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Wyszukujesz frazę "87.80.-y" wg kryterium: Temat


Wyświetlanie 1-12 z 12
Tytuł:
Small Angle X-Rays Scattering Studies of Biomolecules
Autorzy:
Funari, S. S.
Powiązania:
https://bibliotekanauki.pl/articles/2030570.pdf
Data publikacji:
2002-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.10.-i
87.80.-y
64.75.+g
Opis:
The building units of biological systems, the biomolecules, cannot easily be organized or even classified into defined categories. They can be as simple as water or complex as tintin, a muscle protein extremely large with several thousand atoms. To understand their function, one must know their characteristics, where they occur and what they do. One approach to reach such an ambitious task is to determine their structure, as single molecules or assembled into aggregates. Small angle X-ray scattering is the most important method for this purpose. We present studies carried out on several systems, and aiming at different questions about them. We start with lipids, the main components of the cell membranes. These membranes form the cell boundaries, the moiety required for the so-called membrane proteins, but also influence significantly several aspects of biological activity. More complex systems like a muscle fibre is also presented, showing that changes in the structure are related to the movement mechanism. It becomes easy to conclude that knowing the structures and the changes occurring in them is an important way to understand the function of biomolecules and therefore their role in the life cycle.
Źródło:
Acta Physica Polonica A; 2002, 101, 5; 647-658
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of Small Variations in Optical Properties of Turbid Inclusions with Respect to Surrounding Turbid Medium
Autorzy:
Bliznakova, I.
Vankov, O.
Dreischuh, T.
Avramov, L.
Stoyanov, D.
Powiązania:
https://bibliotekanauki.pl/articles/1795702.pdf
Data publikacji:
2009-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.15.N-
87.64.-t
87.64.Cc
87.80.-y
87.80.Ek
Opis:
Special optical system for non-invasive determination of small variations in the optical properties of homogeneous turbid inclusions embedded into large turbid medium is proposed and developed experimentally. Results for different choice of the optical parameters of both media are presented. The minimum detectable changes in the inclusion optical properties are estimated to be less than 5% with respect to the surrounding medium. It is shown that the output signals depend not only on the relative magnitude but also on the sign of the difference in optical properties of both media. The results could be used for developing techniques and algorithms for distinguishing of different kinds of abnormal formations.
Źródło:
Acta Physica Polonica A; 2009, 116, 4; 681-683
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes of the Electrode Surface Roughness Induced by High-Voltage Electric Pulses as Revealed by AFM
Autorzy:
Rodaitė-Riševičienė, R.
Saulis, G.
Snitka, V.
Powiązania:
https://bibliotekanauki.pl/articles/1807928.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.80.-y
82.45.Fk
68.37.Ps
Opis:
The changes of the surface topography of stainless-steel and aluminium electrodes occurring due to the action of electric pulses which are utilized for cell electroporation, have been studied by using atomic force microscopy. The surfaces of the polished stainless-steel electrodes were smooth - the average roughness was 13-17 nm and the total roughness 140-180 nm. The total roughness of the aluminium electrodes was about 320 nm. After the treatment of the chambers filled with 154 mM NaCl solution by a series of short (20-40 μs), high-voltage (4 kV) pulses with the total dissolution charge of 0.20-0.26 A s/$cm^{2}$, the roughness of the surface of the electrodes has increased, depending on the total amount of the electric charge that has passed through the unit area of the electrode. Up to a two- and threefold increase of the surface roughness of the stainless-steel and aluminium anodes respectively was observed due to the dissolution of the anode material. Therefore, the use of high-voltage electric pulses leads to the increase of the inhomogeneity of the electric field at the electrode, which facilitates the occurrence of the electric breakdown of the liquid samples and causes non-equal treatment of each cell.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1095-1097
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Challenges in Biology and Medicine with Synchrotron Infrared Light
Autorzy:
Dumas, P.
Miller, L.
Tobin, M.
