154 research outputs found

    The effect of low doses of glyphosate on reactive oxygen species production by human granulocytes

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    Glyphosate is the base of numerous herbicides used widely all over the world. Strong hepato- and nephrotoxicity of high doses of this reagent was reported in laboratory animal studies. In European Union countries the acceptable daily intake for humans is set at 0.5 mg/kg body weight. We investigated the effects of glyphosate on peripheral blood polymorphonuclear cells (PMNs) at relatively low concentrations of the reagent, from 0.01 mg/L to 10 mg/L (from ~0.06 μM to 59 μM). As the biological half-life of this compound in the human body is estimated to be 3 to 10 hours, we decided to incubate blood samples with glyphosate for a period of one hour. Such incubation caused a statistically significant increase of reactive oxygen species production in granulocytes stimulated with N-formylmethionine-leucyl-phenylalanine and Escherichia coli cells. This increase was not associated with the toxic effects of glyphosate or with increased phagocytic activity of granulocytes. The reagent, when applied at specified concentrations, did not induce a respiratory burst in granulocytes or affect the amount of production of reactive oxygen species in blood samples stimulated with 12-myristate phorbol 13-acetate. On the basis of the results obtained, it may be suggested that glyphosate affects signaling pathways leading to NADPH oxidase activation, independent of protein kinase C activation. Thus, it can be concluded that although low doses of glyphosate are not harmful to humans, synergistic effects of this compound with other environmental pollutants may be an important part of pathogenic mechanisms. DOI: http://dx.doi.org/10.5281/zenodo.842857

    Performance Analysis of Dynamic PUCCH Allocation Algorithm in LTE Network

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    The aim of the presented paper was to verify the impact of Dynamic PUCCH Resource Allocation Algorithm of the LTE cellular system on the maximum uplink cell throughput and call setup success rate - CSSR. Paper includes the laboratory testbed description and presents the results of an experiment confirming the improvement of both key performance indicators KPIs. Apart from the presentation of the Dynamic PUCCH Resource allocation algorithm, the paper also includes a description of legacy LTE uplink (PUCCH and PUSCH) channels dimensioning process thus filling the gap of such a tutorial in the available literature

    Performance Analysis of Dynamic PUCCH Allocation Algorithm in LTE Network

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    The aim of the presented paper was to verify the impact of Dynamic PUCCH Resource Allocation Algorithm of the LTE cellular system on the maximum uplink cell throughput and call setup success rate - CSSR. Paper includes the laboratory testbed description and presents the results of an experiment confirming the improvement of both key performance indicators KPIs. Apart from the presentation of the Dynamic PUCCH Resource allocation algorithm, the paper also includes a description of legacy LTE uplink (PUCCH and PUSCH) channels dimensioning process thus filling the gap of such a tutorial in the available literature

