Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "87.50.-a" wg kryterium: Wszystkie pola


Tytuł:
Investigating Mechanisms of Radiation-Induced DNA Damage Using Low-Energy Photons
Autorzy:
Folkard, M.
Prise, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/2044651.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.-a
Opis:
Central to any mechanistic biophysical model of radiation damage to DNA is the relationship between the amount and distribution of energy deposited in the DNA helix and the subsequent production of DNA damage. It is now clear from a number of studies that the minimum energy required to produce bond breaks in DNA is significantly lower than might be expected. For example, some biophysical models have assumed that it takes several 10s of eV to produce a double-strand break in DNA. However, using low-energy photons, we have shown that energy depositions as low as 7 eV can induce double-strand break and that this is enhanced when the DNA is hydrated, showing that free radical damage is also important.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 265-271
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Irradiation of Living Cells with Single Ions at the Ion Microprobe SNAKE
Autorzy:
Hauptner, A.
Cremer, T.
Deutsch, M.
Dietzel, S.
Drexler, G. A.
Greubel, C.
Hable, V.
Krücken, R.
Löwe, R.
Strickfaden, H.
Dollinger, G.
Friedl, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/2044655.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
29.27.Eg
61.80.Jh
87.16.Sr
87.50.Gi
Opis:
The irradiation setup at the ion microprobe SNAKE is used to irradiate living cells with single energetic ions. The irradiation accuracy of 0.55μm and respectively 0.40μm allows to irradiate substructures of the cell nucleus. By the choice of ion atomic number and energy the irradiation can be performed with a damage density adjustable over more than three orders of magnitude. Immunofluorescence detection techniques show the distribution of proteins involved in the repair of DNA double-strand breaks. In one of the first experiments the kinetics of appearance of irradiation-induced foci in living HeLa cells was examined. In other experiments a new effect was detected which concerned the interaction between irradiation events performed at different time points within the same cell nucleus.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 273-278
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mössbauer Studies of Cu(II) Ions Interaction with the Non-Heme Iron and Cytochrome b$\text{}_{559}$ in a Chlamydomonas reinhardtii PSI Minus Mutant
Autorzy:
Burda, K.
Kruk, J.
Strzałka, K.
Stanek, J.
Schmid, G. H.
Kruse, O.
Powiązania:
https://bibliotekanauki.pl/articles/2044646.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.39.Jn
82.39.Rt
82.50.Nd
87.15.He
87.64.Pj
89.60.Fe
Opis:
Mössbauer spectroscopy was applied, for the first time, to study the interaction of copper ions with the non-heme iron and the heme iron of cytochrome b$\text{}_{559}$ in photosystem II thylakoids isolated from a Chlamydomonas reinhardtii photosystem I minus mutant. We showed that copper ions oxidize the heme iron and change its low spin state into a high spin state. This is probably due to deprotonation of the histidine coordinating the heme. We also found that copper preserves the non-heme iron in a low spin ferrous state, enhancing the covalence of iron bonds as compared to the untreated sample. We suggest that a disruption of hydrogen bonds stabilizing the quinone-iron complex by Cu$\text{}^{2+}$ is the mechanism responsible for a new arrangement of the binding site of the non-heme iron leading to its more "tense" structure. Such a diamagnetic state of the non-heme iron induced by copper results in a magnetic decoupling of iron from the primary quinone acceptor. These results indicate that Cu does not cause removal of the non-heme iron from its binding site. The observed Cu$\text{}^{2+}$ action on the non-heme iron and cytochrome b$\text{}_{559}$ is similar to that previously observed forα-tocopherol quinone.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 237-247
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single Proton Hit Facility at the IFJ PAN in Cracow
Autorzy:
Polak, W.
Lekki, J.
Veselov, O.
Stachura, Z.
Styczeń, J.
Powiązania:
https://bibliotekanauki.pl/articles/2044772.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.Gi
87.50.-a
Opis:
This work presents the final development stage and optimization results of the single proton hit facility in Cracow. The setup parameters: proton beam energy 2 MeV, hit resolution 30μm, intensity ≈1000 proton/s, proton registration efficiency 100%, blanking efficiency 99.8%. On-line observation allows targeting cells inside a Petri dish mounted at a 3D precise moving stage. To target a particular cell a semiautomatic cell visualization and recognition system is used.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 417-420
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The GSI Heavy Ion Microbeam: A Tool for the Investigation of Cellular Response to High LET Radiations
Autorzy:
Barberet, Ph.
