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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ökotoxikologische Charakterisierung von Nonylphenol Isomeren /

Preuß, Thomas G. January 2007 (has links)
Techn. Hochsch., Diss.--Aachen, 2006.
2

The effect of endocrine disruptors on the growth and development of the Pacific oyster, Crassostrea gigas (Thunberg)

Nice, Helen Elizabeth January 2001 (has links)
No description available.
3

Biodegradation and Environmental Fate of Nonylphenol

Bertin, Marcus A. 06 October 2004 (has links)
No description available.
4

Bacterial Degradation of Nonylphenol in the Love River, Kaohsiung

Huang, Wei-chun 21 August 2009 (has links)
Alkylphenol polyethoxylates (APEOs) are commonly present in both industrial and municipal wastewaters. They belong to the nonionic surfactants which have been widely used for years. APEOs themselves are nontoxic to organisms. When released into the environment, the EO chain of APEOs are degraded chemically and biologically. Some of the products, such as nonylphenol and octylphenol, are persistant. According to the partition coefficient constant, the alkylphenols are adsorpted in the sediments and accumulated in the environment. Nonylphenol (NP) is an analog of 17£]-estradiol, a sex hormone. It is one of the environmental hormones which can get into the organisms through the food chain and may interfere with the reproduction function. Previous studies showed the Love River in Kaohsiung was polluted with APEOs considerably. Bacteria capable of using nonylphenol as the sole carbon source were isolated by the enrichment procedures. Some of the bacterial isolates were identified as Serratia marcescens (strain A), Vibrio sp. (strain B) and Aeromonadaceae sp. (strain C) by the 16S rRNA phylogeny. The rates of NP degradation were evaluated by the HPLC-UV. S. marcescens strain A manifested the best degradative. It could degrade almost 25 ppm of NP in 28 days. The degradative capability of Vibrio sp. (strain B), Aeromonadaceae sp. (strain C) and the enriched mix culture were 65%, 25% and 30%, respectively. Additionally, to know the limitation of degrading nonylphenol by strain A, we set the concentration to 100 ppm for the test. Strain A could degrade 72 ppm in this test. Bacterial composition of the enriched consortia was grouped by the DGGE method. The dominants were Ochrobactrum sp. and Alcaligenaceae sp. which may be to applied to environmental bioremediation.
5

Metabolismus und Verhalten definierter Nonylphenolisomere in Belebtschlamm

Naaßner, Markus. Unknown Date (has links) (PDF)
Techn. Hochsch., Diss., 2004--Aachen.
6

Determination of Alkylphenol and Alkylphenol Polyethoxylates in Water and Sediments by Liquid Chromatography Tandem Mass Spectrometry

Cho, Chun-Liang 30 August 2010 (has links)
Alkylphenol polyethoxylates are one of the most importantclasses of nonionic surfactants. They are widely used in the household detergents and dyeing industry. Indeed, alkylphenols have been estimated that they are persistence organic pollutions which are not easily biodegraded by microorganisms and demonstrated as endocrine disruptors. Therefore alkylphenols regard as environmental hormones. The purpose in this research is developing the method which can be used for detection and quantification of alkylphenols and alkylphenol polyethoxylates in waters and sediments. LC-MS/MS was used as the analytical instrument which can analyze alkylphenols combined with long ethoxylate chain with improved sensitivity and selectivity. The extraction is liquid-liquid extraction. The mobile phase consisting of acetonitrile, water and methanol(43/14/43%, v/v/v) with 20mM ammonium acetate added was used for HPLC separation. The recoveries of alkylphenols and alkylphenol polyethoxylates from water and sediments were 83.0~95.1% and 84.8~94.6%. Decision limit(CC£\) and detection capability(CC£]) of water were 0.10~1.65 ng/L and 0.13~2.03 ng/L. CC£\ and CC£] of sediments were 0.05~0.95 ng/g and 0.06~1.18 ng/g.
7

