Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA in Groundwater under Acidic Conditions

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Penghua Yin

2016-06-01

Full Text Available Perfluorooctanoic acid (PFOA is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C–50 °C, persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO4−• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO4−•, followed by a HF elimination process aided by •OH, which produces one-CF2-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn−1F2n−1COOH. The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs.

Rapid fluorometric determination of perfluorooctanoic acid by its quenching effect on the fluorescence of quantum dots

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Liu, Qi; Huang, Aizhen; Wang, Nan, E-mail: nwang@hust.edu.cn; Zheng, Guan; Zhu, Lihua

2015-05-15

Analysis of perfluorooctanoic acid (PFOA) usually requires a combination of high-performance liquid chromatography and mass spectrometry, which is expensive and time-consuming. In the present work, water-soluble CdS quantum dots (QDs) were employed to develop a simple and rapid fluorometric method for the determination of PFOA. Strongly fluorescent CdS QDs were prepared by using 3-mercaptopropionic acid (MPA) as a stabilizer. It was observed that PFOA strongly quenched the fluorescence emission of the MPA-CdS QDs because PFOA promotes the aggregation of MPA-CdS QDs through a fluorine–fluorine affinity interaction. Under optimum conditions, the fluorescence intensity of MPA-CdS QDs was observed to decrease linearly with an increase in the concentration of PFOA from 0.5 to 40 μmol L{sup −1}, with a limit of detection of 0.3 μmol L{sup −1}. This new method was successfully implemented for the analysis of PFOA-spiked textile samples, with recoveries ranging from 95% to 113%. - Highlights: • PFOA significantly quenched the fluorescence emission of quantum dots (QDs). • A rapid and simple fluorescence sensor was proposed for determining PFOA by QDs. • PFOA determination could be completed within approximately 10 min. • The developed method had a working range of 0.5 to 40 μmol L{sup −1} and a detection limit of 0.3 μmol L{sup −1}.

Toxicity of perfluorooctanoic acid towards earthworm and enzymatic activities in soil.

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He, Wenxiang; Megharaj, Mallavarapu; Naidu, Ravi

2016-07-01

Perfluorooctanoic acid (PFOA) is a widespread persistent organic contaminant in the environment that has recently raised much of regulatory and public concern. Therefore, assessment of its ecological risk is a top priority research. Hence, this study investigated the toxicity of PFOA to beneficial microbial processes in the soil such as activities of dehydrogenase, urease and potential nitrification in addition to earthworm survival, weight loss and PFOA bioaccumulation in two contrasting soils. In general, PFOA caused inhibition of all the measured microbial processes in a dose-dependent manner and the inhibition was higher in Williamtown (WT) soil than Edinburgh (EB) soil. Thus, WT soil being sandy in nature with low clay content showed higher PFOA bioavailability and hence showed higher toxicity. There was no mortality in earthworms exposed up to 100 mg PFOA/kilogram soil in both the soils; however, there was a significant weight loss from 25 mg/kg onwards. This study clearly demonstrates that soil contamination of PFOA can lead to adverse effects on soil health.

Modeled Perfluorooctanoic Acid (PFOA) Exposure and Liver Function in a Mid-Ohio Valley Community.

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Darrow, Lyndsey A; Groth, Alyx C; Winquist, Andrea; Shin, Hyeong-Moo; Bartell, Scott M; Steenland, Kyle

2016-08-01

Perfluorooctanoic acid (PFOA or C8) has hepatotoxic effects in animals. Cross-sectional epidemiologic studies suggest PFOA is associated with liver injury biomarkers. We estimated associations between modeled historical PFOA exposures and liver injury biomarkers and medically validated liver disease. Participants completed surveys during 2008-2011 reporting demographic, medical, and residential history information. Self-reported liver disease, including hepatitis, fatty liver, enlarged liver and cirrhosis, was validated with healthcare providers. Alanine aminotransferase (ALT), γ-glutamyltransferase (GGT) and direct bilirubin, markers of liver toxicity, were obtained from blood samples collected in the C8 Health Project (2005-2006). Historically modeled PFOA exposure, estimated using environmental fate and transport models and participant residential histories, was analyzed in relation to liver biomarkers (n = 30,723, including 1,892 workers) and liver disease (n = 32,254, including 3,713 workers). Modeled cumulative serum PFOA was positively associated with ALT levels (p for trend indicating possible liver toxicity. An increase from the first to the fifth quintile of cumulative PFOA exposure was associated with a 6% increase in ALT levels (95% CI: 4, 8%) and a 16% increased odds of having above-normal ALT (95% CI: odds ratio: 1.02, 1.33%). There was no indication of association with either elevated direct bilirubin or GGT; however, PFOA was associated with decreased direct bilirubin. We observed no evidence of an effect of cumulative exposure (with or without a 10-year lag) on all liver disease (n = 647 cases), nor on enlarged liver, fatty liver, and cirrhosis only (n = 427 cases). Results are consistent with previous cross-sectional studies showing association between PFOA and ALT, a marker of hepatocellular damage. We did not observe evidence that PFOA increases the risk of clinically diagnosed liver disease. Darrow LA, Groth AC, Winquist A, Shin HM, Bartell SM

Ferric ion mediated photochemical decomposition of perfluorooctanoic acid (PFOA) by 254 nm UV light

International Nuclear Information System (INIS)

Wang Yuan; Zhang Pengyi; Pan Gang; Chen Hao

2008-01-01

The great enhancement of ferric ion on the photochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) under 254 nm UV light was reported. In the presence of 10 μM ferric ion, 47.3% of initial PFOA (48 μM) was decomposed and the defluorination ratio reached 15.4% within 4 h reaction time. While the degradation and defluorination ratio greatly increased to 80.2% and 47.8%, respectively, when ferric ion concentration increased to 80 μM, and the corresponding half-life was shortened to 103 min. Though the decomposition rate was significantly lowered under nitrogen atmosphere, PFOA was efficiently decomposed too. Other metal ions like Cu 2+ and Zn 2+ also slightly improved the photochemical decomposition of PFOA under irradiation of 254 nm UV light. Besides fluoride ion, other intermediates during PFOA decomposition including formic acid and five shorter-chain perfluorinated carboxylic acids (PFCAs) with C7, C6, C5, C4 and C3, respectively, were identified and quantified by IC or LC/MS. The mixture of PFOA and ferric ion had strong absorption around 280 nm. It is proposed that PFOA coordinates with ferric ion to form a complex, and its excitation by 254 nm UV light leads to the decomposition of PFOA in a stepwise way

Issues raised by the reference doses for perfluorooctane sulfonate and perfluorooctanoic acid.

Science.gov (United States)

Dong, Zhaomin; Bahar, Md Mezbaul; Jit, Joytishna; Kennedy, Bruce; Priestly, Brian; Ng, Jack; Lamb, Dane; Liu, Yanju; Duan, Luchun; Naidu, Ravi

2017-08-01

On 25th May 2016, the U.S. EPA released reference doses (RfDs) for Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA) of 20ng/kg/day, which were much more conservative than previous values. These RfDs rely on the choices of animal point of departure (PoD) and the toxicokinetics (TK) model. At this stage, considering that the human evidence is not strong enough for RfD determination, using animal data may be appropriate but with more uncertainties. In this article, the uncertainties concerning RfDs from the choices of PoD and TK models are addressed. Firstly, the candidate PoDs should include more critical endpoints (such as immunotoxicity), which may lead to lower RfDs. Secondly, the reliability of the adopted three-compartment TK model is compromised: the parameters are not non-biologically plausible; and this TK model was applied to simulate gestation and lactation exposures, while the two exposure scenarios were not actually included in the model structure. Copyright © 2017. Published by Elsevier Ltd.

Perfluorooctanoic acid exposure for 28 days affects glucose homeostasis and induces insulin hypersensitivity in mice

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Yan, Shengmin; Zhang, Hongxia; Zheng, Fei; Sheng, Nan; Guo, Xuejiang; Dai, Jiayin

2015-06-01

Perfluoroalkyl acids (PFAAs) are widely used in many applications due to their unique physical and chemical characteristics. Because of the increasing prevalence of metabolic syndromes, including obesity, dyslipidemia and insulin resistance, concern has arisen about the roles of environmental pollutants in such diseases. Earlier epidemiologic studies showed a potential association between perfluorooctanoic acid (PFOA) and glucose metabolism, but how PFOA influences glucose homeostasis is still unknown. Here, we report on the modulation of the phosphatidylinositol 3-kinase-serine/threonine protein kinase (PI3K-AKT) signaling pathway in the livers of mice after 28 d of exposure to PFOA. Compared with normal mice, PFOA exposure significantly decreased the expression of the phosphatase and tensin homologue (PTEN) protein and affected the PI3K-AKT signaling pathway in the liver. Tolerance tests further indicated that PFOA exposure induced higher insulin sensitivity and glucose tolerance in mice. Biochemical analysis revealed that PFOA exposure reduced hepatic glycogen synthesis, which might be attributed to gluconeogenesis inhibition. The levels of several circulating proteins were altered after PFOA exposure, including proteins potentially related to diabetes and liver disease. Our results suggest that PFOA affected glucose metabolism and induced insulin hypersensitivity in mice.

Removal of emerging perfluorooctanoic acid and perfluorooctane sulfonate contaminants from lake water.

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Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Sarker, Dipok Chandra; Suja, Fatihah

2017-08-01

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the major polyfluoroalkyl substances (PFASs) contaminating global water environment. This study investigated the efficiency of granular activated carbon (GAC), ultrafiltration (UF) and nanofiltration (NF) treatment for removing PFOS and PFOA contaminants from lake water. NF gave greater removal of all contaminant types (in terms of organic matter, PFOS and PFOA) than GAC treatment which in turn was greater than UF treatment. The lower removal by UF was due to larger pore size of the membrane compared to the size of the target contaminants. For all treatment processes, lower pH (4) in the feedwater showed greater rejection of the organics and selected PFASs. This was likely due to increase in the electrostatic repulsion between solute and sorbent. It could be observed that on increasing the concentration of organics in the feed solution, the rejection of PFOA/PFOS decreased which was due to competition between organics and PFOS/PFOA for binding sites on the membrane/activated carbon surface. It was also noted that protein content led to greater influence for lower rejection of the PFOA/PFOS than carbohydrate or DOC content. This study demonstrated the potential use of membrane processes for removing emerging persistent organic pollutant removal from lake water.

Degradation of Perfluorooctanoic Acid and Perfluoroctane Sulfonate by Enzyme Catalyzed Oxidative Humification Reactions

Science.gov (United States)

Huang, Q.

2016-12-01

Poly- and perfluoroalkyl substances (PFASs) are alkyl based chemicals having multiple or all hydrogens replaced by fluorine atoms, and thus exhibit high thermal and chemical stability and other unusual characteristics. PFASs have been widely used in a wide variety of industrial and consumer products, and tend to be environmentally persistent. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are two representative PFASs that have drawn particular attention because of their ubiquitous presence in the environment, resistance to degradation and toxicity to animals. This study examined the decomposition of PFOA and PFOS in enzyme catalyzed oxidative humification reactions (ECOHR), a class of reactions that are ubiquitous in the environment involved in natural organic humification. Reaction rates and influential factors were examined, and high-resolution mass spectrometry was used to identify possible products. Fluorides and partially fluorinated compounds were identified as likely products from PFOA and PFOS degradation, which were possibly formed via a combination of free radical decomposition, rearrangements and coupling processes. The findings suggest that PFOA and PFOS may be transformed during humification, and ECOHR can potentially be used for the remediation of these chemicals.

Efficient photocatalytic degradation of perfluorooctanoic acid by a wide band gap p-block metal oxyhydroxide InOOH

Science.gov (United States)

Xu, Jingjing; Wu, Miaomiao; Yang, Jingwen; Wang, Zhengmei; Chen, Mindong; Teng, Fei

2017-09-01

In this work, we prepared a new wide band gap semiconductor, p-block metal oxyhydroxide InOOH, which exhibits efficient activity for perfluorooctanoic acid (PFOA) degradation under mild conditions and UV light irradiation. The apparent rate constant for PFOA degradation by InOOH is 27.6 times higher than that for P25 titania. Results show that ionized PFOA (C7F15COO-) can be adsorbed much more efficiently on the surface of InOOH than P25. Then, the adsorbed C7F15COO- can be decomposed directly by photo-generated holes to form C7F15COOrad radicals. This process is the key step for the photocalytic degradation of PFOA. Major degradation intermediates, fluoride ions and perfluorinated carboxylic acids (PFCAs) with shorter chain lengths were detected during PFOA degradation. A possible pathway for photocatalytic degradation of PFOA is proposed based on the experimental results. Therefore, this studies indicates a potential new material and method for the efficient treatment of PFCA pollutants under mild conditions.

Toxicogenomic analysis of the hepatic effects of perfluorooctanoic acid on rare minnows (Gobiocypris rarus)

International Nuclear Information System (INIS)

Wei Yanhong; Liu Yang; Wang Jianshe; Tao Yi; Dai Jiayin

2008-01-01

Perfluorooctanoic acid (PFOA) is a ubiquitous environmental contaminant that has been detected in a variety of terrestrial and aquatic organisms. To assess the effects of PFOA in fish and predict its potential mode of action, a toxicogenomic approach was applied to hepatic gene expression profile analysis in male and female rare minnows (Gobiocypris rarus) using a custom cDNA microarray containing 1773 unique genes. Rare minnows were treated with continuous flow-through exposure to PFOA at concentrations of 3, 10, and 30 mg/L for 28 days. Based on the observed histopathological changes, the livers from fish exposed to 10 mg/L PFOA were selected for further hepatic gene expression analysis. While 124 and 171 genes were significantly altered by PFOA in males and females, respectively, of which 43 genes were commonly regulated in both sexes. The affected genes are involved in multiple biological processes, including lipid metabolism and transport, hormone action, immune responses, and mitochondrial functions. PFOA exposure significantly suppressed genes involved in fatty acid biosynthesis and transport but induced genes associated with intracellular trafficking of cholesterol. Alterations in expression of genes associated with mitochondrial fatty acid β-oxidation were only observed in female rare minnows. In addition, PFOA inhibited genes responsible for thyroid hormone biosynthesis and significantly induced estrogen-responsive genes. These findings implicate PFOA in endocrine disruption. This work contributes not only to the elucidation of the potential mode of toxicity of PFOA to aquatic organisms but also to the use of toxicogenomic approaches to address issues in environmental toxicology

The role of hepatocyte nuclear factor 4-alpha in perfluorooctanoic acid- and perfluorooctanesulfonic acid-induced hepatocellular dysfunction

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Beggs, Kevin M., E-mail: kbeggs2@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); McGreal, Steven R., E-mail: smcgreal@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); McCarthy, Alex [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); Gunewardena, Sumedha, E-mail: sgunewardena@kumc.edu [Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Blvd, 2027 HLSIC, Kansas City, KS 66160 (United States); Lampe, Jed N., E-mail: jlampe@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); Lau, Christoper, E-mail: lau.christopher@epa.gov [Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Apte, Udayan, E-mail: uapte@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States)

2016-08-01

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), chemicals present in a multitude of consumer products, are persistent organic pollutants. Both compounds induce hepatotoxic effects in rodents, including steatosis, hepatomegaly and liver cancer. The mechanisms of PFOA- and PFOS-induced hepatic dysfunction are not completely understood. We present evidence that PFOA and PFOS induce their hepatic effects via targeting hepatocyte nuclear factor 4-alpha (HNF4α). Human hepatocytes treated with PFOA and PFOS at a concentration relevant to occupational exposure caused a decrease in HNF4α protein without affecting HNF4α mRNA or causing cell death. RNA sequencing analysis combined with Ingenuity Pathway Analysis of global gene expression changes in human hepatocytes treated with PFOA or PFOS indicated alterations in the expression of genes involved in lipid metabolism and tumorigenesis, several of which are regulated by HNF4α. Further investigation of specific HNF4α target gene expression revealed that PFOA and PFOS could promote cellular dedifferentiation and increase cell proliferation by down regulating positive targets (differentiation genes such as CYP7A1) and inducing negative targets of HNF4α (pro-mitogenic genes such as CCND1). Furthermore, in silico docking simulations indicated that PFOA and PFOS could directly interact with HNF4α in a similar manner to endogenous fatty acids. Collectively, these results highlight HNF4α degradation as novel mechanism of PFOA and PFOS-mediated steatosis and tumorigenesis in human livers. - Highlights: • PFOA and PFOS cause decreased HNF4α protein expression in human hepatocytes. • PFOA and PFOS promote changes associated with lipid metabolism and carcinogenesis. • PFOA and PFOS induced changes in gene expression associated with cellular dedifferentiation. • PFOA and PFOS induce expression of Nanog, a transcription factor involved in stem cell development.

Perfluorooctanoic acid (PFOA) - main concerns and regulatory developments in Europe from an environmental point of view

Energy Technology Data Exchange (ETDEWEB)

Vierke, Lena [Federal Environment Agency, Dessau-Rosslau (Germany); Leuphana University of Lueneburg, Lueneburg (Germany); Staude, Claudia; Biegel-Engler, Annegret; Drost, Wiebke; Schulte, Christoph [Federal Environment Agency, Dessau-Rosslau (Germany)

2012-12-15

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most investigated substances of the group of per- and polyfluorinated chemicals (PFCs). Whereas for PFOS regulatory measures are already in force on international level (inclusion in Stockholm Convention on Persistent Organic Pollutants) such activities are missing for PFOA. The environmental concerns of PFOA, which are summarized in the present study, underline the necessity of regulatory measures on an international level for PFOA. Since it seems more likely to agree on a regulation within the European Union first, a regulatory strategy based on the European chemicals regulation REACH (EC No. 1907/2006), is discussed in the present study. PFOA is persistent in the environment, ubiquitous present in surface waters, and subject to long-range transport. It accumulates in biota, especially in top predators. PFOA is increasingly analyzed in food items, and in drinking water. PFOA's intrinsic properties such as its persistency (P), its potential for bioaccumulation (B) and its toxicity (T) suggest that PFOA is a promising candidate for being identified as a Substance of Very High Concern (SVHC) under REACH. Because of the dispersive occurrence of PFOA in the environment, the presence in imported products, and the use of PFCs, which can degrade to PFOA in various consumer products, a restriction under REACH seems to be the most effective regulatory measure to minimize human and environmental exposure to PFOA in the European Union. Due to its intrinsic properties, PFOA fulfills the REACH PBT-criteria. The next regulatory step will be the identification of PFOA and its ammonium salt (APFO) as SVHC according to REACH and the addition to the REACH Candidate List. As a second step, a restriction proposal will be prepared to include both substances and precursors into REACH Annex XVII. (orig.)

An erythrosin B-based "turn on" fluorescent sensor for detecting perfluorooctane sulfonate and perfluorooctanoic acid in environmental water samples.

Science.gov (United States)

Cheng, Zhen; Du, Lingling; Zhu, Panpan; Chen, Qian; Tan, Kejun

2018-05-04

Because of the serious harm to animals and the environment associated with perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), a rapid, sensitive and low-cost method for detecting PFOS and PFOA is of great importance. In this paper, a novel sensing method has been proposed for the highly sensitive detection of PFOS and PFOA in environmental water samples based on the "turn-on" switch of erythrosine B (EB)-hexadecyltrimethylammonium bromide (CTAB) system. In pH 8.55 Britton-Robinson (BR) buffer, EB can react with CTAB by electrostatic attraction, resulting in a strong fluorescence quenching of EB. With a subsequent addition of the CTAB, a red-shift occurred (11 nm), followed by a significant increase in fluorescence at high surfactant concentrations. It was found that PFOS and PFOA can obviously enhance fluorescence intensity of EB-CTAB system. The enhanced fluorescence intensity is proportional to the concentration of PFOS and PFOA in the range of 0.05-10 μM with detection limit of 12.8 nM and 11.8 nM (3σ), respectively. The presented assay has been successfully applied to sensing PFOS and PFOA in real water samples with RSD ≤ 4.3% and 2.9%, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

Perfluorooctanoic acid and perfluorooctane sulfonate in Michigan and New York waters

Energy Technology Data Exchange (ETDEWEB)

Sinclair, E.; Kannan, K. [Wadsworth Center, Albany, NY (United States); Taniyasu, Sachi; Yamashita, Nobuyoshi [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)

2004-09-15

Perfluorooctane sulfonate (PFOS), a perfluorinated organic contaminant, has become the subject of many recent investigations. PFOS and its precursor compounds have been used in a wide variety of consumer and industrial products. Other related perfluorinated compounds have also been reported to occur in the environment. For example, perfluorohexane sulfonate (PFHxS) is an impurity associated with PFOS. Perfluorooctanoic acid (PFOA) has found widespread use as an emulsifier for polymerization of fluoropolymers. These perfluorinated alkylated substances (PASs) are known to be resistant to degradation. Water analysis of PFOS and PFOA has been carried out with several methods. The most commonly used methods involve solid phase extraction (SPE) followed by HPLC-MS-MS. Method detection limits for PFOS and PFOA varied between 5 and 17 ng/L and 9 and 25 ng/L respectively. Generally PFOS and PFOA concentrations in ambient waters, with no point source of pollution, are less than 5 ng/L. We have developed a method using the Oasis HLB solid phase cartridge to achieve the required method detection limits. We have measured PFOS and PFOA concentration in surface waters collected from Michigan and New York. PFOS and PFOA have been detected in the blood and liver of fish at {mu}g/L concentrations both in Japan and the USA. The current ion-pairing, liquid/liquid extraction method is suitable for these concentrations and we have measured PFOS and PFOA in the livers of fish from Michigan and New York waters. We have compared the data for fish and water concentrations and calculated bioaccumulation factors.

Perfluorooctanoic acid stimulated mitochondrial biogenesis and gene transcription in rats

International Nuclear Information System (INIS)

Walters, M.W.; Bjork, J.A.; Wallace, K.B.

2009-01-01

Perfluorooctanoic acid (PFOA), used in the production of non-stick surface compounds, exhibits a worldwide distribution in the serum of humans and wildlife. In rodents PFOA transactivates PPARα and PPARγ nuclear receptors and increases mitochondrial DNA (mtDNA) copy number, which may be critical to the altered metabolic state of affected animals. A key regulator of mitochondrial biogenesis and transcription of mitochondrial genes is the PPARγ coactivator-1α (Pgc-1α) protein. The purpose of this study was to determine if Pgc-1α is implicated in the stimulation of mitochondrial biogenesis that occurs following the treatment of rats with PFOA. Livers from adult male Sprague-Dawley rats that received a 30 mg/kg daily oral dose of PFOA for 28 days were used for all experiments. Analysis of mitochondrial replication and transcription was performed by real time PCR, and proteins were detected using western blotting. PFOA treatment caused a transcriptional activation of the mitochondrial biogenesis pathway leading to a doubling of mtDNA copy number. Further, transcription of OXPHOS genes encoded by mtDNA was 3-4 times greater than that of nuclear encoded genes, suggestive of a preferential induction of mtDNA transcription. Western blot analysis revealed an increase in Pgc-1α, unchanged Tfam and decreased Cox II and Cox IV subunit protein expression. We conclude that PFOA treatment in rats induces mitochondrial biogenesis at the transcriptional level with a preferential stimulation of mtDNA transcription and that this occurs by way of activation of the Pgc-1α pathway. Implication of the Pgc-1α pathway is consistent with PPARγ transactivation by PFOA and reveals new understanding and possibly new critical targets for assessing or averting the associated metabolic disease.

Photochemical defluorination of aqueous perfluorooctanoic acid (PFOA) by Fe(0)/GAC micro-electrolysis and VUV-Fenton photolysis.

Science.gov (United States)

Zhang, Li-Hong; Cheng, Jian-Hua; You, Xia; Liang, Xiao-Yan; Hu, Yong-You

2016-07-01

Perfluorooctanoic acid (PFOA) is extremely persistent and bioaccumulative in the environment; thus, it is very urgent to investigate an effective and moderate technology to treat the pollution of PFOA. In this study, a process combined iron and granular activated carbon (Fe(0)/GAC) micro-electrolysis with VUV-Fenton system is employed for the remediation of PFOA. Approximately 50 % PFOA (10 mg L(-1)) could be efficiently defluorinated under the following conditions: pH 3.0, dosage of Fe 7.5 g L(-1), dosage of GAC 12.5 g L(-1), and concentration of H2O2 22.8 mmol L(-1). Meanwhile, during the process, evident defluorination was observed and the concentration of fluoride ion was eventually 3.23 mg L(-1). The intermediates including five shorter-chain perfluorinated carboxylic acids (PFCAs), i.e., C7, C6, C5, C4, and C3, were also analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) and defluorination mechanisms of PFOA was proposed, which involved photochemical of OH·, direct photolysis (185-nm VUV), and photocatalytic degradation of PFOA in the presence of Fe(3+) (254-nm UV).

Effects of Perfluorooctanoic Acid on Metabolic Profiles in Brain and Liver of Mouse Revealed by a High-throughput Targeted Metabolomics Approach

Science.gov (United States)

Yu, Nanyang; Wei, Si; Li, Meiying; Yang, Jingping; Li, Kan; Jin, Ling; Xie, Yuwei; Giesy, John P.; Zhang, Xiaowei; Yu, Hongxia

2016-04-01

Perfluorooctanoic acid (PFOA), a perfluoroalkyl acid, can result in hepatotoxicity and neurobehavioral effects in animals. The metabolome, which serves as a connection among transcriptome, proteome and toxic effects, provides pathway-based insights into effects of PFOA. Since understanding of changes in the metabolic profile during hepatotoxicity and neurotoxicity were still incomplete, a high-throughput targeted metabolomics approach (278 metabolites) was used to investigate effects of exposure to PFOA for 28 d on brain and liver of male Balb/c mice. Results of multivariate statistical analysis indicated that PFOA caused alterations in metabolic pathways in exposed individuals. Pathway analysis suggested that PFOA affected metabolism of amino acids, lipids, carbohydrates and energetics. Ten and 18 metabolites were identified as potential unique biomarkers of exposure to PFOA in brain and liver, respectively. In brain, PFOA affected concentrations of neurotransmitters, including serotonin, dopamine, norepinephrine, and glutamate in brain, which provides novel insights into mechanisms of PFOA-induced neurobehavioral effects. In liver, profiles of lipids revealed involvement of β-oxidation and biosynthesis of saturated and unsaturated fatty acids in PFOA-induced hepatotoxicity, while alterations in metabolism of arachidonic acid suggesting potential of PFOA to cause inflammation response in liver. These results provide insight into the mechanism and biomarkers for PFOA-induced effects.

Photocatalytic degradation of perfluorooctanoic acid with beta-Ga2O3 in anoxic aqueous solution.

Science.gov (United States)

Zhao, Baoxiu; Lv, Mou; Zhou, Li

2012-01-01

Perfluorooctanoic acid (PFOA) is a new-found hazardous persistent organic pollutant, and it is resistant to decomposition by hydroxyl radical (HO*) due to its stable chemical structure and the high electronegativity of fluorine. Photocatalytic reduction of PFOA with beta-Ga2O3 in anoxic aqueous solution was investigated for the first time, and the results showed that the photoinduced electron (e(cb-)) coming from the beta-Ga2O3 conduction band was the major degradation substance for PFOA, and shorter-chain perfluorinated carboxylic acids (PFCAs, CnF2n+i1COOH, 1 < or = n < or = 6) were the dominant products. Furthermore, the concentration of F- was measured by the IC technique and defluorination efficiency was calculated. After 3 hr, the photocatalytic degradation efficiency was 98.8% and defluorination efficiency was 31.6% in the presence of thiosulfate and bubbling N2. The degradation reaction followed first-order kinetics (k = 0.0239 min(-1), t1/2 = 0.48 hr). PFCAs (CnF2n+1COOH, 1 < or = n < or = 7) were detected and measured by LC-MS and LC-MS/MS methods. It was deduced that the probable photocatalytic degradation mechanism involves e(cb-) attacking the carboxyl of CnF2n+1COOH, resulting in decarboxylation and the generation of CnF2n+1*. The produced CnF2n+1* reacted with H2O, forming CnF2n+1OH, then CnF2n+1OH underwent HF loss and hydrolysis to form CnF2n+1COOH.

Sex-related difference in the inductions by perfluoro-octanoic acid of peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase in rat liver.

Science.gov (United States)

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

Inductions by perfluoro-octanoic acid (PFOA) of hepatomegaly, peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase were compared in liver between male and female rats. Marked inductions of these four parameters were seen concurrently in liver of male rats, whereas the inductions in liver of female rats were far less pronounced. The sex-related difference in the response of rat liver to PFOA was much more marked than that seen with p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). Hormonal manipulations revealed that this sex-related difference in the inductions is strongly dependent on sex hormones, namely that testosterone is necessary for the inductions, whereas oestradiol prevented the inductions by PFOA. PMID:2570571

Highly efficient removal of perfluorooctanoic acid from aqueous solution by H2O2-enhanced electrocoagulation-electroflotation technique

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Bo Yang

2016-03-01

Full Text Available Electrocoagulation (EC technique was used to investigate the removal performance of aqueous perfluorooctanoic acid (PFOA with relatively high concentration as simulating the wastewater from organic fluorine industry. A comparison was done with the similar amount of coagulant between EC and chemical coagulation process. PFOA removal obtained was higher with EC process, especially for Fe anode. Several factors were studied to optimize the EC process. At the optimal operating parameters including 37.5 mA/cm2 of current density, initial pH 3.77, and 180 rpm of mixing speed, 93% of PFOA could be removed with 100 mg/L of initial concentration after 90-min electrolysis. Furthermore, the remove efficiency could be obviously improved by H2O2 intermittent addition, which removed more than 99% of PFOA within 40-min EC. It could be attributed to that H2O2 facilitated the oxidative transformation from ferrous to ferric ion. In addition, the adsorptive removal of aqueous PFOA on Fe flocs during EC was also verified by fourier transform infrared spectra.

Demographic, reproductive, and dietary determinants of perfluorooctane sulfonic (PFOS) and perfluorooctanoic acid (PFOA) concentrations in human colostrum

Science.gov (United States)

Jusko, Todd A.; Oktapodas, Marina; Murinová, L’ubica Palkovičová; Babinská, Katarina; Babjaková, Jana; Verner, Marc-André; DeWitt, Jamie C.; Thevenet-Morrison, Kelly; Čonka, Kamil; Drobná, Beata; Chovancová, Jana; Thurston, Sally W.; Lawrence, B. Paige; Dozier, Ann M.; Järvinen, Kirsi M.; Patayová, Henrieta; Trnovec, Tomáš; Legler, Juliette; Hertz-Picciotto, Irva; Lamoree, Marja H.

2017-01-01

To determine demographic, reproductive, and maternal dietary factors that predict perfluoroalkyl substance (PFAS) concentrations in breast milk, we measured perfluorooctane sulfonic (PFOS) and perfluorooctanoic acid (PFOA) concentrations, using liquid chromatography-mass spectrometry, in 184 colostrum samples collected from women participating in a cohort study in eastern Slovakia between 2002 and 2004. During their hospital delivery stay, mothers completed a food frequency questionnaire, and demographic and reproductive data were also collected. PFOS and PFOA predictors were identified by optimizing multiple linear regression models using Akaike’s information criterion (AIC). The geometric mean concentration in colostrum was 35.3 pg/ml for PFOS and 32.8 pg/ml for PFOA., In multivariable models, parous women had 40% lower PFOS (95% CI: −56 to −17%) and 40% lower PFOA (95% CI: −54 to −23%) concentrations compared with nulliparous women. Moreover, fresh/frozen fish consumption, longer birth intervals, and Slovak ethnicity were associated with higher PFOS and PFOA concentrations in colostrum. These results will help guide the design of future epidemiologic studies examining milk PFAS concentrations in relation to health endpoints in children. PMID:27244128

Evaluation of perfluorooctanoate for potential genotoxicity

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John L. Butenhoff

2014-01-01

Full Text Available Perfluorooctanoate (PFOA is a fully fluorinated eight-carbon fatty acid analog with exceptional stability toward degradation that has been used as an industrial surfactant and has been detected in environmental and biological matrices. Exposures to PFOA in the workplace and in the environment have continuously stimulated investigations into its potential human health hazards. In this article, the results of fifteen unpublished genotoxicity assays conducted with perfluorooctanoate (as either the linear or linear/branched ammonium salt (APFO or the linear/branched sodium salt are reported and include: seven mutation assays (three in vitro reverse mutation assays with histidine auxotrophic strains of Salmonella typhimurium, two in vitro reverse mutation assays with the tryptophan auxotrophic Escherichia coli WP2uvr strain, one in vitro mitotic recombination (gene conversion assay with Saccharomyces cerevisiae D4, and an in vitro Chinese hamster ovary (CHO HGPRT forward mutation assay; seven studies to assess potential for chromosomal damage (three in vitro CHO chromosomal aberration studies, an in vitro human whole blood lymphocyte chromosomal aberration study, and three in vivo mouse micronucleus assays; and an in vitro C3H 10T1/2 cell transformation assay. Although PFOA has not been demonstrated to be metabolized, all in vitro assays were conducted both in the presence and in the absence of a mammalian hepatic microsomal activation system. These assays were originally described in twelve contract laboratory reports which have been available via the United States Environmental Protection Agency public docket (Administrative Record 226 for over a decade; however, the details of these assays have not been published previously in the open scientific literature. With the exception of limited positive findings at high and cytotoxic concentrations in some assay trials which reflected the likely consequence of cytotoxic disruption of normal cellular

Hepatic and renal Bcrp transporter expression in mice treated with perfluorooctanoic acid

International Nuclear Information System (INIS)

Eldasher, Lobna M.; Wen, Xia; Little, Michael S.; Bircsak, Kristin M.; Yacovino, Lindsay L.; Aleksunes, Lauren M.

