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1
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Fluorescence Spectroscopy in Camptothecins Studies

100%
Kruszewski S., Kruszewska D.
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issue 1
99-102
EN
The application of fluorescence spectroscopy methods to determining the properties of analogues of camptothecin, promising anticancer agents, are described in this paper. The fluorescence anisotropy measurements provide useful information about the binding of camptothecin and its analogues to cell membranes and human serum albumin (HSA) that is important for potential clinical applications of these agents, and permit the selection from many camptothecin analogues those ones exhibiting desirable biomedical properties. Fluorescence anisotropy measurements prove that 3 new camptothecin analogues: 7-tert-butyldimethylsilyl-10-hydroxy-campthothecin, 7-trimethyl-silylethyl-10-hydroxy-camptothecin and 7-trimethyl-silyl-ethyl-10-amino-camptothecin exhibit high affinity of their lactone forms to membranes and low affinity of their carboxylate forms to HSA. Such properties should ensure high stability of these agents in physiological fluids, including blood.
2
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Gold Nanoparticles with Elongated Shapes: Synthesis and Optical Properties

80%
Olejnik M., Agarwal A., Zaleszczyk W., Kotov N., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
346-349
EN
We use a seed-mediated growth to fabricate gold nanorods in water solution. By changing the amount of silver salt we demonstrate the control of aspect ratio of the obtained rods. The microscopic and spectroscopic analyses provide ways to characterize the morphology and the optical properties of the gold nanorods. Nanorods synthesized using this approach feature length of the order of 50-60 nm, which translates into longitudinal plasmon resonances in the near infrared spectrum region.
3
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Optical Spectroscopy Study of the Interaction Between Quercetin and Human Serum Albumin

80%
Wybranowski T., Kruszewski S.
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vol. 125
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issue 4A
A-57-A-60
EN
Optical methods are very useful for the study on behavior of molecules in albumin-containing solutions. The interaction between quercetin (QUE) and human serum albumin (HSA) under physiological conditions was investigated by the methods of UV-Vis absorption and fluorescence spectroscopy. Fluorescence data show that enhancing of quercetin fluorescence in the presence of HSA is the result of formation of the HSA-QUE complex. On the basis of fluorescence data, the binding affinity constant of quercetin to HSA is determined. In this paper we have attempted to perform a kinetic study of the oxidation of quercetin in presence of human serum albumin by absorption spectroscopy. It has been shown that quercetin easily oxidizes at pH 7.4. The addition of HSA to quercetin solution induces changes in the absorption spectrum. In the human serum albumin solution, the time of quercetin oxidation is longer than in the case of quercetin diluted in phosphate buffered saline. Human albumin also contributes to stabilization of quercetin. These results suggest that HSA prevents degradation of quercetin in blood.
4
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X-Ray Fluorescence Techniques in Medical Applications: Reference Values of Elements in Human Serum, Urine and Hair

80%
Majewska U., Banaś D., Braziewicz J., Kubala-Kukuś A., Pajek M., Sychowska I., Wudarczyk-Moćko J., Antczak G., Borkowska B., Góźdź S.
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vol. 125
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issue 4
864-868
EN
The aim of undertaken long-term studies of the elemental composition of human serum, urine, and hair is to define reference values of elements concentration. For this purpose the total reflection X-ray fluorescence method was applied to determination of several elements concentration in human serum, urine and hair (S, K, Ca, Fe, Cu, Zn, Br, P, Cr, and Rb in serum samples; Fe, Cu, Zn, Rb, Cr, Mn, and Sr in urine samples; S, K, Ca, Fe, Cu, Br, Zn, Cl, Ti, Cr, Mn, Ni, and Se in hair samples) in the range of concentration from ppb to several hundred ppm. The method of selection of the control group, the experimental setup and its calibration procedure are described. We also present sample preparation methods and procedure of measurements.
5
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Determination of the Protein-Binding Properties of Camptothecins by Means of Optical Spectroscopy Methods

80%
Ziomkowska B., Cyrankiewicz M., Wybranowski T., Kruszewski S.
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vol. 125
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issue 4A
A-61-A-65
EN
Optical spectroscopy methods are widely used in studies of drugs. The affinity of camptothecins - anticancer agents - to human serum albumin (HSA) was determined in this work. Camptothecins (CPTs) exist in two forms: active lactone and open ring inactive carboxylate. In blood, the hydrolysis process of lactone form occurs which leads to deactivation of CPTs. Research is being done on biophysical properties of synthesized CPT compounds, in particular on binding to albumin. The affinity to plasma proteins is an important determinant of stability of CPTs in blood. The following analogues of CPT were tested in this paper: irinotecan, SN-38, topotecan, and 9-amino camptothecin. Using the method of fluorescence anisotropy measurement, the association constants of the studied compounds to HSA were determined. The authors attempted to determine the deactivation rate of topotecan in HSA solution using Principal Component Analysis and Factor Analysis of absorption spectra recorded during hydrolysis process of lactone form.
6
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X-ray Diffraction and Elemental Analysis of Medical and Environmental Samples

80%
Bielecka K., Kurtek W., Banaś D., Kubala-Kukuś A., Braziewicz J., Majewska U., Pajek M., Wudarczyk-Moćko J., Stabrawa I.
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vol. 125
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issue 4
911-918
EN
The results of the elemental and chemical composition analysis of human medical samples (blood, serum, hair, urine, tooth, kidney stones, gallstones) and environmental samples (slag, cereal, vegetables, flour, pork bones, pork meat, fish) are presented. The analysis were performed by application of the total reflection X-ray fluorescence, wavelength dispersive X-ray fluorescence and X-ray powder diffraction methods. With X-ray fluorescence methods the following elements were identified: O, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Zr, I, Ba, and Pb, whose concentrations were from a few ng/g to tens of percent. For some samples the elemental analysis was extended by X-ray powder diffraction measurements. With this method the chemical composition was determined. In the paper the experimental setups, methodology of samples preparation and methods of carrying out the measurements are described. As an example the X-ray spectra registered for gallstone sample are discussed in detail. Finally, the results of X-ray diffraction and elemental analysis for selected medical and environmental samples are summarized.
7
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Influence of Various Impurities on the Optical Properties of YbF_3-Doped CaF_2 Crystals

80%
Stef M., Pruna A., Pecingina-Garjoaba N., Nicoara I.
Acta Physica Polonica A
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2007
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vol. 112
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issue 5
1007-1012
EN
Calcium fluoride crystals doped with YbF_3 and co-doped with LiF and NaF were grown using the vertical Bridgman method. Several of rare-earth ions (such as Eu, Sm, Ho, Tm, and Yb) can be stabilized in the divalent state in the CaF_2. The change of valence was attained by various methods. The optical absorption spectra reveal the characteristic absorption bands of the Yb^{3+} and Yb^{2+} ions. This means that the developed crystal growth process achieves a good Yb^{3+} to Yb^{2+} conversion in the as-grown crystals. The influence of other impurities, such as Na^+ or Li^+, on the absorption and emission spectrum of YbF_3-doped CaF_2 was studied. The Li^+ and Na^+ ions drastically decrease the absorption coefficient of the Yb^{2+} ions in the UV band and the emission intensity by excitation in 230 nm.
8
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Effect of Endurance Training and Testosterone Treatment on the Fluorescence Spectra of Rat Serum

80%
Drzazga Z., Schisler I., Michnik A., Sadowska-Krępa E., Kłapcińska B., Gibińska J.
Acta Physica Polonica A
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2016
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vol. 129
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issue 1
15-19
EN
The paper presents an investigation into the effects of endurance training and testosterone enanthate (TE) treatment on rat blood serum by fluorescence spectroscopy. Blood serum was collected from adolescent male Wistar rats randomized between the untrained controls and trained animals, either steroid untreated or receiving I.M. injections (8 or 80 mg/kg_{BW}) of testosterone enanthate. Fluorescence measurements were performed for undiluted or 20- and 500-fold diluted serum and analysed separately in the ultraviolet and visible light regions. In both regions the impact of the TE administration was more pronounced than the effect of endurance training. Moreover, in the visible region of spectrum, originated from a number of fluorescent metabolites, the influence of studied factors was more noticeable. The opposite effect of endurance training and administration of TE on serum emission was found for a lower (8 mg/kg_{BW}) dose of testosterone, whereas a high-dose TE (80 mg/kg_{BW}) treatment resulted in a return of fluorescence intensity.
9
Content available remote

Fluorescence Mapping of PCP Light-Harvesting Complexes Coupled to Silver Nanowires

80%
Krajnik B., Piatkowski D., Olejnik M., Czechowski N., Hofmann E., Heiss W., Mackowski S.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
259-262
EN
In this work we demonstrate confocal fluorescence imaging of hybrid nanostructures composed of silver nanowires and peridinin-chlorophyll-protein light-harvesting complexes. The length of silver nanowires, which reaches 10 μm, allows for determination of the nanowire position and consequently direct correlation with the fluorescence image. In this way we probe the influence of plasmon induced electromagnetic field on the fluorescence of light-harvesting complexes. When the nanowires are spaced from the light-harvesting complexes by a 10 nm thick dielectric layer, we observe a fluorescence enhancement, which depends upon the laser excitation wavelength. The measured enhancement values are 2.5 and 1.9 for 405 nm and 485 nm, respectively. Larger enhancement for the 405 nm excitation is attributed to direct creation of plasmon excitations in the silver nanowires.
10
Content available remote