Treatability And Toxicity Of Nonylphenol Compounds In Anaerobic Batch Reactors

Bozkurt, Hande 01 December 2011 (has links) (PDF)
Nonylphenol (NP) and its ethoxylates are used in formulation of pesticides and detergents, production of personal care products and many industrial sectors such as textile, metal plating, plastic, paper and energy. They are also used in the formulation of household cleaning agents. Industrial uses in the production line make up 55% of the total use / whereas industrial and domestic cleaning processes constitute 30 and 15%, respectively. Since they are widely used in industry and households, NP compounds enter the environment mainly by industrial and municipal wastewater treatment plant effluents. NP is considered strongly toxic and has adverse effects even with short term exposures. Moreover, with its similarities to natural hormones, NP and its ethoxylates are considered as endocrine disrupter compounds. In studies conducted with human cells, chicken embryo, trout and mice eostrogen receptors, positive responses were observed. Due to their lipophilic and hydrophobic characteristics they accumulate in cells, tissues and organic materials such as sludge. For these reasons, fate of NP and its v ethoxylates in wastewater treatment plants and in sludge treatment processes gained importance. Nonylphenol polyethoxylates (NPnEO) are degraded in microbial media and lose their ethoxylates to nonylphenol diethoxylate (NP2EO), nonylphenol monoethoxylate (NP1EO) and NP. Moreover, nonyl phenoxycarboxylic acids (NPnEC) can be formed during some of these reactions. Because the first degradation reactions are fast, concerns and studies are focused mainly on NP2EO, NP1EO, NP, NP1EC and NP2EC. Even though these general degradation information is available, studies on sludge are very rare. In this study, treatability and toxicity of NP2EO in anaerobic batch reactors is investigated. First, with the use of Anaerobic Toxicity Assay (ATA) test, toxic doses of NP2EO which was added to the reactor as the parent component, were determined. Moreover, the degradation of these chemicals were studied in larger scale batch anaerobic digesters. The aim of this part was to observe the degradation patterns and products. Throughout the study the fate of NP and its ethoxylates was followed in aqueous and solid phases by the use of Gas Chromatography / Mass Spectrometry system (GC/MS). ATA tests showed that NP2EO was not toxic to anaerobic microorganisms at the doses investigated in this study. It was rather stimulating and caused an increase in methane production in the reactors. On the other hand the spiked NP2EO&rsquo / s at 0.5 and 2.5 mg/L concentration were completely degraded in the larger scale batch reactors. At the same time, an increase in the concentrations of NP and NP1EO was observed which supported the fact that NP2EO was degraded into NP1EO and NP under anaerobic conditions. Abiotic degradation was not observed.
8

Fate Of Nonylphenol Compounds In Aerobic Semi-continuous Reactor

Ahmad, Muneer 01 August 2012 (has links) (PDF)
In the last few decades, numerous studies have been conducted on xenobiotic compounds due to their vast use in industries, households, etc. and consequently high exposure of these compounds. The main focus of this study is nonylphenol compounds such as nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), nonylphenoxy acetic acid (NP1EC) and nonylphenol (NP), which are among the harmful xenobiotic compounds that can cause endocrine disruption, cancer and other health problems and which are used widely in the production of surfactants and personal care products. In this study, laboratory scale aerobic semi continuous reactors containing Waste Activated Sludge (WAS) spiked with NP2EO were operated for a period of 91 days, to inspect the decomposition of NP2EO in solid and liquid phases. The results obtained on the final day of operation (91st day) showed that NP2EO degraded into product compounds among which NP1EC contributed to 90% of molar mass. In general, NP2EO showed a sharp degradation while NP1EC was produced rapidly. NP1EO also showed a steady degradation. However, NP was accumulated in the reactor. During the study, TS, VS, TSS and VSS degradation was also monitored and the percentage removals were found to be between 40-60%. COD removal on the other hand was between 64-66%.
9

The Effect of Capsazepine and Nonylphenol on Calcium Signaling and Viability in MDCK Renal Tubular Cells

Tsai, Jeng-yu 27 January 2011 (has links)
The effect of capsazepine and nonylphenol on cytosolic free Ca2+ concentrations ([Ca2+]i) in MDCK renal tubular cells is unclear. This study explored whether capsazepine and nonylphenol changed basal [Ca2+]i levels in suspended MDCK cells by using fura-2 as a Ca2+-selective fluorescent dye. Capsazepine at concentrations between 10 and 200 microM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partially by 40% after removing extracellular Ca2+. Capsazepine induced Mn2+ quench of fura-2 fluorescence, indirectly implicating Ca2+ entry. Capsazepine-induced Ca2+ influx was not changed by L-type Ca2+ entry inhibitors and protein kinase C modulators [phorbol 12-myristate 13-acetate (PMA) and GF109203X]. In Ca2+-free medium, 100microM capsazepine-induced Ca2+ release was substantially suppressed by pretreatment with thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Pretreatment with capsazepine nearly abolished thapsigargin-induced Ca2+ release. Nonylphenol also increased [Ca2+]i in a concentration- dependent manner like capsazepine does. Similar response in [Ca2+]i rise can be found by inhibition of phospholipase C and using thapsigargin. Different from capasazpine, the [Ca2+]i rise was inhibited by PMA. At concentrations between 5 and 100microM, nonylphenol killed cells in a concentration-dependent manner. Collectively, in MDCK cells, capsazepine induced [Ca2+]i rises by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via non-L-type Ca2+ channels. Nonylphenol induced [Ca2+]i increase in MDCK cells via evoking Ca2+ entry through protein kinase C-regulated Ca2+ channels, and releasing Ca2+ from endoplasmic reticulum and other cellular storage in a phospholipase C-independent manner.
10

