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Fachtagung zur Umweltbewertung von Düngemittelzusatzstoffen

Änderungen im Düngerecht auf nationaler und europäischer Ebene rücken Düngemittelzusatzstoffe (DMZ) und Biostimulanzien verstärkt in den Fokus von Anwendern*Anwenderinnen, Herstellern und Kontrollinstanzen. Die zunehmende Anzahl an Umweltfunden einzelner Stickstoffinhibitoren in Oberflächengewässern und mögliche Konflikte im regulatorischen Bereich, insbesondere für Biostimulanzien, waren Anlass, das Umweltverhalten und die Regulierung von Nitrifikations- und Ureaseinhibitoren (NI und UI) sowie von Biostimulanzien vertiefend zu thematisieren und zu bewerten. Um die in diesen Bereichen bestehenden Kenntnislücken im Austausch mit relevanten Akteuren zu identifizieren und möglichen Handlungsbedarf sowie erste Lösungsansätze aufzuzeigen, veranstaltete das Umweltbundesamt im September 2021 eine Fachtagung zur Umweltbewertung von Düngemittelzusatzstoffen (Schwerpunkt NI/UI) und Biostimulanzien. Die Fachtagung wurde mit 60 eingeladenen Experten*Expertinnen und weiteren 20 Zuhörern*Zuhörerinnen vom Umweltbundesamt durchgeführt. Ziel der Veranstaltung war es, ein gemeinsames Verständnis zwischen den einzelnen Akteuren*Akteurinnen zu schaffen und einen ersten Austausch über umweltfachliche und regulatorische Fragestellungen zu ermöglichen. Der vorliegende Bericht fasst die Erkenntnisse aus den Vorträgen, Diskussionen und Umfragen zusammen. Zu den Tagungsergebnissen zählen unter anderem: Der noch defizitäre Kenntnisstand und die Notwendigkeit der sicheren Zuordnung der Umwelteinträge von NI und UI zu Düngeanwendungen oder anderen Quellen, die als ein dringendes Handlungsfeld identifiziert wurde. Für die Inhibitoren und für Biostimulanzien wurde zudem Verbesserungsbedarf in der Transparenz des Zulassungsprozesses und der Einsatzszenarien formuliert. Erste konkrete Vorschläge für eine erweiterte, tonnageunabhängige ökotoxikologische Bewertungsgrundlage und für die Ableitung geeigneter Schwellenwerte wurden vorgestellt. Quelle: Forschungsbericht

ECHA klassifiziert den Weichmacher BPA sowie drei weitere Chemikalien als besonders besorgniserregende Stoffe

Am 19. Dezember 2016 klassifizierte der Ausschuss der Mitgliedstaaten der Europäischen Chemikalienagentur den Weichmacher Bisphenol A sowie drei weitere Chemikalien als besonders besorgniserregende Stoffe. Damit fällt Bisphenol A in den Annex XIV des Chemikalienregisters REACH. Außerdem wurden drei weitere besonders besorgniserregende Stoffe klassifiziert: Nonadecafluorodecanoic-Säure (PFDA), eine Gruppe von Hemmstoffen namens 4-Heptylphenol, welche in Reinigungsmitteln und Korrosionsschutzmitteln enthalten ist, sowie 4-tert-Pentylphenol, was als Weichmacher und Beschichtungsmittel fungiert. Ab Januar 2017 werden die Stoffe in die Kandidatenliste von REACH aufgenommen und ihr Gebrauch eingeschränkt.

Dissolved organic compounds in geothermal fluids used for energy production

Abstract

Untersuchung des Wirkungsmechanismus für die Veränderung des Wachstums von Brustkrebszellen unter dem Einfluss von Onkostatika und niederfrequenten Magnetfeldern - Vorhaben 3604S04461