2013-01-01

Highlights: ► PFOA increased liver weight and Cyp4a14 mRNA and protein expression in mice. ► PFOA increased kidney Cyp4a14 mRNA in mice. ► PFOA increased Bcrp mRNA and protein in livers, but not kidneys, of mice. ► PFOA inhibited activation of human BCRP ATPase activity in vitro. ► PFOA inhibited human BCRP transport in inverted membrane vesicles. - Abstract: The breast cancer resistance protein (Bcrp) is an efflux transporter that participates in the biliary and renal excretion of drugs and environmental chemicals. Recent evidence suggests that pharmacological activation of the peroxisome proliferator activated receptor alpha (PPARα) can up-regulate the hepatic expression of Bcrp. The current study investigated the regulation of hepatic and renal Bcrp mRNA and protein in mice treated with the PPARα agonist perfluorooctanoic acid (PFOA) and the ability of PFOA to alter human BCRP function in vitro. Bcrp mRNA and protein expression were quantified in the livers and kidneys of male C57BL/6 mice treated with vehicle or PFOA (1 or 3 mg/kg/day oral gavage) for 7 days. PFOA treatment increased liver weights as well as the hepatic mRNA and protein expression of the PPARα target gene, cytochrome P450 4a14. Compared to vehicle-treated control mice, PFOA increased hepatic Bcrp mRNA and protein between 1.5- and 3-fold. Immunofluorescent staining confirmed enhanced canalicular Bcrp staining in liver sections from PFOA-treated mice. The kidney expression of cytochrome P450 4a14 mRNA, but not Bcrp, was increased in mice treated with PFOA. Micromolar concentrations of PFOA decreased human BCRP ATPase activity and inhibited BCRP-mediated transport in inverted membrane vesicles. Together, these studies demonstrate that PFOA induces hepatic Bcrp expression in mice and may inhibit human BCRP transporter function at concentrations that exceed levels observed in humans

Occurrence of Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Milk and Yogurt and Their Risk Assessment

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Zhenni Xing

2016-10-01

Full Text Available Although perfluorooctanoic acid (PFOA and perfluorooctane sulfonate (PFOS have been identified in milk and dairy products in many regions, knowledge on their occurrence in Xinjiang (China is rare. This study was conducted to measure the levels of PFOA and PFOS in milk and yogurt from Xinjiang and to investigate the average daily intake (ADI of these two compounds. PFOA and PFOS levels were analyzed using ultrasonic extraction with methanol and solid-phase extraction followed by liquid chromatography–mass spectrometry. Retail milk and yogurt samples present higher detection rates (39.6% and 48.1% and mean concentrations (24.5 and 31.8 ng/L of PFOS than those of PFOA (33.0% and 37.0%; 16.2 and 22.6 ng/L, respectively. For raw milk samples, only PFOS was detected. The differences in the levels of the two compounds between samples from the north and south regions were observed, and northern regions showed higher pollution levels than southern regions. On the basis of the retail milk measurements and consumption data, the ADIs of PFOA and PFOS for Xinjiang adults were calculated to be 0.0211 and 0.0318 ng/kg/day, respectively. Furthermore, the estimated intakes of PFOA and PFOS varied among different groupings (age, area, gender, and race and increased with increasing age. Relevant hazard ratios were found to be far less than 1.0, and this finding suggested that no imminent health damages were produced by PFOA and PFOS intake via milk and yogurt consumption in the Xinjiang population.

Occurrence of Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Milk and Yogurt and Their Risk Assessment.

Science.gov (United States)

Xing, Zhenni; Lu, Jianjiang; Liu, Zilong; Li, Shanman; Wang, Gehui; Wang, Xiaolong

2016-10-21

Although perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been identified in milk and dairy products in many regions, knowledge on their occurrence in Xinjiang (China) is rare. This study was conducted to measure the levels of PFOA and PFOS in milk and yogurt from Xinjiang and to investigate the average daily intake (ADI) of these two compounds. PFOA and PFOS levels were analyzed using ultrasonic extraction with methanol and solid-phase extraction followed by liquid chromatography-mass spectrometry. Retail milk and yogurt samples present higher detection rates (39.6% and 48.1%) and mean concentrations (24.5 and 31.8 ng/L) of PFOS than those of PFOA (33.0% and 37.0%; 16.2 and 22.6 ng/L, respectively). For raw milk samples, only PFOS was detected. The differences in the levels of the two compounds between samples from the north and south regions were observed, and northern regions showed higher pollution levels than southern regions. On the basis of the retail milk measurements and consumption data, the ADIs of PFOA and PFOS for Xinjiang adults were calculated to be 0.0211 and 0.0318 ng/kg/day, respectively. Furthermore, the estimated intakes of PFOA and PFOS varied among different groupings (age, area, gender, and race) and increased with increasing age. Relevant hazard ratios were found to be far less than 1.0, and this finding suggested that no imminent health damages were produced by PFOA and PFOS intake via milk and yogurt consumption in the Xinjiang population.

Immunomodulation and hormonal disruption without compromised disease resistance in perfluorooctanoic acid (PFOA) exposed Japanese quail

International Nuclear Information System (INIS)

Smits, Judit E.G.; Nain, Sukhbir

2013-01-01

This study evaluated the impact of oral perfluorooctanoic acid (PFOA) on Japanese quail at concentrations found in American and Belgian workers at PFOA manufacturing facilities. Three arms of the immune system were tested; T cell, B cell, and innate immunity. After 6 weeks exposure, quail were challenged with E. coli infection to test the ultimate measure of immunotoxicity, disease resistance. The T cell response was lower in the high exposure groups. Antibody mediated, and innate immune responses were not different. Growth rate was higher, whereas thyroid hormone levels were lower in PFOA-exposed birds. Morbidity/mortality from disease challenge was not different among the control and PFOA-exposed groups, and no overt PFOA toxicity was observed pre-disease challenge. Although PFOA at ‘worst case scenario’ levels caused T cell immunosuppression, this did not translate into increased disease susceptibility, demonstrating that immunotoxicity testing must be interpreted with caution since disease resistance is the ultimate concern. -- Highlights: •Birds orally exposed to high levels of PFOA for 8 wks showed no signs of toxicity. •PFOA exposure caused immunotoxicity by suppressing the T cell mediated response. •PFOA exposure did not affect antibody mediated, or innate immunity. •PFOA exposure did not cause increased morbidity/mortality after E. coli infection. •PFOA exposed birds showed endocrinological changes that may warrant further study. -- Oral exposure of quail to the pollutant, PFOA, resulted in hormonal and immunological changes, but did not compromise disease resistance after challenge by a common avian pathogen

Highly efficient electrochemical degradation of perfluorooctanoic acid (PFOA) by F-doped Ti/SnO{sub 2} electrode

Energy Technology Data Exchange (ETDEWEB)

Yang, Bo, E-mail: boyang@szu.edu.cn [Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Jiang, Chaojin [Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); Yu, Gang, E-mail: yg-den@tsinghua.edu.cn [School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Zhuo, Qiongfang [South China Institute of Environmental Sciences, The Ministry of Environment Protection, Guangzhou 510655 (China); Deng, Shubo [School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Wu, Jinhua [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Zhang, Hong [Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China)

2015-12-15

Highlights: • A novel SnO{sub 2} electrode is prepared by F doping instead of the traditional Sb doping. • SnF{sub 4} as single-source precursor is used to fabricate the long-life Ti/SnO{sub 2}–F anode. • F-doped Ti/SnO{sub 2} anode possesses high OEP and decomposition ability for PFOA. • Further mechanistic detail of PFOA degradation on Ti/SnO{sub 2}–F electrode is proposed. - Abstract: The novel F-doped Ti/SnO{sub 2} electrode prepared by SnF{sub 4} as the single-source precursor was used for electrochemical degradation of aqueous perfluorooctanoic acid (PFOA). Higher oxidation reactivity and significantly longer service life were achieved for Ti/SnO{sub 2}–F electrode than Ti/SnO{sub 2}–X (X = Cl, Br, I, or Sb) electrode, which could decomposed over 99% of PFOA (50 mL of 100 mg L{sup −1}) within 30-min electrolysis. The property of Ti/SnO{sub 2}–F electrode and its electrooxidation mechanism were investigated by XRD, SEM–EDX, EIS, LSV, and interfacial resistance measurements. We propose that the similar ionic radii of F and O as well as strong electronegativity of F caused its electrochemical stability with high oxygen evolution potential (OEP) and smooth surface to generate weakly adsorbed ·OH. The preparation conditions of electrode were also optimized including F doping amount, calcination temperature, and dip coating times, which revealed the formation process of electrode. Additionally, the major mineralization product, F{sup −}, and low concentration of shorter chain perfluorocarboxylic acids (PFCAs) were detected in solution. So the reaction pathway of PFOA electrooxidation was proposed by intermediate analysis. These results demonstrate that Ti/SnO{sub 2}–F electrode is promising for highly efficient treatment of PFOA in wastewater.

The mammary gland is a sensitive pubertal target in CD-1 and C57Bl/6 mice following perinatal perfluorooctanoic acid (PFOA) exposure.

Science.gov (United States)

Tucker, Deirdre K; Macon, Madisa B; Strynar, Mark J; Dagnino, Sonia; Andersen, Erik; Fenton, Suzanne E

2015-07-01

Perfluorooctanoic acid (PFOA) is a developmental toxicant in mice, with varied strain outcomes depending on dose and period of exposure. The impact of PFOA on female mouse pubertal development at low doses (≤1mg/kg) has yet to be determined. Therefore, female offspring from CD-1 and C57Bl/6 dams exposed to PFOA, creating serum concentrations similar to humans, were examined for pubertal onset, including mammary gland development. Pups demonstrated a shorter PFOA elimination half-life than that reported for adult mice. Prenatal exposure to PFOA caused significant mammary developmental delays in female offspring in both strains. Delays started during puberty and persisted into young adulthood; severity was dose-dependent. Also an evaluation of female serum hormone levels and pubertal timing onset revealed no effects of PFOA compared to controls in either strain. These data suggest that the mammary gland is more sensitive to early low level PFOA exposures compared to other pubertal endpoints, regardless of strain. Published by Elsevier Inc.

Sex-related differences in the enhancing effects of perfluoro-octanoic acid on stearoyl-CoA desaturase and its influence on the acyl composition of phospholipid in rat liver. Comparison with clofibric acid and tiadenol.

Science.gov (United States)

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

The effects of the peroxisome proliferators clofibric acid (p-chlorophenoxyisobutyric acid), tiadenol [2,2'-(decamethylenedithio)diethanol] and perfluoro-octanoic acid (PFOA) on hepatic stearoyl-CoA desaturation in male and female rats were compared. Treatment of male rats with the three peroxisome proliferators increased markedly the activity of stearoyl-CoA desaturase. Administration of clofibric acid or tiadenol to female rats increased greatly the hepatic activity of stearoyl-CoA desaturase, the extent of the increases being slightly less pronounced than those of male rats. In contrast with the other two peroxisome proliferators, however, PFOA did not change the activity of stearoyl-CoA desaturase in female rats. Hormonal manipulations revealed that this sex-related difference in the effect of PFOA on stearoyl-CoA desaturase activity is strongly dependent on testosterone. The increase in stearoyl-CoA desaturase activity by peroxisome proliferators was not accompanied by any notable increases in the microsomal content of cytochrome b5 or the activity of NADH: cytochrome b5 reductase. The administration of the peroxisome proliferators greatly altered the acyl composition of hepatic phosphatidylcholine and phosphatidylethanolamine (namely the proportions of C18:1 and C20:3,n-9 fatty acids increased in both phospholipids), and the alterations were partially associated with the increase in stearoyl-CoA desaturase activity. PMID:2574572

Vertical eddy diffusion as a key mechanism for removing perfluorooctanoic acid (PFOA) from the global surface oceans

International Nuclear Information System (INIS)

Lohmann, Rainer; Jurado, Elena; Dijkstra, Henk A.; Dachs, Jordi

2013-01-01

Here we estimate the importance of vertical eddy diffusion in removing perfluorooctanoic acid (PFOA) from the surface Ocean and assess its importance as a global sink. Measured water column profiles of PFOA were reproduced by assuming that vertical eddy diffusion in a 3-layer ocean model is the sole cause for the transport of PFOA to depth. The global oceanic sink due to eddy diffusion for PFOA is high, with accumulated removal fluxes over the last 40 years of 660 t, with the Atlantic Ocean accounting for 70% of the global oceanic sink. The global oceans have removed 13% of all PFOA produced to a depth greater than 100 m via vertical eddy diffusion; an additional 4% has been removed via deep water formation. The top 100 m of the surface oceans store another 21% of all PFOA produced (∼1100 t). Highlights: •Eddy diffusion has removed ∼660 t of PFOA from surface oceans over the last 40 years. •Atlantic Ocean accounts for 70% of the global oceanic sink of PFOA. •Vertical eddy diffusion has moved ∼13% of PFOA to oceans deeper than 100 m. •Around 4% of PFOA has been removed via deep water formation. •The top 100 m of global oceans contain ∼21% of historical PFOA production. -- Vertical eddy diffusion is an important removal process for hydrophilic organic pollutants such as PFOA from the surface ocean

Perfluorooctanoic acid exposure induces endoplasmic reticulum stress in the liver and its effects are ameliorated by 4-phenylbutyrate.

Science.gov (United States)

Yan, Shengmin; Zhang, Hongxia; Wang, Jianshe; Zheng, Fei; Dai, Jiayin

2015-10-01

Perfluoroalkyl acids (PFAAs) are a group of widely used anthropogenic compounds. As one of the most dominant PFAAs, perfluorooctanoic acid (PFOA) has been suggested to induce hepatotoxicity and several other toxicological effects. However, details on the mechanisms for PFOA-induced hepatotoxicity still need to be elucidated. In this study, we observed the occurrence of endoplasmic reticulum (ER) stress in mouse livers and HepG2 cells after PFOA exposure using several familiar markers for the unfolded protein response (UPR). ER stress in HepG2 cells after PFOA exposure was not significantly influenced by autophagy inhibition or stimulation. The antioxidant defense system was significantly disturbed in mouse livers after PFOA exposure, and reactive oxygen species (ROS) were increased in cells exposed to PFOA for 24 h. However, N-acetyl-L-cysteine (NAC) pretreatment did not satisfactorily alleviate the UPR in cells exposed to PFOA even though the increase of ROS was less evident. Furthermore, exposure of HepG2 cells to PFOA in the presence of sodium 4-phenylbutyrate (4-PBA), a chemical chaperone and ER stress inhibitor, suggested that 4-PBA alleviated the UPR and autophagosome accumulation induced by PFOA in cells. In addition, several toxicological effects attributed to PFOA exposure, including cell cycle arrest, proteolytic activity impairment, and neutral lipid accumulation, were also improved by 4-PBA cotreatment in cells. In vivo study demonstrated that PFOA-induced lipid metabolism perturbation and liver injury were partially ameliorated by 4-PBA in mice after 28 days of exposure. These findings demonstrated that PFOA-induced ER stress leading to UPR might play an important role in PFOA-induced hepatotoxic effects, and chemical chaperone 4-PBA could ameliorate the effects. Copyright © 2015. Published by Elsevier Inc.

Developmental toxicity of perfluorononanoic acid in mice

Science.gov (United States)

Perfluorononanoic acid (PFNA) is a ubiquitous and persistent environmental contaminant. Although its levels in the environment and in humans are lower than those of perfluorooctane sulfonate(PFOS) or perfluorooctanoic acid (PFOA), a steady trend of increases in the general popula...

ß-Ga2O3 nanorod synthesis with a one-step microwave irradiation hydrothermal method and its efficient photocatalytic degradation for perfluorooctanoic acid.

Science.gov (United States)

Zhao, Baoxiu; Li, Xiang; Yang, Long; Wang, Fen; Li, Jincheng; Xia, Wenxiang; Li, Weijiang; Zhou, Li; Zhao, Colin

2015-01-01

ß-Ga2O3 nanorod was first directly prepared by the microwave irradiation hydrothermal way without any subsequent heat treatments, and its characterizations were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), UV-Vis diffuse reflection spectroscopy techniques, and also its photocatalytic degradation for perfluorooctanoic acid (PFOA) was investigated. XRD patterns revealed that ß-Ga2O3 crystallization increased with the enhancement of microwave power and the adding of active carbon (AC). PFOA, as an environmental and persistent pollutant, is hard decomposed by hydroxyl radicals (HO·); however, it is facilely destroyed by ß-Ga2O3 photocatalytic reaction in an anaerobic atmosphere. The important factors such as pH, ß-Ga2O3 dosage and bubbling atmosphere were researched, and the degradation and defluorination was 98.8% and 56.2%, respectively. Reductive atmosphere reveals that photoinduced electron may be the major reactant for PFOA. Furthermore, the degradation kinetics for PFOA was simulated and constant and half-life was calculated, respectively. © 2014 The American Society of Photobiology.

Multimedia fate modeling of perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS) in the shallow lake Chaohu, China.

Science.gov (United States)

Kong, Xiangzhen; Liu, Wenxiu; He, Wei; Xu, Fuliu; Koelmans, Albert A; Mooij, Wolf M

2018-06-01

Freshwater shallow lake ecosystems provide valuable ecological services to human beings. However, these systems are subject to severe contamination from anthropogenic sources. Per- and polyfluoroalkyl substances (PFASs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS), are among the contaminants that have received substantial attention, primarily due to abundant applications, environment persistence, and potential threats to ecological and human health. Understanding the environmental behavior of these contaminants in shallow freshwater lake environments using a modeling approach is therefore critical. Here, we characterize the fate, transport and transformation of both PFOA and PFOS in the fifth largest freshwater lake in China (Chaohu) during a two-year period (2013-2015) using a fugacity-based multimedia fate model. A reasonable agreement between the measured and modeled concentrations in various compartments confirms the model's reliability. The model successfully quantifies the environmental processes and identifies the major sources and input pathways of PFOA and PFOS to the Chaohu water body. Sensitivity analysis reveals the critical role of nonlinear Freundlich sorption, which contributes to a variable fraction of the model true uncertainty in different compartments (8.1%-93.6%). Through additional model scenario analyses, we further elucidate the importance of nonlinear Freundlich sorption that is essential for the reliable model performance. We also reveal the distinct composition of emission sources for the two contaminants, as the major sources are indirect soil volatilization and direct release from human activities for PFOA and PFOS, respectively. The present study is expected to provide implications for local management of PFASs pollution in Lake Chaohu and to contribute to developing a general model framework for the evaluation of PFASs in shallow lakes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sorption of a branched nonylphenol isomer and perfluorooctanoic acid on geosorbents and carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Li, Chengliang

2011-10-13

As metabolites of organic surfactants, both nonylphenol (NP) and perfluorooctanoic acid (PFOA) are toxic and ubiquitous in the environment. Their sorption on soils and sediments is of importance for their fate and transport in the environment. Especially in China, there is still a lack of consolidated knowledge on the sorption behavior of NP and PFOA on geosorbents such as Yangtze River sediments. Thus, the present thesis investigates the sorption of a branched NP isomer [4-(1-ethyl-1, 3-dimethylpentyl) phenol] (NP111) and PFOA on Yangtze River sediments and their model components, i.e. a clay mineral (illite), metal oxides (goethite and {delta}-Al{sub 2}O{sub 3}) and organic matter (isolated from Yangtze River sediments and commercial organic matter) by both batch and dialysis techniques. NP111 is the most environmentally relevant NP isomer and its fate in the environment is unknown. Because PFOA is weakly adsorbed on geosorbents, multi-walled carbon nanotubes (MWCNTs) were studied as promising adsorbents. One of the MWCNTs studied contained traces of metal catalyst on the outer surface. Sorption isotherms of NP111 and PFOA on the sediments and their model components were fitted well by the Freundlich model. Sorption of NP111 on the sediments depended largely on their organic carbon content, resulting in organic carbon-normalized sorption coefficient (K{sub OC}) values between 6.3 x 10{sup 3} and 1.1 x 10{sup 4} L kg{sup -1}. The sorption of NP111 on {delta}-Al{sub 2}O{sub 3} and illite was comparable to that on sediments, but significantly lower than that on goethite. In contrast, the sorption of PFOA on the sediments was significantly lower. The affinity of PFOA to goethite and {delta}-Al{sub 2}O{sub 3} was slightly higher than to the sediments, but it was negligible to natural organic matter and illite. The results suggest that the organic carbon content of the sediments plays a dominant role in the sorption of NP111, whereas goethite acts as a potential sink

Perfluorooctanoic acid (PFOA), an emerging drinking water contaminant: a critical review of recent literature.

Science.gov (United States)

Post, Gloria B; Cohn, Perry D; Cooper, Keith R

2012-07-01

Perfluorooctanoic acid (PFOA) is an anthropogenic contaminant that differs in several ways from most other well-studied organic chemicals found in drinking water. PFOA is extremely resistant to environmental degradation processes and thus persists indefinitely. Unlike most other persistent and bioaccumulative organic pollutants, PFOA is water-soluble, does not bind well to soil or sediments, and bioaccumulates in serum rather than in fat. It has been detected in finished drinking water and drinking water sources impacted by releases from industrial facilities and waste water treatment plants, as well as in waters with no known point sources. However, the overall occurrence and population exposure from drinking water is not known. PFOA persists in humans with a half-life of several years and is found in the serum of almost all U.S. residents and in populations worldwide. Exposure sources include food, food packaging, consumer products, house dust, and drinking water. Continued exposure to even relatively low concentrations in drinking water can substantially increase total human exposure, with a serum:drinking water ratio of about 100:1. For example, ongoing exposures to drinking water concentrations of 10 ng/L, 40 ng/L, 100 ng/L, or 400 ng/L are expected to increase mean serum levels by about 25%, 100%, 250%, and 1000%, respectively, from the general population background serum level of about 4 ng/mL. Infants are potentially a sensitive subpopulation for PFOA's developmental effects, and their exposure through breast milk from mothers who use contaminated drinking water and/or from formula prepared with contaminated drinking water is higher than in adults exposed to the same drinking water concentration. Numerous health endpoints are associated with human PFOA exposure in the general population, communities with contaminated drinking water, and workers. As is the case for most such epidemiology studies, causality for these effects is not proven. Unlike most other

Molecular characterization of cytochrome P450 1A and 3A and the effects of perfluorooctanoic acid on their mRNA levels in rare minnow (Gobiocypris rarus) gills

Energy Technology Data Exchange (ETDEWEB)

Liu Yong; Wang Jianshe; Wei Yanhong; Zhang Hongxia; Liu Yang [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Beijing 100101 (China); Dai Jiayin [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Beijing 100101 (China)], E-mail: daijy@ioz.ac.cn

2008-07-07

Perfluorooctanoic acid (PFOA), a potentially toxic perfluorinated compound (PFC), has been widely disseminated in the environment. In the present study, rare minnows (Gobiocypris rarus) exposed to PFOA exhibited histopathological gill damage, including epithelial hyperplasia of the lamellae, inflammatory cell infiltration, and lamellar fusion. Cytochrome P450s (CYPs) play a central role in the metabolism and biotransformation of a wide range of endogenous substrates and foreign compounds. Thus, we studied the CYPs and the effects of waterborne PFOA on their corresponding mRNA levels in the gills of rare minnows. Two novel CYP cDNAs (CYP1A and CYP3A) were identified in rare minnow and their mRNAs were ubiquitously expressed in all tissues examined. Upregulation of CYP3A mRNA was observed in the gills of male rare minnows exposed to 30 mg/L PFOA, while no significant changes occurred in exposed females. In contrast, down regulation of CYP1A mRNA was detected in the gills of male and female minnows exposed to PFOA. However, the effect of PFOA on gill mRNA levels of their potential regulators, aryl hydrocarbon receptor (AhR) for CYP1A, and pregnane X receptor (PXR) for CYP3A, were not consistent with the observed effects of PFOA on the corresponding CYP mRNA concentrations. This suggests a different or more complex transcriptional regulation of CYP expression following PFOA exposure.

Distribution and long-range transport of polyfluoroalkyl substances in the Arctic, Atlantic Ocean and Antarctic coast.

Science.gov (United States)

Zhao, Zhen; Xie, Zhiyong; Möller, Axel; Sturm, Renate; Tang, Jianhui; Zhang, Gan; Ebinghaus, Ralf

2012-11-01

The global distribution and long-range transport of polyfluoroalkyl substances (PFASs) were investigated using seawater samples collected from the Greenland Sea, East Atlantic Ocean and the Southern Ocean in 2009-2010. Elevated levels of ΣPFASs were detected in the North Atlantic Ocean with the concentrations ranging from 130 to 650 pg/L. In the Greenland Sea, the ΣPFASs concentrations ranged from 45 to 280 pg/L, and five most frequently detected compounds were perfluorooctanoic acid (PFOA), perfluorohexanesulfonate (PFHxS), perfluorohexanoic acid (PFHxA), perfluorooctane sulfonate (PFOS) and perfluorobutane sulfonate (PFBS). PFOA (15 pg/L) and PFOS (25-45 pg/L) were occasionally found in the Southern Ocean. In the Atlantic Ocean, the ΣPFASs concentration decreased from 2007 to 2010. The elevated PFOA level that resulted from melting snow and ice in Greenland Sea implies that the Arctic may have been driven by climate change and turned to be a source of PFASs for the marine ecosystem. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of developmental exposure to perfluorooctanoic acid (PFOA) on long bone morphology and bone cell differentiation

Energy Technology Data Exchange (ETDEWEB)

Koskela, A., E-mail: antti.koskela@oulu.fi [Institute of Cancer Research and Translational Medicine, MRC Oulu and Department of Anatomy and Cell Biology, Faculty of Medicine, University of Oulu, Oulu (Finland); Finnilä, M.A. [Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu (Finland); Korkalainen, M. [National Institute for Health and Welfare, Department of Health Protection, Kuopio (Finland); Spulber, S. [Department of Neuroscience, Karolinska Institutet, Stockholm (Sweden); Koponen, J. [National Institute for Health and Welfare, Department of Health Protection, Kuopio (Finland); Håkansson, H. [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Tuukkanen, J. [Institute of Cancer Research and Translational Medicine, MRC Oulu and Department of Anatomy and Cell Biology, Faculty of Medicine, University of Oulu, Oulu (Finland); Viluksela, M. [National Institute for Health and Welfare, Department of Health Protection, Kuopio (Finland); Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio (Finland)

2016-06-15

Perfluorooctanoic acid (PFOA) is a ubiquitous and persistent environmental chemical, which has been used extensively due to its stability and surface tension-lowering properties. Toxicological effects include induction of neonatal mortality and reproductive toxicity. In this study, pregnant C57BL/6 mice were exposed orally to 0.3 mg PFOA/kg/day throughout pregnancy, and female offspring were studied at the age of 13 or 17 months. Morphometrical and biomechanical properties of femurs and tibias were analyzed with micro-computed tomography and 3-point bending, and bone PFOA concentrations were determined by mass spectrometry. The effects of PFOA on bone cell differentiation were studied in osteoclasts from C57BL/6 mice and in the MC3T3 pre-osteoblast cell line. PFOA exposed mice showed increased femoral periosteal area as well as decreased mineral density of tibias. Biomechanical properties of these bones were not affected. Bone PFOA concentrations were clearly elevated even at the age of 17 months. In osteoblasts, low concentrations of PFOA increased osteocalcin (OCN) expression and calcium secretion, but at PFOA concentrations of 100 μM and above osteocalcin (OCN) expression and calcium secretion were decreased. The number of osteoclasts was increased at all PFOA concentrations tested and resorption activity dose-dependently increased from 0.1–1.0 μM, but decreased at higher concentrations. The results show that PFOA accumulates in bone and is present in bones until the old age. PFOA has the potential to influence bone turnover over a long period of time. Therefore bone is a target tissue for PFOA, and altered bone geometry and mineral density seem to persist throughout the life of the animal. - Highlights: • Bone is a target tissue for PFOA both in vivo and in vitro. • Maternal exposure during pregnancy results in PFOA accumulation in bone of the offspring. • PFOA is present in bones until the old age. • PFOA causes mild alterations in bone morphometry

Effects of developmental exposure to perfluorooctanoic acid (PFOA) on long bone morphology and bone cell differentiation

International Nuclear Information System (INIS)

Koskela, A.; Finnilä, M.A.; Korkalainen, M.; Spulber, S.; Koponen, J.; Håkansson, H.; Tuukkanen, J.; Viluksela, M.

2016-01-01

Perfluorooctanoic acid (PFOA) is a ubiquitous and persistent environmental chemical, which has been used extensively due to its stability and surface tension-lowering properties. Toxicological effects include induction of neonatal mortality and reproductive toxicity. In this study, pregnant C57BL/6 mice were exposed orally to 0.3 mg PFOA/kg/day throughout pregnancy, and female offspring were studied at the age of 13 or 17 months. Morphometrical and biomechanical properties of femurs and tibias were analyzed with micro-computed tomography and 3-point bending, and bone PFOA concentrations were determined by mass spectrometry. The effects of PFOA on bone cell differentiation were studied in osteoclasts from C57BL/6 mice and in the MC3T3 pre-osteoblast cell line. PFOA exposed mice showed increased femoral periosteal area as well as decreased mineral density of tibias. Biomechanical properties of these bones were not affected. Bone PFOA concentrations were clearly elevated even at the age of 17 months. In osteoblasts, low concentrations of PFOA increased osteocalcin (OCN) expression and calcium secretion, but at PFOA concentrations of 100 μM and above osteocalcin (OCN) expression and calcium secretion were decreased. The number of osteoclasts was increased at all PFOA concentrations tested and resorption activity dose-dependently increased from 0.1–1.0 μM, but decreased at higher concentrations. The results show that PFOA accumulates in bone and is present in bones until the old age. PFOA has the potential to influence bone turnover over a long period of time. Therefore bone is a target tissue for PFOA, and altered bone geometry and mineral density seem to persist throughout the life of the animal. - Highlights: • Bone is a target tissue for PFOA both in vivo and in vitro. • Maternal exposure during pregnancy results in PFOA accumulation in bone of the offspring. • PFOA is present in bones until the old age. • PFOA causes mild alterations in bone morphometry

Genotypic variation and mechanism in uptake and translocation of perfluorooctanoic acid (PFOA) in lettuce (Lactuca sativa L.) cultivars grown in PFOA-polluted soils.

Science.gov (United States)

Xiang, Lei; Chen, Lei; Yu, Le-Yi; Yu, Peng-Fei; Zhao, Hai-Ming; Mo, Ce-Hui; Li, Yan-Wen; Li, Hui; Cai, Quan-Ying; Zhou, Dong-Mei; Wong, Ming-Hung

2018-05-02

The cultivation of crop cultivars with low pollutant accumulation is an important strategy to reduce the potential health risks of food produced from polluted soils. In this study, we identified three loose-leaf lettuce cultivars with low accumulation of perfluorooctanoic acid (PFOA), a highly toxic and persistent organic pollutant. PFOA concentrations in the shoots of low-PFOA cultivars were 3.7-5.5-fold lower than those of high-PFOA cultivars. The identification of low-PFOA cultivars could contribute to ensuring food safety despite cultivation in highly polluted soils (1 mg/kg) based on the tolerable daily PFOA intake (1.5 μg/kg/d). We detected lower desorbing fractions of PFOA in rhizosphere soil, lower bioconcentration factors, and higher distribution in the cell walls and organelles of roots in low-PFOA cultivars, all of which are key factors in limiting PFOA uptake and translocation from soil to shoots, than in high-PFOA cultivars. This study reveals the mechanism of PFOA uptake from soil to crop and lays a foundation for establishing a cost-effective strategy to plant crops in polluted soil and reduce exposure risk due to persistent organic pollutants in crops. Copyright © 2018 Elsevier B.V. All rights reserved.