Heiss, M.
Du, G.
Fischer, B. E.
Taucher-Scholz, G.
Powiązania:
https://bibliotekanauki.pl/articles/2044671.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
41.75.Ak
87.50.-a
Opis:
Since the mid 1990's, an increasing number of charged particle microbeams have been designed to deliver a preset number of ions to individual living cells with the micron resolution. These tools provide a powerful technique to investigate the cellular response to low doses of radiations. During the last years, the single ion hit facility in operation on the GSI microbeam since 1987 has been upgraded for the irradiation of individual living cells in vitro. This setup presents two main peculiarities compared to the microbeams used up to now for cell irradiation. First, the beam's micrometric size is obtained by magnetic focusing and not by a simple collimation. This allows obtaining a smaller beam spot, a better defined linear energy transfer, and a high irradiation throughput. Then, the GSI microbeam is able to focus ions from carbon to uranium with energies between 1.4 MeV/u to 11.4 MeV/u. The range of accessible linear energy transfer is thus considerably extended compared to light ions microbeam in operation today. The design of the GSI microbeam is described, including the beam control, the online cell localisation, the cell dish designed specifically for microbeam irradiation, and the cell irradiation procedures. Experimental tests performed to check the global aiming accuracy as well as the first cellular irradiations are presented.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 329-334
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding Radiation Damage to Cells Using Microbeams
Autorzy:
Folkard, M.
Prise, K. M.
Shao, C.
Gilchrist, S.
Schettino, G.
Michette, A. G.
Vojnovic, B.
Powiązania:
https://bibliotekanauki.pl/articles/2044649.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
41.75.Ak
87.50.-a
Opis:
Cellular micro-irradiation techniques provide unique experimental opportunities for understanding how ionizing radiation interacts with living cells and tissues. Using microbeams, it is possible to deliver precise doses of radiation to selected individual cells, or sub-cellular targets in vitro. This technique continues to be applied to the investigation of a number of phenomena currently of great interest to the radiobiological community. In particular, it is the study of so-called "non-targeted" effects (where cells are seen to respond indirectly to ionizing radiation) that are benefiting most from the use of microbeam approaches.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 257-264
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Realization of a Phase Noise Measurement Bench Using Cross Correlation and Double Optical Delay Line
Autorzy:
Salzenstein, P.
Cussey, J.
Jouvenceau, X.
Tavernier, H.
Larger, L.
Rubiola, E.
Sauvage, G.
Powiązania:
https://bibliotekanauki.pl/articles/2047892.pdf
Data publikacji:
2007-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
06.30.Ft
43.50.Yw
87.64.M-
87.57.cm
Opis:
In this paper there are presented first results obtained with a phase noise measurement bench operating in X-band, realized in our laboratory, using double optical delay line and cross correlation. Phase noise floor using a microwave sapphire oscillator is better than -160 dB rad$\text{}^{2}$/Hz at 10 kHz from the 10 GHz carrier, using a 2 km optical delay line.
Źródło:
Acta Physica Polonica A; 2007, 112, 5; 1107-1111
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of Encapsulated Magnetite in PLGA Nanospheres
Autorzy:
Koneracká, M.
Závišová, V.
Timko, M.
Kopčanský, P.
Tomašovičová, N.
Csach, K.
Powiązania:
https://bibliotekanauki.pl/articles/1813943.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Rv
75.50.Mm
87.83.+a
Opis:
In this study, the biocompatible magnetic fluid was encapsulated in biodegradable polymer PLGA (poly D, L/lactide-co-glycolide acid) by the nanoprecipitation method. We characterized these spheres in terms of morphology, magnetite content and magnetic properties. The results showed good encapsulation with magnetite content 22wt% and magnetization 3.4 mT. The transmission electron microscopy and scanning electron microscopy images showed that magnetic particles have almost a spherical shape with approximate size 250 nm. Infrared spectroscopy and thermogravimetric analysis measurements were used to confirm incorporation of magnetic particles into the PLGA polymer.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 595-598
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical Comparison between the Pulsed Electric Field and Thermal Decontamination Methods of Hospital Wastewater
Autorzy:
Gusbeth, C.
Frey, W.
Schwartz, T.
Rieder, A.