    Spektroskopia fluorescencyjna kolagenu w różnych rozpuszczalnikach

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    Introduction. Research was carried out into the influence of microenvironment created by 6 solvents on the spectroscopic characteristics of four types of collagen protein. The solvents were selected on the basis of polarity, pH, the presence of a functional group, as well as their application in fixing biological material for histopathological and spectroscopic examinations. As an amino acid with the highest light-absorbing capacity, tryptophan exhibits the spectral properties of whole protein agglomerates. Protein conformation changes occurring in different environments and changes in functional groups surrounding tryptophan allowed to register protein spectra. The aim of the study was to find out whether changing the collagen microenvironment using six selected solvents allows to differentiate four types of collagen by means of stationary fluorescence spectroscopy. Material and methods. The research material consisted of four types of human collagen: I, II, III, and IV. The classification of collagen types was based on the spatial arrangement of α chains of each collagen type as adopted by Bornstein and Traub. The emission spectra were recorded with the use of a Hitachi F-7000 spectrofluorimeter and analysed with Origin 8.0 Pro software. Results. Preliminary tests allowed to determine the most optimal excitation wavelength of polar (λ = 270 nm) and non-polar (λ = 350 nm) solvents. The observed spectra shapes and maxima at a specific excitation wavelength were characteristic for the corresponding solvent. Differences among the fluorescence spectra of the four types of collagen were not observed. Conclusions and discussion. Stationary fluorescence spectroscopy does not allow to differentiate four collagen types using the selected solvents. A major hindrance of this method consists in its high sensitivity to environment changes which may preclude the optimisation of research and in consequence render the approach inferior to techniques using electrophoretic devices, mass spectrometry, or chromatography.Wstęp. Przeprowadzono badania wpływu mikrośrodowiska wybranych sześciu rozpuszczalników na właściwości spektroskopowe czterech typów białka kolagenowego. Rozpuszczalniki zostały wyselekcjonowane na podstawie polarności, pH, obecności grup funkcyjnych, a także wykorzystania ich do utrwalania materiału biologicznego do badań histopatologicznych, jak również badań spektroskopowych. Tryptofan, jako aminokwas o najsilniejszej zdolności absorbowania światła odwzorowuje spektralne właściwości całych aglomeratów białkowych. Zmiany konformacyjne białka w różnym środowisku oraz zmiany otaczających tryptofan grup funkcyjnych pozwoliły na zarejestrowanie widm białek. Celem badania było sprawdzenie, czy zmiana mikrośrodowiska kolagenu z wykorzystaniem sześciu wybranych rozpuszczalników pozwoli na różnicowanie czterech typów kolagenu metodą stacjonarnej spektroskopii fluorescencyjnej. Materiały i metody. Materiał do badań stanowiły cztery typy kolagenu ludzkiego: I, II, III i IV. Podział typów kolagenu opierał się na przyjętym przez Bordsteina i Trauba ułożeniu przestrzennym łańcuchów α każdego z typów kolagenu. Widma emisji rejestrowane były przy użyciu spektrofluorymetrumetru Hitachi F-7000 i opracowane z wykorzystaniem programu Origin 8.0 Pro. Wyniki. Badania wstępne pozwoliły na wyznaczenie najbardziej optymalnych długości fali wzbudzenia dla rozpuszczalników polarnych (λ = 270 nm) i niepolarnych (λ = 350 nm). Obserwowany kształt oraz maksimum widm przy określonej długości fali wzbudzenia był charakterys-tyczny dla odpowiedniego rozpuszczalnika. Nie zaobserwo-wano różnic w widmach fluorescencji pomiędzy czterema typami kolagenu. Wnioski i dyskusja. Stacjonarna spektroskopia fluorescencyjna nie pozwala na rozróżnienie czterech typów kolagenu z zastosowaniem wybranych rozpuszczalników. Dużym utrudnieniem w pomiarach fluorescencyjnych stanowi jej wysoka czułość na zmiany środowiska, która niestety może powodować uniemożliwienie optymalizacji badań, dlatego ustępuje miejsca metodom z użyciem aparatury elektroforetycznej, spektrometrii mas lub chromatografii