Calculation of chemical elimination half-life from blood with an ongoing exposure source: the example of perfluorooctanoic acid (PFOA).

Science.gov (United States)

Russell, Mark H; Waterland, Robert L; Wong, Fiona

2015-06-01

Determination of the chemical clearance rate from human blood is a critical component of toxicokinetic exposure assessment. Analysis of temporal biomonitoring data without consideration of ongoing exposure results in calculation of apparent elimination half-life values that are longer than the intrinsic value. The intrinsic elimination half-life is solely a function of the rate of elimination while the apparent elimination half-life reflects the processes of both elimination and ongoing exposure. Confusion between intrinsic and apparent half-life values can lead to misinterpretation of biomonitoring data and can result in exaggerated predictions in subsequent modeling efforts. This work provides a review of the first-order equations that have been developed to calculate intrinsic and apparent half-life values and the potential bias that can result from confusing these two values. Published human biomonitoring data for perfluorooctanoic acid (PFOA) are analyzed using these equations to provide examples of low, medium and high bias in determination of the intrinsic elimination half-life from plasma or serum, the components of blood typically analyzed for PFOA. An approach is also provided to estimate the extent of exposure reduction that is indicated by declining longitudinal or cross-sectional biomonitoring data. Based on the evaluation methodology presented in this work, the intrinsic elimination half-life of PFOA in humans is 2.4years, representing the average of independent estimates of 2.5years (95% CI, 2.4-2.7) and 2.3years (95% CI, 2.1-2.4). The declining concentration of PFOA in blood of the general USA adult population represents an estimated exposure reduction of 20-30% over the period 1999-2008. Copyright © 2014 Elsevier Ltd. All rights reserved.

Associations of in Utero Exposure to Perfluorinated Alkyl Acids with Human Semen Quality and Reproductive Hormones in Adult Men

DEFF Research Database (Denmark)

Vested, Anne; Ramlau-Hansen, Cecilia Høst; Olsen, Sjurdur Frodi

2013-01-01

Perfluorinated alkyl acids (PFAAs), persistent chemicals with unique water-, dirt-, and oil-repellent properties, are suspected of having endocrine-disrupting activity. The PFAA compounds perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are found globally in humans; because...

Programming of metabolic effects in C57BL/6JxFVB mice by in utero and lactational exposure to perfluorooctanoic acid.

Science.gov (United States)

van Esterik, J C J; Bastos Sales, L; Dollé, M E T; Håkansson, H; Herlin, M; Legler, J; van der Ven, L T M

2016-03-01

Perfluorooctanoic acid (PFOA) is known to cause developmental toxicity and is a suggested endocrine disrupting compound (EDC). Early life exposure to EDCs has been implicated in programming of the developing organism for chronic diseases later in life. Here we study perinatal metabolic programming by PFOA using an experimental design relevant for human exposure. C57BL/6JxFVB hybrid mice were exposed during gestation and lactation via maternal feed to seven low doses of PFOA at and below the NOAEL used for current risk assessment (3-3000 µg/kg body weight/day). After weaning, offspring were followed for 23-25 weeks without further exposure. Offspring showed a dose-dependent decrease in body weight from postnatal day 4 to adulthood. Growth under high fat diet in the last 4-6 weeks of follow-up was increased in male and decreased in female offspring. Both sexes showed increased liver weights, hepatic foci of cellular alterations and nuclear dysmorphology. In females, reductions in perigonadal and perirenal fat pad weights, serum triglycerides and cholesterol were also observed. Endocrine parameters, such as glucose tolerance, serum insulin and leptin, were not affected. In conclusion, our study with perinatal exposure to PFOA in mice produced metabolic effects in adult offspring. This is most likely due to disrupted programming of metabolic homeostasis, but the assayed endpoints did not provide a mechanistic explanation. The BMDL of the programming effects in our study is below the current point of departure used for calculation of the tolerable daily intake.

Perflurooctanoic Acid Induces Developmental Cardiotoxicity in Chicken Embryos and Hatchlings

Science.gov (United States)

Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxi...

The roles of protein and lipid in the accumulation and distribution of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in plants grown in biosolids-amended soils.

Science.gov (United States)

Wen, Bei; Wu, Yali; Zhang, Hongna; Liu, Yu; Hu, Xiaoyu; Huang, Honglin; Zhang, Shuzhen

2016-09-01

The roles of protein and lipid in the accumulation and distribution of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in seven species of plants from biosolids-amended soils were investigated. The PFOS and PFOA root concentration factors (Croot/Csoil) ranged from 1.37 to 4.68 and 1.69 to 10.3 (ng/groot)/(ng/gsoil), respectively, while the translocation factors (Cshoot/Croot) ranged from 0.055 to 0.16 and 0.093 to 1.8 (ng/gshoot)/(ng/groot), respectively. The PFOS and PFOA accumulations in roots correlated positively with root protein contents (P distribution of PFOS and PFOA in plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Perfluorooctanoic acid affects endocytosis involving clathrin light chain A and microRNA-133b-3p in mouse testes

Energy Technology Data Exchange (ETDEWEB)

Lu, Yin; Wang, Jianshe [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, PR China. (China); Yan, Shengmin [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

2017-03-01

Perfluorooctanoic acid (PFOA) is an abundant perfluoroalkyl substance widely applied in industrial and consumer products. Among its potential health hazards, testicular toxicity is of major concern. To explore the potential effect of miRNA on post-translational regulation after PFOA exposure, changes in miRNAs were detected via miRNA array. Seventeen miRNAs were differentially expressed (eight upregulated, nine downregulated) in male mouse testes after exposure to 5 mg/kg/d of PFOA for 28 d (> 1.5-fold and P < 0.05 compared with the control). Eight of these miRNAs were further selected for TaqMan qPCR analysis. Proteomic profile analysis indicated that many changed proteins after PFOA treatment, including intersectin 1 (ITSN1), serine protease inhibitor A3K (Serpina3k), and apolipoprotein a1 (APOA1), were involved in endocytosis and blood-testis barrier (BTB) processes. These changes were further verified by immunohistochemical and Western blot analyses. Endocytosis-related genes were selected for qPCR analysis, with many found to be significantly changed after PFOA treatment, including epidermal growth factor receptor pathway substrate 8 (Eps8), Eps15, cortactin, cofilin, espin, vinculin, and zyxin. We further predicted the potential interaction between changed miRNAs and proteins, which indicated that miRNAs might play a role in the post-translational regulation of gene expression after PFOA treatment in mouse testes. Among them, miR-133b-3p/clathrin light chain A (CLTA) was selected and verified in vitro by transfection and luciferase activity assay. Results showed that PFOA exposure affects endocytosis in mouse testes and that CLTA is a potential target of miR-133b-3p. - Highlights: • Endocytosis and blood-testis barrier proteins were changed after PFOA exposure. • Seventeen miRNAs were differentially expressed in testes after PFOA exposure. • MiRNAs might play a role in gene regulation in testes after PFOA exposure.CLTA is a potential target of miR-133b

Perfluorooctanoic acid affects endocytosis involving clathrin light chain A and microRNA-133b-3p in mouse testes

International Nuclear Information System (INIS)

Lu, Yin; Wang, Jianshe; Guo, Xuejiang; Yan, Shengmin; Dai, Jiayin

2017-01-01

Perfluorooctanoic acid (PFOA) is an abundant perfluoroalkyl substance widely applied in industrial and consumer products. Among its potential health hazards, testicular toxicity is of major concern. To explore the potential effect of miRNA on post-translational regulation after PFOA exposure, changes in miRNAs were detected via miRNA array. Seventeen miRNAs were differentially expressed (eight upregulated, nine downregulated) in male mouse testes after exposure to 5 mg/kg/d of PFOA for 28 d (> 1.5-fold and P < 0.05 compared with the control). Eight of these miRNAs were further selected for TaqMan qPCR analysis. Proteomic profile analysis indicated that many changed proteins after PFOA treatment, including intersectin 1 (ITSN1), serine protease inhibitor A3K (Serpina3k), and apolipoprotein a1 (APOA1), were involved in endocytosis and blood-testis barrier (BTB) processes. These changes were further verified by immunohistochemical and Western blot analyses. Endocytosis-related genes were selected for qPCR analysis, with many found to be significantly changed after PFOA treatment, including epidermal growth factor receptor pathway substrate 8 (Eps8), Eps15, cortactin, cofilin, espin, vinculin, and zyxin. We further predicted the potential interaction between changed miRNAs and proteins, which indicated that miRNAs might play a role in the post-translational regulation of gene expression after PFOA treatment in mouse testes. Among them, miR-133b-3p/clathrin light chain A (CLTA) was selected and verified in vitro by transfection and luciferase activity assay. Results showed that PFOA exposure affects endocytosis in mouse testes and that CLTA is a potential target of miR-133b-3p. - Highlights: • Endocytosis and blood-testis barrier proteins were changed after PFOA exposure. • Seventeen miRNAs were differentially expressed in testes after PFOA exposure. • MiRNAs might play a role in gene regulation in testes after PFOA exposure.CLTA is a potential target of miR-133b

Investigation of the Effects of Perfluorooctanoic Acid (PFOA and Perfluorooctane Sulfonate (PFOS on Apoptosis and Cell Cycle in a Zebrafish (Danio rerio Liver Cell Line

Directory of Open Access Journals (Sweden)

Yuan Cui

2015-12-01

Full Text Available This study aimed to explore the effects of perfluorooctanoic acid (PFOA and perfluorooctane sulfonate (PFOS on apoptosis and cell cycle in a zebrafish (Danio rerio liver cell line (ZFL. Treatment groups included a control group, PFOA-IC50, PFOA-IC80, PFOS-IC50 and PFOS-IC80 groups. IC50 and IC80 concentrations were identified by cellular modeling and MTT assays. mRNA levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were detected by qPCR. Cell apoptosis and cell cycle were detected by flow cytometry and the protein levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were determined by western blotting. Both PFOA and PFOS inhibited the growth of zebrafish liver cells, and the inhibition rate of PFOS was higher than that of PFOA. Bcl-2 expression levels in the four groups were significantly higher than the control group and Bcl-2 increased significantly in the PFOA-IC80 group. However, the expression levels of Bax in the four treatment groups were higher than the control group. The percentage of cell apoptosis increased significantly with the treatment of PFOA and PFOS (p < 0.05. Cell cycle and cell proliferation were blocked in both the PFOA-IC80 and PFOS-IC80 groups, indicating that PFOA-IC80 and PFOS-IC50 enhanced apoptosis in ZFL cells.

Perfluoroalkyl Acid Concentrations in Blood Samples Subjected to Transportation and Processing Delay

DEFF Research Database (Denmark)

Bach, Cathrine Carlsen; Henriksen, Tine Brink; Bossi, Rossana

2015-01-01

and transportation prior to processing and samples with immediate processing and freezing. METHODS: Pregnant women recruited at Aarhus University Hospital, Denmark, (n = 88) provided paired blood samples. For each pair of samples, one was immediately processed and plasma was frozen, and the other was delayed...... and transported as whole blood before processing and freezing of plasma (similar to the Danish National Birth Cohort). We measured 12 perfluoroalkyl acids and present results for compounds with more than 50% of samples above the lower limit of quantification. RESULTS: For samples taken in the winter, relative...... differences between the paired samples ranged between -77 and +38% for individual perfluoroalkyl acids. In most cases concentrations were lower in the delayed and transported samples, e.g. the relative difference was -29% (95% confidence interval -30; -27) for perfluorooctane sulfonate. For perfluorooctanoate...

Carryover of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from soil to plant and distribution to the different plant compartments studied in cultures of carrots (Daucus carota ssp. Sativus), potatoes (Solanum tuberosum), and cucumbers (Cucumis Sativus).

Science.gov (United States)

Lechner, Mareike; Knapp, Holger

2011-10-26

A vegetation study was carried out to investigate the carryover of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) from soil mixed with contaminated sewage sludge to potato, carrot, and cucumber plants. Analysis was done by liquid-extraction using acetonitrile with dispersive SPE cleanup and subsequent HPLC-MS/MS. In order to assess the transfer potential from soil, transfer factors (TF) were calculated for the different plant compartments: TF = [PFC](plant (wet substance))/[PFC](soil (dry weight)). The highest TF were found for the vegetative plant compartments with average values for PFOS below those for PFOA: cucumber, 0.17 (PFOS), 0.88 (PFOA); potato, 0.36 (PFOS), 0.40 (PFOA); carrot, 0.38 (PFOS), 0.53 (PFOA). Transfer of PFOA and PFOS into potato peelings (average values of TF: PFOA 0.03, PFOS 0.04) exceeded the carryover to the peeled tubers (PFOA 0.01, PFOS potatoes (TF < 0.01). For PFOA, it was higher (TF: 0.03).

Physiologically based pharmacokinetic modeling of human exposure to perfluorooctanoic acid suggests historical non drinking-water exposures are important for predicting current serum concentrations.

Science.gov (United States)

Worley, Rachel Rogers; Yang, Xiaoxia; Fisher, Jeffrey

2017-09-01

Manufacturing of perfluorooctanoic acid (PFOA), a synthetic chemical with a long half-life in humans, peaked between 1970 and 2002, and has since diminished. In the United States, PFOA is detected in the blood of >99% of people tested, but serum concentrations have decreased since 1999. Much is known about exposure to PFOA in drinking water; however, the impact of non-drinking water PFOA exposure on serum PFOA concentrations is not well characterized. The objective of this research is to apply physiologically based pharmacokinetic (PBPK) modeling and Monte Carlo analysis to evaluate the impact of historic non-drinking water PFOA exposure on serum PFOA concentrations. In vitro to in vivo extrapolation was utilized to inform descriptions of PFOA transport in the kidney. Monte Carlo simulations were incorporated to evaluate factors that account for the large inter-individual variability of serum PFOA concentrations measured in individuals from North Alabama in 2010 and 2016, and the Mid-Ohio River Valley between 2005 and 2008. Predicted serum PFOA concentrations were within two-fold of experimental data. With incorporation of Monte Carlo simulations, the model successfully tracked the large variability of serum PFOA concentrations measured in populations from the Mid-Ohio River Valley. Simulation of exposure in a population of 45 adults from North Alabama successfully predicted 98% of individual serum PFOA concentrations measured in 2010 and 2016, respectively, when non-drinking water ingestion of PFOA exposure was included. Variation in serum PFOA concentrations may be due to inter-individual variability in the disposition of PFOA and potentially elevated historical non-drinking water exposures. Published by Elsevier Inc.

Application of physiologically-based pharmacokinetic modeling to explore the role of kidney transporters in renal reabsorption of perfluorooctanoic acid in the rat

Energy Technology Data Exchange (ETDEWEB)

Worley, Rachel Rogers, E-mail: idz7@cdc.gov [Agency for Toxic Substances and Disease Registry, Division of Community Health Investigations, 4770 Buford Highway, Atlanta, GA 30341 (United States); Interdisciplinary Toxicology Program, University of Georgia, 341 Pharmacy South, Athens, GA 30602 (United States); Fisher, Jeffrey [Interdisciplinary Toxicology Program, University of Georgia, 341 Pharmacy South, Athens, GA 30602 (United States); Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Road, Jefferson, AR 72079 (United States)

2015-12-15

ABSTRACT: Renal elimination and the resulting clearance of perfluorooctanoic acid (PFOA) from the serum exhibit pronounced sex differences in the adult rat. The literature suggests that this is largely due to hormonally regulated expression of organic anion transporters (OATs) on the apical and basolateral membranes of the proximal tubule cells that facilitate excretion and reabsorption of PFOA from the filtrate into the blood. Previously developed PBPK models of PFOA exposure in the rat have not been parameterized to specifically account for transporter-mediated renal elimination. We developed a PBPK model for PFOA in male and female rats to explore the role of Oat1, Oat3, and Oatp1a1 in sex-specific renal reabsorption and excretion of PFOA. Descriptions of the kinetic behavior of these transporters were extrapolated from in vitro studies and the model was used to simulate time-course serum, liver, and urine data for intravenous (IV) and oral exposures in both sexes. Model predicted concentrations of PFOA in the liver, serum, and urine showed good agreement with experimental data for both male and female rats indicating that in vitro derived physiological descriptions of transporter-mediated renal reabsorption can successfully predict sex-dependent excretion of PFOA in the rat. This study supports the hypothesis that sex-specific serum half-lives for PFOA are largely driven by expression of transporters in the kidney and contribute to the development of PBPK modeling as a tool for evaluating the role of transporters in renal clearance. - Highlights: • The PBPK model for PFOA in the rat explores the role of OATs in sex-specific clearance. • Descriptions of OAT kinetics were extrapolated from in vitro studies. • Model predictions showed good fit with experimental data for male and female rats.

Application of physiologically-based pharmacokinetic modeling to explore the role of kidney transporters in renal reabsorption of perfluorooctanoic acid in the rat

International Nuclear Information System (INIS)

Worley, Rachel Rogers; Fisher, Jeffrey

2015-01-01

ABSTRACT: Renal elimination and the resulting clearance of perfluorooctanoic acid (PFOA) from the serum exhibit pronounced sex differences in the adult rat. The literature suggests that this is largely due to hormonally regulated expression of organic anion transporters (OATs) on the apical and basolateral membranes of the proximal tubule cells that facilitate excretion and reabsorption of PFOA from the filtrate into the blood. Previously developed PBPK models of PFOA exposure in the rat have not been parameterized to specifically account for transporter-mediated renal elimination. We developed a PBPK model for PFOA in male and female rats to explore the role of Oat1, Oat3, and Oatp1a1 in sex-specific renal reabsorption and excretion of PFOA. Descriptions of the kinetic behavior of these transporters were extrapolated from in vitro studies and the model was used to simulate time-course serum, liver, and urine data for intravenous (IV) and oral exposures in both sexes. Model predicted concentrations of PFOA in the liver, serum, and urine showed good agreement with experimental data for both male and female rats indicating that in vitro derived physiological descriptions of transporter-mediated renal reabsorption can successfully predict sex-dependent excretion of PFOA in the rat. This study supports the hypothesis that sex-specific serum half-lives for PFOA are largely driven by expression of transporters in the kidney and contribute to the development of PBPK modeling as a tool for evaluating the role of transporters in renal clearance. - Highlights: • The PBPK model for PFOA in the rat explores the role of OATs in sex-specific clearance. • Descriptions of OAT kinetics were extrapolated from in vitro studies. • Model predictions showed good fit with experimental data for male and female rats.

Formation of C₇F15COOH (PFOA) and other perfluorocarboxylic acids during the atmospheric oxidation of 8:2 fluorotelomer alcohol

DEFF Research Database (Denmark)

Wallington, T. J.; Hurley, M. D.; Xia, J.

2006-01-01

Calculations using a three-dimensional global atmospheric chemistry model (IMPACT) indicate that n-C8F17CH2CH2-OH (widely used in industrial and consumer products) degrades in the atmosphere to give perfluorooctanoic acid (PFOA) and other perfluorocarboxylic acids (PFCAs). PFOA is persistent, bio...

Comparison of human whole blood, plasma, and serum matrices for the determination of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals

International Nuclear Information System (INIS)

Ehresman, David J.; Froehlich, John W.; Olsen, Geary W.; Chang, Shu-Ching; Butenhoff, John L.

2007-01-01

Interest in human exposure to perfluorinated acids, including perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHS), perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) has led to their measurement in whole blood, plasma and serum. Comparison of measurements in these different blood-based matrices, however, has not been rigorously investigated to allow for across-matrix comparisons. This research evaluated concentrations of PFBS, PFHS, PFOS, and PFOA in whole blood collected in heparin (lithium) and ethylenediamine tetraacetic acid (EDTA), plasma samples collected in heparin and EDTA, and serum (from whole blood allowed to clot). Blood samples were collected from 18 voluntary participants employed at 3M Company. Solid phase extraction methods were used for all analytical sample preparations, and analyses were completed using high-pressure liquid chromatography/tandem mass spectrometry methods. Serum concentrations ranged from: limit of quantitation (LOQ, 5 ng/mL) to 25 ng/mL for PFBS; LOQ (5 ng/mL) to 75 ng/mL for PFHS; LOQ (5 ng/mL) to 880 ng/mL for PFOS; and LOQ (5 or 10 ng/mL) to 7320 ng/mL for PFOA. Values less than the LOQ were not included in the statistical analyses of the mean of the ratios of individual values for the matrices. PFBS was not quantifiable in most samples. Serum to plasma ratios for PFHS, PFOS, and PFOA were 1:1 and this ratio was independent of the level of concentrations measured. Serum or plasma to whole blood ratios, regardless of the anticoagulant used, approximated 2:1. The difference between plasma and serum and whole blood corresponded to volume displacement by red blood cells, suggesting that the fluorochemicals are not found intracellularly or attached to the red blood cells

Hepatic Metabolism of Perfluorinated Carboxylic Acids and Polycholorotrifluoroethylene: A Nuclear Magnetic Resonance Investigation in Vivo

Science.gov (United States)

1993-01-14

I14JAN93 Annual Technical Report 15DEC91-1ý+JAN9 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Hepatic Metabolism of Perfluorinated Carboxylic Acids and G-FS...13. ABSTRACT (Maximum 200 words) This report describes our studies of the effects of perfluorooctanoic acid (PFOA) and perfluorodecanolc acid (PFDA) on...metabolism. 31 p NMR was used to examine the effects of PFDA. PFOA. and clofibrate (C LOF) in both rats and guinea pigs. A unique effect is revealed in

Transport and retention of 14C-perfluorooctanoic acid (PFOA) in saturated limestone and sand porous media: Effects of input concentration, ionic strength and cation type

Science.gov (United States)

Xueyan, L.; Gao, B.; Sun, Y.; Wu, J.

2017-12-01

Perfluorooctanoic acid (PFOA) has been used in a wide variety of industrial and consumer product applications. PFOA has been detected around the world at ng/L to μg/L levels in groundwater, and at ng/g levels in soil.The physicochemical properties of porous media were proven to play pivotal roles in determining the transport behavior of various pollutants. It is anticipated that physicochemical properties of porous media will strongly influence the transport behavior of PFOA. In addition, previous investigations have revealed that input concentration significantly influence the transport behavior of nanoparticles and antibiotics. Thus, this study was designed experimentally and fundamentally to gain insight into transport and retention of PFOA in various porous medias at different input concentrations, solution IS and cation type. Unlike in quartz sand porous media, the BTCs in limestone porous media exhibited increasing retention rate and high degree of tailing in limestone porous media. Results showed that higher relative retention occurred in limestone porous media than in quartz sand porous media under the same solution chemistry. This result was attributed to the less negative zeta-potentials, rougher surface and larger specific surface area, and the presence of hydroxyl groups and organic matters of limestone grains. Higher ionic strength and Ca2+ had little impact on the mobility of PFOA in quartz sand porous media, but significantly enhanced the retention of PFOA in limestone porous media. The difference is likely due to the compression of the electrical double layer, and the surface-charge neutralization and cation-bridging effect of Ca2+. Higher input concentration resulted in lower relative PFOA retention in limestone porous media, but the influence were insignificant in quartz sand porous media. This effect is likely because attachment sites in limestone responced to the variety of input concentration differently than quartz.

Phenotypic Dichotomy Following Developmental Exposure to Perfluorooctanic Acid (PFOA) Exposure in CD-1 Mice: Low Doses Induce Elevated Serum, Leptin, Insulin, and Overweight in Mid-Life.

Science.gov (United States)

The synthetic surfactant, perfluorooctanoic acid (PFOA) is a proven developmental toxicant in mice, causing prenatal pregnancy loss, increased neonatal mortality, delayed eye opening, and abnormal mammary gland growth in animals exposed during fetal life. PFOA is found in the ser...

Distribution and long-range transport of polyfluoroalkyl substances in the Arctic, Atlantic Ocean and Antarctic coast

International Nuclear Information System (INIS)

Zhao Zhen; Xie Zhiyong; Möller, Axel; Sturm, Renate; Tang Jianhui; Zhang Gan; Ebinghaus, Ralf

2012-01-01

The global distribution and long-range transport of polyfluoroalkyl substances (PFASs) were investigated using seawater samples collected from the Greenland Sea, East Atlantic Ocean and the Southern Ocean in 2009–2010. Elevated levels of ΣPFASs were detected in the North Atlantic Ocean with the concentrations ranging from 130 to 650 pg/L. In the Greenland Sea, the ΣPFASs concentrations ranged from 45 to 280 pg/L, and five most frequently detected compounds were perfluorooctanoic acid (PFOA), perfluorohexanesulfonate (PFHxS), perfluorohexanoic acid (PFHxA), perfluorooctane sulfonate (PFOS) and perfluorobutane sulfonate (PFBS). PFOA (15 pg/L) and PFOS (25–45 pg/L) were occasionally found in the Southern Ocean. In the Atlantic Ocean, the ΣPFASs concentration decreased from 2007 to 2010. The elevated PFOA level that resulted from melting snow and ice in Greenland Sea implies that the Arctic may have been driven by climate change and turned to be a source of PFASs for the marine ecosystem. - Highlights: ► PFOA is released from the Arctic snow and ice and might be transport southwards to the Atlantic. ► Decline temporal trends of PFASs are present in the Northern Hemisphere in the Atlantic. ► PFOS has elevate concentration in comparison to PFOA in the Southern Ocean. - Polyfluoroalkyl substances (PFASs) have been reported for the Arctic, Atlantic and the Southern Ocean, which improves understanding the fate of PFASs in the global oceans.

Perfluoroalkyl acids and their precursors in Swedish food: The relative importance of direct and indirect dietary exposure.

Science.gov (United States)

Gebbink, Wouter A; Glynn, Anders; Darnerud, Per Ola; Berger, Urs

2015-03-01

We analyzed food market basket samples obtained in Sweden from 1999, 2005, and 2010 for perfluoroalkyl acids (PFAAs) and a range of precursor compounds. Perfluorooctane sulfonic acid (PFOS) precursors were detected in all food year pools with the highest concentrations in 1999. Six polyfluoroalkyl phosphate diesters (diPAPs, 4:2/6:2, 6:2/6:2, 6:2/8:2, 8:2/8:2, 6:2/10:2, and 10:2/10:2) were detected in the year pools with the highest ∑diPAP concentrations in 1999 and 2005. All precursors were predominantly found in meat, fish, and/or eggs based on analysis of individual food groups from 1999. Based on year pools, PFOS precursors contributed between 4 and 1% as an indirect source to total dietary PFOS intakes between 1999 and 2010. Perfluorohexanoic acid (PFHxA) exposure originated entirely from diPAPs, whereas for perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), diPAPs contributed between 1 and 19% to total exposure. The lowest precursor contributions were generally seen in food samples from 2010. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Perfluoroalkyl Acid Concentrations in Blood Samples Subjected to Transportation and Processing Delay.

Science.gov (United States)

Bach, Cathrine Carlsen; Henriksen, Tine Brink; Bossi, Rossana; Bech, Bodil Hammer; Fuglsang, Jens; Olsen, Jørn; Nohr, Ellen Aagaard

2015-01-01

In studies of perfluoroalkyl acids, the validity and comparability of measured concentrations may be affected by differences in the handling of biospecimens. We aimed to investigate whether measured plasma levels of perfluoroalkyl acids differed between blood samples subjected to delay and transportation prior to processing and samples with immediate processing and freezing. Pregnant women recruited at Aarhus University Hospital, Denmark, (n = 88) provided paired blood samples. For each pair of samples, one was immediately processed and plasma was frozen, and the other was delayed and transported as whole blood before processing and freezing of plasma (similar to the Danish National Birth Cohort). We measured 12 perfluoroalkyl acids and present results for compounds with more than 50% of samples above the lower limit of quantification. For samples taken in the winter, relative differences between the paired samples ranged between -77 and +38% for individual perfluoroalkyl acids. In most cases concentrations were lower in the delayed and transported samples, e.g. the relative difference was -29% (95% confidence interval -30; -27) for perfluorooctane sulfonate. For perfluorooctanoate there was no difference between the two setups [corresponding estimate 1% (0, 3)]. Differences were negligible in the summer for all compounds. Transport of blood samples and processing delay, similar to conditions applied in some large, population-based studies, may affect measured perfluoroalkyl acid concentrations, mainly when outdoor temperatures are low. Attention to processing conditions is needed in studies of perfluoroalkyl acid exposure in humans.

The bioconcentration factor of perfluorooctane sulfonate is significantly larger than that of perfluorooctanoate in wild turtles (Trachemys scripta elegans and Chinemys reevesii): an Ai river ecological study in Japan.

Science.gov (United States)

Morikawa, Akiko; Kamei, Naoya; Harada, Kouji; Inoue, Kayoko; Yoshinaga, Takeo; Saito, Norimitsu; Koizumi, Akio

2006-09-01

Turtles rank high in the river food chain, and are suitable for predicting the bioconcentrations of chemicals through the food chain. Trachemys scripta elegans (N=46) and Chinemys reevesii (N=51) were captured in a river in Japan, from September to October 2003 and April to June 2004. Surface water samples were collected simultaneously from the same sites at which the turtles were caught. Serum perfluorooctane sulfonate (PFOS) ranged from 2.4 to 486 microg/L, while water PFOS levels ranged from 2.9 to 37 ng/L. The geometric mean (GM) (geometric standard deviation, GSD) of the bioconcentration factor (BCF) of PFOS was 10,964 (2.5). In contrast, the perfluorooctanoate (PFOA) level in water ranged from 16.7-87,100 ng/L, and serum PFOA ranged from <0.2 to 870 microg/L. The GM (GSD) of the BCF of PFOA was 3.2 (7.9). Furthermore, the BCF of PFOA decreased as the PFOA level in the surface water increased. PFOS could be preferentially bioconcentrated in biota, and PFOA, slightly bioconcentrated.

Investigation on the distribution and fate of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in a sewage-impacted bay

International Nuclear Information System (INIS)

Wang, Shiliang; Wang, Hui; Zhao, Wei; Cao, Yuanxin; Wan, Yi

2015-01-01

The distribution and fate of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) were investigated in the water and sediment of Bohai Bay, China, during 2011–2013. A total of 360 water samples and 60 sediment samples were collected from 20 locations. The median concentrations of PFOS and PFOA were 4.8 and 12.15 ng/L in the water, and 2.65 and 0.62 ng/g-dry in the sediment, respectively. Significant enrichment were observed for PFOS and PFOA in water of sea surface microlayer. The concentrations of these two compounds showed an apparent gradient from nearshore to offshore stations. The correlation analysis and the distribution tendencies indicated that freshwater inflowing to the bay was the main source of PFOS and PFOA. The salinity of seawater and the total organic carbon (TOC) content of sediment heavily affected the spatial distribution and the partitioning of PFOS and PFOA in the sediment-water system. - Highlights: • We investigated the distribution and partitioning of PFOS and PFOA in Bohai Bay. • The PFOS and PFOA concentration showed a gradient from nearshore to offshore sites. • The PFOS and PFOA enriched significantly in the sea surface microlayer of water. • Inflowing freshwater was the main source of PFOS and PFOA in Bohai Bay. • Salinity and TOC deeply affected the distribution and partitioning of PFOS and PFOA. - The spatial and temporal distribution and the partitioning of perfluorooctane sulfonate and perfluorooctanoate were determined in the seawater-sediment system of Bohai Bay

Occurrence and fate of perfluorinated acids in two wastewater treatment plants in Shanghai, China.

Science.gov (United States)

Zhang, Chaojie; Yan, Hong; Li, Fei; Zhou, Qi

2015-02-01

Perfluorinated acids (PFAs) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. The discharge of wastewater effluent from municipal wastewater treatment plants (WWTPs) is a significant source of PFAs to the environment. In this study, wastewater and sludge samples were collected from two WWTPs in Shanghai, China, to investigate the contamination level and fate of PFAs in different stages of processing. The total concentrations of PFAs (∑PFAs) in influent from plants A and B were 2,452 and 292 ng L(-1), respectively. Perfluoropentanoic acid (1,520 ± 80 ng L(-1) in plant A and 89.2 ± 12.1 ng L(-1) in plant B) was the predominant PFA in influent waters, followed by perfluorooctanoic acid. The concentration of ∑PFAs ranged from 75.0 to 126.0 ng g(-1) dry weight in sludge samples from plant B, with perfluorooctanesulfonic acid as the predominant contaminant. The concentrations and fate of PFAs in different WWTPs vary. The ∑PFAs entering plant A decreased significantly in the final effluent of activated sludge process, while that in plant B increased significantly in the final effluent of sequencing batch reactor system. The concentration changes could be due to the sorption onto sludge, or the degradation of PFAs precursors.