Powiązania:
https://bibliotekanauki.pl/articles/1807927.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.cj
87.14.ej
92.40.kc
Opis:
Filtered wastewater samples were inoculated with Enterococcus faecium and exposed to different pulsed electric field (PEF) treatment energies at 40, 50 and 60°C. A lethal effect of heat treatment on E. faecium can be observed for T > 56°C and a heating duration of 4 min. A treatment with 60°C, 4 min, provokes a bacterial reduction of 4 log. A combined treatment of inoculated wastewater samples with pulsed electric field and heat (40, 50 and 60°C) reduced the bacterial contamination considerably. At a suspension temperature of 60°C pulsed electric field inactivation resulted in a complete bacterial decontamination (8 log reduction rate). Moreover, it was demonstrated that naturally occurring nuclease activities were not changed by the pulsed electric field treatment. In contrast to a thermal treatment with temperature over 72°C, for 4 min., the nuclease activity was reduced up to 90%. In this case, inactivation is only 4 log. The same inactivation rate can be obtained by a combination of heat treatment (60°C) and pulsed electric field treatment (30 J/ml).
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1092-1094
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Pulsed High-Voltage Stimulation οn Pholiota Nameko Mushroom Yield
Autorzy:
Takaki, K.
Yamazaki, N.
Mukaigawa, S.
Fujiwara, T.
Kofujita, H.
Takahasi, K.
Narimatsu, M.
Nagane, K.
Powiązania:
https://bibliotekanauki.pl/articles/1807916.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.-a
52.90.+z
82.39.Rt
Opis:
A pulsed high voltage was applied to logs for mushroom cultivation to investigate an effect of pulse high voltage on mushroom growth. Inductive energy storage system was utilized to construct a pulsed power generator with compact size. Copper fuse of 0.03 mm diameter was used as an opening switch to interrupt large circuit current in short time. The voltage charged in primary energy storage capacitor was multiplied using secondary energy storage inductor. The output voltage of the pulsed power generator was 120 kV with 100 ns pulse width at 14 kV charging voltage of 0.22 μF primary energy storage capacitor and 15 μH secondary energy storage inductor. This pulsed high voltage was applied to 90 cm length logs inoculated Pholiota nameko fungus. The yield of Pholiota nameko mushrooms was successfully improved with the pulse voltage stimulation. The total weight of the cropped Pholiota nameko after the pulse voltage stimulation was 6.3 kg for fifteen logs and this value was 1.5 times larger than 4.3 kg of total weight without the stimulation. The number of logs with lower than 0.27 kg cropped Pholiota nameko weight which was an average value for control group was only one in fifteen, whereas four logs in control group showed almost zero weight of cropped Pholiota nameko.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1062-1065
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Heating by Tunable Arrays of Nanoparticles in Cancer Therapy
Autorzy:
Zablotskii, V.
Lunov, O.
Gómez-Polo, C.
Powiązania:
https://bibliotekanauki.pl/articles/1810619.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.55.D-
87.55.de
89.20.-a
75.50.Tt
Opis:
Detailed knowledge about the temperature distribution achieved in the target area is essential for the development of magnetic hyperthermia treatments. However, the temperature inhomogeneity was found in all local hyperthermia studies. As a consequence of the impossibility of guaranteeing the temperature and thus the thermal dose distribution, hyperthermia is never applied as a single treatment modality. We suggest a model that enables the calculations and optimization of the spatial-time distribution of the temperature in the target volume (i.e. tumor) caused by magnetically heated elements: (i) arrays of clusters of iron oxides magnetite $(Fe_3O_4)$ magnetic nanoparticles, and (ii) arrays of magnetic needles. In order to find the spatial-time temperature distribution in tumor, the bioheat transfer equation is solved for the two above-mentioned arrays of magnetically heated sources embedded in the tumor. The temporal and spatial temperature distributions were calculated with regard to the effect of blood perfusion in the tumor. It is shown that a matrix of magnetic micro-needles injected in the tumor could provide rather uniform tumor heating with the center-edge temperature difference smaller than 3°C at any times during the magnetic hyperthermia treatments. The temperature profiles can be suitably adjusted by a proper choice of the magnetic nanoparticles arrangement.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 413-417
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Mini-Disk Resonator Integrated into a Compact Optoelectronic Oscillator
Autorzy:
Salzenstein, P.
Tavernier, H.