    Fluorescence Spectroscopy of Collagen in Several Solvents

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    Introduction. Research was carried out into the influence of microenvironment created by 6 solvents on the spectroscopic characteristics of four types of collagen protein. The solvents were selected on the basis of polarity, pH, the presence of a functional group, as well as their application in fixing biological material for histopathological and spectroscopic examinations. As an amino acid with the highest light-absorbing capacity, tryptophan exhibits the spectral properties of whole protein agglomerates. Protein conformation changes occurring in different environments and changes in functional groups surrounding tryptophan allowed to register protein spectra. The aim of the study was to find out whether changing the collagen microenvironment using six selected solvents allows to differentiate four types of collagen by means of stationary fluorescence spectroscopy. Material and methods. The research material consisted of four types of human collagen: I, II, III, and IV. The classification of collagen types was based on the spatial arrangement of α chains of each collagen type as adopted by Bornstein and Traub. The emission spectra were recorded with the use of a Hitachi F-7000 spectrofluorimeter and analysed with Origin 8.0 Pro software. Results. Preliminary tests allowed to determine the most optimal excitation wavelength of polar (λ = 270 nm) and non-polar (λ = 350 nm) solvents. The observed spectra shapes and maxima at a specific excitation wavelength were characteristic for the corresponding solvent. Differences among the fluorescence spectra of the four types of collagen were not observed. Conclusions and discussion. Stationary fluorescence spectroscopy does not allow to differentiate four collagen types using the selected solvents. A major hindrance of this method consists in its high sensitivity to environment changes which may preclude the optimisation of research and in consequence render the approach inferior to techniques using electrophoretic devices, mass spectrometry, or chromatography.Wstęp. Przeprowadzono badania wpływu mikrośrodowiska wybranych sześciu rozpuszczalników na właściwości spektroskopowe czterech typów białka kolagenowego. Rozpuszczalniki zostały wyselekcjonowane na podstawie polarności, pH, obecności grup funkcyjnych, a także wykorzystania ich do utrwalania materiału biologicznego do badań histopatologicznych, jak również badań spektroskopowych. Tryptofan, jako aminokwas o najsilniejszej zdolności absorbowania światła odwzorowuje spektralne właściwości całych aglomeratów białkowych. Zmiany konformacyjne białka w różnym środowisku oraz zmiany otaczających tryptofan grup funkcyjnych pozwoliły na zarejestrowanie widm białek. Celem badania było sprawdzenie, czy zmiana mikrośrodowiska kolagenu z wykorzystaniem sześciu wybranych rozpuszczalników pozwoli na różnicowanie czterech typów kolagenu metodą stacjonarnej spektroskopii fluorescencyjnej. Materiały i metody. Materiał do badań stanowiły cztery typy kolagenu ludzkiego: I, II, III i IV. Podział typów kolagenu opierał się na przyjętym przez Bordsteina i Trauba ułożeniu przestrzennym łańcuchów α każdego z typów kolagenu. Widma emisji rejestrowane były przy użyciu spektrofluorymetrumetru Hitachi F-7000 i opracowane z wykorzystaniem programu Origin 8.0 Pro. Wyniki. Badania wstępne pozwoliły na wyznaczenie najbardziej optymalnych długości fali wzbudzenia dla rozpuszczalników polarnych (λ = 270 nm) i niepolarnych (λ = 350 nm). Obserwowany kształt oraz maksimum widm przy określonej długości fali wzbudzenia był charakterys-tyczny dla odpowiedniego rozpuszczalnika. Nie zaobserwo-wano różnic w widmach fluorescencji pomiędzy czterema typami kolagenu. Wnioski i dyskusja. Stacjonarna spektroskopia fluorescencyjna nie pozwala na rozróżnienie czterech typów kolagenu z zastosowaniem wybranych rozpuszczalników. Dużym utrudnieniem w pomiarach fluorescencyjnych stanowi jej wysoka czułość na zmiany środowiska, która niestety może powodować uniemożliwienie optymalizacji badań, dlatego ustępuje miejsca metodom z użyciem aparatury elektroforetycznej, spektrometrii mas lub chromatografii

    Influence of deep-freezing on the autofluorescent properties of human plasma proteins