In diesem Projekt sollte der molekulare Mechanismus untersucht werden, der für die Abschwächung der antiproliferativen Wirkung des antiöstrogen wirkenden Krebsmedikaments Tamoxifen und des Zirbeldrüsenhormons Melatonin auf Brustkrebszellen durch niederfrequente elektromagnetische Felder verantwortlich ist. Zur Exposition der Zellen in kontrollierten und sehr homogenen Magnetfeldern wurden eigens neuartige Magnetfeldinkubatoren konstruiert. In den mit 1,2 µT exponierten MCF-7p40 Zellen wurden auf Mikroarrays 20 Gene als mindestens zweifach erhöht exprimiert nachgewiesen, in den MCF-7p181 Zellen 61 Gene. 16 Gene waren in den MCF-7 p40 Zellen schwächer exprimiert, in den p181 Zellen 41 Gene. Von den besonders interessanten Genen konnte durch RT-PCR und Western-Blot die verstärkte Expression der Koaktivatoren, AIB1 und SRC-1, und des Urokinase-Plasminogen-Aktivators und des Plasminogenaktivator-Inhibitors bestätigt werden. Die Korepressoren N-Cor und SMRT und verschiedene Metastase-Suppressorgene waren in den exponierten Zellen schwächer exprimiert. Untersuchungen zur Signaltransduktion zeigten, dass nur die MAP-Kinase Erk1 nach einer Stunde im Magnetfeld stärker aktiviert war, die Stress-aktivierten MAP-Kinasen, junK und p38, wurden durch das Magnetfeld nicht aktiviert oder sogar leicht abgeschwächt. Die Versuche zur Melatoninwirkung im Magnetfeld zeigten, dass sich die Expression der beiden Melatoninrezeptoren, MT1 und RZRa, bei 1,2 µT nur unwesentlich verändert. Bei den Targetgenen des Melatonins wurde die Expression der Tumorsuppressorgene p53 und p21waf im Magnetfeld verringert, während die Abschwächung der Expression von BRCA1 und c-myc durch Melatonin im Magnetfeld geringer ausfiel. // ABSTRACT // In the present project we investigated the molecular mechanism of the decreased antiproliferative effect of the antiestrogenic drug Tamoxifen and the pineal gland hormone Melatonin on breast cancer cells in the presence of low-frequency electromagnetic fields. New unique incubators were developed for the exposure of the cells to controlled, highly homogenous magnetic fields. MCF-7 p40 cells exposed to 1.2 µT expressed 20 genes more than two times stronger than control cells, MCF-7p181 cells 61 genes. 16 genes were expressed weaker in MCF-7p40 cells, 41 genes in MCF-7p181. The increased expression of the particularly interesting coactivators, AIB1 and SRC-1, and of urokinase plasminogen activator and plasminogen-activator inhibitor was confirmed using RT-PCR and Western blot. The corepressors, N-Cor and SMRT, and arious metastasis-suppressor genes were expressed lower in the exposed cells. Investigations of signal transduction revealed only MAP-kinase Erk1 being more strongly activated after one hour exposure to the magnetic field, while stress-activated MAP-kinases, junK and p38, were not activated by the magnetic field or even slightly deactivated. Experiments on Melatonin action in the magnetic field showed that expression of the two Melatonin receptors, MT1 and RZRa, was only marginally altered at 1,2 µT. Of the target genes of Melatonin expression of tumorsuppressors p53 and p21waf was decreased in the magnetic field whereas the decrease in expression of BRCA1 and c-myc by Melatonin was less strong in the magnetic field.

The fate of nitrification and urease inhibitors in simulated bank filtration

The application of nitrification and urease inhibitors (NUI) in conjunction with nitrogen (N) fertilizers improves the efficiency of N fertilizers. However, NUI are frequently found in surface waters through leaching or surface runoff. Bank filtration (BF) is considered as a low-cost water treatment system providing high quality water by efficiently removing large amounts of organic micropollutants from surface water. The fate of NUI in managed aquifer recharge systems such as BF is poorly known. The aim of this work was to investigate sorption and degradation of NUI in simulated BF under near-natural conditions. Besides, the effect of NUI on the microbial biomass of slowly growing microorganisms and the role of microbial biomass on NUI removal was investigated. Duplicate sand columns (length 1.7 m) fed with surface water were spiked with a pulse consisting of four nitrification (1,2,4-triazole, dicyanodiamide, 3,4-dimethylpyrazole and 3-methylpyrazole) and two urease inhibitors (n-butyl-thiophosphoric acid triamide and n-(2-nitrophenyl) phosphoric triamide). The average spiking concentration of each NUI was 5 ÎÌg/L. Experimental and modeled breakthrough curves of NUI indicated no retardation for any of the inhibitors. Therefore, biodegradation was identified as the main elimination pathway for all substances and was highest in zones of high microbial biomass. Removal of 1,2,4-triazole was 50% and n-butyl-thiophosphoric acid triamide proved to be highly degradable and was completely removed after a hydraulic retention time (HRT) of 24 h. 50% of the mass recovery for nitrification inhibitors except for 3,4-dimethylpyrazole was observed at the effluent (4 days HRT). In addition, a mild effect of NUI on microbial biomass was noted. This study highlights that the degradation of NUI in BF depends on HRT and microbial biomass. © 2023 Elsevier

Population genetic structure of Microdochium majus and Microdochium nivale associated with foot rot of cereals in the Czech Republic and adaptation to penthiopyrad

Microdochium nivale and Microdochium majus cause brown foot rot and snow mould in cereals. The aim of the present study was to evaluate the population genetic structure of Microdochium spp. associated with foot rot of wheat in the Czech Republic and the reaction of that population to the succinate dehydrogenase inhibitor (SDHI) fungicide penthiopyrad. Using amplified fragment length polymorphism (AFLP) analysis to examine genetic structure, agar dilution to measure inhibitory effect, and various statistical methods to analyse populations, two genetic populations were found corresponding to the species Microdochium majus and M. nivale and restricted gene flow in populations between years was determined. This study demonstrates for the first time the occurrence of SDHI-insensitive reaction in populations of M. nivale and M. majus. Low sensitivity was identified in both species, but it was observed more frequently in M. majus populations. Quelle: https://link.springer.com

Competition in chromate adsorption onto micro-sized granular ferric hydroxide

Hexavalent chromium is highly toxic and elaborate technology is necessary for ensured removal during drinking water production. The present study aimed at estimating the potential of a micro-sized iron hydroxide (nGFH] adsorbent for chromate removal in competition to ions presents in drinking water. Freundlich and Langmuir models were applied to describe the adsorption behaviour. The results show a high dependency on the pH value with increasing adsorption for decreasing pH values. The adsorption capacity in deionized water (DI) at pH 7 was 5.8mg/g Cr(VI) while it decreased to 1.9mg/g Cr(VI) in Berlin drinking water (DW) at initial concentrations of 1.2mg/L. Desorption experiments showed reversible adsorption indicating ion exchange and outer sphere complexes as main removal mechanisms. Competing ions present in DW were tested for interfering effects on chromate adsorption. Bicarbonate was identified as main inhibitor of chromate adsorption. Sulfate, silicate and phosphate also decreased chromate loadings, while calcium enhanced chromate adsorption. Adsorption kinetics were highly dependent on particle size and adsorbent dose. Adsorption equilibrium was reached after 60ââą ¯min for particles smaller than 63nm, while 240 min were required for particles from 125nm to 300nm. Adsorption kinetics in single solute systems could be modelled using the homogeneous surface diffusion model (HSDM) with a surface diffusion coefficient of 4x10-14m2/s. Competitive adsorption could be modelled using simple equations dependent on time, adsorption capacity and concentrations only. © 2018 Elsevier Ltd. All rights reserved.

Is there synergistic interaction between fungicides inhibiting different enzymes in the ergosterol biosynthesis pathway in toxicity tests with the green alga Raphidocelis subcapitata?