Evaluation of the Estrogenic and Osmoregulatory Impacts of Exposure to 4-Nonylphenol Pollution in the Estuarine Arrow Goby, Clevelandia ios

Johnson, Kaitlin Marie 01 June 2016 (has links) (PDF)
Recent evidence indicates that some of California’s coastal estuaries are contaminated with the chemical 4-nonylphenol (4-NP). Tissue burdens of 4-NP detected in the intertidal arrow goby (Clevelandia ios) in California are among the highest recorded worldwide, however, it remains unknown whether these fish are impacted by this 4-NP contamination. 4-NP is an established endocrine disrupting compound with estrogenic properties that can alter reproductive function. Furthermore, evidence that estrogens can modulate iono- and osmo-regulatory function in fishes implies that estuarine fishes exposed to 4-NP may also experience an impaired ability to maintain hydromineral balance. In Chapter 1 of this research, the time course of detectable xenoestrogen biomarker responses including gene transcripts encoding vitellogenins (vtgA and vtgC), choriogenins (chgL and chgHm), and estrogen receptors esr1 and esr2a were examined using quantitative real-time reverse transcription PCR (qRT-PCR) in adult male arrow gobies exposed to either 4-NP or E2. Specifically, adult gobies were treated with 4-NP at 10 μg/L (low 4-NP dose), or 4-NP at 100 μg/L (high 4-NP dose), ethanol vehicle (negative control), or 17β-estradiol (E2) at 50 ng/L (positive control) for 21 days. This 21 day exposure period was following by a 21 day depuration period to assess the time pattern of biomarker recovery. Results from these experiments indicated that 4-NP can induce increases in relative mRNA levels encoding vitellogenins, choriogenins, and estrogen receptor esr1 – but not esr2a – in the liver within 72 hrs, and that these transcriptional changes return to pre-exposure levels within 12 days of the termination of 4-NP or E2 exposure. In sum, these findings validate the use of mRNA levels for several estrogen-responsive genes as accurate biomarkers for short-term 4-NP exposure in the arrow goby. In Chapter 2, I evaluated the effects of 4-NP and E2 exposures on the osmoregulatory ability of C. ios. I exposed adult arrow gobies to 4-NP (10 μg/L or 100 μg/L) or E2 (50 ng/L) for 14 days, and then transferred the fish from a 33 ppt salinity (control) environment to either 20 ppt, or 5 ppt conditions. Whole body water content was then measured, and the relative mRNA levels for the ion channels Na+/K+/2Cl--cotransporter1 (nkcc1) and Na+/H+ exchanger-3 (nhe3), and the aquaporin water channel aquaporin-3 (aqp3) were quantified in the gill epithelium by qRT-PCR. Results showed that fish treated with 4-NP exhibited higher whole body water content, suggesting that 4-NP exposure results in excessive water uptake during hypoosmotic challenge. 4-NP treated gobies also exhibited elevated nkcc1 and reduced nhe3 and aqp3 mRNAs in the gill even prior to transfer of fish from the 33 ppt acclimation salinity. At 6 hrs after salinity transfer, transcripts encoding nkcc1 remained elevated in the gill epithelium of 4-NP treated gobies transferred to 20 ppt or maintained at 33 ppt (salinity control), while nhe3 and aqp3 mRNAs were still less abundant in gills of these fish. These findings point to impaired maintenance of water balance in gobies exposed to 4-NP, with those changes in fluid homeostasis possibly mediated in part by changes in gill ionic regulation. Taken as a entirety, the findings provided by this research reinforces accumulating data showing the potential for 4-NP to disrupt reproductive physiology in vertebrates, and points to the possibility that 4-NP may impair the ability of fish to regulate ion and water balance under changing salinity conditions.

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