Volyanskiy, K.
Kim, N.
Larger, L.
Rubiola, E.
Powiązania:
https://bibliotekanauki.pl/articles/1795637.pdf
Data publikacji:
2009-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
06.30.Ft
43.50.Yw
87.64.M-
87.57.cm
Opis:
This work consists in the design, fabrication and characterization of mini-disk $MgF_{2}$ resonators for integration into optoelectronic oscillator and first experimental results of implementation in microwave free spectral range oscillator with taper coupling optoelectronic oscillator.
Źródło:
Acta Physica Polonica A; 2009, 116, 4; 661-663
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Rule for Evolution of Cooperation in Quantum Games
Autorzy:
Sun, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1807768.pdf
Data publikacji:
2009-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.50.Le
03.67.-a
87.23.-n
Opis:
Cooperation is essential to biological organizations and human society. In this paper, the conditions of dilemmas resolving by quantum strategies in the three games, Prisoners' Dilemma, Chicken Game and Stag Hunt, are presented. The rule for the evolution of cooperation in general quantum games, b/c > $coth^{2}γ$, is put forward. The formation of the rule is similar to those of the five rules in the classical game theory summarized by Nowak. b/c is still the benefit-to-cost ratio of the altruistic act, while γ is a measure for the game's entanglement. The rule is the prerequisite for the realization of cooperation in quantum games.
Źródło:
Acta Physica Polonica A; 2009, 116, 2; 135-140
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Upgrade of the Electroporation Device KEA-MOBIL
Autorzy:
Sack, M.
Attmann, F.
Stängle, R.
Wolf, A.
Frey, W.
Müller, G.
Powiązania:
https://bibliotekanauki.pl/articles/1807923.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.cj
Opis:
For the production of synthetic bio-fuel the use of green biomass enables additional resources of raw material supplementary to the commonly used dry material. An electroporation assisted drying process gives the opportunity of a more efficient dewatering than only pressing and subsequent drying. Experiments showed a lower relative humidity of the pressed material after electroporation compared to pressing the raw material only. Moreover, the drying process of the electroporated material was much shorter. This is because the pores formed in the cell membranes foster a better extraction of water during pressing and enhance the diffusion process during the drying process. The paper presents exemplarily the experimental results for green rye. For the electroporation-assisted drying process the electric contact to the plant material has to be established by means of the juice inside the plants only rather than adding additional water. Hence, for experiments in larger scale, the existing electroporation device KEA-MOBIL has been equipped with a new combined electroporation reactor and press. The reactor has a plate electrode system, whose upper electrode additionally serves as a piston to apply mechanical force to extract juice for a good electrical contact between plant material and the electrodes. A two-stage Marx generator serves as a pulse source. To reduce the insulation distance to the walls of the shielding cabin the Marx generator is operated in ground symmetric configuration. The device has been designed for a batch-wise throughput of 50 kg/h. An automatic feeding device enables the alternating use of two test vessels. The device has been tested on-site on a farm with green rye and grass.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1081-1083
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of $Fe_3O_4$ Magnetic Nanoparticles Modified with Dextran and Investigation of Their Interaction with Protein Amyloid Aggregates
Autorzy:
Koneracká, M.
Antošová, A.
Závišová, V.
Lancz, G.
Gažová, Z.
Šipošová, K.
Juríková, A.
Csach, K.
Kováč, J.
Tomašovičová, N.
Fabián, M.
Kopčanský, P.
Powiązania:
https://bibliotekanauki.pl/articles/1535048.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Mm
87.14.em
87.19.xr
Opis:
Functionalised magnetic nanoparticles composed of $Fe_3O_4$ particles stabilised by sodium oleate and subsequently modified with dextran (MFDEX) were prepared by the co-precipitation method. Their morphology and particle size distribution were observed by scanning electron microscopy and photon cross correlation spectroscopy. In order to confirm the modification of magnetite surface with dextran physical techniques, including infrared spectroscopy, thermal analysis, and magnetic measurement, were used. Finally, the effect of MFDEX on amyloid fibrillar aggregates of human insulin and hen egg white lysozyme, typical amyloidogenic proteins, was investigated. In vitro interaction of MFDEX with protein amyloid fibrils resulted into destruction of amyloid aggregates. The anti-amyloid activity makes MFDEX of potential interest as therapeutic agent against amyloid-related diseases.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 983-985
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies