Wyniki wyszukiwania - Biblioteka Nauki

1

Dzialanie toksyczne kwasu mrowkowego

100%

Skrzydlewska E.

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tom 26

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nr 1

57-63

2

Wspolczesne spojrzenie na peroksydacje lipidow

63%

Luczaj W. , Skrzydlewska E.

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2006

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tom 52

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nr 2

173-179

3

Spektrometria mas z indukcyjnie sprzężoną plazmą i analizatorem czasu przelotu jonów (ICP-TOFMS)

63%

Skrzydlewska E. , Balcerzak M.

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tom [Z] 57, 9-10

907--933

EN

This paper presents a powerful analytical technique which uses an inductively coupled plasma (ICP) ionization source and mass spectrometric (MS) detector with a time of flight (TOF) analyzer. The technique has been introduced in 1993 and has attracted rapidly the attention of researchers in the field of atomic spectroscopy as a method that offers substantial improvement of figures of merit of widely used ICP-MS technique with quadrupole filters. A mass spectrum in ICP-TOFMS technique is generated for a packet of ions simultaneously extracted from a continuous ion beam generated in plasma and accelerated to the same kinetic energy (Ek = 0.5 mv2). Setting the ions to the same kinetic energy results in different velocities acquired by the ions of different masses. The separation of the ions of different m/z is accomplished due to different times of their passing a fixed path (field-free region) in the instrument. Extremely low time difference (nanosecond regime) between adjacent masses reflects in quasi-simultaneous detection of all isotopes reaching the detector. The technique offers extremely high speed: spectral frequency 20-30 kHz (i.e. 20000-30000 mass spectra can be accumulated per second), an ability to obtain full elemental analysis for a packet of ions extracted from a continuous ion beam and a significantly better, as compared with quadrupole ICP-MS, precision of the measurements. Analytical performance and applicability of the technique in multi-clemental analysis of various materials have been extensively examined since 1998 when the ICP-TOFMS spectrometers have been commercially available (from LECO, USA („LECO Renaissance") and GBC, Australia („Optimass 8000")). The technique has turned to be particularly suited for detection of fast transient signals generated, e.g. by laser ablation, chromatographic systems, capillary clectrophoresis and FIA. The basic principles, analytical capabilities of the ICP-TOFMS technique and characteristics of the instruments used are discussed in this paper. Analytical applications of the technique are presented.

4

Determination of traces of toxic elements in laminated plastic food packaging materials by inductively coupled plasma time-of-flight mass spectrometry (ICP-TOFMS)

63%

Skrzydlewska E. , Balcerzak M.

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tom Vol. 48, No. 6

909-918

EN

The content of Cr, As, Cd, Sb and Pb has been determined in laminated plastic food-packaging materials of polyethylene (an overprinted low-density polyethylene/Al/polyethylene terephthalate/low-density polyethylene (LDPE/A1/PET/LDPE)) and polypropylene (an overprinted oriented polypropylene/oriented polypropylene (OPP/OPP)) matrices. The samples were digested in the mixture of nitric acid and hydrogen peroxide in the high-pressure microwave mineralizer. Inductively coupled plasma-time of flight-mass spectrometry (ICP-TOFMS) has been used for the detection of the analytes. The obtained detection limits were within the range 0.010 ((123)Sb)-0.117 ((75)As) ng g(-1)'. In LDPE/A1/PET/LDPE matrix one determined chromium (0.33 mg kg(-1), antimony (1.81 mg kg(-1)) and lead (0.53 mg kg(-1)) while only chromium (0.31 mg kg(-1)) and lead (1.06 mg kg(-1)) were detected in OPP/ OPP. The contents of other elements were below the detection limits. Certified reference material: polyethylene BCR-681 served for the accuracy studies.

PL

Oznaczono śladowe ilości chromu, arsenu, kadmu, antymonu i ołowiu w dwóch rodzajach laminatów: z matrycą polietylenową (zadrukowany polietylen o małej gęstości/Al/polite-reftalan etylenu/polietylen o małej gęstości (LDPE/A1/PET/LDPE)) i polipropylenową (zadrukowany orientowany polipropylen/orientowany polipropylen (OPP/OPP)). Próbki laminatów rozkładano w mieszaninie kwasu azotowego i nadtlenku wodoru w wysokociśnieniowym mineralizatorze mikrofalowym. Do detekcji analitów zastosowano spektrometr mas z jonizacją w indukcyjnie sprzężonej plazmie i analizatorem czasu przelotu jonów (ICP-TOFMS). Uzyskano granice detekcji w zakresie 0,010 ((123)Sb)-0,117 ((75)As) ng g(-1). W laminacie LDPE/A1/PET/LDPE oznaczono chrom, antymon i ołów w ilościach odpowiednio: 0,33; 1,81 i 0,53 mg kg(-1). W drugim badanym materiale (OPP/OPP) oznaczono chrom (0,31 mg kg(-1)) i ołów (l ,06 mg kg(-1)). Stężenia pozostałych pierwiastków były poniżej uzyskanych granic detekcji. Analiza certyfikowanego materiału odniesienia: polietylenu BCR-681 posłużyła do oceny dokładności uzyskanych wyników.

5

Amifostine antioxidant effect on serum of rats treated with cyclophosphodamide

63%

Stankiewicz A. , Skrzydlewska E.