Interactions of Photosystem I with Plasmonic nanostructures

80%
Hussels M., Nieder J.
Acta Physica Polonica A
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2012
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vol. 122
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issue 2
269-274
EN
The plasmonic interaction effects of various nanostructures on the fluorescence properties of photosystem I as found by single-molecule spectroscopy are summarized. The used nanostructures are spherical Au nanoparticles, silver island films as well as hexagonal arrays of nanometer-sized Au- and Ag-triangles (the Fischer patterns). The fluorescence emission of photosystem I is intensified due to coupling with these nanostructures. For single photosystem I complexes, enhancement factors of up to 37 were observed. The average enhancements vary between 2.2 for Au Fischer pattern and 9 for spherical Au nanoparticles. The enhancement of the fluorescence of photosystem I demonstrates in all cases a strong wavelength dependence. This wavelength dependence can be explained by the spatially largely extended multichromophore composition of photosystem I complexes. From the viewpoint of the usability of these nanostructures for spectroscopic signal enhancement, the Fischer patterns are beneficial, due to their very low autoluminescence.
11
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Optical Biopsy Method for Breast Cancer Diagnosis Based on Artificial Neural Network Classification οf Fluorescence Landscape Data

80%
Dramićanin T., Zeković I., Dimitrijević B., Ribar S., Dramićanin M.
Acta Physica Polonica A
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2009
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vol. 116
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issue 4
690-692
EN
Supervised self-organizing map, a type of artificial neural network, is applied for classification of human breast tissue samples utilizing data obtained from fluorescence landscape measurements. Female breast tissue samples were taken soon after the surgical resection, identified and stored at -80°C until fluorescence measurements. From fluorescence landscapes obtained in UV-VIS region spectral features showing statistically significant differences between malignant and normal samples are identified and further quantified to serve as a training input to neural network. Additional set of samples was used as a test group input to trained network in order to evaluate performance of proposed optical biopsy method. Classification sensitivity of 83.9% and specificity of 88.9% are found.
12
Content available remote

Development of Low-Cost Photodynamic Therapy Device

80%
Momchilov N., Bliznakova I., Borisova E., Troyanova P., Avramov L.
Acta Physica Polonica A
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2007
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vol. 112
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issue 5
1125-1130
EN
Photodiagnosis and photodynamic therapy of non-melanoma skin cancers using delta-aminolevulinic acid/protoporphyrin IX (5-ALA/PpIX) give a combined application with broadest dissemination in the current clinical practice. The problems with using of lasers as light sources are the expenses associated with the operation of these types of installations. This is why we test the capability of cheaper sources - light-emitting diodes at 405 nm for fluorescence excitation of PpIX and 635 nm for photodynamic action initiation. A LED matrix is developed in our laboratory using two types of LEDs and a combined photodiagnosis/photodynamic theory device applicable for clinical practice is built. Geometrically matrix is formed in such way that power density at 635 nm is about 40 mW/cm^2, which allow to reach treatment doses for a 15-20 min irradiation depending of the lesion size in the focus of the system. The therapeutic mode of system developed can be used also with some other photosensitizers from the porphyrins derivatives family.
13
Content available remote

Laser- and Light-Induced Autofluorescence Spectroscopy of Human Skin in Dependence on Excitation Wavelengths

80%
Bliznakova I., Borisova E., Avramov L.
Acta Physica Polonica A
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2007
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vol. 112
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issue 5
1131-1136
EN
Human skin contains various types of native fluorophores and absorbers with unique absorption and emission spectra, different quantum efficiency, concentration and spatial distribution within the skin. Autofluorescence spectroscopy is applied as diagnostic tool for cutaneous tumor detection that increases the importance of evaluation of natural existing fluorophores and unification of data for given class of pathologies. In the current study, several excitation sources in the region 337-405 nm are applied, to achieve information about typical autofluorescent properties of normal human skin.
14
Content available remote

PAAm-Kappa Carrageenan Composites: Drying and Swelling with Various Kappa Carrageenan Contents

70%
Akin Evıngür G., Pekcan Ö.
Acta Physica Polonica A
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2012
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vol. 121
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issue 1
169-171
EN
The purpose of this study is to discuss the role of kappa-carrageenan (κ-car) in the drying and swelling of polyacrylamide (PAAm)-κ-car composite. The fluorescence intensity of pyranine increased and decreased as drying and swelling time were increased respectively for all samples. The desorption coefficient, D_{d}, decreased as κ-car contents were increased for a given temperature during drying. However, cooperative diffusion coefficient, D_{s}, increased as κ-car contents were increased during swelling at a given temperature.
15
Content available remote

Construction of Double Cladding Small Dispersion Photonic Crystal Fiber to Guide Ultrashort Pulse at 800~nm

61%
Stawska H., Bereś-Pawlik E.
Acta Physica Polonica A
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2012
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vol. 122
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issue 5
896-899
EN
The methods using femtosecond lasers are very popular in the world recently. They are used for different research methods. We begin to use a multi-photon autofluorescence method for cancer tissue detection. We plan to use this method with special photonic crystal fiber optic sensors. We would like to use to this detection femtosecond oscillator for 800 nm region. However, according to our information there is no fiber which can provide these femtosecond signals at 800 nm region without dispersion and nonlinear effect. Applying typical fiber causes dispersion of guided signals. Therefore we are preparing suitably designed fibers. Double-clad photonic fibers can play a dual role of ultrashort pulse delivery and efficient collection of nonlinear optical signals. In the paper a new design of double cladding small dispersion photonic crystal fiber is proposed. Simulations of both structure and dispersion in proposed fibers are presented.
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