Powiązania:
https://bibliotekanauki.pl/articles/1808306.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.80.Dj
87.80.-y
87.64.km
87.56.B-
87.19.xj
87.16.-b
87.15.bd
78.30.-j
Opis:
The brightness (or brilliance) of synchrotron radiation was exploited in infrared microspectrosocopy. Among application of this synchrotron-based microanalytical technique, biological and biomedical investigations, at the diffraction-limited spot size, are exhibit of an increasing interest among almost all the existing infrared beamline worldwide. This paper is presenting the main properties of such a source, coupled with an infrared microscope. Several important applications in biomedical field are reported: cancer cells studies and drug effects, human substantia nigra in Parkinson's disease, β-amyloids deposits in Alzheimer's disease.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 446-454
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of the Vibroacoustic Environment Conditions on Functional Stability of Drivers
Autorzy:
Damijan, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1537357.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.40.-a
43.80.-n
43.80.-p
87.50.Y-
Opis:
Despite new technological solutions and attempts to improve the working conditions during the operation of vehicles, city bus drivers are still exposed to negative impacts of noise and vibrations. This research project was undertaken in response to the lack of holistic analyses of the environmental factors that might impact on the city bus drivers at work. No extensive major research was done to investigate the influence of the conditions at work on functional stability of bus drivers and basic physiological parameters of the human body (systolic and diastolic pressure, pulse rate, temperature in the ear channel, loading of postural muscles, blood circulation determined with the use of a thermovision camera, fatty tissue content, body mass and physical condition (squeezing and pressing exercises). the main purpose of this research program was to show the impacts that the conditions at work might have on bus drivers or to demonstrate that these impacts do no exist.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 23-26
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Resonance Imaging at Low Magnetic Field Using Hyperpolarized $\text{}^{3}$He Gas
Autorzy:
Suchanek, M.
Cieślar, K.
Pałasz, T.
Suchanek, K.
Dohnalik, T.
Olejniczak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2042109.pdf
Data publikacji:
2005-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
32.80.Bx
67.65.+z
75.50.-y
87.61.-c
Opis:
A low magnetic field magnetic resonance imaging system for small animal lung imaging using hyperpolarized $\text{}^{3}$He gas is presented. The hyperpolarized $\text{}^{3}$He gas at 1 mbar pressure and 30% polarization is obtained by the metastability exchange optical pumping technique. The magnetic resonance imaging unit is based on a permanent magnet of open geometry, built from a new generation Nd-B-Fe magnetic material. It produces the magnetic field of 88 mT with homogeneity better than 50 ppm in the 10 cm diameter sphere, after application of passive shimming. The magnetic field gradients of 30 mT/m are generated by a set of biplanar, actively shielded gradient coils. The first $\text{}^{1}$H images of various biological objects, as well as $\text{}^{3}$He images of the rat lung in vivo obtained in the described system are shown. In terms of sensitivity and resolution, the technique is superior to conventional $\text{}^{1}$H magnetic resonance imaging, and offers great possibilities in early diagnosis of lung diseases.
Źródło:
Acta Physica Polonica A; 2005, 107, 3; 491-506
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetocaloric Properties of Fe₇₅Mo₈Cu₁B₁₆ and Fe₈₁Mo₈Cu₁B₁₀ Metallic Glasses
Autorzy:
Hasiak, M.
Miglierini, M.
Kaleta, J.
Bujdoš, M.
Powiązania:
https://bibliotekanauki.pl/articles/1387599.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
71.23.Cq
76.80.+y
87.64.Pj
Opis:
Microstructure and thermomagnetic properties for the Fe₇₅Mo₈Cu₁B₁₆ and Fe₈₁Mo₈Cu₁B₁₀ metallic glasses in the as-quenched state and after heat treatment at 643 K and 723 K are studied. The inverse change of the Curie point was observed for Fe₇₅Mo₈Cu₁B₁₆ metallic glass after annealing below the onset of crystallization. It is attributed to structural relaxation of the amorphous phase. The maximum of magnetic entropy change calculated for magnetic field of 1.0 T occurs for the Fe₇₅Mo₈Cu₁B₁₆ alloy annealed at 643 K at temperature close to the Curie point and equals 0.74 J kg¯¹ K¯¹.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 608-610
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mössbauer and SQUID Characterization of Iron in Human Tissue: Case of Globus Pallidus
Autorzy:
Miglierini, M.
Boča, R.
Kopáni, M.
Lančok, A.
Powiązania:
https://bibliotekanauki.pl/articles/1382185.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.80.+y
31.30.Gs
75.75.-c
87.85.jc
Opis:
Lyophilized samples of human brain tissue from the region of Globus Pallidus were investigated in powder form by $\text{}^{57}Fe$ Mössbauer spectroscopy and SQUID magnetometry. The obtained hyperfine parameters including isomer shift and quadrupole splitting exhibit a ferritin-like behaviour with high-spin Fe(III) sites. Three types of features were derived from temperature development of magnetic susceptibility: dominating diamagnetism, dominating paramagnetism, and intermediate states. The magnetic characteristics of the samples do not correlate with age of the donors.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 240-241
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Methods of the Cells Separation in Human Blood
Autorzy:
Włoch, A.
Czyż, H.
Jasiński, T.
Powiązania:
https://bibliotekanauki.pl/articles/1402588.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
47.35.Rs
62.60.+v
83.80.Hj
87.50.Y-
Opis:
This work deals with the problem of ultrasound in the context of biomedical and clinical applications. Ultrasonic waves can be used for the separation of cells in human blood. Under the influence of ultrasonic waves cells included in the liquid experience a certain characteristic displacement was referred to as drift. Presented work suggests that only radiation pressure should be taken into account as a mechanism of drifting in this situation. It has been demonstrated that the growth of cells concentration around the points of stable equilibrium is exponential. The time constant of this growth was estimated and the formulae which determine the time needed to obtain the assumed concentration increase have been derived. The theoretical studies of acoustic agglomeration of particles in the liquid have become a new focus in the ultrasonic research.
Źródło:
Acta Physica Polonica A; 2015, 128, 2; 234-236
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Structure and Heat Generation in the Co-Precipitated Magnetite Nanoparticles
Autorzy:
Pawlik, P.
Pruba, M.
Pawlik, K.
Kotynia, K.
Powiązania:
https://bibliotekanauki.pl/articles/1030238.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
78.67.Bf
78.70.Ck
76.80.+y
87.50.S-
Opis:
In the present studies the phase structure and magnetic ordering of magnetite nanoparticles were investigated. The powder samples were obtained by co-precipitation from Fe(III) and Fe(II) salts. SiO₂ coating was performed using the modified Stöber process. X-ray diffraction studies revealed presence of the only one Fe₃O₄ crystalline phase both for the non-coated and SiO₂-coated samples. The Mössbauer studies have shown differences in shapes of measured spectral lines for Fe₃O₄ particles subjected to the Stöber process and non-coated particles. The heating efficiency was measured for glycerol dispersed nanoparticles. The analysis have shown changes in specific loss power depending on the concentration of the nanoparticles and amplitude of alternating magnetic field.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1217-1221
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EPR Study of Gamma Irradiated Cholestanone Single Crystal
Autorzy:
Caliskan, B.
Powiązania:
https://bibliotekanauki.pl/articles/1206732.pdf
Data publikacji:
2014-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.64.kh
87.80.Lg
61.72.Hh
33.35.+r
76.30.Rn
32.10.Fn
33.15.Pw
71.18.+y
76.30.-v
61.82.Pv
61.72.-y
Opis:
Cholestanone ($C_{27}H_{46}O$) single crystals were irradiated with ⁶⁰Co-γ rays at room temperature. The spectra were recorded for different orientations of the crystal in the magnetic field at 120 K using the EPR technique. Radiation damage center was attributed to $CHCH_2CH_2$ radical. The principal values of the hyperfine coupling tensor of the unpaired electron with the protons and the principal values of the g tensor were determined. The results were found to be in good agreement with the existing literature.
Źródło:
Acta Physica Polonica A; 2014, 125, 1; 135-138
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ion and Electron Beam Induced Luminescence οf Rare Earth Doped YAG Crystals
Autorzy:
Gawlik, G.
Sarnecki, J.
Jóźwik, I.
Jagielski, J.
Pawłowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1504113.pdf
Data publikacji:
2011-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.60.Hk
52.59.Bi
79.20.Rf
61.80.Lj
41.75.Ak
41.75.Cn
61.72.S-
61.72.-y
29.40.-n
77.84.Bw
79.60.Ht
87.53.Bn
78.55.-m
78.60.-b
77.55.Px
77.55.-g
25.40.Lw
Opis:
The aim of this work was the evaluation of ion-beam induced luminescence for the characterization of luminescent oxide materials containing rare earth elements. The yttrium aluminium garnet epilayers doped with Nd, Pr, Ho, and Tm atoms were used. The ion-beam induced luminescence spectra were excited using 100 keV $H_2^{+}$ ion beam and were recorded in the wavelengths ranging from 300 nm up to 1000 nm. The separate parts of the surface of the same samples were used for ion-beam induced luminescence and cathodoluminescence experiments. Cathodoluminescence spectra have been recorded in the range from 370 nm up to 850 nm at 20 keV e-beam in scanning electron microscope equipped with a grating spectrometer coupled with a photomultiplier. The observed narrow ion-beam induced luminescence lines can be ascribed to the well known radiative transitions in the rare-earth ions in the YAG crystals. The cathodoluminescence spectra reveal essentially the same emission lines as ion-beam induced luminescence. The decrease of the ion-beam induced luminescence lines intensity has been observed under the increasing ion fluences. The ion-beam induced luminescence may be used for characterization of transparent luminescent materials as an alternative method for cathodoluminescence and can be especially useful for observation of ion-beam damage formation in crystals.
Źródło:
Acta Physica Polonica A; 2011, 120, 1; 181-183
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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