Polish Journal of Environmental Studies

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2005

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tom 14

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nr 3

EN

Amifostine is one of the cytoprotective drugs used during anticancer therapy. Amifostine as a thiol compound possesses antioxidant properties and protects only healthy cells against damage, mainly by scavenging reactivity oxygen species, competing with oxygen to prevent oxygen radical interactions with DNA, and promoting cell repair through hydrogen donation to reactive oxygen species. The aim of the present study was to evaluate antioxidative ability of amifostine in blood serum of rats exposed to cyclophosphamide during two weeks after drug administration. We show that amifostine only to a small degree prevents disorganisation of antioxidant systems of blood serum of rats caused by cyclophosphamide action. It is probably connected with low concentrations of amifostine active metabolites in the serum.

6

Participation of green and black tea in maintaining redox balance

51%

Ostrowska J. , Stankiewicz A. , Skrzydlewska E.

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tom 53

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nr Supplement 1

7

Nowoczesne techniki analityczne wykorzystujące plazmę indukcyjnie sprzężoną jako źródło wzbudzenia i jonizacji

51%

Skrzydlewska E. , Balcerzak M. , Pasławski P.

Wiadomości Chemiczne

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2002

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tom [Z] 56, 5-6

493--521

EN

Plasma spectrometric techniques: inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS) are rapidly becoming the most important analytical tools for the determination of trace amounts of elements. High speed, excellent detection limits, wide dynamic range and possibility of accurate multi-element analysis make the techniques particularly suited to the determination of ppb and sub-ppb levels of the analytes in complex matrices. Mass spectrometric methods offer unique capability of rapid isotopic ratios measurements. Plasma techniques have found wide applications in analysis of geological, environmental and clinical samples. They have proved to be very useful in speciation studies due to extremely low sensitivities offered and the ease of on-line combination with separation techniques, in particular with chromatography. A brief review of ICP-AES and ICP-MS techniques is presented in the paper. The possibility and limitations of the techniques as analytical tools are discussed. The most important analytical parameters are collected in Table 1. Detailed characteristics of equipment used: sample introduction systems, analyzers and detectors are given. The discussion of experimental parameters, including the choice of analytical wavelengths (ICP-AES) and isotopes (ICP-MS), is presented. The main physical, matrix, chemical and spectral interferences occurring in analysis of real samples are characterized.

8

Isolation and analysis of phospholipids

51%

Ostrowska J. , Skrzydlewska E. , Figaszewski Z. A.

Chemia Analityczna

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2000

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tom Vol. 45, No. 5

613-629

EN

Different chromatographic methods used for the determination of phospholipids isolated from natural biological membranes have been described. A particular attention is given to the choice of the HPLC technique, and to the separation conditions: stationary phase, composition of mobile phase and detectors.

PL

W artykule dokonano przeglądu literatury na temat izolacji fosfolipidów z błon biologicznych. Szczególną uwagę zwrócono na wykorzystanie do tego celu techniki HPLC, na warunki rozdziału: fazy stacjonarne, skład faz ruchomych oraz detektory.

9

Black tea protection against oxidative modifications of lipids in rats

51%

Luczak W. , Augustyniak A. , Skrzydlewska E.

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nr Supplement 4

10

Effect of vitamin E derivative [U83836E] on membranes of rat liver cells after methanol intoxication

51%

Skrzydlewska E. , Dobrzynska I. , Kasacka I. , Figaszewski Z.

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tom 10

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nr 2

EN

Methanol oxidation in vivo to formaldehyde and next to formate, which takes place mainly in the liver, is accompanied by free radicals generation. The goal of this paper is to desribe the effect of vitamin E derivative (U83836E) on rat liver cell membranes during methanol intoxication (3.0 g/kg body weight). This study has been concerned with measurement of lipid peroxidation and surface charge density of liver cells and activity of lysosomal enzyme - cathepsin B - in cytosol of liver cells and the blood serum. An ultrastructural study of liver cells has also been conducted. It has been proven that methanol administration causes an increase in lipid peroxidation products (by 33%) as well as in surface charge density (by 64%) of the liver cells. This might have resulted from the membrane liver cell damage visible in the electron microscope and in leak of cathepsin B into cytosol (increase in activity by 28%) as well as the leak of cathepsin B from cytosol into the blood (increase in serum activity by 27%). Administration of U83836E to rats intoxicated with methanol partially prevented the above changes. Obtained results suggest that U83836E acts as an effective antioxidant in methanol intoxication.

11

Green tea effect on antioxidant status of erythrocytes and on haematological parameters in rats

45%

Zapora E. , Holub M. , Waszkiewicz E. , Dabrowska M. , Skrzydlewska E.

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nr 1

139-145

EN

The aim of this study was to estimate the influence of ethanol intoxication as well as in vitro effect of ethanol, acetaldehyde, and tBOOH on antioxidant status of erythrocytes and on haematological parameters in rats. It has been shown that ethanol intoxication caused a decrease in SOD, CAT, GSH-Px, and GSSG-R activities and in GSH and vitamin E levels in erythrocytes as well as in RBC count, and HGB and HCT values. These changes were accompanied by an enhanced lipid peroxidation estimated on the basis of MDA level. Green tea administration partially prevented the observed changes. In the in vitro experiment, ethanol and to a higher degree acetaldehyde and tBOOH caused a decrease in the activity of erythrocyte antioxidant enzymes (SOD, CAT, GSH-Px, GSSG-R) and in the concentration of non-enzymatic antioxidants (GSH, vitamins E and C). All the examined compounds enhanced lipid peroxidation process. However, a green tea due to its antioxidant properties partially protected erythrocytes against ethanol, acetaldehyde, and tBOOH action.

12

Antioxidant status and proteolytic-antiproteolytic balance in colorectal cancer

45%

Skrzydlewska E. , Stankiewicz A. , Michalak K. , Sulkowska M. , Zalewski B.

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tom 39

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nr 1

13