas of good homogeneity, suitable for successful and reliable X-ray absorption near edge structure analysis. This paper presents sulphur speciation data collected from three different human prostate cancer cell lines (PC-3, LNCaP and DU-145). Sulphur X-ray absorption near edge structure analysis was performed on K-edge structure. The spectra of cells were compared with those of cancerous tissue and with organic substances as well as inorganic compounds.
Źródło:
Acta Physica Polonica A; 2008, 114, 2; 463-470
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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

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