Comparative Serum Fatty Acid Profiles of Captive and Free-Ranging Cheetahs (Acinonyx jubatus) in Namibia.

Science.gov (United States)

Tordiffe, Adrian S W; Wachter, Bettina; Heinrich, Sonja K; Reyers, Fred; Mienie, Lodewyk J

2016-01-01

Cheetahs (Acinonyx jubatus) are highly specialised large felids, currently listed as vulnerable on the IUCN red data list. In captivity, they are known to suffer from a range of chronic non-infectious diseases. Although low heterozygosity and the stress of captivity have been suggested as possible causal factors, recent studies have started to focus on the contribution of potential dietary factors in the pathogenesis of these diseases. Fatty acids are an important component of the diet, not only providing a source of metabolisable energy, but serving other important functions in hormone production, cellular signalling as well as providing structural components in biological membranes. To develop a better understanding of lipid metabolism in cheetahs, we compared the total serum fatty acid profiles of 35 captive cheetahs to those of 43 free-ranging individuals in Namibia using gas chromatography-mass spectrometry. The unsaturated fatty acid concentrations differed most remarkably between the groups, with all of the polyunsaturated and monounsaturated fatty acids, except arachidonic acid and hypogeic acid, detected at significantly lower concentrations in the serum of the free-ranging animals. The influence of age and sex on the individual fatty acid concentrations was less notable. This study represents the first evaluation of the serum fatty acids of free-ranging cheetahs, providing critical information on the normal fatty acid profiles of free-living, healthy individuals of this species. The results raise several important questions about the potential impact of dietary fatty acid composition on the health of cheetahs in captivity.

Potentiometric Measurement of Transition Ranges and Titration Errors for Acid/Base Indicators

Science.gov (United States)

Flowers, Paul A.

1997-07-01

Sophomore analytical chemistry courses typically devote a substantial amount of lecture time to acid/base equilibrium theory, and usually include at least one laboratory project employing potentiometric titrations. In an effort to provide students a laboratory experience that more directly supports their classroom discussions on this important topic, an experiment involving potentiometric measurement of transition ranges and titration errors for common acid/base indicators has been developed. The pH and visually-assessed color of a millimolar strong acid/base system are monitored as a function of added titrant volume, and the resultant data plotted to permit determination of the indicator's transition range and associated titration error. Student response is typically quite positive, and the measured quantities correlate reasonably well to literature values.

Comparative Serum Fatty Acid Profiles of Captive and Free-Ranging Cheetahs (Acinonyx jubatus) in Namibia

Science.gov (United States)

Wachter, Bettina; Heinrich, Sonja K.; Reyers, Fred; Mienie, Lodewyk J.

2016-01-01

Cheetahs (Acinonyx jubatus) are highly specialised large felids, currently listed as vulnerable on the IUCN red data list. In captivity, they are known to suffer from a range of chronic non-infectious diseases. Although low heterozygosity and the stress of captivity have been suggested as possible causal factors, recent studies have started to focus on the contribution of potential dietary factors in the pathogenesis of these diseases. Fatty acids are an important component of the diet, not only providing a source of metabolisable energy, but serving other important functions in hormone production, cellular signalling as well as providing structural components in biological membranes. To develop a better understanding of lipid metabolism in cheetahs, we compared the total serum fatty acid profiles of 35 captive cheetahs to those of 43 free-ranging individuals in Namibia using gas chromatography-mass spectrometry. The unsaturated fatty acid concentrations differed most remarkably between the groups, with all of the polyunsaturated and monounsaturated fatty acids, except arachidonic acid and hypogeic acid, detected at significantly lower concentrations in the serum of the free-ranging animals. The influence of age and sex on the individual fatty acid concentrations was less notable. This study represents the first evaluation of the serum fatty acids of free-ranging cheetahs, providing critical information on the normal fatty acid profiles of free-living, healthy individuals of this species. The results raise several important questions about the potential impact of dietary fatty acid composition on the health of cheetahs in captivity. PMID:27992457

Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.

Science.gov (United States)

Yamada, Ami; Bemrah, Nawel; Veyrand, Bruno; Pollono, Charles; Merlo, Mathilde; Desvignes, Virginie; Sirot, Véronique; Oseredczuk, Marine; Marchand, Philippe; Cariou, Ronan; Antignac, Jean-Phillippe; Le Bizec, Bruno; Leblanc, Jean-Charles

2014-07-30

In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination.

Exposure assessment of tetrafluoroethylene and ammonium perfluorooctanoate 1951-2002.

Science.gov (United States)

Sleeuwenhoek, Anne; Cherrie, John W

2012-03-01

To develop a method to reconstruct exposure to tetrafluoroethylene (TFE) and ammonium perfluorooctanoate (APFO) in plants producing polytetrafluoroethylene (PTFE) in the absence of suitable objective measurements. These data were used to inform an epidemiological study being carried out to investigate possible risks in workers employed in the manufacture of PTFE and to study trends in exposure over time. For each plant, detailed descriptions of all occupational titles, including tasks and changes over time, were obtained during semi-structured interviews with key plant personnel. A semi-quantitative assessment method was used to assess inhalation exposure to TFE and inhalation plus dermal exposure to APFO. Temporal trends in exposure to TFE and APFO were investigated. In each plant the highest exposures for both TFE and APFO occurred in the polymerisation area. Due to the introduction of control measures, increasing process automation and other improvements, exposures generally decreased over time. In the polymerisation area, the annual decline in exposure to TFE varied by plant from 3.8 to 5.7% and for APFO from 2.2 to 5.5%. A simple method for assessing exposure was developed which used detailed process information and job descriptions to estimate average annual TFE and APFO exposure on an arbitrary semi-quantitative scale. These semi-quantitative estimates are sufficient to identify relative differences in exposure for the epidemiological study and should good data become available, they could be used to provide quantitative estimates for all plants across the whole period of operation. This journal is © The Royal Society of Chemistry 2012

Nuclear magnetic resonance and LC/MS characterization of native and new mass-labeled fluorinated telomer alcohols, acids and unsaturated acids

Energy Technology Data Exchange (ETDEWEB)

Arsenault, G.; Chittim, B.; McAlees, A.; Yeo, B. [Wellington Laboratories Inc., Guelph, ON (Canada); Ellis, D.; Mabury, S.; Stock, N. [Toronto Univ., ON (Canada); Halldorson, T.; Tomy, G. [Dept. of Fisheries and Oceans, Winnipeg, MB (Canada); McCrindle, R. [Guelph Univ., ON (Canada)

2004-09-15

A variety of fluorinated compounds are used in a multitude of consumer products because of their ability to repel water and oil, resistance to heat, and chemical inertness. Recently, scientists and regulators have begun raising concerns about the potential health and environmental impact of perfluorinated compounds. Exposure to perfluoroalkyl acids, such as Perfluorooctanoic acid (PFOA), has been identified as a potential human health concern. A study has shown that telomer alcohols such as 2-perfluorooctylethanol can be metabolized by living organisms or biodegrade under environmental conditions to sequentially give the saturated fluorinated telomer acid (2- perfluorooctylethanoic acid), then the unsaturated telomer acid (2H-Perfluorooct-2-enoic acid), and eventually PFOA. Additional experimental work is necessary to determine the extent, if any, to which telomer product degradation may be a source of PFOA. The analysis for fluorinated compounds in environmental samples is performed, primarily, using LC/MS techniques. These analyses have been hindered by the lack of any commercially available mass-labeled fluorinated compounds for use as surrogates and thus may be restricting the amount of research conducted in this area. We have now synthesized the mass-labeled perfluoroalkyl telomer alcohols and the corresponding acids and unsaturated acids. We report in this study their 1H-, 2H-, 19F- and 13C-NMR characterizations along with GC/MS and LC/MS data and evaluation of their use as surrogate standards.

Prenatal Phthalate, Perfluoroalkyl Acid, and Organochlorine Exposures and Term Birth Weight in Three Birth Cohorts

DEFF Research Database (Denmark)

Lenters, Virissa; Portengen, Lützen; Rignell-Hydbom, Anna

2016-01-01

body mass index. To identify independent associations, we applied the elastic net penalty to linear regression models. RESULTS: Two phthalate metabolites (MEHHP, MOiNP), perfluorooctanoic acid (PFOA), and p,p´-DDE were most consistently predictive of term birth weight based on elastic net penalty.......82 ng/g lipid), respectively; and MOiNP was associated with higher birth weight (46 g; 95% CI: -5, 97 per 2.22 ng/mL). CONCLUSIONS: This study suggests that several of the environmental contaminants, belonging to three chemical classes, may be independently associated with impaired fetal growth...

Comparative hepatotoxicity of 6:2 fluorotelomer carboxylic acid and 6:2 fluorotelomer sulfonic acid, two fluorinated alternatives to long-chain perfluoroalkyl acids, on adult male mice.

Science.gov (United States)

Sheng, Nan; Zhou, Xiujuan; Zheng, Fei; Pan, Yitao; Guo, Xuejiang; Guo, Yong; Sun, Yan; Dai, Jiayin

2017-08-01

Due to their structural similarities, 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA) are often used as alternatives to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), respectively. With limited health risk data and 6:2 FTSA detection in water and sludge, the toxicity of these chemicals is of growing concern. Here, adult male mice were exposed with 5 mg/kg/day of 6:2 FTCA or 6:2 FTSA for 28 days to investigate their hepatotoxicological effects. In contrast to 6:2 FTCA, 6:2 FTSA was detected at high and very high levels in serum and liver, respectively, demonstrating bioaccumulation potential and slow elimination. Furthermore, 6:2 FTSA induced liver weight increase, inflammation, and necrosis, whereas 6:2 FTCA caused no obvious liver injury, with fewer significantly altered genes detected compared with that of 6:2 FTSA (39 vs. 412). Although PFOA and PFOS commonly activate peroxisome proliferator-activated receptor α (PPARα), 6:2 FTSA induced an increase in PPARγ and related proteins, but not in lipid metabolism-related genes such as PPARα. Our results showed that 6:2 FTCA and 6:2 FTSA exhibited weak and moderate hepatotoxicity, respectively, compared with that reported for legacies PFOA and PFOS.

Two cloud-point phenomena in tetrabutylammonium perfluorooctanoate aqueous solutions: anomalous temperature-induced phase and structure transitions.

Science.gov (United States)

Yan, Peng; Huang, Jin; Lu, Run-Chao; Jin, Chen; Xiao, Jin-Xin; Chen, Yong-Ming

2005-03-24

This paper reported the phase behavior and aggregate structure of tetrabutylammonium perfluorooctanoate (TBPFO), determined by differential scanning calorimeter, electrical conductivity, static/dynamic light scattering, and rheology methods. We found that above a certain concentration the TBPFO solution showed anomalous temperature-dependent phase behavior and structure transitions. Such an ionic surfactant solution exhibits two cloud points. When the temperature was increased, the solution turned from a homogeneous-phase to a liquid-liquid two-phase system, then to another homogeneous-phase, and finally to another liquid-liquid two-phase system. In the first homogeneous-phase region, the aggregates of TBPFO were rodlike micelles and the solution was Newtonian fluid. While in the second homogeneous-phase region, the aggregates of TBPFO were large wormlike micelles, and the solution behaved as pseudoplastic fluid that also exhibited viscoelastic behavior. We thought that the first cloud point might be caused by the "bridge" effect of the tetrabutylammonium counterion between the micelles and the second one by the formation of the micellar network.

Foodstuff analyses show that seafood and water are major perfluoroalkyl acids (PFAAs) sources to humans in Korea

Energy Technology Data Exchange (ETDEWEB)

Heo, Jin-Ju; Lee, Ji-Woo [Department of Civil and Environmental Engineering, Pusan National University, Busan, 609-735 (Korea, Republic of); Kim, Seung-Kyu [Department of Marine Science, College of Natural Sciences, Incheon National University, Incheon, 406-772 (Korea, Republic of); Oh, Jeong-Eun, E-mail: jeoh@pusan.ac.kr [Department of Civil and Environmental Engineering, Pusan National University, Busan, 609-735 (Korea, Republic of)

2014-08-30

Graphical abstract: - Highlights: • 16 PFAAs in 397 samples of 66 food types and 34 tap water samples were analyzed. • Dietary exposure to PFAAs was estimated by using the PFAAs measured concentrations. • The major contributors of PFAAs dietary exposure were confirmed. - Abstract: We measured concentrations of PFAAs in 397 foods, of 66 types, in Korea, and determined the daily human dietary PFAAs intake and the contribution of each foodstuff to that intake. The PFAAs concentration in the 66 different food types ranged from below the detection limit to 48.3 ng/g. Perfluorooctane sulfonate (PFOS) and long-chain perfluorocarboxylic acids (PFCAs) were the dominant PFAAs in fish, shellfish, and processed foods, while perfluorooctanoic acid (PFOA) and short-chain PFCAs dominated dairy foodstuffs and beverages. The Korean adult dietary intake ranges, estimated for a range of scenarios, were 0.60–3.03 and 0.17–1.68 ng kg{sup −1} bw d{sup −1} for PFOS and PFOA, respectively, which were lower than the total daily intake limits suggested by European Food Safety Authority (PFOS: 150 ng kg{sup −1} bw d{sup −1}; PFOA: 1500 ng kg{sup −1} bw d{sup −1}). The major contributors to PFAAs dietary exposure varied with subject age and PFAAs. For example, fish was a major contributor of PFOS but dairy foods were major contributors of PFOA. However, tap water was a major contributor to PFOA intake when it was the main source of drinking water (rather than bottled water)

Foodstuff analyses show that seafood and water are major perfluoroalkyl acids (PFAAs) sources to humans in Korea

International Nuclear Information System (INIS)

Heo, Jin-Ju; Lee, Ji-Woo; Kim, Seung-Kyu; Oh, Jeong-Eun

2014-01-01

Graphical abstract: - Highlights: • 16 PFAAs in 397 samples of 66 food types and 34 tap water samples were analyzed. • Dietary exposure to PFAAs was estimated by using the PFAAs measured concentrations. • The major contributors of PFAAs dietary exposure were confirmed. - Abstract: We measured concentrations of PFAAs in 397 foods, of 66 types, in Korea, and determined the daily human dietary PFAAs intake and the contribution of each foodstuff to that intake. The PFAAs concentration in the 66 different food types ranged from below the detection limit to 48.3 ng/g. Perfluorooctane sulfonate (PFOS) and long-chain perfluorocarboxylic acids (PFCAs) were the dominant PFAAs in fish, shellfish, and processed foods, while perfluorooctanoic acid (PFOA) and short-chain PFCAs dominated dairy foodstuffs and beverages. The Korean adult dietary intake ranges, estimated for a range of scenarios, were 0.60–3.03 and 0.17–1.68 ng kg −1 bw d −1 for PFOS and PFOA, respectively, which were lower than the total daily intake limits suggested by European Food Safety Authority (PFOS: 150 ng kg −1 bw d −1 ; PFOA: 1500 ng kg −1 bw d −1 ). The major contributors to PFAAs dietary exposure varied with subject age and PFAAs. For example, fish was a major contributor of PFOS but dairy foods were major contributors of PFOA. However, tap water was a major contributor to PFOA intake when it was the main source of drinking water (rather than bottled water)

Perfluoroalkyl acids and their precursors in Swedish food: The relative importance of direct and indirect dietary exposure

International Nuclear Information System (INIS)

Gebbink, Wouter A.; Glynn, Anders; Darnerud, Per Ola; Berger, Urs

2015-01-01

We analyzed food market basket samples obtained in Sweden from 1999, 2005, and 2010 for perfluoroalkyl acids (PFAAs) and a range of precursor compounds. Perfluorooctane sulfonic acid (PFOS) precursors were detected in all food year pools with the highest concentrations in 1999. Six polyfluoroalkyl phosphate diesters (diPAPs, 4:2/6:2, 6:2/6:2, 6:2/8:2, 8:2/8:2, 6:2/10:2, and 10:2/10:2) were detected in the year pools with the highest ∑diPAP concentrations in 1999 and 2005. All precursors were predominantly found in meat, fish, and/or eggs based on analysis of individual food groups from 1999. Based on year pools, PFOS precursors contributed between 4 and 1% as an indirect source to total dietary PFOS intakes between 1999 and 2010. Perfluorohexanoic acid (PFHxA) exposure originated entirely from diPAPs, whereas for perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), diPAPs contributed between 1 and 19% to total exposure. The lowest precursor contributions were generally seen in food samples from 2010. - Highlights: • Three PFOS precursors and six diPAPs were detected in food pools. • Precursor concentrations were highest in 1999 and 2005 food pools, and lowest in 2010. • The relative importance of precursors to total PFOS dietary intake was <4%. • The relative importance of diPAPs as an indirect dietary source of PFCAs was chain length dependent. - The relative contribution of precursors to PFOS dietary intakes is small, whereas the contribution of diPAPs to PFCA dietary intakes varies with the PFCA chain length

Inhibition effects of perfluoroalkyl acids on progesterone production in mLTC-1.

Science.gov (United States)

Zhao, Wei; Cui, Ruina; Wang, Jianshe; Dai, Jiayin

2017-06-01

Perfluoroalkyl substances (PFASs) are a class of fluorine substituted carboxylic acid, sulfonic acid and alcohol, structurally similar to their corresponding parent compounds. Previous study demonstrated the potential endocrine disruption and reproductive toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid, two dominant PFASs in animals and humans. We explored the relationship between eleven perfluoroalkyl acids (PFAAs) with different carbon chain length and their ability to inhibit progesterone production in mouse Leydig tumor cells (mLTC-1). We found an obvious dose-response relationship between progesterone inhibition rate and PFAA exposure concentration in mLTC-1. The relative inhibition rate of progesterone by PFAAs was linearly related to the carbon chain length and molar refractivity of PFAAs. Mitochondrial membrane potential (MMP) decreased after PFAA exposure at the half-maximal inhibitory effect concentration (IC 50 ) of progesterone production in mLTC-1, while the reactive oxygen species (ROS) content increased significantly. These results imply that the inhibition effect of PFAAs on progesterone production might be due, in part, to ROS damage and the decrease in MMP in mLTC-1. Copyright © 2016. Published by Elsevier B.V.

Predicting sorption of organic acids to a wide range of carbonized sorbents

Science.gov (United States)

Sigmund, Gabriel; Kah, Melanie; Sun, Huichao; Hofmann, Thilo

2016-04-01

Many contaminants and infochemicals are organic acids that undergo dissociation under environmental conditions. The sorption of dissociated anions to biochar and other carbonized sorbents is typically lower than that of neutral species. It is driven by complex processes that are not yet fully understood. It is known that predictive approaches developed for neutral compounds are unlikely to be suitable for organic acids, due to the effects of dissociation on sorption. Previous studies on the sorption of organic acids to soils have demonstrated that log Dow, which describes the decrease in hydrophobicity of acids upon dissociation, is a useful alternative to log Kow. The aim of the present study was to adapt a log Dow based approach to describe the sorption of organic acids to carbonized sorbents. Batch experiments were performed with a series of 9 sorbents (i.e., carbonized wood shavings, pig manure, and sewage sludge, carbon nanotubes and activated carbon), and four acids commonly used for pesticidal and biocidal purposes (i.e., 2,4-D, MCPA, 2,4-DB, and triclosan). Sorbents were comprehensively characterized, including by N2 and CO2 physisorption, Fourier transform infrared spectroscopy, and elemental analysis. The wide range of sorbents considered allows (i) discussing the mechanisms driving the sorption of neutral and anionic species to biochar, and (ii) their dependency on sorbate and sorbent properties. Results showed that the sorption of the four acids was influenced by factors that are usually not considered for neutral compounds (i.e., pH, ionic strength). Dissociation affected the sorption of the four compounds, and sorption of the anions ranged over five orders of magnitude, thus substantially contributing to sorption in some cases. For prediction purposes, most of the variation in sorption to carbonized sorbents (89%) could be well described with a two-parameter regression equation including log Dow and sorbent specific surface area. The proposed model

Enhanced adsorption of perfluorooctane sulfonate and perfluorooctanoate by bamboo-derived granular activated carbon.

Science.gov (United States)

Deng, Shubo; Nie, Yao; Du, Ziwen; Huang, Qian; Meng, Pingping; Wang, Bin; Huang, Jun; Yu, Gang

2015-01-23

A bamboo-derived granular activated carbon with large pores was successfully prepared by KOH activation, and used to remove perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from aqueous solution. The granular activated carbon prepared at the KOH/C mass ratio of 4 and activation temperature of 900°C had fast and high adsorption for PFOS and PFOA. Their adsorption equilibrium was achieved within 24h, which was attributed to their fast diffusion in the micron-sized pores of activated carbon. This granular activated carbon exhibited the maximum adsorbed amount of 2.32mmol/g for PFOS and 1.15mmol/g for PFOA at pH 5.0, much higher than other granular and powdered activated carbons reported. The activated carbon prepared under the severe activation condition contained many enlarged pores, favorable for the adsorption of PFOS and PFOA. In addition, the spent activated carbon was hardly regenerated in NaOH/NaCl solution, while the regeneration efficiency was significantly enhanced in hot water and methanol/ethanol solution, indicating that hydrophobic interaction was mainly responsible for the adsorption. The regeneration percent was up to 98% using 50% ethanol solution at 45°C. Copyright © 2014 Elsevier B.V. All rights reserved.

Perfluorinated carboxylic acids in human breast milk from Spain and estimation of infant's daily intake

Energy Technology Data Exchange (ETDEWEB)

Motas Guzmàn, Miguel [Área de Toxicología, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Clementini, Chiara [University of Siena, Department of Physical Sciences, Earth and Environment, Via Mattioli, 4, 53100 Siena (Italy); Pérez-Cárceles, Maria Dolores; Jiménez Rejón, Sandra [Department of Legal Medicine, School of Medicine, University of Murcia & Instituto Murciano de Investigacion Biomedica (IMIB), (IMIB-VIRGEN DE LA ARRIXACA), Murcia (Spain); Cascone, Aurora; Martellini, Tania [Department of Chemistry “Ugo Schiff”, via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze (Italy); Guerranti, Cristiana [University of Siena, Department of Physical Sciences, Earth and Environment, Via Mattioli, 4, 53100 Siena (Italy); Bioscience Research Center, Via Aurelia Vecchia 32, 58015 Orbetello, GR (Italy); Cincinelli, Alessandra, E-mail: acincinelli@unifi.it [Department of Chemistry “Ugo Schiff”, via della Lastruccia 3, 50019 Sesto Fiorentino, Firenze (Italy)

2016-02-15

Human milk samples were collected from 67 mothers in 2014 at a Primary Care Centre in Murcia (Spain) and analyzed for perfluorinated carboxylic acids (PFCAs). Concentrations measured for perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA) and perfluorododecanoic acid (PFDoDA) ranged from < LOQ (< 10 ng/L) to 397 ng/L with a mean concentration of 66 ± 68 ng/L and a median of 29 ng/L. The presence of these compounds was revealed in 50 samples out of 67 analyzed. Influence of number of pregnancies and food habits on PFCAs concentrations was also investigated. Statistically significant differences in PFCA levels were found when the women were divided into maternal age classes and into the categories primiparae and multiparae. A greater transfer of PFC during breastfeeding by primiparous was evidenced and thus a higher exposure to these contaminants for the first child. Moreover, it was possible to hypothesize that the content of PFCs is in general correlated to the eating habits of donors and, in particular, with the fish consumption. Finally, PFOA daily intakes and risk index (RI) were estimated for the first six months of life and we found that ingestion rates of PFOA did not exceed the tolerable daily intake (TDI) recommended by the European Food Safety Authority (EFSA). - Graphical abstract: Figure SI 1. Concentrations (ng/L) of PFCs recovered in 67 samples of human breast milk. - Highlights: • Perfluorinated carboxylic acids were analyzed in a set of 67 breast milk samples collected from Spanish women. • PFOA appeared as the major contributor to the total perfluorinated carboxylic acids. • PFOA concentrations were significantly higher in milk of primiparous participants. • PFOA daily intake and risk index were estimated for the firsts six month of life.

Perfluorinated carboxylic acids in human breast milk from Spain and estimation of infant's daily intake

International Nuclear Information System (INIS)

Motas Guzmàn, Miguel; Clementini, Chiara; Pérez-Cárceles, Maria Dolores; Jiménez Rejón, Sandra; Cascone, Aurora; Martellini, Tania; Guerranti, Cristiana; Cincinelli, Alessandra

2016-01-01

Human milk samples were collected from 67 mothers in 2014 at a Primary Care Centre in Murcia (Spain) and analyzed for perfluorinated carboxylic acids (PFCAs). Concentrations measured for perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA) and perfluorododecanoic acid (PFDoDA) ranged from < LOQ (< 10 ng/L) to 397 ng/L with a mean concentration of 66 ± 68 ng/L and a median of 29 ng/L. The presence of these compounds was revealed in 50 samples out of 67 analyzed. Influence of number of pregnancies and food habits on PFCAs concentrations was also investigated. Statistically significant differences in PFCA levels were found when the women were divided into maternal age classes and into the categories primiparae and multiparae. A greater transfer of PFC during breastfeeding by primiparous was evidenced and thus a higher exposure to these contaminants for the first child. Moreover, it was possible to hypothesize that the content of PFCs is in general correlated to the eating habits of donors and, in particular, with the fish consumption. Finally, PFOA daily intakes and risk index (RI) were estimated for the first six months of life and we found that ingestion rates of PFOA did not exceed the tolerable daily intake (TDI) recommended by the European Food Safety Authority (EFSA). - Graphical abstract: Figure SI 1. Concentrations (ng/L) of PFCs recovered in 67 samples of human breast milk. - Highlights: • Perfluorinated carboxylic acids were analyzed in a set of 67 breast milk samples collected from Spanish women. • PFOA appeared as the major contributor to the total perfluorinated carboxylic acids. • PFOA concentrations were significantly higher in milk of primiparous participants. • PFOA daily intake and risk index were estimated for the firsts six month of life.

Occurrence and assessment of perfluoroalkyl acids (PFAAs) in commonly consumed seafood from the coastal area of Bangladesh.

Science.gov (United States)

Habibullah-Al-Mamun, Md; Ahmed, Md Kawser; Raknuzzaman, Mohammad; Islam, Md Saiful; Ali, Mir Mohammad; Tokumura, Masahiro; Masunaga, Shigeki

2017-11-30

This study reports the first evidence of the occurrence of PFAAs in commonly consumed seafood from the coastal area of Bangladesh. Fifteen target PFAAs in 48 seafood samples (5 finfish and 2 shellfish species) were measured by HPLC-MS/MS. The ΣPFAAs in finfish and shellfish were in the range of 0.32-14.58 and 1.31-8.34 (ng/g wet weight), respectively. Perfluorooctanesulfonate (PFOS) in finfish (0.1-3.86ng/g ww), whereas perfluorooctanoic acid (PFOA) in shellfish (0.07-2.39ng/g ww) were the most abundant PFAAs. The results were comparable with other studies worldwide, particularly from China, Spain, Sweden, and USA. The majority of monitored PFAAs did not show clear seasonal variation. However, seafood from the southeast area (Cox's Bazar and Chittagong) showed relatively higher levels of PFAAs. Moreover, the dietary exposure assessment revealed that the daily intakes of PFAAs via seafood consumption were far less than the health-based guidelines, indicating low health risk for the Bangladeshi coastal residents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of perfluorodecanoic(PFDA) and perfluorooctanoic (PFOA) acids on hepatic carnitine palmitoyltransferase (CPT) activity in rats

International Nuclear Information System (INIS)

Vanden Heuvel, J.P.; Kuslikis, B.I.; Peterson, R.E.

1990-01-01

PFDA has been hypothesized to cause a diversion of fatty acids from oxidation toward esterification in rat liver. Normal regulation of this partitioning is exerted by CPT, an enzyme inhibited by several peroxisome proliferators. Effects of the peroxisome proliferators PFDA and PFOA on hepatic mitochondrial fatty acid oxidation and CPT activity were examined. PFDA or PFOA added to isolated rat liver mitochondria in concentrations of 0.2, 2, 20 and 200 μg per mg mitochondrial protein had no effect on CPT activity nor on mitochondrial oxidation of [1- 14 C] palmitoyl-CoA or [1- 14 C] palmitoyl-carnitine (quantitated by 14 CO 2 plus acid soluble 14 C production). Three days after rats were treated with PFDA or PFOA (37.5 or 150 μmol/kg, ip) or vehicle, liver mitochondria were isolated. Mitochondrial oxidation of [1- 14 C] palmitoyl-CoA or [1- 14 C]palmitoyl-carnitine was unaffected by PFDA and PFOA. CPT activity and inhibition of CPT activity by malonyl-CoA was also unaffected by PFDA and PFOA. Therefore, PFDA and PFOA did not have a major inhibitory effect on hepatic mitochondrial oxidation of palmitoyl-CoA or palmitoyl-carnitine, nor did they interfere with hepatic CPT activity either in vitro or in vivo

Exposure to PFOS, PFHxS, or PFHxA, but not GenX, Nafion BP1, or ADONA, Elicits Developmental Neurotoxicity in Larval Zebrafish

Science.gov (United States)

Exposure to polyfluoroalkyl substances (PFAS) like perfluorooctane sulfonic acid (PFOS) or perfluorooctanoic acid (PFOA) are associated with developmental toxicity, neurotoxicity, and carcinogenesis. Legacy PFAS have therefore been replaced with shorter carbon chain and polyfluor...

Perfluoroalkyl substances measured in breast milk and child neuropsychological development in a Norwegian birth cohort study

NARCIS (Netherlands)

Forns, J.; Iszatt, N.; White, R.A.; Mandal, S.; Sabaredzovic, A.; Lamoree, M.H.; Thomsen, C.; Haug, L.S.; Stigum, H.; Eggesbo, M.

2015-01-01

Perfluoroalkyl substances (PFASs) are chemicals with potential neurotoxic effects although the current evidence is still limited. This study investigated the association between perinatal exposure to perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) and neuropsychological

Optimization of sample preparation and chromatography for the determination of perfluoroalkyl acids in sediments from the Yangtze Estuary and East China Sea.

Science.gov (United States)

Wang, Qian-Wen; Yang, Gui-Peng; Zhang, Ze-Ming; Zhang, Jing

2018-08-01

Perfluoroalkyl acids (PFAAs) are ubiquitous pollutants present in various environmental media, including marine sediments. A method was proposed for the determination of 17 target PFAA analytes in marine sediment samples (n = 49) collected from the Yangtze Estuary and East China Sea. The proposed method involves the use of an optimized pretreatment procedure and ultrahigh-performance liquid chromatography electrospray ionization-tandem mass spectrometry in dynamic multiple reaction monitoring mode. The method relied on extraction cycles using methanol followed by concentration, filtration, and small volume injection to UHPLC-MS/MS. The recovery, time efficiency, and detection limit of the proposed method are improved relative to those of traditional methods. Limits of detection varied from 0.003 to 0.045 ng/g, and spike recoveries to sediment ranged from 90% to 110% with suitable precisions (1.7%-14.6%). PFAAs were widely present in the samples, and ΣPFAAs ranged from 0.67 ng/g dw to 36.75 ng/g dw. Results indicated that terrigenous input strongly influences PFAA distribution in sediments from the study areas. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) were identified as the dominant perfluorocarboxylic acid (PFCA) and perfluoroalkylsulfonate (PFSA) in sediment samples from the Yangtze Estuary and the East China Sea. Preliminary environmental risk assessment indicated that PFOS may pose a higher environmental risk than PFOA. Furthermore, risk quotient values indicated that PFOS poses a significant risk to the aquatic ecosystem of the study areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

The developmental toxicity of perfluoroalkyl acids and their derivatives

International Nuclear Information System (INIS)

Lau, Christopher; Butenhoff, John L.; Rogers, John M.

2004-01-01

Perfluoroalkyl acids such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have applications in numerous industrial and consumer products. Although the toxicology of some of these compounds has been investigated in the past, the widespread prevalence of PFOS and PFOA in humans, as demonstrated in recent bio-monitoring studies, has drawn considerable interest from the public and regulatory agencies as well as renewed efforts to better understand the hazards that may be inherent in these compounds. This review provides a brief overview of the perfluoroalkyl chemicals and a summary of the available information on the developmental toxicity of the eight-carbon compounds, PFOS and PFOA. Although the teratological potentials of some of these chemicals had been studied in the past and the findings were generally unremarkable, results from recent postnatal studies on developmental and reproductive indices have prompted consideration of their relevance to human health risk. Based on current understanding of the developmental effects of PFOS and PFOA in rodents, several avenues of research are suggested that would further support the risk assessment of these perfluorinated organic chemicals

Occurrence and transport of 17 perfluoroalkyl acids in 12 coastal rivers in south Bohai coastal region of China with concentrated fluoropolymer facilities

International Nuclear Information System (INIS)

Wang, Pei; Lu, Yonglong; Wang, Tieyu; Fu, Yaning; Zhu, Zhaoyun; Liu, Shijie; Xie, Shuangwei; Xiao, Yang; Giesy, John P.

2014-01-01

Perfluoroalkyl acids (PFAAs) are emerging contaminants that have raised great concern in recent years. While PFAAs manufacturing becomes regulated in developed countries, production has been partly shifted to China. Eight fluoropolymer manufacturing facilities located in the South Bohai coastal region, one of the most populated areas of China, have been used to manufacture PFAA-related substances since 2001. The environmental consequence of the intensive production of PFAAs in this region remains largely unknown. We analyzed 17 PFAAs in twelve coastal rivers of this region, and found staggeringly high concentrations of perfluorooctanoic acid (PFOA) ranging from 0.96 to 4534.41 ng/L. The highest concentration was observed in the Xiaoqing River which received effluents from certain fluoropolymer facilities. Principal component analysis indicated similar sources of several perfluoroalkyl carboxylic acids (PFCAs) in all rivers, which indicated that atmospheric transport, wastewater treatment and surface runoff also acted as important supplements to direct discharge to surface water. - Highlights: • PFAAs were detected in rapidly urbanized regions. • PFOA was found predominant followed by short chain PFCAs. • Fluoropolymer facilities were associated with PFAAs contamination. • Higher PFAAs levels were found near the PTFE production facilities. • Diffusion of PFAAs from rivers to the sea was influenced by tide and current. - High level of PFOA was detected in the river water due to the fluoropolymer industries in South Bohai coastal region

Airborne Precursors Predict Maternal Serum Perfluoroalkyl Acid Concentrations.

Science.gov (United States)

Makey, Colleen M; Webster, Thomas F; Martin, Jonathan W; Shoeib, Mahiba; Harner, Tom; Dix-Cooper, Linda; Webster, Glenys M

2017-07-05

Human exposure to persistent perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctanesulfonate (PFOS), can occur directly from contaminated food, water, air, and dust. However, precursors to PFAAs (PreFAAs), such as dipolyfluoroalkyl phosphates (diPAPs), fluorotelomer alcohols (FTOHs), perfluorooctyl sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs), which can be biotransformed to PFAAs, may also be a source of exposure. PFAAs were analyzed in 50 maternal sera samples collected in 2007-2008 from participants in Vancouver, Canada, while PFAAs and PreFAAs were measured in matching samples of residential bedroom air collected by passive sampler and in sieved vacuum dust (<150 μm). Concentrations of PreFAAs were higher than for PFAAs in air and dust. Positive associations were discovered between airborne 10:2 FTOH and serum PFOA and PFNA and between airborne MeFOSE and serum PFOS. On average, serum PFOS concentrations were 2.3 ng/mL (95%CI: 0.40, 4.3) higher in participants with airborne MeFOSE concentrations in the highest tertile relative to the lowest tertile. Among all PFAAs, only PFNA in air and vacuum dust predicted serum PFNA. Results suggest that airborne PFAA precursors were a source of PFOA, PFNA, and PFOS exposure in this population.

Fatty acid composition of cooked chicken meat and chicken meat products as influenced by price range at retail.

Science.gov (United States)

Gibbs, Rachael A; Rymer, Caroline; Givens, D I

2013-06-01

The primary objective was to determine fatty acid composition of skinless chicken breast and leg meat portions and chicken burgers and nuggets from the economy price range, standard price range (both conventional intensive rearing) and the organic range from four leading supermarkets. Few significant differences in the SFA, MUFA and PUFA composition of breast and leg meat portions were found among price ranges, and supermarket had no effect. No significant differences in fatty acid concentrations of economy and standard chicken burgers were found, whereas economy chicken nuggets had higher C16:1, C18:1 cis, C18:1 trans and C18:3 n-3 concentrations than had standard ones. Overall, processed chicken products had much higher fat contents and SFA than had whole meat. Long chain n-3 fatty acids had considerably lower concentrations in processed products than in whole meat. Overall there was no evidence that organic chicken breast or leg meat had a more favourable fatty acid composition than had meat from conventionally reared birds. Copyright © 2012 Elsevier Ltd. All rights reserved.

Longitudinal Associations of Exposure to Perfluoroalkylated Substances in Childhood and Adolescence and Indicators of Adiposity and Glucose Metabolism 6 and 12 Years Later

DEFF Research Database (Denmark)

Domazet, Sidsel Louise; Grøntved, Anders; Timmermann, Clara Amalie Gade

2016-01-01

OBJECTIVE: To investigate the long-term association of exposure to perfluoroalkylated substances, including perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), during childhood (9 years) and adolescence (15 years) on indicators of adiposity and glucose metabolism in adolescence...

Male reproductive system parameters in a two-generation reproduction study of ammonium perfluorooctanoate in rats and human relevance.

Science.gov (United States)

York, Raymond G; Kennedy, Gerald L; Olsen, Geary W; Butenhoff, John L

2010-04-30

Ammonium perfluorooctanoate (ammonium PFOA) is an industrial surfactant that has been used primarily as a processing aid in the manufacture of fluoropolymers. The environmental and metabolic stability of PFOA together with its presence in human blood and long elimination half-life have led to extensive toxicological studies in laboratory animals. Two recent publications based on observations from the Danish general population have reported: (1) a negative association between serum concentrations of PFOA in young adult males and their sperm counts and (2) a positive association among women with time to pregnancy. A two-generation reproduction study in rats was previously published (2004) in which no effects on functional reproduction were observed at doses up to 30mg ammonium PFOA/kg body weight. The article contained the simple statement: "In males, fertility was normal as were all sperm parameters". In order to place the recent human epidemiological data in perspective, herein we provide the detailed male reproductive parameters from that study, including sperm quality and testicular histopathology. Sperm parameters in rats from the two-generation study in all ammonium PFOA treatment groups were unaffected by treatment with ammonium PFOA. These observations reflected the normal fertility observations in these males. No evidence of altered testicular and sperm structure and function was observed in ammonium PFOA-treated rats whose mean group serum PFOA concentrations ranged up to approximately 50,000ng/mL. Given that median serum PFOA in the Danish cohorts was approximately 5ng/mL, it seems unlikely that concentrations observed in the general population, including those recently reported in Danish general population, could be associated causally with a real decrement in sperm number and quality.

Predicting Chemical Toxicity from Proteomics and Computational Chemistry

Science.gov (United States)

2008-07-30

perfluorooctanoic acid , perfluorodecanoic acid , clofibrate , and diethylhexyl phthalate) show that the leading eigenvalue of the D/D matrix derived from embedded... clofibrate , and DEHP, show that this approach clusters the first three highly-fluorinated and mechanistically similar chemicals together, while

Perfluoroalkyl Acids in Maternal Serum and Indices of Fetal Growth

DEFF Research Database (Denmark)

Bach, Cathrine C; Bech, Bodil H; Nohr, Ellen A

2015-01-01

BACKGROUND: Previous studies indicated an association between intrauterine exposure to perfluorooctane sulfonate (PFOS) or perfluorooctanoate (PFOA) and lower birth weight. However, these perfluoroalkyl acids (PFAAs) have to some extent been substituted by other compounds on which little is known...... was restricted to term births (n=1426). For PFOS, the birth weight estimates for the highest versus lowest quartile were -50 [95 % CI: -123; 23] g in all births and -62 [95 % CI: -126; 3] g in term births. For the other PFAAs, the direction of the associations was inconsistent, and no overall association...... with birth weight was apparent. No PFAAs were associated with birth length or head circumference at birth. CONCLUSIONS: Overall, we did not find strong or consistent associations between PFAAs and birth weight or other indices of fetal growth, though estimated mean birth weights were lower among those...

[Commentary on] Serum vaccine antibody concentrations in children exposed to perfluorinated compounds

DEFF Research Database (Denmark)

Grandjean, P.; Andersen, Elisabeth Wreford; Budtz-Jorgenser

2012-01-01

The article presents insights into a study which examined the role of perfluorinated compounds (PFC) in antibody response to childhood vaccinations. The prevalence of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) which were mentioned in the study was reported by the U...

Simple intake and pharmacokinetic modeling to characterize exposure of Americans to perfluoroctanoic acid, PFOA.

Science.gov (United States)

Lorber, Matthew; Egeghy, Peter P

2011-10-01

Models for assessing intakes of perfluorooctanoic acid, PFOA, are described and applied. One model is based on exposure media concentrations and contact rates. This model is applied to general population exposures for adults and 2-year old children. The other model is a simple one-compartment, first-order pharmacokinetic (PK) model. Parameters for this model include a rate of elimination of PFOA and a blood volume of distribution. The model was applied to data from the National Health and Nutritional Examination Survey, NHANES, to backcalculate intakes. The central tendency intake estimate for adults and children based on exposure media concentrations and contact rates were 70 and 26 ng/day, respectively. The central tendency adult intake derived from NHANES data was 56 and 37 ng/day for males and females, respectively. Variability and uncertainty discussions regarding the intake modeling focus on lack of data on direct exposure to PFOA used in consumer products, precursor compounds, and food. Discussions regarding PK modeling focus on the range of blood measurements in NHANES, the appropriateness of the simple PK model, and the uncertainties associated with model parameters. Using the PK model, the 10th and 95th percentile long-term average adult intakes of PFOA are 15 and 130 ng/day.

A convenient catalyst system for microwave accelerated cross-coupling of a range of aryl boronic acids with aryl chlorides

Directory of Open Access Journals (Sweden)

Milton Edward J

2007-05-01

Full Text Available Abstract A convenient microwave accelerated cross-coupling procedure between aryl chlorides with a range of boronic acids has been developed. An explanation for the low reactivity of highly fluorinated boronic acids in Suzuki coupling is provided.

Polyfluorinated alkyl phosphate ester surfactants - current knowledge and knowledge gaps

DEFF Research Database (Denmark)

Taxvig, Camilla; Rosenmai, Anna Kjerstine; Vinggaard, Anne Marie

2014-01-01

as in human blood, urine and milk. Due to their long half-life in human beings, there is an increased risk that exposure to these compounds can cause adverse effects. However, except for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), there is a large data gap regarding toxicological...

Quantitative characterization of short- and long-chain perfluorinated acids in solid matrices in Shanghai, China.

Science.gov (United States)

Li, Fei; Zhang, Chaojie; Qu, Yan; Chen, Jing; Chen, Ling; Liu, Ying; Zhou, Qi

2010-01-01

Perfluorinated acids (PFAs) have been recognized as emerging environmental pollutants because of their widespread occurrences, persistence, and bioaccumulative and toxicological effects. PFAs have been detected in aquatic environment and biota in China, but the occurrences of these chemicals have not been reported in solid matrices in China. In the present study, short- and long-chain PFAs (C2-C14) have been quantitatively determined in solid matrices including sediments, soils and sludge collected in Shanghai, China. The results indicate that sludge contains more PFAs than sediments and soils, and the total PFAs concentrations in sediments, soil and sludge are 62.5-276 ng g(-1), 141-237 ng g(-1) and 413-755 ng g(-1), respectively. In most cases, trifluoroacetic acid was the major PFA and accounted for 22-90% of the total PFAs. Although the levels of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were not only lower than trifluoroacetic acid, but also lower than some short-chain PFCAs (PFAs, respectively. Meanwhile, unlike previous studies, PFOS levels were not always higher than PFOA in solids collected in Shanghai, China. Given that some short-chain PFAs such as trifluoroacetic acid are mildly phytotoxic and their higher levels in solid matrices were collected in Shanghai, China, these chemicals should be included in future environmental monitoring efforts.

Determination of perfluorinated sulfonate and perfluorinated acids in tissues of free-living European beaver (castor fiber L.) by d-SPE/ micro-UHPLC-MS/MS.

Science.gov (United States)

Surma, Magdalena; Giżejewski, Zygmunt; Zieliński, Henryk

2015-10-01

Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the main representatives of an rising class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). In this study, determination of selected PFCs concentration in liver, brain, tail, adipose and peritoneum tissues of free-living European beaver (Castor fiber L.) was addressed. Tissue samples, collected from beavers living in Masurian Lakeland (NE Poland), were analyzed by dispersive Solid Phase Extraction (d-SPE) with micro-UHPLC-MS/MS system. In a group of ten selected pefrluorinated compounds only two perfluorinated acids (PFOA and PFNA) and one perfluorinated sulfonate (PFOS) were quantified. PFOA was detected in all analysed tissue samples in both female and male beavers in a range from 0.55 to 0.98ngg(-1) ww whereas PFOS was identified in all analyzed female beaver tissues and only in liver, subcutaneous adipose and peritoneum tissues of male beavers at the concentration level from 0.86 to 5.08ngg(-1) ww. PFNA was only identified in female beaver tissues (liver, subcutaneous adipose and peritoneum) in a range from 1.50 to 6.61ngg(-1) ww. This study demonstrated the bioaccumulation of PFCs in tissue samples collected from beavers living in area known as green lungs of Poland. The results provided in this study indicate for the increasing risk of PFCs occurrence in the environment and the level of PFCs in tissue of free-living European beavers may serve as bioindicator of environmental pollution by these compounds. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparative in vitro toxicity assessment of perfluorinated carboxylic acids.

Science.gov (United States)

Mahapatra, Cecon T; Damayanti, Nur P; Guffey, Samuel C; Serafin, Jennifer S; Irudayaraj, Joseph; Sepúlveda, Maria S

2017-06-01

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic fluorinated compounds that are highly bioaccumulative and persistent organic pollutants. Perfluorooctanoic acid (PFOA), an eight-carbon chain perfluorinated carboxylic acid, was used heavily for the production of fluoropolymers, but concerns have led to its replacement by shorter carbon chain homologues such as perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA). However, limited toxicity data exist for these substitutes. We evaluated the toxicity of PFOA, PFHxA and PFBA on a zebrafish liver cell line and investigated the effects of exposure on cell metabolism. Gross toxicity after 96 h of exposure was highest for PFOA and PFO - , while PFHxA and PFBA exhibited lower toxicity. Although the structural similarity of these compounds to fatty acids suggests the possibility of interference with the transport and metabolism of lipids, we could not detect any differential expression of peroxisome proliferator-activated receptor (ppar-α, -β and -γ), fabp3 and crot genes after 96 h exposure to up to 10 ppm of the test compounds. However, we observed localized lipid droplet accumulation only in PFBA-exposed cells. To study the effects of these compounds on cell metabolism, we conducted fluorescence lifetime imaging microscopy using naturally fluorescent biomarkers, NADH and FAD. The fluorescence lifetimes of NADH and FAD and the bound/free ratio of each of these coenzymes decreased in a dose- and carbon length-dependent manner, suggesting disruption of cell metabolism. In sum, our study revealed that PFASs with shorter carbon chains are less toxic than PFOA, and that exposure to sublethal dosage of PFOA, PFHxA or PFBA affects cell metabolism. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hongxia; Cui, Ruina [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029 (China); Hu, Jiayue [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

2016-08-05

Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

International Nuclear Information System (INIS)

Zhang, Hongxia; Cui, Ruina; Guo, Xuejiang; Hu, Jiayue; Dai, Jiayin

2016-01-01

Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

IMMUNE FUNCTION IN INTACT AND PPARΑ KNOCKOUT MICE EXPOSED TO PFOA

Science.gov (United States)

Perfluorooctanoic acid (PFOA), used in fluoropolymer production, is environmentally persistent, present in human and wildlife populations worldwide, and associated with health effects in laboratory animals, including immunomodulation. PFOA toxicity may be mediated by the peroxiso...

U.S. Domestic Cats as Sentinels for Perfluoroalkyl Substances: Possible Linkages with Housing, Obesity and Disease

Science.gov (United States)

Perfluoroalkyl substances (PFAS), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) , are persistent, globally distributed, anthropogenic compounds. The primary source(s) for human exposure are not well understood although within home exposure is likely i...

Long-range atmospheric transport of volatile monocarboxylic acids with Asian dust over a high mountain snow site, central Japan

Directory of Open Access Journals (Sweden)

T. Mochizuki

2016-11-01

Full Text Available To understand the long-range transport of monocarboxylic acids from the Asian continent to the Japanese islands, we collected snowpack samples from a pit sequence (depth ca. 6 m at the Murodo-Daira snowfield near the summit of Mt. Tateyama, central Japan, in 2009 and 2011. Snow samples (n = 16 were analyzed for normal (C1–C10, branched chain (iC4–iC6, aromatic (benzoic and toluic acid isomers, and hydroxyl (glycolic and lactic monocarboxylic acids, together with inorganic ions and dissolved organic carbon (DOC. Acetic acid (C2 was found to be a dominant species (average 125 ng g−1, followed by formic acid (C1 (85.7 ng g−1 and isopentanoic acid (iC5 (20.0 ng g−1. We found a strong correlation (r =  0.88 between formic plus acetic acids and non-sea-salt Ca2+ that is a proxy of Asian dust. Contributions of total monocarboxylic acids to DOC in 2009 (21.2 ± 11.6 % were higher than that in 2011 (3.75 ± 2.62 %, being consistent with higher intensity of Asian dust in 2009 than in 2011. Formic plus acetic acids also showed a positive correlation (r =  0.90 with benzoic acid that is a tracer of automobile exhaust, indicating that monocarboxylic acids and their precursors are largely emitted from anthropogenic sources in China and/or secondarily produced in the atmosphere by photochemical processing. In addition, the ratio of formic plus acetic acids to nss–Ca2+ (0.27 was significantly higher than those (0.00036–0.0018 obtained for reference dust materials of Chinese loess deposits from the Tengger and Gobi deserts. This result suggests that volatile and semi-volatile organic acids are adsorbed on the alkaline dust particles during long-range atmospheric transport. Entrainment of organic acids by dusts is supported by a good correlation (r = 0.87 between formic plus acetic acids and pH of melt snow samples. Our study suggests that Asian alkaline dusts may be a carrier of volatile monocarboxylic

Meat fatty acid and cholesterol level of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau.

Science.gov (United States)

Sun, Tao; Liu, Zhiyun; Qin, Liping; Long, Ruijun

2012-08-30

Meat safety and nutrition are major concerns of consumers. The development of distinctive poultry production methods based on locally available natural resources is important. Grasshoppers are rich in important nutrients and occur in dense concentrations in most rangelands of northern China. Foraging chickens could be used to suppress grasshopper infestations. However, knowledge of the fatty acid content of meat from free-range broilers reared on alpine rangeland is required. Rearing conditions and diet did not significantly (P > 0.05) affect concentrations of saturated fatty acid (SFA), arachidonic acid, docosahexaenoic acid or the ratio of total n-6 to total n-3 fatty acids. Breast muscle of chickens that had consumed grasshoppers contained significantly (P 0.05) higher than intensively reared birds. Compared with meat from intensively reared birds, meat from free-range broilers had less cholesterol and higher concentrations of total lipid and phospholipids. Chickens eating grasshoppers in rangeland produce superior quality meat and reduce the grasshopper populations that damage the pastures. This provides an economic system of enhanced poultry-meat production, which derives benefits from natural resources rather than artificial additives. Copyright © 2012 Society of Chemical Industry.

The use of carbon adsorbents for the removal of perfluoroalkyl acids from potable reuse systems.

Science.gov (United States)

Inyang, Mandu; Dickenson, Eric R V

2017-10-01

Bench- and pilot-scale sorption tests were used to probe the performance of several biochars at removing perfluoroalkyl acids (PFAA) from field waters, compared to granular activated carbon (GAC). Screening tests using organic matter-free water resulted in hardwood (HWC) (K d  = 41 L g -1 ) and pinewood (PWC) (K d  = 49 L g -1 ) biochars having the highest perfluorooctanoic acid (PFOA) removal performance that was comparable to bituminous coal GAC (K d  = 41 L g -1 ). PWC and HWC had a stronger affinity for PFOA sorbed in Lake Mead surface water (K F  = 11 mg (1-n) L n g -1 ) containing a lower (2 mg L -1 ) dissolved organic carbon (DOC) concentration than in a tertiary-filtered wastewater (K F  = 8 mg (1-n) L n g -1 ) with DOC of 4.9 mg L -1 . A pilot-scale study was performed using three parallel adsorbers (GAC, anthracite, and HWC biochar) treating the same tertiary-filtered wastewater. Compared to HWC, and anthracite, GAC was the most effective in mitigating perfluoropentanoic acid (PFPnA), perfluorohexanoic acid (PHxA), PFOA, perfluorooctane sulfonic acid (PFOS), and DOC (45-67% removed at 4354 bed volumes) followed by HWC, and then anthracite. Based on bench- and pilot-scale results, shorter-chain PFAA [perfluorobutanoic acid (PFBA), PFPnA, or PFHxA] were more difficult to remove with both biochar and GAC than the longer-chain, PFOS and PFOA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Method Development for the Determination of Fluorotelomer Alcohols in Soils by Gas Chromatography Mass Spectrometry

Science.gov (United States)

Fluorotelomer alcohols (FTOHs) have been widely studied as precursors to perfluorocarboxylates, e.g. 8:2 FTOH degrades to perfluorooctanoic acid (PFOA). This presentation describes an analytical method for the extraction and analysis of 6:2, 8:2, and 10:2 FTOHs. Gas chromatograph...

Degradability of an Acrylate-Linked, Fluorotelomer Polymer in Soil

Science.gov (United States)

Fluorotelomer polymers are used in a broad array of products in modern societies worldwide and, if they degrade at significant rates, potentially are a significant source of perfluorooctanoic acid (PFOA) and related compounds to the environment. To evaluate this possibility, we i...

Emanation-thermal characteristics of Ba-salts of some aromatic acids in the temperature range between 298 and 373 K

Energy Technology Data Exchange (ETDEWEB)

Balek, V; Prachar, M [Ustav Jaderneho Vyzkumu, Rez (Czechoslovakia); Kroupa, J [Vyzkumny Ustav Syntetickych Pryskyric a Laku, Pardubice (Czechoslovakia)

1977-01-01

The paper presents the emanation-thermal characteristics of Ba salts of some monocarboxylic acids (phtalic, isophtalic and terephtalic) and dicarboxylic acids (benzoic, salicylic, 1,4-aminobenzoic, 1,2-Cl-benzoic and 1,2-I-benzoic). It is shown that the emanation thermal characteristics measured in the temperature range between 298 and 373 K are suitable for estimating diffusion properties of studied organic solids. An apparatus for determining emanation-thermal characteristics is proposed.

Quantitative characterization of short- and long-chain perfluorinated acids in solid matrices in Shanghai, China

International Nuclear Information System (INIS)

Li, Fei; Zhang, Chaojie; Qu, Yan; Chen, Jing; Chen, Ling; Liu, Ying; Zhou, Qi

2010-01-01

Perfluorinated acids (PFAs) have been recognized as emerging environmental pollutants because of their widespread occurrences, persistence, and bioaccumulative and toxicological effects. PFAs have been detected in aquatic environment and biota in China, but the occurrences of these chemicals have not been reported in solid matrices in China. In the present study, short- and long-chain PFAs (C2-C14) have been quantitatively determined in solid matrices including sediments, soils and sludge collected in Shanghai, China. The results indicate that sludge contains more PFAs than sediments and soils, and the total PFAs concentrations in sediments, soil and sludge are 62.5-276 ng g -1 , 141-237 ng g -1 and 413-755 ng g -1 , respectively. In most cases, trifluoroacetic acid was the major PFA and accounted for 22-90% of the total PFAs. Although the levels of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were not only lower than trifluoroacetic acid, but also lower than some short-chain PFCAs (< C8) in some individual cases, PFOA and PFOS were still the major pollution compounds in most cases and they constituted 2-34% and 1-9% of the total PFAs, respectively. Meanwhile, unlike previous studies, PFOS levels were not always higher than PFOA in solids collected in Shanghai, China. Given that some short-chain PFAs such as trifluoroacetic acid are mildly phytotoxic and their higher levels in solid matrices were collected in Shanghai, China, these chemicals should be included in future environmental monitoring efforts.

Temporal trends (1999–2010) of perfluoroalkyl acids in commonly consumed food items

International Nuclear Information System (INIS)

Johansson, Jana H.; Berger, Urs; Vestergren, Robin; Cousins, Ian T.; Bignert, Anders; Glynn, Anders; Darnerud, Per Ola

2014-01-01

The aim of this study was to determine how dietary exposure to PFAAs has changed over the period when major production changes occurred. Archived samples (1999–2010) of eggs, milk and farmed rainbow trout were analyzed by ultra performance liquid chromatography coupled to tandem mass spectrometry. Statistically significant decreasing trends were observed for concentrations of perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS) in fish (p < 0.002 and p < 0.032, respectively) and eggs (p < 0.001 for both compounds). Concentrations of PFOS in fish and eggs decreased by a factor of 10 and 40, respectively. In eggs there was also a statistically significant decreasing trend in concentrations of perfluorooctanoic acid (PFOA). The results of this study demonstrate that PFAA concentrations in food items from agricultural food chains and aquatic food chains close to sources respond rapidly to changes in environmental emissions. Implications for the overall understanding of human exposure are discussed. - Highlights: • Food items sampled yearly (1999–2010) were analyzed for perfluoroalkyl acids. • Significantly declining trends were observed for PFOS and PFHxS in farmed fish and eggs. • In eggs, an additional significant decreasing trend was found for PFOA. • A decrease in human dietary exposure to PFHxS, PFOS and PFOA is suggested. - Concentrations of PFOS in farmed fish and in hen's eggs decreased between 1999 and 2010. Furthermore, we observed decreasing trends of PFOA in eggs and PFHxS in fish

Multipulse NMR study of the lamellar mesophase of some liquid crystals

International Nuclear Information System (INIS)

Jasinski, A.; Morris, P.G.; Mansfield, P.

1977-01-01

Multipulse NMR techniques have been used to investigate the dynamic jproperties of cesium perfluoro-octanoate (CsPFO) and ammonium perfluoro-octanoate (APFO) + water systems, which are liquid crystals, over a wide range of temperautre and concentration. Axially symmetric fluorine chemical shift tensors have been measured for the CF 2 and CF 3 groups by performing a rotation study of an aligned sample (50% CsPFO : 50% D 2 O) at room temperature. The order parameter S in the lamellar mesophase of 72,2% CsPFO : 27,8% D 2 O and 70% APFO : 30% D 2 O has been obtained over as temperature range 20 0 C - 85 0 C by fitting the multipulse spectra. (author)

Brominated flame retardants and perfluorinated chemicals, two groups of persistent contaminants in Belgian human blood and milk

Energy Technology Data Exchange (ETDEWEB)

Roosens, Laurence [Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); D' Hollander, Wendy; Bervoets, Lieven [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Reynders, Hans; Van Campenhout, Karen [Environment and Health Unit, Department of Environment, Nature and Energy, Flemish Government - Koning Albert II-laan 20, Bus 8, 1000 Brussels (Belgium); Cornelis, Christa; Van Den Heuvel, Rosette; Koppen, Gudrun [Unit Environmental Risk and Health, Flemish Institute of Technological Research (VITO), Boeretang 200, 2400 Mol (Belgium); Covaci, Adrian, E-mail: adrian.covaci@ua.ac.b [Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

2010-08-15

We assessed the exposure of the Flemish population to brominated flame retardants (BFRs) and perfluorinated compounds (PFCs) by analysis of pooled cord blood, adolescent and adult serum, and human milk. Levels of polybrominated diphenyl ethers (PBDEs) in blood (range 1.6-6.5 ng/g lipid weight, lw) and milk (range 2.0-6.4 ng/g lw) agreed with European data. Hexabromocyclododecane ranged between <2.1-5.7 ng/g lw in milk. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) dominated in blood and ranged between 1 and 171 ng/mL and <0.9-9.5 ng/mL, respectively. Total PFC levels in milk ranged between <0.5-29 ng/mL. A significant increase in PBDE concentrations was detected from newborns (median 2.1) to the adolescents and adults (medians 3.8 and 4.6 ng/g lw, respectively). An identical trend was observed for PFOS, but not for PFOA. We estimated that newborn exposure to BFRs and PFCs occurs predominantly post-natally, whereas placental transfer has a minor impact on the body burden. - The exposure to BFRs and PFCs of general Flemish population has been assessed throughout several age groups.

Effective atomic numbers and electron densities of bacteriorhodopsin and its comprising amino acids in the energy range 1 keV–100 GeV

Energy Technology Data Exchange (ETDEWEB)

Ahmadi, Morteza; Lunscher, Nolan [Waterloo Institute for Nanotechnology and Department of Systems Design Engineering, University of Waterloo, 200 University Ave., W., Waterloo, Ontario, Canada N2L 3G1 (Canada); Yeow, John T.W., E-mail: jyeow@uwaterloo.ca [Waterloo Institute for Nanotechnology and Department of Systems Design Engineering, University of Waterloo, 200 University Ave., W., Waterloo, Ontario, Canada N2L 3G1 (Canada)

2013-04-01

Recently, there has been an interest in fabrication of X-ray sensors based on bacteriorhodopsin, a proton pump protein in cell membrane of Halobacterium salinarium. Therefore, a better understanding of interaction of X-ray photons with bacteriorhodopsin is required. We use WinXCom program to calculate the mass attenuation coefficient of bacteriorhodopsin and its comprising amino acids for photon energies from 1 keV to 100 GeV. These amino acids include alanine, arginine, asparagine, aspartic acid, glutamine, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, Asx1, Asx2, Glx1 and Glx2. We then use that data to calculate effective atomic number and electron densities for the same range of energy. We also emphasize on two ranges of energies (10–200 keV and 1–20 MeV) in which X-ray imaging and radiotherapy machines work.

Impact of Microbial Growth on Subsurface Perfluoroalkyl Acid Transport

Science.gov (United States)

Weathers, T. S.; Higgins, C. P.; Sharp, J.

2014-12-01

The fate and transport of poly and perfluoroalkyl substances (PFASs) in the presence of active microbial communities has not been widely investigated. These emerging contaminants are commonly utilized in aqueous film-forming foams (AFFF) and have often been detected in groundwater. This study explores the transport of a suite of perfluorocarboxylic acids and perfluoroalkylsulfonates, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), in microbially active settings. Single point organic carbon normalized sorption coefficients derived by exposing inactive cellular material to PFASs result in more than an order of magnitude increase in sorption compared to soil organic carbon sorption coefficients found in literature. For example, the sorption coefficients for PFOS are 4.05±0.07 L/kg and 2.80±0.08 L/kg for cellular organic carbon and soil organic carbon respectively. This increase in sorption, coupled with enhanced extracellular polymeric substance production observed during growth of a common hydrocarbon degrading soil microbe exposed to source-level concentrations of PFASs (10 mg/L of 11 analytes, 110 mg/L total) may result in PFAS retardation in situ. To address the upscaling of this phenomenon, flow-through columns packed with low-organic carbon sediment and biostimulated with 10 mg/L glucose were exposed to PFAS concentrations from 15 μg/L to 10 mg/L of each 11 analytes. Breakthrough and tailing of each analyte was measured and modeled with Hydrus-1D to explore sorption coefficients over time for microbially active columns.

Usnic acid controls the acidity tolerance of lichens

International Nuclear Information System (INIS)

Hauck, Markus; Juergens, Sascha-Rene

2008-01-01

The hypotheses were tested that, firstly, lichens producing the dibenzofuran usnic acid colonize substrates characterized by specific pH ranges, secondly, this preferred pH is in a range where soluble usnic acid and its corresponding anion occur in similar concentrations, and thirdly, usnic acid makes lichens vulnerable to acidity. Lichens with usnic acid prefer an ambient pH range between 3.5 and 5.5 with an optimum between 4.0 and 4.5. This optimum is close to the pK a1 value of usnic acid of 4.4. Below this optimum pH, dissolved SO 2 reduces the chlorophyll fluorescence yield more in lichens with than without their natural content of usnic acid. This suggests that usnic acid influences the acidity tolerance of lichens. The putative mechanism of the limited acidity tolerance of usnic acid-containing lichens is the acidification of the cytosol by molecules of protonated usnic acid shuttling protons through the plasma membrane at an apoplastic pH a1 . - Combined field and experimental data suggest that usnic acid makes lichens sensitive to acidity at pH <3.5

Nanoporous anodic aluminum oxide with a long-range order and tunable cell sizes by phosphoric acid anodization on pre-patterned substrates

Science.gov (United States)

Surawathanawises, Krissada; Cheng, Xuanhong

2014-01-01

Nanoporous anodic aluminum oxide (AAO) has been explored for various applications due to its regular cell arrangement and relatively easy fabrication processes. However, conventional two-step anodization based on self-organization only allows the fabrication of a few discrete cell sizes and formation of small domains of hexagonally packed pores. Recent efforts to pre-pattern aluminum followed with anodization significantly improve the regularity and available pore geometries in AAO, while systematic study of the anodization condition, especially the impact of acid composition on pore formation guided by nanoindentation is still lacking. In this work, we pre-patterned aluminium thin films using ordered monolayers of silica beads and formed porous AAO in a single-step anodization in phosphoric acid. Controllable cell sizes ranging from 280 nm to 760 nm were obtained, matching the diameters of the silica nanobead molds used. This range of cell size is significantly greater than what has been reported for AAO formed in phosphoric acid in the literature. In addition, the relationships between the acid concentration, cell size, pore size, anodization voltage and film growth rate were studied quantitatively. The results are consistent with the theory of oxide formation through an electrochemical reaction. Not only does this study provide useful operational conditions of nanoindentation induced anodization in phosphoric acid, it also generates significant information for fundamental understanding of AAO formation. PMID:24535886

Electrocoagulation mechanism of perfluorooctanoate (PFOA) on a zinc anode: Influence of cathodes and anions.

Science.gov (United States)

Wang, Yujuan; Lin, Hui; Jin, Fangyuan; Niu, Junfeng; Zhao, Jinbo; Bi, Ying; Li, Ying

2016-07-01

Batch experiments were conducted to investigate the effects of cathode materials and anions (Cl(-), SO4(2-), NO3(-), and CO3(2-)/HCO3(-)) on perfluorooctanoate (PFOA) removal in electrocoagulation process using zinc anode. The results indicated that the hydroxide flocs generated in-situ in the electrocoagulation process using the stainless steel rod as cathode were more effective than those using aluminum rod as cathode for the removal of PFOA after 20min of electrocoagulation at a current density of 0.5mAcm(-2). Hydroxide flocs generated in-situ in the electrocoagulation in the presence of Cl(-)/NO3(-) could effectively remove PFOA from aqueous solution with the removal ratios of 99.7%/98.1% and 98.9%/97.3% using stainless steel rod and aluminum rod as cathode, respectively. However, the PFOA removal ratios were 96.2%/4.1% and 7.4%/4.6% using stainless steel rod and aluminum rod as cathode, respectively, in the presence of SO4(2-) and CO3(2-)/HCO3(-). The different removal ratios of PFOA during the electrocoagulation process were primarily due to the fact that the hydroxide flocs generated in-situ were different in the presence of diverse cathodes and anions. We firstly demonstrated that Zn0.70Al0.30(OH)2(CO3)0.15·xH2O and ZnO generated in-situ in the electrocoagulation process (except for CO3(2-)/HCO3(-)) using zinc anode and aluminum/stainless steel rod cathode governed the sorption of PFOA. The adsorbent hydroxide flocs in-situ generated in the presence of Cl(-) could effectively remove PFOA from aqueous solution containing CO3(2-)/HCO3(-) anion at the initial hydroxide flocs concentration of 2000mgL(-1). These results provided an effective and alternative method to remove PFOA from aqueous solution containing CO3(2-)/HCO3(-) anion. Copyright © 2016 Elsevier B.V. All rights reserved.

Contamination by perfluorinated compounds in water near waste recycling and disposal sites in Vietnam.

Science.gov (United States)

Kim, Joon-Woo; Tue, Nguyen Minh; Isobe, Tomohiko; Misaki, Kentaro; Takahashi, Shin; Viet, Pham Hung; Tanabe, Shinsuke

2013-04-01

There are very few reports on the contamination by perfluorinated chemicals (PFCs) in the environment of developing countries, especially regarding their emission from waste recycling and disposal sites. This is the first study on the occurrence of a wide range of PFCs (17 compounds) in ambient water in Vietnam, including samples collected from a municipal dumping site (MD), an e-waste recycling site (ER), a battery recycling site (BR) and a rural control site. The highest PFC concentration was found in a leachate sample from MD (360 ng/L). The PFC concentrations in ER and BR (mean, 57 and 16 ng/L, respectively) were also significantly higher than those detected in the rural control site (mean, 9.4 ng/L), suggesting that municipal solid waste and waste electrical and electronic equipment are potential contamination sources of PFCs in Vietnam. In general, the most abundant PFCs were perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUDA; waste materials.

Reductive Degradation of Perfluorinated Compounds in Water using Mg-aminoclay coated Nanoscale Zero Valent Iron

OpenAIRE

Arvaniti, Olga S.; Hwang, Yuhoon; Andersen, Henrik Rasmus; Stasinakis, Athanasios S.; Thomaidis , Nikolaos S.; Aloupi, Maria

2015-01-01

Perfluorinated Compounds (PFCs) are extremely persistent micropollutants that are detected worldwide. We studied the removal of PFCs (perfluorooctanoic acid; PFOA, perfluorononanoic acid; PFNA, perfluorodecanoic acid; PFDA and perfluorooctane sulfonate; PFOS) from water by different types of nanoscale zero-valent iron (nZVI). Batch experiments showed that an iron dose of 1 g•L-1 in the form of Mg-aminoclay (MgAC) coated nZVI, at an initial pH of 3.0 effectively removed 38 % to 96 % of individ...

Bilateral uric acid nephrolithiasis and ureteral hypertrophy in a free-ranging river otter (Lontra canadensis)

Science.gov (United States)

Grove, Robert A.; Bildfell, Rob; Henny, Charles J.; Buhler, D.R.

2003-01-01

We report the first case of uric acid nephrolithiasis in a free-ranging river otter (Lontra canadensis). A 7 yr old male river otter collected from the Skagit River of western Washington (USA) had bilateral nephrolithiasis and severely enlarged ureters (one of 305 examined [0.33%]). The uroliths were 97% uric acid and 3% protein. Microscopic changes in the kidney were confined to expansion of renal calyces, minor loss of medullary tissue, and multifocal atrophy of the cortical tubules. No inflammation was observed in either kidney or the ureters. The ureters were enlarged due to marked hypertrophy of smooth muscle plus dilation of the lumen. Fusion of the major calyces into a single ureteral lumen was several cm distal to that of two adult male otters used as histopathologic control specimens. This case report is part of a large contaminant study of river otters collected from Oregon and Washington. It is important to understand diseases and lesions of the otter as part of our overall evaluation of this population.

Association between thyroid profile and perfluoroalkyl acids: Data from NHNAES 2007–2008

International Nuclear Information System (INIS)

Jain, Ram B.

2013-01-01

The effect of six perfluoroalkyl acids (PFAAs), namely, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDE), perfluorohexane sulfonic acid (PFHxS), 2-(N-methyl-perfluorooctane sulfonamide) acetic acid (MPAH), and perfluorononanoic acid (PFNA) on the levels of six thyroid function variables, namely, thyroid stimulating hormone (TSH), free and total thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin (TGN) was evaluated. Data from National Health and Nutrition Examination Survey for the years 2007–2008 were used for this evaluation. TSH levels increased with increase in levels of PFOA (p<0.01). There were no statistically significant associations between the levels of FT3, and FT4 with the levels of any of the six PFAAs. Levels of TT3 were found to increase with the levels of PFOA (p=0.01) and TT4 levels were found to increase with increase in PFHxS levels (p<0.01). Males had statistically significantly higher levels of FT3 than females and females had statistically significantly higher levels of TT4 than males. As compared to non-Hispanics whites and Hispanics, non-Hispanic blacks had lower levels of TSH, FT3, TT3, and TT4 but Hispanics had the lowest levels of TGN. Age was negatively associated with FT3 and TT3 but positively associated with FT4 and TT4. Non-smokers had higher levels of TSH and TT4 than smokers and smokers had higher levels of FT3 and TGN than non-smokers. Iodine deficiency was associated with increased levels of TSH, TT3, TT4, and TGN. -- Highlights: • Levels of total triiodothyronine were found to increase with the levels of PFOA. • Total thyroxine increased with increase in levels of perfluorohexane sulfonic acid. • There was a positive association between the levels of PFOA and TSH. • Iodine deficiency was associated with elevated levels of TSH, total T3 and T4. • Iodine deficiency was associated with elevated levels of thyroglobulin

Association between thyroid profile and perfluoroalkyl acids: Data from NHNAES 2007–2008

Energy Technology Data Exchange (ETDEWEB)

Jain, Ram B., E-mail: Jain.ram.b@gmail.com

2013-10-15

The effect of six perfluoroalkyl acids (PFAAs), namely, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDE), perfluorohexane sulfonic acid (PFHxS), 2-(N-methyl-perfluorooctane sulfonamide) acetic acid (MPAH), and perfluorononanoic acid (PFNA) on the levels of six thyroid function variables, namely, thyroid stimulating hormone (TSH), free and total thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin (TGN) was evaluated. Data from National Health and Nutrition Examination Survey for the years 2007–2008 were used for this evaluation. TSH levels increased with increase in levels of PFOA (p<0.01). There were no statistically significant associations between the levels of FT3, and FT4 with the levels of any of the six PFAAs. Levels of TT3 were found to increase with the levels of PFOA (p=0.01) and TT4 levels were found to increase with increase in PFHxS levels (p<0.01). Males had statistically significantly higher levels of FT3 than females and females had statistically significantly higher levels of TT4 than males. As compared to non-Hispanics whites and Hispanics, non-Hispanic blacks had lower levels of TSH, FT3, TT3, and TT4 but Hispanics had the lowest levels of TGN. Age was negatively associated with FT3 and TT3 but positively associated with FT4 and TT4. Non-smokers had higher levels of TSH and TT4 than smokers and smokers had higher levels of FT3 and TGN than non-smokers. Iodine deficiency was associated with increased levels of TSH, TT3, TT4, and TGN. -- Highlights: • Levels of total triiodothyronine were found to increase with the levels of PFOA. • Total thyroxine increased with increase in levels of perfluorohexane sulfonic acid. • There was a positive association between the levels of PFOA and TSH. • Iodine deficiency was associated with elevated levels of TSH, total T3 and T4. • Iodine deficiency was associated with elevated levels of thyroglobulin.

Effects of salinity and organic matter on the partitioning of perfluoroalkyl acid (PFAs) to clay particles.

Science.gov (United States)

Jeon, Junho; Kannan, Kurunthachalam; Lim, Byung J; An, Kwang Guk; Kim, Sang Don

2011-06-01

The influence of salinity and organic matter on the distribution coefficient (K(d)) for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in a brackish water-clay system was studied. The distribution coefficients (K(d)) for PFAs onto inorganic clay surfaces increased with salinity, providing evidence for electrostatic interaction for the sorption of PFAs, whereas the relationship between K(d) and organic carbon content (f(oc)) suggested that hydrophobic interaction is the primary driving force for the sorption of PFAs onto organic matter. The organic carbon normalized adsorption coefficient (K(oc)) of PFAs can be slightly overestimated due to the electrostatic interaction within uncoated inorganic surfaces. In addition, the dissolved organic matter released from coated clay particles seemed to solvate PFA molecules in solution, which contributed to a decrease in K(d). A positive relationship between K(d) and salinity was apparent, but an empirical relationship for the 'salting-out' effect was not evident. The K(d) values of PFAs are relatively small compared with those reported for persistent organic pollutants. Thus, sorption may not be a significant route of mass transfer of PFAs from water columns in estuarine environments. However, enhancement of sorption of PFAs to particulate matter at high salinity values could evoke potential risks to benthic organisms in estuarine areas.

Counter-current acid leaching process for the removal of Cu, Pb, Sb and Zn from shooting range soil.

Science.gov (United States)

Lafond, Stéphanie; Blais, Jean-François; Mercier, Guy; Martel, Richard

2013-01-01

This research explores the performance of a counter-current leaching process (CCLP) for Cu, Pb, Sb and Zn extraction in a polluted shooting range soil. The initial metal concentrations in the soil were 1790 mg Cu/kg, 48,300 mg Pb/kg, 840 mg Sb/kg and 368 mg Zn/kg. The leaching process consisted of five one-hour acid leaching steps, which used 1 M H2SO4 + 4 M NaCl (20 degrees C, soil suspension = 100 g/L) followed by two water rinsing steps. Ten counter-current remediation cycles were completed and the average metal removal yields were 98.3 +/- 0.3% of Cu, 99.5 +/- 0.1% of Pb, 75.5 +/- 5.1% of Sb and 29.1 +/- 27.2% of Zn. The quality of metal leaching did not deteriorate throughout the 10 remediation cycles completed for this study. The CCLP reduced acid and salt use by approximately 68% and reduced water consumption by approximately 60%, exceeding reductions achieved by a standard acid leaching process.

Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts

International Nuclear Information System (INIS)

Wang, Hongliang; Wang, Huamin; Kuhn, Eric; Tucker, Melvin P.; Yang, Bin

2017-01-01

Super Lewis acids containing the triflate anion [e.g., Hf(OTf) 4 , Ln(OTf) 3 , In(OTf) 3 , Al(OTf) 3 ] and noble metal catalysts (e.g., Ru/C, Ru/Al2O 3 ) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote oxygenation reactions catalyzed by super Lewis acids.

Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts

Energy Technology Data Exchange (ETDEWEB)

Wang, Hongliang [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Current address: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193 PR China; Wang, Huamin [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Kuhn, Eric [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Tucker, Melvin P. [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Yang, Bin [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA

2017-11-14

Super Lewis acids containing the triflate anion (e.g. Hf(OTf)4, Ln(OTf)3, Al(OTf)3) and noble metal catalysts (e.g. Ru/C, Ru/Al2O3) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage via selective bonding to etheric oxygens while the noble metal catalysed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt% of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates via protonating hydroxyls and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote oxygenation reactions catalysed by super Lewis acids.

Reductive Degradation of Perfluorinated Compounds in Water using Mg-aminoclay coated Nanoscale Zero Valent Iron

DEFF Research Database (Denmark)

Arvaniti, Olga S.; Hwang, Yuhoon; Andersen, Henrik Rasmus

2015-01-01

Perfluorinated Compounds (PFCs) are extremely persistent micropollutants that are detected worldwide. We studied the removal of PFCs (perfluorooctanoic acid; PFOA, perfluorononanoic acid; PFNA, perfluorodecanoic acid; PFDA and perfluorooctane sulfonate; PFOS) from water by different types...... of the nZVI. A maximum removal was observed for all PFCs with high nZVI concentration, freshly synthesized nZVI, low pH and low temperature. A mass balance experiment with PFOS in a higher concentration of nZVI revealed that the removal was due to both sorption and degradation. Fluoride production...

Toxicokinetics of perfluorooctanoate (PFOA) in rainbow trout(Oncorhynchus mykiss)

Science.gov (United States)

Perfluoroalkyl acids (PFAAs) are widely used as stain resistant coatings for cloth, paper, and leather, and as surfactants, fire-fighting foams, and photographic developers. Individual PFAAs have been shown to accumulate in fish and wildlife; however, the extent of this accumulat...

Research Article. Perfluoroalkylated substances in human urine: results of a biomonitoring pilot study

Directory of Open Access Journals (Sweden)

Hartmann Christina

2017-04-01

Full Text Available Perfluoroalkylated substances (PFASs are a class of synthetic chemicals used in a wide range of processes and products due to their unique physicalchemical properties. Through intake of PFASs via food or several consumer products, humans can be exposed. Long-chain PFASs have been associated with adverse effects in laboratory animals, and there is also evidence for adverse health effects in humans. Although investigations of human exposure are mainly conducted in blood samples, some studies have shown that especially short-chain PFASs can be detected in human urine. In the present study, a sensitive analytical method was adapted for the measurement of 12 PFASs in human urine samples by HPLC-MS/MS. For verifying this method, concentrations in 11 male and female participants aged 25-46 years were analysed. In the study population, ranges of urinary PFASs concentrations were n.d.- 8.5 ng/l for perfluoropentanoic acid, acid, n.d.-1.8 ng/l for perfluorohexane sulphonate, n.d.-0.99 ng/l for perfluoroheptanoic acid, 0.79-5.1 ng/l for perfluorooctanoic acid, acid. For the other investigated PFASs, no urinary exposure could be identified in any of the samples. The present study shows that several shortchain PFASs are detectable in human urine.

A national discharge load of perfluoroalkyl acids derived from industrial wastewater treatment plants in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Hee-Young; Seok, Hyun-Woo [Department of Civil and Environmental Engineering, Pusan National University, Busan 46241 (Korea, Republic of); Kwon, Hye-Ok; Choi, Sung-Deuk [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of); Seok, Kwang-Seol [Chemical Research Division, National Institute of Environmental Research, Incheon 22689 (Korea, Republic of); Oh, Jeong Eun [Department of Civil and Environmental Engineering, Pusan National University, Busan 46241 (Korea, Republic of)

2016-09-01

Levels of 11 perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were measured in wastewater (influent and effluent) and sludge samples collected from 25 industrial wastewater treatment plants (I-WWTPs) in five industrial sectors (chemicals, electronics, metals, paper, and textiles) in South Korea. The highest ∑{sub 11}PFAAs concentrations were detected in the influent and effluent from the paper (median: 411 ng/L) and textile (median: 106 ng/L) industries, and PFOA and PFOS were the predominant PFAAs (49–66%) in wastewater. Exceptionally high levels of PFAAs were detected in the sludge associated with the electronics (median: 91.0 ng/g) and chemical (median: 81.5 ng/g) industries with PFOS being the predominant PFAA. The discharge loads of 11 PFAAs from I-WWTP were calculated that total discharge loads for the five industries were 0.146 ton/yr. The textile industry had the highest discharge load with 0.055 ton/yr (PFOA: 0.039 ton/yr, PFOS: 0.010 ton/yr). Municipal wastewater contributed more to the overall discharge of PFAAs (0.489 ton/yr) due to the very small industrial wastewater discharge compared to municipal wastewater discharge, but the contribution of PFAAs from I-WWTPs cannot be ignored. - Highlights: • 11 PFAAs in wastewater and sludge from 5 industrial sectors were investigated. • PFOA and PFOS were the dominant in wastewater while PFOS was predominant in sludge. • The total discharge loads from 5 industrial sectors 0.146 ton/yr. • The textile industry showed the highest discharge load with 0.055 ton/yr.

Footprints of Urban Micro-Pollution in Protected Areas: Investigating the Longitudinal Distribution of Perfluoroalkyl Acids in Wildlife Preserves.

Directory of Open Access Journals (Sweden)

Ignacio A Rodriguez-Jorquera

Full Text Available Current approaches to protect biodiversity by establishing protected areas usually gloss over water pollution as a threat. Our objective was to determine the longitudinal and seasonal distribution of perfluoroalkyl acids (PFAAs in water column and sediments from a wastewater dominated stream that enters preservation areas. Water samples were collected along the longitudinal section (six sites, 1000 m away from each other of the stream during the dry and wet seasons. Sediments were collected from three sites along the stream from three depths. Water and sediments were analyzed for PFAAs using high performance liquid chromatography-tandem mass spectrometry. Eleven PFAAs with 5 to 14 carbon atoms were detected in the water column at all sampling points, with a minor reduction at the last point suggesting a dilution effect. The most detected PFAAs was PFOS, followed by perfluorooctanoic acid (PFOA, and perfluorohexanoic acid (PFHxA. Seasonal differences in PFAAs concentrations suggested contribution of stormwater runoff during the wet season. All analyzed PFAAs in sediments were under the limit of quantification, likely due to the high proportion of sand and low organic matter. However, high concentrations of PFAAs were detected in the water column inside the protected areas, which includes PFOS in concentrations considered not safe for avian wildlife. Water samples appear to be more relevant than sediments to determine PFAAs micro-pollution in water bodies with sandy sediments. Inclusion of a management plans on micro-pollution research, monitoring, and mitigation is recommended for protected areas.

Ecological ranges for the pH and NO3 of syntaxa: a new basis for the estimation of critical loads for acid and nitrogen deposition

NARCIS (Netherlands)

Wamelink, G.W.W.; Goedhart, P.W.; Malinowska, A.H.; Frissel, J.Y.; Wegman, R.M.A.; Slim, P.A.; Dobben, van H.F.

2011-01-01

Question: Can the abiotic ranges of syntaxonomic units (associations) in terms of pH and nitrate concentration be estimated and then in principle be used to estimate critical loads for acid and nitrogen deposition? Location: Europe. Methods: Using splines, abiotic ranges of syntaxonomic units were

Persistente fluorforbindelser reducerer immunfunktionen

DEFF Research Database (Denmark)

Heilmann, Carsten; Jensen, Lise; Weihe, Pal

2014-01-01

Perfluorinated compounds are highly stable and useful industrial chemicals. Both perfluorooctane sulfonic acid and perfluorooctanoic acid cause immunotoxic effects in animal models at serum concentrations similar to human levels. In children who have undergone routine vaccinations, serum...... concentrations of these substances are inversely associated with concentrations of antibodies against diphtheria and tetanus. Prevention of such effects will require a decrease of exposure limits by at least 100-fold. Immunotoxicity is not included in routine testing of industrial chemicals but urgently needs...

Persistente fluorforbindelser reducerer immunfunktionen

DEFF Research Database (Denmark)

Heilmann, Carsten; Jensen, Lise; Weihe, Pal

2015-01-01

Perfluorinated compounds are highly stable and useful industrial chemicals. Both perfluorooctane sulfonic acid and perfluorooctanoic acid cause immunotoxic effects in animal models at serum concentrations similar to human levels. In children who have undergone routine vaccinations, serum...... concentrations of these substances are inversely associated with concentrations of antibodies against diphtheria and tetanus. Prevention of such effects will require a decrease of exposure limits by at least 100-fold. Immunotoxicity is not included in routine testing of industrial chemicals but urgently needs...

Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts.

Science.gov (United States)

Wang, Hongliang; Wang, Huamin; Kuhn, Eric; Tucker, Melvin P; Yang, Bin

2018-01-10

Super Lewis acids containing the triflate anion [e.g., Hf(OTf) 4 , Ln(OTf) 3 , In(OTf) 3 , Al(OTf) 3 ] and noble metal catalysts (e.g., Ru/C, Ru/Al 2 O 3 ) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf) 4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote deoxygenation reactions catalyzed by super Lewis acids. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liquid chromatography-tandem mass spectrometry and passive sampling: powerful tools for the determination of emerging pollutants in water for human consumption.

Science.gov (United States)

Mirasole, Cristiana; Di Carro, Marina; Tanwar, Shivani; Magi, Emanuele

2016-09-01

Among the wide range of emerging pollutants, perfluorinated compounds and various pharmaceuticals, such as nonsteroidal anti-inflammatory drugs, are showing growing concern. These contaminants can be found in freshwater ecosystems because of their incomplete removal during wastewater treatments so, their water solubility and poor degradability result in their continuous discharge and pseudo-persistent contamination. Usually, expected levels of these analytes are particularly low; therefore, sensitive and selective analytical techniques are required for their determination. Moreover, sampling and preconcentration are fundamental steps to reach the low detection limits required. The polar organic chemical integrative sampler (POCIS) represents a modern sampling approach that allows the in-situ preconcentration of ultra-trace pollutants. In this work, a fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the determination of diclofenac, ketoprofen, mefenamic acid, naproxen, ibuprofen, perfluorooctanoic acid, perfluorooctanesulfonate and caffeine in water for human consumption. The chromatographic separation of analytes was achieved in less than 6 min. Quantitative analysis was performed in multiple reaction monitoring mode using ketoprofen-d3 as internal standard. Two different sites of Northern Italy were studied deploying POCIS for four weeks in both inlet and outlet of two drinking water treatment plants. The evaluation of time-weighted average concentration of contaminants was accomplished after the calibration of POCIS; to this aim, the sampling rate values for each compound were obtained by means of a simple calibration system developed in our laboratory. Ketoprofen, perfluorooctane sulfonate, perfluorooctanoate and caffeine were measured in both sites at the ng l(-1) level. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Promoted degradation of perfluorooctanic acid by persulfate when adding activated carbon

Energy Technology Data Exchange (ETDEWEB)

Lee, Yu-Chi [Research Center for Environmental Pollution Prevention and Control Technology, Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Rd., Taipei 106, Taiwan, ROC (China); Lo, Shang-Lien, E-mail: sllo@ntuedu.tw [Research Center for Environmental Pollution Prevention and Control Technology, Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Rd., Taipei 106, Taiwan, ROC (China); Kuo, Jeff [Department of Civil and Environmental Engineering, California State University, 800 North, State College Blvd., Fullerton (United States); Huang, Chin-Pao [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States)

2013-10-15

Highlights: • PFOA removal and defluorination with AC/PS are 12 and 19 times higher than PS only • AC can activate PS to accelerate the decomposition and mineralization of PFOA. • With AC/PS, a lower reaction temperature and a shorter reaction time would suffice • A 2-cycle schematic reaction mechanism was proposed to describe PS oxidation of PFOA. -- Abstract: Treatment of persistent perfluorooctanoic acid (PFOA) in water using persulfate (PS) oxidation typically requires an elevated temperature or UV irradiation, which is energy-consuming. Under relatively low temperatures of 25–45 °C, activated carbon (AC) activated PS oxidation of PFOA was evaluated for its potential of practical applications. With presence of AC in PS oxidation, PFOA removal efficiency at 25 °C reached 682% with a high defluorination efficiency of 549% after 12 h and few intermediates of short-chain perfluorinated carboxylic acids (PFCAs) were found. The removal and defluorination rates with the combined AC/PS system were approximately 12 and 19 times higher than those of the PS-only system, respectively. Activated carbon not only removes PFOA through adsorption, but also activates PS to form sulfate radicals that accelerate the decomposition and mineralization of PFOA. The activation energy for PS oxidation of PFOA was reduced from 668 to 261 kJ/mol by the catalytic effect of AC, which implies a lower reaction temperature and a shorter reaction time would suffice. A 2-cycle schematic reaction mechanism was used to describe PS oxidation of PFOA with the generation of various intermediates and end-products.

Promoted degradation of perfluorooctanic acid by persulfate when adding activated carbon

International Nuclear Information System (INIS)

Lee, Yu-Chi; Lo, Shang-Lien; Kuo, Jeff; Huang, Chin-Pao

2013-01-01

Highlights: • PFOA removal and defluorination with AC/PS are 12 and 19 times higher than PS only • AC can activate PS to accelerate the decomposition and mineralization of PFOA. • With AC/PS, a lower reaction temperature and a shorter reaction time would suffice • A 2-cycle schematic reaction mechanism was proposed to describe PS oxidation of PFOA. -- Abstract: Treatment of persistent perfluorooctanoic acid (PFOA) in water using persulfate (PS) oxidation typically requires an elevated temperature or UV irradiation, which is energy-consuming. Under relatively low temperatures of 25–45 °C, activated carbon (AC) activated PS oxidation of PFOA was evaluated for its potential of practical applications. With presence of AC in PS oxidation, PFOA removal efficiency at 25 °C reached 682% with a high defluorination efficiency of 549% after 12 h and few intermediates of short-chain perfluorinated carboxylic acids (PFCAs) were found. The removal and defluorination rates with the combined AC/PS system were approximately 12 and 19 times higher than those of the PS-only system, respectively. Activated carbon not only removes PFOA through adsorption, but also activates PS to form sulfate radicals that accelerate the decomposition and mineralization of PFOA. The activation energy for PS oxidation of PFOA was reduced from 668 to 261 kJ/mol by the catalytic effect of AC, which implies a lower reaction temperature and a shorter reaction time would suffice. A 2-cycle schematic reaction mechanism was used to describe PS oxidation of PFOA with the generation of various intermediates and end-products

Heat capacity and thermodynamics of solid and liquid pyridine-3-carboxylic acid (nicotinic acid) over the temperature range 296 K to 531 K

International Nuclear Information System (INIS)

Joseph, Abhinav; Bernardes, Carlos E.S.; Minas da Piedade, Manuel E.

2012-01-01

Highlights: ► We determined the heat capacity of solid and liquid nicotinic acid by DSC. ► We determined Δ 357.8K 305.6K H m o (NA,crII) by Calvet microcalorimetry. ► We studied the thermodynamics of the cr II → cr I phase transition. ► We determined the Δ f G m o –T diagram of nicotinic acid for T = (296 to 531) K. - Abstract: The molar heat capacity of pyridine-3-carboxylic acid (nicotinic acid) for T = (296 to 531) K was investigated by differential scanning calorimetry (DSC) and Calvet-drop microcalorimetry. The measurements extended up to the liquid range and also covered the interval where a reversible and fast solid-solid (cr II → cr I) phase transition occurs. The molar enthalpies and entropies of that phase transition and of fusion were obtained as T trs = (455.0 ± 0.2) K, Δ trs H m o = (0.90 ± 0.10) kJ ⋅ mol −1 , Δ trs S m o = (1.98 ± 0.22) J ⋅ K −1 ⋅ mol −1 , T fus = (509.91 ± 0.04) K, Δ fus H m o = (28.2 ± 0.1) kJ ⋅ mol −1 , and Δ fus S m o = (55.30 ± 0.16) J ⋅ K −1 ⋅ mol −1 . By combining these experimental results with the previously reported Δ sub H m (NA,cr II) at T = 366.5 K, the corresponding entropy in the gaseous state calculated at the B3LYP/6-31+G(d,p) level of theory, and Δ f H m o (NA),cr II) at T = 298.15 K, it was possible to estimate the standard molar Gibbs energy of formation functions necessary for the construction of the Δ f G m ∘ vs. T diagram illustrating the enantiotropic nature of this system.

Perfluorinated alkylated acids in groundwater and drinking water: identification, origin and mobility.

Science.gov (United States)

Eschauzier, Christian; Raat, Klaasjan J; Stuyfzand, Pieter J; De Voogt, Pim

2013-08-01

Human exposure to perfluorinated alkylated acids (PFAA) occurs primarily via the dietary intake and drinking water can contribute significantly to the overall PFAA intake. Drinking water is produced from surface water and groundwater. Waste water treatment plants have been identified as the main source for PFAA in surface waters and corresponding drinking water. However, even though groundwater is an important source for drinking water production, PFAA sources remain largely uncertain. In this paper, we identified different direct and indirect sources of PFAA to groundwater within the catchment area of a public supply well field (PSWF) in The Netherlands. Direct sources were landfill leachate and water draining from a nearby military base/urban area. Indirect sources were infiltrated rainwater. Maximum concentrations encountered in groundwater within the landfill leachate plume were 1.8 μg/L of non branched perfluorooctanoic acid (L-PFOA) and 1.2 μg/L of perfluorobutanoic acid (PFBA). Sum concentrations amounted to 4.4 μg/L total PFAA. The maximum concentration of ΣPFAA in the groundwater originating from the military camp was around 17 ng/L. Maximum concentrations measured in the groundwater halfway the landfill and the PWSF (15 years travel distance) were 29 and 160 ng/L for L-PFOA and PFBA, respectively. Concentrations in the groundwater pumping wells (travel distance >25 years) were much lower: 0.96 and 3.5 ng/L for L-PFOA and PFBA, respectively. The chemical signature of these pumping wells corresponded to the signature encountered in other wells sampled which were fed by water that had not been in contact with potential contaminant sources, suggesting a widespread diffuse contamination from atmospheric deposition. Copyright © 2013 Elsevier B.V. All rights reserved.

Determination of perfluoroalkylated substances (PFASs) in drinking water from the Netherlands and Greece.

Science.gov (United States)

Zafeiraki, Effrosyni; Costopoulou, Danae; Vassiliadou, Irene; Leondiadis, Leondios; Dassenakis, Emmanouil; Traag, Wim; Hoogenboom, Ron L A P; van Leeuwen, Stefan P J

2015-01-01

In the present study 11 perfluoroalkylated substances (PFASs) were analysed in drinking tap water samples from the Netherlands (n = 37) and from Greece (n = 43) by applying LC-MS/MS and isotope dilution. PFASs concentrations above the limit of quantification, LOQ (0.6 ng/l) were detected in 20.9% of the samples from Greece. Total PFAS concentrations ranged between Netherlands. This seems attributable to the source, which is purified surface water in this area. Short-chain PFASs and especially perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorobutane sulfonate (PFBS), and perfluorohexane sulfonate (PFHxS) were detected most frequently, whereas long-chain PFASs (C > 8) were only rarely detected. In the drinking water samples from the eastern part of the Netherlands, where drinking water is sourced from groundwater reservoirs, no PFASs were detected. This demonstrates that exposure to PFASs through drinking water in the Netherlands is dependent on the source. Additionally, five samples of bottled water from each country were analysed in the current study, with all of them originating from ground wells. In these samples, all PFASs were below the LOQ.

