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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Testing the role of reactive oxygen and nitrogen species in stomatal signalling

100%
Jalakas P., Brosche M.
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
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2013
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tom 94
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nr 2
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Nitrogen species and macroelements in aerosols over the Southern Baltic Sea

100%
Nadstazik A., Marks R., Schulz M.
Oceanologia
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2000
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tom 42
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nr 4
The annual cycle of atmospheric nitrogen species and macroelements (Na+, K+, Ca2+, Mg2+ and Cl−) over the south-eastern Baltic region was investigated. A one-year record enabled the variability of nitrogen species and macroelements in the aerosol over the coastal station at Hel to be traced. The highest concentrations of sea salt components were recorded in summer, while anthropogenic nitrate concentrations were highest in winter. When the air masses were of mixed marine and continental origin, the nitric acid reacted with coarse sea salt particles to form stable, coarse sodium nitrate. This seems to be a permanent removal pathway for nitrate. Anthropogenic aerosol species like NH+4 or NO− 3 formed by gas-to-particle conversion were generally associated with fine particles (<1 μm). Coarse particles like sodium or chloride resulted from resuspension from seawater.
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Reactive oxygen and nitrogen species as products of polyamines catabolism in dark-induced senesence of barley leaves

84%
Sobieszczuk-Nowicka E., Zmienko A., Pietrowska-Borek M., Malecka A., Figlerowicz M., Legocka J.
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
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2013
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tom 94
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nr 2
4

Determination of nitrogen species [nitrate, nitrite and ammonia ions] in environmental samples by ion chromatography

84%
Michalski R., Kurzyca I.
Polish Journal of Environmental Studies
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2006
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tom 15
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nr 1
The necessity of environmental protection has stimulated development of all kinds of methods allowing determination of different pollutants in different elements of the natural environment, including methods for determining inorganic nitrogen ions. Many of the methods used so far have proven insufficiently sensitive, selective or accurate and recently much attention has been paid to ion chromatography, which seems most promising. This paper reviews applications of ion chromatography for determining nitrate, nitrite and ammonium ions in environmental samples and in food products along with ISO standards and the relevant methods proposed by the US EPA and Dionex. Literature examples describe the application of ion chromatography for determining NO3 ⁻, NO2 ⁻ and NH4 ⁺ ions in water, waste water, air, food products and other complex matrix samples. Critical analysis of the methods based on ion chromatography is presented.
5
Content available remote

Effect of alpha-lipoic acid on LPS-induced oxidative stress in the heart

67%
Goraca A., Piechota A., Huk-Kolega H.
Journal of Physiology and Pharmacology
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2009
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tom 60
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nr 1
61-68
Lipopolysaccharide (LPS) is a gram-negative bacterial endotoxin and a major factor that contributes to multiple organ failure, including heart injury. Myocardial dysfunction in septic shock depends on the presence of proinflammatory cytokines and reactive oxygen/nitrogen species. In this study, the effect of early administration of an antioxidant, -lipoic acid (LA) on lipid peroxidation, hydrogen peroxide (H2O2), sulphydryl groups (-SH groups) and total protein concentration and the glutathione redox system was evaluated in the heart homogenates obtained from LPS-induced endotoxic shock rats (Escherichia coli 026:B6, 30 mg/kg, i.v.). The animals were treated intravenously with saline or LA (60 mg/kg or 100 mg/kg i.v.) 30 min after LPS injection. Five hours after LPS, LA or saline administration, the animals were sacrificed and their hearts were isolated for measurements. Injection of LPS alone resulted in the development of shock and oxidative stress that was indicated by a significant increase in thiobarbituric acid reactive substances (TBARS) and H2O2 concentrations, a decrease in concentration of -SH groups and reduced glutathione, and by decrease in glutathione redox ratio reduced glutathione (GSH)/oxidized glutathione (GSSG) in the heart. Administration of LA after the LPS challenge resulted in an increase in the sulfhydryl group content and a decrease in TBARS and H202 concentrations in the heart as compared with the LPS group. In addition, the treatment of LA after LPS challenge significantly decreased the level of GSSG, increased the level of GSH in heart homogenates resulting in an increase of the GSH/GSSG ratio compared with the LPS group. There was no difference in oxidative stress reduction between 60 mg/kg and 100 mg/kg doses. These results indicate that early administration of LA is highly effective in dampening endotoxin-induced oxidative stress in the heart and in improving the glutathione redox system. This study supports the idea that -LA is a free radical scavenger and a potent antioxidant.
6
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
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Flavonoids and the aging brain

67%
Schmitt-Schillig S., Schaffer S., Weber C. C., Eckert G. P., Muller W. E.
Journal of Physiology and Pharmacology. Supplement
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2005
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tom 56
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nr 1
23-36
Like in all other organs, the functional capacity of the human brain deteriorates over time. Pathological events such as oxidative stress, due to the elevated release of free radicals and reactive oxygen or nitrogen species, the subsequently enhanced oxidative modification of lipids, protein, and nucleic acids, and the modulation of apoptotic signaling pathways contribute to loss of brain function. The identification of neuroprotective food components is one strategy to facilitate healthy brain aging. Flavonoids were shown to activate key enzymes in mitochondrial respiration and to protect neuronal cells by acting as antioxidants, thus breaking the vicious cycle of oxidative stress and tissue damage. Furthermore, recent data indicate a favorable effect of flavonoids on neuro-inflammatory events. Whereas most of these effects have been shown in vitro, limited data in vivo are available, suggesting a rather low penetration of flavonoids into the brain. Nevertheless, several reports support the concept that flavonoid intake inhibits certain biochemical processes of brain aging, and might thus prevent to some extent the decline of cognitive functions with aging as well as the development or the course of neurodegenerative diseases. However, more data are needed to assess the true impact of flavonoids on brain aging.
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