Products used for plant protection or as biocides often contain more than one active substance together with numerous formulation additives. The environmental risk assessment for such commercial mixtures applies as default the concept of concentration addition. There is remaining regulatory concern, however, that underestimation of risks can occur if components in the mixture interact synergistically, i.e., elicit effects greater than those predicted by concentration addition. While cases of true synergism appear to be rare, the combination of substances targeting different steps in the same biosynthesis pathway was pointed out as one potential case of synergistic interaction although mechanistic explanations are lacking. The present study aimed to verify this hypothesis using the green alga Raphidocelis subcapitata as the regulatory standard test organism for which such synergism had been indicated earlier. Algal growth inhibition tests were conducted with mixtures of ergosterol biosynthesis inhibitors (tebuconazole, fenpropidin, and fenpropimorph). The fungicides were first tested individually to derive reliable data for a mixture toxicity prediction. The here determined toxicity estimates for two of the fungicides were considerably lower than the endpoints in the regulatory dossiers, which had been used for earlier mixture toxicity predictions. Experimentally observed toxicity estimates for the mixtures deviated <2.6-fold from the predicted values. Hence, the hypothesis of synergistic interaction between fungicides targeting different enzymes in the ergosterol biosynthesis was clearly not confirmed for the green alga R. subcapitata. Overall, the present study demonstrates the importance of reliable and correct input data for mixture toxicity predictions in order to avoid erroneous conclusions on non-additive (synergistic) interactions. © Springer Science+Business Media, LLC, part of Springer Nature 2018

Sulfur and nitrogen mustards induce characteristic poly(ADP-ribosyl)ation responses in HaCaT keratinocytes with distinctive cellular consequences

Mustard agents are potent DNA alkylating agents with mutagenic, cytotoxic and vesicant properties. They include bi-functional agents, such as sulfur mustard (SM) or nitrogen mustard (mustine, HN2), as well as mono-functional agents, such as "half mustardŁ (CEES). Whereas SM has been used as a chemical warfare agent, several nitrogen mustard derivatives, such as chlorambucil and cyclophosphamide, are being used as established chemotherapeutics. Upon induction of specific forms of genotoxic stimuli, several poly(ADP-ribose) polymerases (PARPs) synthesize the nucleic acid-like biopolymer poly(ADP-ribose) (PAR) by using NAD+ as a substrate. Previously, it was shown that SM triggers cellular poly(ADP-ribosyl) ation (PARylation), but so far this phenomenon is poorly characterized. In view of the protective effects of PARP inhibitors, the latter have been proposed as a treatment option of SM-exposed victims. In an accompanying article (Debiak et al., 2016), we have provided an optimized protocol for the analysis of the CEES-induced PARylation response in HaCaT keratinocytes, which forms an experimental basis to further analyze mustard-induced PARylation and its functional consequences, in general. Thus, in the present study, we performed a comprehensive characterization of the PARylation response in HaCaT cells after treatment with four different mustard agents, i.e., SM, CEES, HN2, and chlorambucil, on a qualitative, quantitative and functional level. In particular, we recorded substance-specific as well as dose- and time-dependent PARylation responses using independent bioanalytical methods based on single-cell immuno-fluorescence microscopy and quantitative isotope dilution mass spectrometry. Furthermore, we analyzed if and how PARylation contributes to mustard-induced toxicity by treating HaCaT cells with CEES, SM, and HN2 in combination with the clinically relevant PARP inhibitor ABT888. As evaluated by a novel immunofluorescence-based protocol for the detection of N7-ETE-guanine DNA adducts, the excision rate of CEES-induced DNA adducts was not affected by PARP inhibition. Furthermore, while CEES induced moderate changes in cellular NAD+ levels, annexin V/PI flow cytometry analysis revealed that these changes did not affect CEES-induced short-term cytotoxicity 24 h after treatment. In contrast, PARP inhibition impaired cell proliferation and clonogenic survival, and potentiated micronuclei formation of HaCaT cells upon CEES treatment. Similarly, PARP inhibition affected clonogenic survival of cells treated with bi-functional mustards such as SM and HN2. In conclusion, we demonstrate that PARylation plays a functional role in mustard-induced cellular stress response with substance-specific differences. Since PARP inhibitors exhibit therapeutic potential to treat SM-related pathologies and to sensitize cancer cells for mustard-based chemotherapy, potential long-term effects of PARP inhibition on genomic stability and carcinogenesis should be carefully considered when pursuing such a strategy.Quelle: http://www.sciencedirect.com

BfN Schriften 239 - Immunogenicity of GM peas. Review of immune effects in mice fed on genetically modified peas and wider impacts for GM risk assessment

This report reviews a scientific study by Prescott et al. (2005) which identified a higher immunogenic potential for a bean-derived alpha amylase inhibitor expressed in GM peas compared to the native bean-derived protein using a mouse model.

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