Nationwide Distribution of Per- and Polyfluoroalkyl Substances in Outdoor Dust in Mainland China From Eastern to Western Areas.

Science.gov (United States)

Yao, Yiming; Sun, Hongwen; Gan, Zhiwei; Hu, Hongwei; Zhao, Yangyang; Chang, Shuai; Zhou, Qixing

2016-04-05

From eastern to western areas, per- and polyfluoroalkyl substances (PFASs) were detected at substantial levels in the outdoor dust across mainland China. Urban samples generally showed higher levels compared with those of rural samples. Compared with neutral PFASs, ionizable PFASs (C4-C12 perfluoroalkyl carboxylic acids and C4/C8 perfluoroalkyl sulfonic acids) were more abundant, with the highest total concentration up to 1.6 × 10(2) ng/g and perfluorooctanoic acid (PFOA) being a predominant analogue. Fluorotelomer alcohols (FTOHs) and polyfluoroalkyl phosphoric acid diesters (DiPAPs) were both detected in most samples with total concentrations of 0.12-32 and 0.030-20 ng/g, respectively. Perfluorooctane sulfonamidoethanols/sulfonamides (FOSE/As) were detected at low frequencies (eastern plain areas were characterized by a higher contribution of long-chain ionizable PFASs; whereas the western high plateau areas were characterized by the dominating contribution of short-chain analogues. The difference suggests that the long-range atmospheric transport potential of PFASs from source regions to the inland is probably limited by the increase in altitude, and different sources from adjacent regions may influence the western border area of China.

Environmental exposure to human carcinogens in teenagers and the association with DNA damage

DEFF Research Database (Denmark)

Franken, Carmen; Koppen, Gudrun; Lambrechts, Nathalie

2017-01-01

) metabolites. In blood, arsenic, polychlorinated biphenyl (PCB) congeners 118 and 156, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and perfluorooctanoic acid (PFOA) were analyzed. Levels of methylmercury (MeHg) were measured in hair. Multiple linear regression models were used to establish...... between blood arsenic, hair MeHg, PCB 156 and HCB, and urinary 8-OHdG. The latter exposure biomarkers were also associated with higher fish intake. Urinary nickel and t,t-muconic acid were inversely associated with the alkaline comet assay. Conclusion This cross-sectional study found associations between...

Perfluoroalkyl acid distribution in various plant compartments ...

Science.gov (United States)

Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var.dulce), tomato (Lycopersicon lycopersicum), and sugar snap pea (Pisum sativum var. macrocarpon) from an industrially impacted biosolids-amended soil, a municipal biosolids­ amended soil, and a control soil. Individual concentrations of PFAAs, on a dry weight basis, in mature, edible portions of crops grown in soil amended with PFAA industrially impacted biosolids were highest for perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate (PFBA;232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit. Comparatively, PFAA concentrations in edible compartments of crops grown in the municipal biosolids-amended soil and in the control soil were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated for the root, shoot, and fruit compartments (as applicable) of all crops grown in the industrially impacted soil. BAFs were highest for PFBA in the shoots of all crops, as well as in the fruit compartment of pea. Root­ soil concentration factors (RCFs) for tomato and pea were independent of PFAA chain length, while radish and celery RCFs showed a slight decrease with increasing chain length. Shoot-soil concentration factors (SCFs) for all crops showed a decrease with incre

Transcriptomic responses of European flounder (Platichthys flesus) to model toxicants

Energy Technology Data Exchange (ETDEWEB)

Williams, Tim D. [School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)], E-mail: t.d.williams@bham.ac.uk; Diab, Amer [Institute of Aquaculture, University of Stirling, Stirling, Scotland FK9 4LA (United Kingdom); Ortega, Fernando [School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Sabine, Victoria S. [Institute of Aquaculture, University of Stirling, Stirling, Scotland FK9 4LA (United Kingdom); Godfrey, Rita E.; Falciani, Francesco; Chipman, J. Kevin [School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); George, Stephen G. [Institute of Aquaculture, University of Stirling, Stirling, Scotland FK9 4LA (United Kingdom)

2008-11-11

The temporal transcriptomic responses in liver of Platichthys flesus to model environmental pollutants were studied over a 16-day time span after intraperitoneal injection with cadmium chloride (50 {mu}g/kg in saline), 3-methylcholanthrene (25 mg/kg in olive oil), Aroclor 1254 (50 mg/kg in olive oil), tert-butyl-hydroperoxide (5 mg/kg in saline), Lindane (25 mg/kg in olive oil), perfluoro-octanoic acid (100 mg/kg in olive oil) and their vehicles, olive oil (1 ml/kg) or saline (0.9%). Statistical, gene ontology and supervised analysis clearly demonstrated the progression from acute effects, biological responses to and recovery from the treatments. Key biological processes disturbed by the individual treatments were characterised by gene ontology analyses and individual toxicant-responsive genes and pathways were identified by supervised analyses. Responses to the polyaromatic and chlorinated aromatic compounds showed a degree of commonality but were distinguishable and they were clearly segregated from the responses to the pro-oxidants cadmium and the organic hydroperoxide, as well as from the peroxisomal proliferator, perfluoro-octanoic acid. This study demonstrated the utility of the microarray technique in the identification of toxicant-responsive genes and in discrimination between modes of toxicant action.

Transcriptomic responses of European flounder (Platichthys flesus) to model toxicants

International Nuclear Information System (INIS)

Williams, Tim D.; Diab, Amer; Ortega, Fernando; Sabine, Victoria S.; Godfrey, Rita E.; Falciani, Francesco; Chipman, J. Kevin; George, Stephen G.

2008-01-01

The temporal transcriptomic responses in liver of Platichthys flesus to model environmental pollutants were studied over a 16-day time span after intraperitoneal injection with cadmium chloride (50 μg/kg in saline), 3-methylcholanthrene (25 mg/kg in olive oil), Aroclor 1254 (50 mg/kg in olive oil), tert-butyl-hydroperoxide (5 mg/kg in saline), Lindane (25 mg/kg in olive oil), perfluoro-octanoic acid (100 mg/kg in olive oil) and their vehicles, olive oil (1 ml/kg) or saline (0.9%). Statistical, gene ontology and supervised analysis clearly demonstrated the progression from acute effects, biological responses to and recovery from the treatments. Key biological processes disturbed by the individual treatments were characterised by gene ontology analyses and individual toxicant-responsive genes and pathways were identified by supervised analyses. Responses to the polyaromatic and chlorinated aromatic compounds showed a degree of commonality but were distinguishable and they were clearly segregated from the responses to the pro-oxidants cadmium and the organic hydroperoxide, as well as from the peroxisomal proliferator, perfluoro-octanoic acid. This study demonstrated the utility of the microarray technique in the identification of toxicant-responsive genes and in discrimination between modes of toxicant action

Key scientific issues in developing drinking water guidelines for perfluoroalkyl acids: Contaminants of emerging concern.

Science.gov (United States)

Post, Gloria B; Gleason, Jessie A; Cooper, Keith R

2017-12-01

Perfluoroalkyl acids (PFAAs), a group of synthetic organic chemicals with industrial and commercial uses, are of current concern because of increasing awareness of their presence in drinking water and their potential to cause adverse health effects. PFAAs are distinctive among persistent, bioaccumulative, and toxic (PBT) contaminants because they are water soluble and do not break down in the environment. This commentary discusses scientific and risk assessment issues that impact the development of drinking water guidelines for PFAAs, including choice of toxicological endpoints, uncertainty factors, and exposure assumptions used as their basis. In experimental animals, PFAAs cause toxicity to the liver, the immune, endocrine, and male reproductive systems, and the developing fetus and neonate. Low-dose effects include persistent delays in mammary gland development (perfluorooctanoic acid; PFOA) and suppression of immune response (perfluorooctane sulfonate; PFOS). In humans, even general population level exposures to some PFAAs are associated with health effects such as increased serum lipids and liver enzymes, decreased vaccine response, and decreased birth weight. Ongoing exposures to even relatively low drinking water concentrations of long-chain PFAAs substantially increase human body burdens, which remain elevated for many years after exposure ends. Notably, infants are a sensitive subpopulation for PFAA's developmental effects and receive higher exposures than adults from the same drinking water source. This information, as well as emerging data from future studies, should be considered in the development of health-protective and scientifically sound guidelines for PFAAs in drinking water.

A comparative study of coagulation, granular- and powdered-activated carbon for the removal of perfluorooctane sulfonate and perfluorooctanoate in drinking water treatment.

Science.gov (United States)

Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Suja, Fatihah

2015-01-01

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent organic pollutants in the environment and their occurrence causes toxicological effects on humans. We examined different conventional coagulant treatments such as alum, ferric chloride and polyaluminium chloride in removing these compounds. These were then compared with a natural coagulant (Moringa oleifera). We also investigated the powdered-activated carbon (PAC) and granular-activated carbon (GAC) for removing these compounds. At an initial dose of 5 mg/L, polyaluminium chloride led to a higher reduction of PFOS/PFOA compared with alum which in turn was higher than ferric. The removal efficiency increased with the increase in coagulant dose and decrease in pH. M. oleifera was very effective in reducing PFOS and PFOA than conventional coagulants, with a reduction efficiencies of 65% and 72%, respectively, at a dose of 30 mg/L. Both PAC and GAC were very effective in reducing these compounds than coagulations. PAC led to a higher reduction in PFOS and PFOA than GAC due to its greater surface area and shorter internal diffusion distances. The addition of PAC (10 min contact time) with coagulation (at 5 mg/L dosage) significantly increased the removal efficiency, and the maximum removal efficiency was for M. oleifera with 98% and 94% for PFOS and PFOA, respectively. The reduction efficiency of PFOS/PFOA was reduced with the increase in dissolved organic concentration due to the adsorption competition between organic molecules and PFOS/PFOA.

Radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid from human serum, with use of 125I-labeled ligands

International Nuclear Information System (INIS)

Maeentausta, O.; Jaenne, O.

1979-01-01

We describe a method for radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid in serum. In the method, 125 I-labeled bile acid conjugates are used as the tracers along with antibodies raised against individual bile acid-bovine serum albumin conjugates. Antibody-bound and free bile acids were separated by polyethylene glycol precipitation (final concentration, 125 g/L). The lowest measurable amounts of the bile acids, expressed as pmol/tube, were: cholic acid conjugates, 2; chenodeoxycholic acid conjugates, 0.5; and deoxycholic acid conjugates, 2. Analytical recovery of bile acids added to bile acid-free serum ranged from 85 to 110%; intra-assay and inter-assay CVs ranged from 8.3 to 5.3% and from 5.3 to 12.2%, respectively. Concentrations (mean +- SD) of the bile acid conjugates in serum from apparently healthy women and men (in μmol/L) were: cholic acid conjugates, 0.43 +- 0.17 (n=126); chenodeoxycholic acid conjugates, 0.47 +- 0.23 (n=111); and deoxycholic acid conjugates, 0.33 +- 0.11 (n=96). The values for primary bile acids were greatly increased in patients with various hepatobiliary diseases

Perfluorooctanoate exposure in a highly exposed community and parent and teacher reports of behaviour in 6-12-year-old children.

Science.gov (United States)

Stein, Cheryl R; Savitz, David A; Bellinger, David C

2014-03-01

In toxicology studies, perfluorinated compounds affect fetal growth, development, viability, and postnatal growth. There are limited epidemiologic studies on child development. We recruited and evaluated 321 children who participated in the C8 Health Project, a 2005-06 survey in a mid-Ohio Valley community highly exposed to perfluorooctanoate (PFOA) through contaminated drinking water. We examined associations between measured childhood PFOA serum concentration and mother and teacher reports of executive function (Behaviour Rating Inventory of Executive Function), attention deficit hyperactivity disorder (ADHD)-like behaviour (Conner's ADHD Diagnostic and Statistical Manual of Mental Disorders IV Scales), and behavioural problems (Behaviour Assessment System for Children) assessed 3 to 4 years later at ages 6-12 years. Overall, neither reports from mothers nor teachers provided clear associations between exposure and child behaviour. Mother reports, however, did suggest favourable associations between exposure and behaviour among boys and adverse associations among girls. On the composite scale from the Behaviour Rating Inventory of Executive Function (n = 318), PFOA exposure had a favourable association among boys (highest vs. lowest quartile β = -6.39; 95% confidence interval [CI] -11.43, -1.35) and an adverse association among girls (highest vs. lowest quartile β = 4.42; 95% CI -0.03, 8.87; interaction P = 0.01). Teacher reports (n = 189) replicated some, but not all of the sex interactions observed in mothers' reports. Aggregate results did not suggest adverse effects of PFOA on behaviour, but sex-specific results raise the possibility of differing patterns by sex. Results are not consistent between mothers' and teachers' reports. Effect modification by sex may warrant further investigation. © 2013 John Wiley & Sons Ltd.

Shifts in production of perfluoroalkyl acids affect emissions and concentrations in the environment of the Xiaoqing River Basin, China

Energy Technology Data Exchange (ETDEWEB)

Wang, Pei [State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Lu, Yonglong, E-mail: yllu@rcees.ac.cn [State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wang, Tieyu [State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Meng, Jing; Li, Qifeng; Zhu, Zhaoyun [State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Sun, Yajun [State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083 (China); Wang, Ruoshi [State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Giesy, John P. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

2016-04-15

Highlights: • Mass loads demonstrated a greater pattern of increasing PFAAs emissions. • High levels of PFOA were identified near a fluoropolymer facility. • Production activities that could generate PFOA emissions were analyzed. • Partitioning coefficients decreased with high levels of short-chain PFCAs in water. - Abstract: Perfluoroalkyl acids (PFAAs) have been widely used in surfactant applications, especially as processing acids for fluoropolymer production. This study provides an analysis of sources of certain PFAAs emitted from the intensive fluoropolymer facilities in the Xiaoqing River Basin of China. Concentrations of perfluorooctanoic acid (PFOA) as great as 0.97 mg/L in surface water and 10.5 μg/g dry weight in surface sediment have been detected near the effluent of one facility (F1) that produces polytetrafluoroethylene (PTFE) and other fluoropolymers with massive capacity. With the great emission of PFAAs to water in natural conditions, the log K{sub OC} values decreased for short-chain PFCAs. Mass loads of PFAAs indicated that emissions of PFAAs from other facilities or sources were much less than those from F1, which emitted 174 kg/d of PFAAs including 159 kg/d of PFOA to the rivers. Even though production and emissions of PFOA have been strictly controlled in other countries since 2006, production of PFOA as well as several other fluoropolymers that use PFOA as processing aids has been increasing at F1 in recent years. We recommended that production shift should be taken into consideration in PFOA elimination actions.

Shifts in production of perfluoroalkyl acids affect emissions and concentrations in the environment of the Xiaoqing River Basin, China

International Nuclear Information System (INIS)

Wang, Pei; Lu, Yonglong; Wang, Tieyu; Meng, Jing; Li, Qifeng; Zhu, Zhaoyun; Sun, Yajun; Wang, Ruoshi; Giesy, John P.

2016-01-01

Highlights: • Mass loads demonstrated a greater pattern of increasing PFAAs emissions. • High levels of PFOA were identified near a fluoropolymer facility. • Production activities that could generate PFOA emissions were analyzed. • Partitioning coefficients decreased with high levels of short-chain PFCAs in water. - Abstract: Perfluoroalkyl acids (PFAAs) have been widely used in surfactant applications, especially as processing acids for fluoropolymer production. This study provides an analysis of sources of certain PFAAs emitted from the intensive fluoropolymer facilities in the Xiaoqing River Basin of China. Concentrations of perfluorooctanoic acid (PFOA) as great as 0.97 mg/L in surface water and 10.5 μg/g dry weight in surface sediment have been detected near the effluent of one facility (F1) that produces polytetrafluoroethylene (PTFE) and other fluoropolymers with massive capacity. With the great emission of PFAAs to water in natural conditions, the log K_O_C values decreased for short-chain PFCAs. Mass loads of PFAAs indicated that emissions of PFAAs from other facilities or sources were much less than those from F1, which emitted 174 kg/d of PFAAs including 159 kg/d of PFOA to the rivers. Even though production and emissions of PFOA have been strictly controlled in other countries since 2006, production of PFOA as well as several other fluoropolymers that use PFOA as processing aids has been increasing at F1 in recent years. We recommended that production shift should be taken into consideration in PFOA elimination actions.

Long range transport of air pollutants in Europe and acid precipitation in Norway

Science.gov (United States)

Jack Nordo

1976-01-01

Observations show that pollutants from large emission sources may cause significant air concentrations 500 to 1000 miles away. Very acid precipitation occurs in such periods. The scavenging is often intensified by the topography. Case studies will be presented, with special emphasis on acid precipitation in Scandinavia. Large scale dispersion models have been developed...

Tissue distribution of perfluoroalkyl acids and health status in wild Mozambique tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa

Institute of Scientific and Technical Information of China (English)

Jacqueline T.Bangma; Olivia Rynders; Joseph R.Sara; Willem J.Smit; John A.Bowden; Jessica L.Reiner; Hannes Botha; Theresa M.Cantu; Marco A.Gouws; Matthew P.Guillette; Jererny P.Koelmel; Wilmien J.Luus-Powell; Jan Myburgh

2017-01-01

This study examined concentrations of 15 perfiuoroalkyl acids (PFAAs) in tissues from male Mozambique dlapia (Oreochromis mossambicus) collected at Loskop Dam,Mpumalanga,South Africa in 2014 and 2016.Nine of the 15 PFAAs were detected frequently and were included in statistical analysis and included two of the most commonly known PFAAs,perfluorooctanesulfonic acid (PFOS) (median,41.6 ng/g) and perfluorooctanoic acid (PFOA) (median,0.0825 ng/g).Of the tissues measured,plasma (2016 and 2014 median,22.2 ng/g) contained the highest PFAA burden followed by (in descending order):liver (median,11.6 ng/g),kidney (median,9.04 ng/g),spleen (median,5.92 ng/g),adipose (median,2.54 ng/g),and muscle (median,1.11 ng/g).Loskop Dam tilapia have been affected by an inflammatory disease of the adipose tissue known as pansteatitis,so this study also aimed to investigate relationships between PFAA tissue concentrations and incidence of pansteatitis or fish health status.Results revealed that healthy tilapia exhibited an overall higher (p-value ＜ 0.05) PFAA burden than pansteatitis-affected tilapia across all tissues.Further analysis showed that organs previously noted in the literature to contain the highest PFAA concentrations,such as kidney,liver,and plasma,were the organs driving the difference in PFAA burden between the two tilapia groups.Care must be taken in the interpretations we draw from not only the results of our study,but also other PFAA measurements made on populations (human and wildhfe ahke) under differing health status.

Tissue distribution of perfluoroalkyl acids and health status in wild Mozambique tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa.

Science.gov (United States)

Bangma, Jacqueline T; Reiner, Jessica L; Botha, Hannes; Cantu, Theresa M; Gouws, Marco A; Guillette, Matthew P; Koelmel, Jeremy P; Luus-Powell, Wilmien J; Myburgh, Jan; Rynders, Olivia; Sara, Joseph R; Smit, Willem J; Bowden, John A

2017-11-01

This study examined concentrations of 15 perfluoroalkyl acids (PFAAs) in tissues from male Mozambique tilapia (Oreochromis mossambicus) collected at Loskop Dam, Mpumalanga, South Africa in 2014 and 2016. Nine of the 15 PFAAs were detected frequently and were included in statistical analysis and included two of the most commonly known PFAAs, perfluorooctanesulfonic acid (PFOS) (median, 41.6ng/g) and perfluorooctanoic acid (PFOA) (median, 0.0825ng/g). Of the tissues measured, plasma (2016 and 2014 median, 22.2ng/g) contained the highest PFAA burden followed by (in descending order): liver (median, 11.6ng/g), kidney (median, 9.04ng/g), spleen (median, 5.92ng/g), adipose (median, 2.54ng/g), and muscle (median, 1.11ng/g). Loskop Dam tilapia have been affected by an inflammatory disease of the adipose tissue known as pansteatitis, so this study also aimed to investigate relationships between PFAA tissue concentrations and incidence of pansteatitis or fish health status. Results revealed that healthy tilapia exhibited an overall higher (p-valuetilapia across all tissues. Further analysis showed that organs previously noted in the literature to contain the highest PFAA concentrations, such as kidney, liver, and plasma, were the organs driving the difference in PFAA burden between the two tilapia groups. Care must be taken in the interpretations we draw from not only the results of our study, but also other PFAA measurements made on populations (human and wildlife alike) under differing health status. Copyright © 2017. Published by Elsevier B.V.

Self-diffusion and molecular association of acetylsalicylic acid and methyl salicylate in methanol- d4 in the temperature range 278-318 K

Science.gov (United States)

Golubev, V. A.; Kumeev, R. S.; Gurina, D. L.; Nikiforov, M. Yu.

2017-05-01

The effect of concentration on the self-diffusion coefficients of acetylsalicylic acid and methyl salicylate in methanol- d4 is investigated in the temperature range of 278-318 K using NMR. It is found that the self-diffusion coefficients increase along with temperature and fall as concentration rises. Within the limit of an infinitely dilute solution, the effective radii of solute molecules, calculated using the Stokes-Einstein equation shrink as the temperature grows. It is shown that the observed reduction of effective radii is associated with an increase in the fraction of solute monomers as the temperature rises. The physicochemical parameters of heteroassociation of acetylsalicylic acid and methyl salicylate with methanol are determined.

Immunomodulatory effects of exposure to polychlorinated biphenyls and perfluoroalkyl acids in East Greenland ringed seals (Pusa hispida)

International Nuclear Information System (INIS)

Levin, Milton; Gebhard, Erika; Jasperse, Lindsay; Desforges, Jean-Pierre; Dietz, Rune; Sonne, Christian; Eulaers, Igor; Covaci, Adrian; Bossi, Rossana; De Guise, Sylvain

2016-01-01

To better elucidate the potential immune-related health effects of exposure to environmentally persistent organic pollutants (POP), such as polychlorinated biphenyls (PCBs) and perfluoroalkyl substances (PFASs), in ringed seals (Pusa hispida), a sentinel Arctic species, we assessed 1) associations between mitogen-induced lymphocyte proliferation and in vivo tissue contaminant burdens, and 2) the concentration-response effects of in vitro exposure to PFASs and PCB congeners on mitogen-induced lymphocyte proliferation. Upon in vitro contaminant exposure, the non-coplanar PCB congeners CB 138, 153, and 180, but not the coplanar CB 169, significantly reduced lymphocyte proliferation between 10 and 20 µg g −1 ww. The respective in vitro EC 50 values for these congeners were 13.3, 20.7, 20.8, and 54.6 µg g −1 ww. No modulation of lymphocyte proliferation was observed upon in vitro exposure to two individual PFASs, perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA), at concentrations up to 1000 ng g-1. In addition, no significant correlations were found between lymphocyte proliferation and any blood or blubber contaminant measured. Taken together, these data suggest this population of ringed seals is not currently at high risk of altered lymphocyte proliferation from exposure to the POPs or PFASs in this study. - Highlights: • Assess relationships between tissue contaminants and changes in immune function. • Risk for contaminant-induced immunotoxicity in East Greenland ringed seal is low. • Weight of evidence suggest non-coplanar PCBs are immunotoxic at high concentrations.

The relationships between sixteen perfluorinated compound concentrations in blood serum and food, and other parameters, in the general population of South Korea with proportionate stratified sampling method.

Science.gov (United States)

Kim, Hee-Young; Kim, Seung-Kyu; Kang, Dong-Mug; Hwang, Yong-Sik; Oh, Jeong-Eun

2014-02-01

Serum samples were collected from volunteers of various ages and both genders using a proportionate stratified sampling method, to assess the exposure of the general population in Busan, South Korea to perfluorinated compounds (PFCs). 16 PFCs were investigated in serum samples from 306 adults (124 males and 182 females) and one day composite diet samples (breakfast, lunch, and dinner) from 20 of the serum donors, to investigate the relationship between food and serum PFC concentrations. Perfluorooctanoic acid and perfluorooctanesulfonic acid were the dominant PFCs in the serum samples, with mean concentrations of 8.4 and 13 ng/mL, respectively. Perfluorotridecanoic acid was the dominant PFC in the composite food samples, ranging from studies. We confirmed from the relationships between questionnaire results and the PFC concentrations in the serum samples, that food is one of the important contribution factors of human exposure to PFCs. However, there were no correlations between the PFC concentrations in the one day composite diet samples and the serum samples, because a one day composite diet sample is not necessarily representative of a person's long-term diet and because of the small number of samples taken. Copyright © 2013 Elsevier B.V. All rights reserved.

Emission of perfluoroalkyl carboxylic acids (PFCA) from heated surfaces made of polytetrafluoroethylene (PTFE) applied in food contact materials and consumer products.

Science.gov (United States)

Schlummer, Martin; Sölch, Christina; Meisel, Theresa; Still, Mona; Gruber, Ludwig; Wolz, Gerd

2015-06-01

Polytetrafluoroethylene (PTFE) has been widely discussed as a source of perfluorooctanoic acid (PFOA), which has been used in the production of fluoropolymers. PTFE may also contain unintended perfluoroalkyl carboxylic acids (PFCAs) caused by thermolysis of PTFE, which has been observed at temperatures above 300°C. Common PTFE coated food contact materials and consumer goods are operated at temperatures above 200°C. However, knowledge on possible emissions of PFCAs is limited. Therefore, it was the aim of this study to investigate and evaluate the emission of PFCAs from PTFE coated products with both, normal use and overheating scenarios. Four pans, claimed to be PFOA free, and nine consumer products were investigated. At normal use conditions (PTFE surfaces were trapped for 1h. Overheating scenarios (>260°C) recorded emissions during a 30min heating of empty pans on a stove. Emissions were analyzed by LC-ESI-MS. Results indicate the emission of PFCAs, whereas no perfluorinated sulfonic acids were traced. At normal use conditions total emissions of PFCAs accounted for 4.75ng per hour. Overheated pans, however, released far higher amounts with up to 12190ng PFCAs per hour at 370°C. Dominating contributors where PFBA and PFOA at normal use and PFBA and PFPeA during overheating. Temperature seems to be the main factor controlling the emission of PFCAs. A worst case estimation of human exposure revealed that emissions of PFCAs from heated PTFE surfaces would be far below the TDI of 1500ng PFOA per kg body weight. Copyright © 2014 Elsevier Ltd. All rights reserved.

Perfluoroalkyl acids-induced liver steatosis: Effects on genes controlling lipid homeostasis

International Nuclear Information System (INIS)

Das, Kaberi P.; Wood, Carmen R.; Lin, Mimi T.; Starkov, Anatoly A.; Lau, Christopher; Wallace, Kendall B.; Corton, J. Christopher; Abbott, Barbara D.

2017-01-01

Highlights: • Structurally diverse PFAAs induced fatty liver and increased TG accumulation in mouse. • Genes of lipid synthesis and degradation were increased after exposure to PFAAs. • PFAAs did not inhibit either mitochondrial fatty acid transport or β-oxidation directly. - Abstract: Persistent presence of perfluoroalkyl acids (PFAAs) in the environment is due to their extensive use in industrial and consumer products, and their slow decay. Biochemical tests in rodent demonstrated that these chemicals are potent modifiers of lipid metabolism and cause hepatocellular steatosis. However, the molecular mechanism of PFAAs interference with lipid metabolism remains to be elucidated. Currently, two major hypotheses are that PFAAs interfere with mitochondrial beta-oxidation of fatty acids and/or they affect the transcriptional activity of peroxisome proliferator-activated receptor α (PPARα) in liver. To determine the ability of structurally-diverse PFAAs to cause steatosis, as well as to understand the underlying molecular mechanisms, wild-type (WT) and PPARα-null mice were treated with perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), or perfluorohexane sulfonate (PFHxS), by oral gavage for 7 days, and their effects were compared to that of PPARα agonist WY-14643 (WY), which does not cause steatosis. Increases in liver weight and cell size, and decreases in DNA content per mg of liver, were observed for all compounds in WT mice, and were also seen in PPARα-null mice for PFOA, PFNA, and PFHxS, but not for WY. In Oil Red O stained sections, WT liver showed increased lipid accumulation in all treatment groups, whereas in PPARα-null livers, accumulation was observed after PFNA and PFHxS treatment, adding to the burden of steatosis observed in control (untreated) PPARα-null mice. Liver triglyceride (TG) levels were elevated in WT mice by all PFAAs and in PPARα-null mice only by PFNA. In vitro β-oxidation of palmitoyl carnitine by isolated rat

Review: Micro-organic contaminants in groundwater in China

Science.gov (United States)

Dong, Weihong; Xie, Wei; Su, Xiaosi; Wen, Chuanlei; Cao, Zhipeng; Wan, Yuyu

2018-03-01

Micro-organic contaminants (MOs) in groundwater, which may have adverse effects on human health and ecosystems worldwide, are gaining increased attention in China. A great deal of research has been conducted to investigate their sources, occurrences and behavior in aquifers. This paper reviews the main sources, distribution, concentrations and behavior of a wide range of MOs in groundwater in China. These MOs include well-established persistent organic pollutants—polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), endocrine disrupting chemicals (poly brominated diphenyl ethers (PBDEs), phthalic acid esters (PAEs), bisphenol A (BPA)—and some contaminants of emerging concern such as pharmaceutical and personal care products (antibiotics, caffeine, shampoos) and perfluorinated compounds (PFCs). The results reveal that the main MOs in groundwater are PAHs, organochlorine pesticides (OCPs), PBDEs, PAEs, and antibiotics. Moreover, some PFCs such as perfluorobutane sulfonic acid (PFBS), perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) have only recently been observed in groundwater as emerging organic contaminants. Additionally, most MOs are distributed in populated and industrialized areas such as the southeast coast of China. Finally, industrial emissions, wastewater treatment plant effluents and agricultural wastewater are found to be dominant sources of MOs in groundwater. Based on the existing pollution levels, regulation and amelioration of MOs are warranted.

Whole-Body Docosahexaenoic Acid Synthesis-Secretion Rates in Rats Are Constant across a Large Range of Dietary α-Linolenic Acid Intakes.

Science.gov (United States)

Domenichiello, Anthony F; Kitson, Alex P; Metherel, Adam H; Chen, Chuck T; Hopperton, Kathryn E; Stavro, P Mark; Bazinet, Richard P

2017-01-01

Docosahexaenoic acid (DHA) is an ω-3 (n-3) polyunsaturated fatty acid (PUFA) thought to be important for brain function. Although the main dietary source of DHA is fish, DHA can also be synthesized from α-linolenic acid (ALA), which is derived from plants. Enzymes involved in DHA synthesis are also active toward ω-6 (n-6) PUFAs to synthesize docosapentaenoic acid n-6 (DPAn-6). It is unclear whether DHA synthesis from ALA is sufficient to maintain brain DHA. The objective of this study was to determine how different amounts of dietary ALA would affect whole-body DHA and DPAn-6 synthesis rates. Male Long-Evans rats were fed an ALA-deficient diet (ALA-D), an ALA-adequate (ALA-A) diet, or a high-ALA (ALA-H) diet for 8 wk from weaning. Dietary ALA concentrations were 0.07%, 3%, and 10% of the fatty acids, and ALA was the only dietary PUFA that differed between the diets. After 8 wk, steady-state stable isotope infusion of labeled ALA and linoleic acid (LA) was performed to determine the in vivo synthesis-secretion rates of DHA and DPAn-6. Rats fed the ALA-A diet had an ∼2-fold greater capacity to synthesize DHA than did rats fed the ALA-H and ALA-D diets, and a DHA synthesis rate that was similar to that of rats fed the ALA-H diet. However, rats fed the ALA-D diet had a 750% lower DHA synthesis rate than rats fed the ALA-A and ALA-H diets. Despite enrichment into arachidonic acid, we did not detect any labeled LA appearing as DPAn-6. Increasing dietary ALA from 3% to 10% of fatty acids did not increase DHA synthesis rates, because of a decreased capacity to synthesize DHA in rats fed the ALA-H diet. Tissue concentrations of DPAn-6 may be explained at least in part by longer plasma half-lives. © 2017 American Society for Nutrition.