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    Background. Fluorescence-based techniques are powerful and valuable tools for studying biological materials. Fluorescence spectroscopy is one of these techniques which measures autofluorescence from a sample containing components such as proteins. The aim of this study was to evaluate the influence of deep freezing on spectroscopic properties of human plasma using fluorescence spectroscopy.Patients, materials and methods. The study group consisted of patients admitted to the Department of Cardiology and Internal Medicine at the University Hospital in Bydgoszcz, due to a preliminary diagnosis of acute coronary syndrome. The overall group comprised 27 patients. From each patient, 4 ml of blood was taken to obtainplasma that was used for further examination. In order to measure plasma spectroscopic properties, a Hitachi F-7000 spectrofluorimeter was used. The received results were analysed and evaluated with Origin 9.0 (OriginLab).Results. Spectroscopic analysis of human plasma before and after freezing allowed us to divide plasma samples into three different subgroups, depending on their fluorescent properties. The first subgroup consisted of plasma samples, which showed entirely differently in spectroscopic analysis after one week of deep-freezing. The second subgroup of plasma samples showed partial changes in the measurements of autofluorescence, and in the third subgroup freezing-resistant plasma samples were included.Conclusions. It seems that the process of deep-freezing could affect the autofluorescent properties of human plasma proteins. The explanation of the specific mechanisms responsible for the change of plasma fluorescent properties during the process of deep-freezing requires further elucidation

    HLAPLJIVI SASTOJCI SMJESA ZA POLJSKE KARPATSKE KOZE UPOTREBOM HS-SPM-GC/MS - KEMOMETRIČKE KLASIFIKACIJE NA TEMELJU DOBI

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    In order to identify the volatile compounds in Polish Carpathian goat meat, baked leg muscle samples from two groups aged 12 and 9 months were subjected to a headspace solid phase microextraction gas chromatography/mass spectrometry (HS–SPME–GC/MS). The multivariate statistics was done, which included the Fisher\u27s ratio method for variables pre-selection, and principal component analysis together with linear discriminant analysis. 93 volatile compounds were found, out of which 49 were confirmed on two columns: non-polar ZB-5MSi and polar ZB-Wax, whereas 5 were verified by using of authentic standards. HS-SPME-GC/MS analysis together with chemometrics occurs to be the effective tool for the discrimination of the meat from the Carpathian goats aged 12 and 9 months. The first two principal components accounted for 88.8% of the total variance. These values for the first three principal components were 94.6% and the classification accuracy values for both groups were 100%.Radi utvrđivanja hlapljivih sastojaka u mesu poljske karpatske koze uzorci pečenog mišića noge u dvije skupine u dobi od 9 i 12 mjeseci podvrgnuti su plinskoj kromatografiji/masenoj spektrometriji (HS-SPM-GC/MS) mikroekstrakcije čvrste faze prostora glave. Obavljena je raznovrsna statistika uključujući metodu Fisherovog omjera za predselekciju varijabla i analiza glavnog sastojka zajedno s linearnom diskriminantnom analizom. Pronađena su 93 hlapljiva sastojka od kojih je 49 potvrđeno u dva stupca: nepolarni ZB-5MSi i polarni ZB-Wax, dok ih je 5 potvrđeno primjenom autentičnih standarda. HS-SPME-GC/MS analiza zajedno s kemometrijom čini se da je djelotvorno sredstvo za razlikovanje mesa karpatskih koza u dobi 12 i 9 mjeseci. Prva dva glavna sastojka iznosila su 88,8% ukupnog neslaganja. Te su vrijednosti za prva tri glavna sastojka bile 94,6%, a vrijednosti točnosti klasifikacije za obje skupine bile su 100%

    Riesz transform characterization of Hardy spaces associated with Schr\"odinger operators with compactly supported potentials

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    Let L=-\Delta+V be a Schr\"odinger operator on R^d, d\geq 3. We assume that V is a nonnegative, compactly supported potential that belongs to L^p(R^d), for some p>d/2. Let K_t be the semigroup generated by -L. We say that an L^1(R^d)-function f belongs to the Hardy space H_L^1 associated with L if sup_{t>0} |K_t f| belongs to L^1(R^d). We prove that f\in H_L^1 if and only if R_j f \in L^1(R^d) for j=1,...,d, where R_j= \frac{d}{dx_j} L^{-1/2} are the Riesz transforms associated with L.Comment: 6 page
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