Distribution profiles of per- and poly fluoroalkyl substances (PFASs) and their re-regulation by ocean currents in the East and South China Sea.

Science.gov (United States)

Zheng, Hongyuan; Wang, Feng; Zhao, Zhen; Ma, Yuxin; Yang, Haizhen; Lu, Zhibo; Cai, Minggang; Cai, Minghong

2017-12-15

We investigated the distribution of 17 individual per- and polyfluoroalkyl substances (PFASs) in 42 surface water samples collected from the East and South China Seas (7.0-36.0°N, 110.0°N-123.0°E). Concentrations of 7 individual PFASs, including perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluoropentanoic acid (PFPA), perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonamide (FOSA), were quantified in the East China Sea, but only concentrations of PFOA and FOSA were quantified in the South China Sea. The total concentrations of the 17 PFASs ranged from 181 to 2658pg/L in the East China Sea and from 62 to 494pg/L in the South China Sea. We also show that river fluxes and ocean currents had a strong influence on the distribution of PFASs in the East China Sea. Using ArcGIS 10.1, we show how ocean currents control the spatial distribution of PFOA in the central South China Sea. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vapor-liquid equilibria for nitric acid-water and plutonium nitrate-nitric acid-water solutions

International Nuclear Information System (INIS)

Maimoni, A.

1980-01-01

The liquid-vapor equilibrium data for nitric acid and nitric acid-plutnonium nitrate-water solutions were examined to develop correlations covering the range of conditions encountered in nuclear fuel reprocessing. The scanty available data for plutonium nitrate solutions are of poor quality but allow an order of magnitude estimate to be made. A formal thermodynamic analysis was attempted initially but was not successful due to the poor quality of the data as well as the complex chemical equilibria involved in the nitric acid and in the plutonium nitrate solutions. Thus, while there was no difficulty in correlating activity coefficients for nitric acid solutions over relatively narrow temperature ranges, attempts to extend the correlations over the range 25 0 C to the boiling point were not successful. The available data were then analyzed using empirical correlations from which normal boiling points and relative volatilities can be obtained over the concentration ranges 0 to 700 g/l Pu, 0 to 13 M nitric acid. Activity coefficients are required, however, if estimates of individual component vapor pressures are needed. The required ternary activity coefficients can be approximated from the correlations

ACETIC ACID AND A BUFFER

DEFF Research Database (Denmark)

2009-01-01

The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

Screening of perfluorinated chemicals (PFCs) in various aquatic organisms

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Sanjuan, Maria; Meyer, Johan; Damasio, Joana; Faria, Melissa; Barata, Carlos; Lacorte, Silvia [IDAEA-CSIC, Department of Environmental Chemistry, Barcelona (Spain)

2010-10-15

The aim of this study was to evaluate the occurrence of five perfluorinated chemicals (perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid) in aquatic organisms dwelling in either freshwater or marine ecosystems. Organisms selected were insect larvae, oysters, zebra mussels, sardines, and crabs, which are widespread in the environment and may represent potential bioindicators of exposure to PFCs. The study comprises the optimization of a solid-liquid extraction method and determination by high-performance liquid chromatography coupled to tandem mass spectrometry. Using spiked zebra mussels at 10 and 100 ng/g level, the method developed provided recoveries of 96% and 122%, and 82% to 116%, respectively, and a limit of detection between 0.07 and 0.22 ng/g ww. The method was highly sensitivity and robust to determine PFC compounds in a wide array of biological matrices, and no matrix interferents nor blank contamination was observed. Among organisms studied, none of the bivalves accumulated PFCs, and contrarily, insect larvae, followed by fish and crabs contained levels ranging from 0.23 to 144 ng/g ww of PFOS, from 0.14 to 4.3 ng/g ww of PFOA, and traces of PFNA and PFHxS. Assessment of the potential use of aquatic organisms for biomonitoring studies is further discussed. (orig.)

Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

Science.gov (United States)

Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

1992-01-01

Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

Acidic pH shock induces the expressions of a wide range of stress-response genes

Directory of Open Access Journals (Sweden)

Hong Soon-Kwang

2008-12-01

Full Text Available Abstract Background Environmental signals usually enhance secondary metabolite production in Streptomycetes by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in Streptomyces strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in S. coelicolor A3(2. Results According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of sigH (heat shock, sigR (oxidative stress, sigB (osmotic shock, and hrdD that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of hspR was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall. Conclusion From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.

Complexity in Acid?Base Titrations: Multimer Formation Between Phosphoric Acids and Imines

OpenAIRE

Malm, Christian; Kim, Heejae; Wagner, Manfred; Hunger, Johannes

2017-01-01

Abstract Solutions of Br?nsted acids with bases in aprotic solvents are not only common model systems to study the fundamentals of proton transfer pathways but are also highly relevant to Br?nsted acid catalysis. Despite their importance the light nature of the proton makes characterization of acid?base aggregates challenging. Here, we track such acid?base interactions over a broad range of relative compositions between diphenyl phosphoric acid and the base quinaldine in dichloromethane, by u...

Analysis of perfluorinated carboxylic acids in soils II: optimization of chromatography and extraction.

Science.gov (United States)

Washington, John W; Henderson, W Matthew; Ellington, J Jackson; Jenkins, Thomas M; Evans, John J

2008-02-15

With the objective of detecting and quantitating low concentrations of perfluorinated carboxylic acids (PFCAs), including perfluorooctanoic acid (PFOA), in soils, we compared the analytical suitability of liquid chromatography columns containing three different stationary phases, two different liquid chromatography-tandem mass spectrometry (LC/MS/MS) systems, and eight combinations of sample-extract pretreatments, extractions and cleanups on three test soils. For the columns and systems we tested, we achieved the greatest analytical sensitivity for PFCAs using a column with a C(18) stationary phase in a Waters LC/MS/MS. In this system we achieved an instrument detection limit for PFOA of 270 ag/microL, equating to about 14 fg of PFOA on-column. While an elementary acetonitrile/water extraction of soils recovers PFCAs effectively, natural soil organic matter also dissolved in the extracts commonly imparts significant noise that appears as broad, multi-nodal, asymmetric peaks that coelute with several PFCAs. The intensity and elution profile of this noise is highly variable among soils and it challenges detection of low concentrations of PFCAs by decreasing the signal-to-noise contrast. In an effort to decrease this background noise, we investigated several methods of pretreatment, extraction and cleanup, in a variety of combinations, that used alkaline and unbuffered water, acetonitrile, tetrabutylammonium hydrogen sulfate, methyl-tert-butyl ether, dispersed activated carbon and solid-phase extraction. For the combined objectives of complete recovery and minimization of background noise, we have chosen: (1) alkaline pretreatment; (2) extraction with acetonitrile/water; (3) evaporation to dryness; (4) reconstitution with tetrabutylammonium-hydrogen-sulfate ion-pairing solution; (5) ion-pair extraction to methyl-tert-butyl ether; (6) evaporation to dryness; (7) reconstitution with 60/40 acetonitrile/water (v/v); and (8) analysis by LC/MS/MS. Using this method, we

Immunomodulatory effects of exposure to polychlorinated biphenyls and perfluoroalkyl acids in East Greenland ringed seals (Pusa hispida)

Energy Technology Data Exchange (ETDEWEB)

Levin, Milton, E-mail: Milton.levin@uconn.edu [Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269-3089 (United States); Gebhard, Erika; Jasperse, Lindsay [Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269-3089 (United States); Desforges, Jean-Pierre; Dietz, Rune; Sonne, Christian; Eulaers, Igor [Department of Bioscience, Arctic Research Centre (ARC), Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde (Denmark); Covaci, Adrian [Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, BE-2610 Wilrijk (Belgium); Bossi, Rossana [Department of Environmental Science, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde (Denmark); De Guise, Sylvain [Department of Pathobiology and Veterinary Science, University of Connecticut, 61 North Eagleville Road, Storrs, CT 06269-3089 (United States)

2016-11-15

To better elucidate the potential immune-related health effects of exposure to environmentally persistent organic pollutants (POP), such as polychlorinated biphenyls (PCBs) and perfluoroalkyl substances (PFASs), in ringed seals (Pusa hispida), a sentinel Arctic species, we assessed 1) associations between mitogen-induced lymphocyte proliferation and in vivo tissue contaminant burdens, and 2) the concentration-response effects of in vitro exposure to PFASs and PCB congeners on mitogen-induced lymphocyte proliferation. Upon in vitro contaminant exposure, the non-coplanar PCB congeners CB 138, 153, and 180, but not the coplanar CB 169, significantly reduced lymphocyte proliferation between 10 and 20 µg g{sup −1} ww. The respective in vitro EC{sub 50} values for these congeners were 13.3, 20.7, 20.8, and 54.6 µg g{sup −1} ww. No modulation of lymphocyte proliferation was observed upon in vitro exposure to two individual PFASs, perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA), at concentrations up to 1000 ng g-1. In addition, no significant correlations were found between lymphocyte proliferation and any blood or blubber contaminant measured. Taken together, these data suggest this population of ringed seals is not currently at high risk of altered lymphocyte proliferation from exposure to the POPs or PFASs in this study. - Highlights: • Assess relationships between tissue contaminants and changes in immune function. • Risk for contaminant-induced immunotoxicity in East Greenland ringed seal is low. • Weight of evidence suggest non-coplanar PCBs are immunotoxic at high concentrations.

Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

Science.gov (United States)

Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

2002-12-06

Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

Peracetic Acid Treatment Generates Potent Inactivated Oral Vaccines from a Broad Range of Culturable Bacterial Species

Science.gov (United States)

Moor, Kathrin; Wotzka, Sandra Y.; Toska, Albulena; Diard, Médéric; Hapfelmeier, Siegfried; Slack, Emma

2016-01-01

Our mucosal surfaces are the main sites of non-vector-borne pathogen entry, as well as the main interface with our commensal microbiota. We are still only beginning to understand how mucosal adaptive immunity interacts with commensal and pathogenic microbes to influence factors such as infectivity, phenotypic diversity, and within-host evolution. This is in part due to difficulties in generating specific mucosal adaptive immune responses without disrupting the mucosal microbial ecosystem itself. Here, we present a very simple tool to generate inactivated mucosal vaccines from a broad range of culturable bacteria. Oral gavage of 1010 peracetic acid-inactivated bacteria induces high-titer-specific intestinal IgA in the absence of any measurable inflammation or species invasion. As a proof of principle, we demonstrate that this technique is sufficient to provide fully protective immunity in the murine model of invasive non-typhoidal Salmonellosis, even in the face of severe innate immune deficiency. PMID:26904024

Effect of Cooking Method on the Proximate, Amino Acid and Fatty Acid Compositions of Clarias gariepinus and Oreochromis niloticus

Directory of Open Access Journals (Sweden)

Omolara Olusola Oluwaniyi

2016-10-01

Full Text Available The proximate, amino acid and fatty acid compositions of the fillet and oil from Clarias gariepinus (Catfish and Oreochromis niloticus (Tilapia were determined. The moisture content ranged from 76.27 % for catfish to 79.97 % for tilapia while the oil content ranged from 7.80 % for tilapia and 11.00 % for catfish. Ash content was in the range 8.03 – 9.16 % and the protein content was 15.83 - 18.48 %. Cooking – boiling, roasting or frying – resulted in a variation in the nutrient composition but with no significant effect on the amino acid composition except for the samples fried with palm oil which resulted in significantly reduced essential amino acids contents. All the fish samples – both fresh and processed – have amino acid scores less than 100, with lysine, threonine and the sulphur-containing amino acids being among the limiting amino acids. Both fish samples contain more unsaturated than saturated fatty acids.

An alginate-antacid formulation localizes to the acid pocket to reduce acid reflux in patients with gastroesophageal reflux disease.

Science.gov (United States)

Rohof, Wout O; Bennink, Roel J; Smout, Andre J P M; Thomas, Edward; Boeckxstaens, Guy E

2013-12-01

Alginate rafts (polysaccharide polymers that precipitate into a low-density viscous gel when they contact gastric acid) have been reported to form at the acid pocket, an unbuffered pool of acid that floats on top of ingested food and causes postprandial acid reflux. We studied the location of an alginate formulation in relation to the acid pocket and the corresponding effects on reflux parameters and acid pocket positioning in patients with gastroesophageal reflux disease (GERD). We randomly assigned patients with symptomatic GERD and large hiatal hernias to groups who were given either (111)In-labeled alginate-antacid (n = 8, Gaviscon Double Action Liquid) or antacid (n = 8, Antagel) after a standard meal. The relative positions of labeled alginate and acid pocket were analyzed for 2 hours by using scintigraphy; reflux episodes were detected by using high-resolution manometry and pH-impedance monitoring. The alginate-antacid label localized to the acid pocket. The number of acid reflux episodes was significantly reduced in patients receiving alginate-antacid (3.5; range, 0-6.5; P = .03) compared with those receiving antacid (15; range, 5-20), whereas time to acid reflux was significantly increased in patients receiving alginate-antacid (63 minutes; range, 23-92) vs those receiving antacid (14 minutes; range, 9-23; P = .01). The acid pocket was located below the diaphragm in 71% of patients given alginate-antacid vs 21% of those given antacid (P = .08). There was an inverse correlation between a subdiaphragm position of the acid pocket and acid reflux (r = -0.76, P acid pocket and displaces it below the diaphragm to reduce postprandial acid reflux. These findings indicate the importance of the acid pocket in GERD pathogenesis and establish alginate-antacid as an appropriate therapy for postprandial acid reflux. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Mass energy-absorption coefficients and average atomic energy-absorption cross-sections for amino acids in the energy range 0.122-1.330 MeV

Energy Technology Data Exchange (ETDEWEB)

More, Chaitali V., E-mail: chaitalimore89@gmail.com; Lokhande, Rajkumar M.; Pawar, Pravina P., E-mail: pravinapawar4@gmail.com [Department of physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

2016-05-06

Mass attenuation coefficients of amino acids such as n-acetyl-l-tryptophan, n-acetyl-l-tyrosine and d-tryptophan were measured in the energy range 0.122-1.330 MeV. NaI (Tl) scintillation detection system was used to detect gamma rays with a resolution of 8.2% at 0.662 MeV. The measured attenuation coefficient values were then used to determine the mass energy-absorption coefficients (σ{sub a,en}) and average atomic energy-absorption cross sections (μ{sub en}/ρ) of the amino acids. Theoretical values were calculated based on XCOM data. Theoretical and experimental values are found to be in good agreement.

Changes in concentrations of perfluorinated compounds, polybrominated diphenyl ethers, and polychlorinated biphenyls in Norwegian breast-milk during twelve months of lactation.

Science.gov (United States)

Thomsen, Cathrine; Haug, Line S; Stigum, Hein; Frøshaug, May; Broadwell, Sharon L; Becher, Georg

2010-12-15

At present, scientific knowledge on depuration rates of persistent organic pollutants (POPs) is limited and the previous assumptions of considerable reduction of body burdens through breast-feeding have recently been challenged. We therefore studied elimination rates of important POPs in nine Norwegian primiparous mothers and one mother breast-feeding her second child by collecting breast-milk samples (n = 70) monthly from about two weeks to up to twelve months after birth. Perfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and polychlorinated biphenyls (PCBs) were determined in the breast-milk samples. Linear mixed effect models were established for selected compounds, and significant decreases in the range of 1.2-4.7% in breast-milk concentrations per month were observed for a wide range of PCBs and PBDEs. For the first time, depuration rates for perfluorooctylsulfonate (PFOS) and perfluorooctanoic acid (PFOA) are presented, being 3.8 and 7.8% per month, respectively (p changes during the lactation period. After a year of nursing the breast-milk concentrations of PFCs, PBDEs, and PCBs were reduced by 15-94%.

Partial molar volumes of proteins: amino acid side-chain contributions derived from the partial molar volumes of some tripeptides over the temperature range 10-90 degrees C.

Science.gov (United States)

Häckel, M; Hinz, H J; Hedwig, G R

1999-11-15

The partial molar volumes of tripeptides of sequence glycyl-X-glycine, where X is one of the amino acids alanine, leucine, threonine, glutamine, phenylalanine, histidine, cysteine, proline, glutamic acid, and arginine, have been determined in aqueous solution over the temperature range 10-90 degrees C using differential scanning densitometry . These data, together with those reported previously, have been used to derive the partial molar volumes of the side-chains of all 20 amino acids. The side-chain volumes are critically compared with literature values derived using partial molar volumes for alternative model compounds. The new amino acid side-chain volumes, along with that for the backbone glycyl group, were used to calculate the partial specific volumes of several proteins in aqueous solution. The results obtained are compared with those observed experimentally. The new side-chain volumes have also been used to re-determine residue volume changes upon protein folding.

Turkey-hen amino acid composition of brain and eyes

International Nuclear Information System (INIS)

Adeyeye, E.I.

2015-01-01

The amino acids composition of the brain and eyes of the mature Turkey-hen (Meleagris gallopavo L.), were determined on dry weight basis. Total essential amino acids ranged from 35.1-36.0 g/100 g as 49.5-49.8% of the total amino acids. The amino acid score showed that lysine ranged from 0.76-0.91 (on whole hen.s egg comparison), 0.85-1.03 (on provisional essential amino acid scoring pattern), and 0.81-0.98 (on suggested requirement of the essential amino acid of a preschool child). The predicted protein efficiency ratio was 1.94-2.41, whilst essential amino acid index range was 1.06-1.08 and the calculated isoelectric point range was 3.97-4.18. The correlation coefficient (rxy) was positively high and significant at r = 0.01 for the total amino acids, amino acid scores (on the whole hen.s egg comparisons made) and the isoelectric point. On the whole, the eyes were better in 12/18 or 66.7% parameters of the amino acids than the brain of Turkey-Hen. (author)

Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

Science.gov (United States)

Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

2016-06-07

An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

Shorter duration of breastfeeding at elevated exposures to perfluoroalkyl substances

DEFF Research Database (Denmark)

Timmermann, Clara Amalie Gade; Budtz-Jørgensen, Esben; Petersen, Maria Skaalum

2017-01-01

. Duration of breastfeeding was assessed by questionnaire and clinical interview. In adjusted linear regression models, a doubling of maternal serum PFASs was associated with a reduction in duration of both total and exclusive breastfeeding, most pronounced for perfluorooctane sulfonic acid (PFOS) where...... a doubling was associated with a reduction in total breastfeeding of 1.4 (95% CI: 0.6; 2.1) months and perfluorooctanoic acid (PFOA) where a doubling was associated with a reduction in exclusive breastfeeding of 0.5 (0.3; 0.7) months. The associations were evident among both primiparous and multiparous women......, and thus cannot be explained by confounding from previous breastfeeding....

Maternal Concentrations of Perfluoroalkyl Substances and Fetal Markers of Metabolic Function and Birth Weight

Science.gov (United States)

Ashley-Martin, Jillian; Dodds, Linda; Arbuckle, Tye E.; Bouchard, Maryse F.; Fisher, Mandy; Morriset, Anne-Sophie; Monnier, Patricia; Shapiro, Gabriel D.; Ettinger, Adrienne S.; Dallaire, Renee; Taback, Shayne; Fraser, William; Platt, Robert W.

2017-01-01

Abstract Perfluoroalkyl substances (PFAS) are ubiquitous, persistent chemicals that have been widely used in the production of common household and consumer goods for their nonflammable, lipophobic, and hydrophobic properties. Inverse associations between maternal or umbilical cord blood concentrations of perfluorooctanoic acid and perfluorooctanesulfonate and birth weight have been identified. This literature has primarily examined each PFAS individually without consideration of the potential influence of correlated exposures. Further, the association between PFAS exposures and indicators of metabolic function (i.e., leptin and adiponectin) has received limited attention. We examined associations between first-trimester maternal plasma PFAS concentrations and birth weight and cord blood concentrations of leptin and adiponectin using data on 1,705 mother-infant pairs from the Maternal Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada birth cohort study that recruited women between 2008 and 2011. Bayesian hierarchical models were used to quantify associations and calculate credible intervals. Maternal perfluorooctanoic acid concentrations were inversely associated with birth weight z score, though the null value was included in all credible intervals (log10 β = −0.10, 95% credible interval: −0.34, 0.13). All associations between maternal PFAS concentrations and cord blood adipocytokine concentrations were of small magnitude and centered around the null value. Follow-up in a cohort of children is required to determine how the observed associations manifest in childhood. PMID:28172036

Perfluoroalkyl substances and time to pregnancy in couples from Greenland, Poland and Ukraine

DEFF Research Database (Denmark)

Jørgensen, Kristian T; Specht, Ina O; Lenters, Virissa

2014-01-01

BACKGROUND: Perfluoroalkyl substances (PFAS) are suggested to affect human fecundity through longer time to pregnancy (TTP). We studied the relationship between four abundant PFAS and TTP in pregnant women from Greenland, Poland and Ukraine representing varying PFAS exposures and pregnancy planning...... behaviors. METHODS: We measured serum levels of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA) in 938 women from Greenland (448 women), Poland (203 women) and Ukraine (287 women). PFAS exposure was assessed...... weaker for women from Poland and Ukraine. PFOS, PFOA and PFHxS were not consistently associated with TTP. CONCLUSIONS: Findings do not provide consistent evidence that environmental exposure to PFAS is impairing female fecundity by delaying time taken to conceive....

Blood serum concentrations of perfluorinated compounds in men from Greenlandic Inuit and European populations

DEFF Research Database (Denmark)

Lindh, Christian H; Rylander, Lars; Toft, Gunnar

2012-01-01

Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are used in large quantities. They are persistent and found in measurable levels in human serum around the world. They have been associated with developmental, hepatic, and carcinogenic ef...... in Ukraine was rather low. In the Greenlandic Inuit population, intake of seafood, tea, age and area of living were significant determinants of PFOS concentrations and explained about 22% of the variation. For the other populations no strong determinants were found....

Identification of GH15 Family Thermophilic Archaeal Trehalases That Function within a Narrow Acidic-pH Range.

Science.gov (United States)

Sakaguchi, Masayoshi; Shimodaira, Satoru; Ishida, Shin-Nosuke; Amemiya, Miko; Honda, Shotaro; Sugahara, Yasusato; Oyama, Fumitaka; Kawakita, Masao

2015-08-01

Two glucoamylase-like genes, TVN1315 and Ta0286, from the archaea Thermoplasma volcanium and T. acidophilum, respectively, were expressed in Escherichia coli. The gene products, TVN1315 and Ta0286, were identified as archaeal trehalases. These trehalases belong to the CAZy database family GH15, although they have putative (α/α)6 barrel catalytic domain structures similar to those of GH37 and GH65 family trehalases from other organisms. These newly identified trehalases function within a narrow range of acidic pH values (pH 3.2 to 4.0) and at high temperatures (50 to 60°C), and these enzymes display Km values for trehalose higher than those observed for typical trehalases. These enzymes were inhibited by validamycin A; however, the inhibition constants (Ki) were higher than those of other trehalases. Three TVN1315 mutants, corresponding to E408Q, E571Q, and E408Q/E571Q mutations, showed reduced activity, suggesting that these two glutamic acid residues are involved in trehalase catalysis in a manner similar to that of glucoamylase. To date, TVN1315 and Ta0286 are the first archaeal trehalases to be identified, and this is the first report of the heterologous expression of GH15 family trehalases. The identification of these trehalases could extend our understanding of the relationships between the structure and function of GH15 family enzymes as well as glycoside hydrolase family enzymes; additionally, these enzymes provide insight into archaeal trehalose metabolism. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Reactions of tritium atoms with amino acids, deuterated amino acids and mixtures of amino acids. Additivity property and isotope effect

International Nuclear Information System (INIS)

Badun, G.A.; Filatov, Eh.S.

1988-01-01

Interaction of tritium atoms with glycine (1) and leucine (2) amino acids, deuterated amino acids, their mixtures and glycylleucine (3) peptide in the 77-300 K temperature range is studied in isothermal and gradient regimes. Tagged amino acids were separated from targets after conducting the reaction. At T 150 K are associated with intermolecular transmission of free valence in the mixture of amino acids. Regularities of the reaction found for the mixture of amino acids are conserved for (3) as well, i.e. the peptide bond does not essentially affect the reaction of isotopic exchange conditioned by atomic tritium

Investigating sources and pathways of perfluoroalkyl acids (PFAAs) in aquifers in Tokyo using multiple tracers

International Nuclear Information System (INIS)

Kuroda, Keisuke; Murakami, Michio; Oguma, Kumiko; Takada, Hideshige; Takizawa, Satoshi

2014-01-01

We employed a multi-tracer approach to investigate sources and pathways of perfluoroalkyl acids (PFAAs) in urban groundwater, based on 53 groundwater samples taken from confined aquifers and unconfined aquifers in Tokyo. While the median concentrations of groundwater PFAAs were several ng/L, the maximum concentrations of perfluorooctane sulfonate (PFOS, 990 ng/L), perfluorooctanoate (PFOA, 1800 ng/L) and perfluorononanoate (PFNA, 620 ng/L) in groundwater were several times higher than those of wastewater and street runoff reported in the literature. PFAAs were more frequently detected than sewage tracers (carbamazepine and crotamiton), presumably owing to the higher persistence of PFAAs, the multiple sources of PFAAs beyond sewage (e.g., surface runoff, point sources) and the formation of PFAAs from their precursors. Use of multiple methods of source apportionment including principal component analysis–multiple linear regression (PCA–MLR) and perfluoroalkyl carboxylic acid ratio analysis highlighted sewage and point sources as the primary sources of PFAAs in the most severely polluted groundwater samples, with street runoff being a minor source (44.6% sewage, 45.7% point sources and 9.7% street runoff, by PCA–MLR). Tritium analysis indicated that, while young groundwater (recharged during or after the 1970s, when PFAAs were already in commercial use) in shallow aquifers (< 50 m depth) was naturally highly vulnerable to PFAA pollution, PFAAs were also found in old groundwater (recharged before the 1950s, when PFAAs were not in use) in deep aquifers (50–500 m depth). This study demonstrated the utility of multiple uses of tracers (pharmaceuticals and personal care products; PPCPs, tritium) and source apportionment methods in investigating sources and pathways of PFAAs in multiple aquifer systems. - Highlights: • Aquifers in Tokyo had high levels of perfluoroalkyl acids (up to 1800 ng/L). • PFAAs were more frequently detected than sewage

Investigating sources and pathways of perfluoroalkyl acids (PFAAs) in aquifers in Tokyo using multiple tracers

Energy Technology Data Exchange (ETDEWEB)

Kuroda, Keisuke, E-mail: keisukekr@gmail.com [Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Murakami, Michio [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Oguma, Kumiko [Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Takada, Hideshige [Laboratory of Organic Geochemistry (LOG), Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Takizawa, Satoshi [Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

2014-08-01

We employed a multi-tracer approach to investigate sources and pathways of perfluoroalkyl acids (PFAAs) in urban groundwater, based on 53 groundwater samples taken from confined aquifers and unconfined aquifers in Tokyo. While the median concentrations of groundwater PFAAs were several ng/L, the maximum concentrations of perfluorooctane sulfonate (PFOS, 990 ng/L), perfluorooctanoate (PFOA, 1800 ng/L) and perfluorononanoate (PFNA, 620 ng/L) in groundwater were several times higher than those of wastewater and street runoff reported in the literature. PFAAs were more frequently detected than sewage tracers (carbamazepine and crotamiton), presumably owing to the higher persistence of PFAAs, the multiple sources of PFAAs beyond sewage (e.g., surface runoff, point sources) and the formation of PFAAs from their precursors. Use of multiple methods of source apportionment including principal component analysis–multiple linear regression (PCA–MLR) and perfluoroalkyl carboxylic acid ratio analysis highlighted sewage and point sources as the primary sources of PFAAs in the most severely polluted groundwater samples, with street runoff being a minor source (44.6% sewage, 45.7% point sources and 9.7% street runoff, by PCA–MLR). Tritium analysis indicated that, while young groundwater (recharged during or after the 1970s, when PFAAs were already in commercial use) in shallow aquifers (< 50 m depth) was naturally highly vulnerable to PFAA pollution, PFAAs were also found in old groundwater (recharged before the 1950s, when PFAAs were not in use) in deep aquifers (50–500 m depth). This study demonstrated the utility of multiple uses of tracers (pharmaceuticals and personal care products; PPCPs, tritium) and source apportionment methods in investigating sources and pathways of PFAAs in multiple aquifer systems. - Highlights: • Aquifers in Tokyo had high levels of perfluoroalkyl acids (up to 1800 ng/L). • PFAAs were more frequently detected than sewage

Proximate composition, amino acid and fatty acid composition of fish maws.

Science.gov (United States)

Wen, Jing; Zeng, Ling; Xu, Youhou; Sun, Yulin; Chen, Ziming; Fan, Sigang

2016-01-01

Fish maws are commonly recommended and consumed in Asia over many centuries because it is believed to have some traditional medical properties. This study highlights and provides new information on the proximate composition, amino acid and fatty acid composition of fish maws of Cynoscion acoupa, Congresox talabonoides and Sciades proops. The results indicated that fish maws were excellent protein sources and low in fat content. The proteins in fish maws were rich in functional amino acids (FAAs) and the ratio of FAAs and total amino acids in fish maws ranged from 0.68 to 0.69. Among species, croaker C. acoupa contained the most polyunsaturated fatty acids, arachidonic acid, docosahexaenoic acid and eicosapntemacnioc acid, showing the lowest value of index of atherogenicity and index of thrombogenicity, showing the highest value of hypocholesterolemic/hypercholesterolemic ratio, which is the most desirable.

A new highly selective metabotropic excitatory amino acid agonist: 2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid

DEFF Research Database (Denmark)

Bräuner-Osborne, Hans; Sløk, F A; Skjaerbaek, N

1996-01-01

The homologous series of acidic amino acids, ranging from aspartic acid (1) to 2-aminosuberic acid (5), and the corresponding series of 3-isoxazolol bioisosteres of these amino acids, ranging from (RS)-2-amino-2-(3-hydroxy-5-methylisoxazol-4-yl)acetic acid (AMAA, 6) to (RS)-2-amino-6-(3-hydroxy-5......-methylisoxazol-4-yl)hexanoic acid (10), were tested as ligands for metabotropic excitatory amino acid receptors (mGlu1 alpha, mGlu2, mGlu4a, and mGlu6). Whereas AMAA (6) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propinoic acid (AMPA, 7) are potent and highly selective agonists at N......-methyl-D-aspartic acid (NMDA) and AMPA receptors, respectively, the higher homologue of AMPA (7), (RS)-2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid (homo-AMPA, 8), is inactive at ionotropic excitatory amino acid receptors. Homo-AMPA (8), which is a 3-isoxazolol bioisostere of 2-aminoadipic acid (3), was...

Specific bile acid radioimmunoassays for separate determinations of unconjugated cholic acid, conjugated cholic acid and conjugated deoxycholic acid in serum and their clinical application

International Nuclear Information System (INIS)

Matern, S.; Gerok, W.

1977-01-01

Specific radioimmunoassays for separate determinations of serum unconjugated cholic, conjugated cholic and conjugated deoxycholic acids have been developed. Prior to the radioimmunoassay, extraction of serum bile acids was performed with Amberlite XAD-2. Unconjugated cholic acid was separated from glyco- and taurocholic acids by thin-layer chromatography. At 50% displacement of bound labeled glyco[ 3 H]cholic acid using antiserum obtained after immunization with cholic acid-bovine serum albumin-conjugate the cross-reactivity of taurocholic acid was 100%, cholic acid 80%, glycochenodeoxycholic acid 10%, chenodeoxycholic acid 7%, conjugated deoxycholic acid 3%, and conjugated lithocholic acid 3 H]cholic acid was linear on a logit-log plot from 5 to 80 pmol of unlabeled glycocholic acid. Fasting serum conjugated cholic acid in healthy subjects was 0.68 +- 0.34 μmol/l. Unconjugated cholic acid was determined by a solid phase radioimmunoassay using the cholic acid antibody chemically bound to Sepharose. The displacement curve of [ 3 H]cholic acid in the solid phase radioimmunoassay was linear on a logit-log plot from 5 to 200 pmol of unlabeled cholic acid. The coefficient of variation between samples was 5%. Fasting serum conjugated deoxycholic acid concentrations in 10 healthy subjects ranged from 0.18 to 0.92 μmol/l determined by a radioimmunoassay using antiserum obtained after immunization with deoxycholic acid-bovine serum albumin-conjugate. The clinical application of these bile acid radioimmunoassays is shown by an 'oral cholate tolerance test' as a sensitive indicator of liver function and by an 'oral cholyglycine tolerance test' as a useful test for bile acid absorption. (orig.) [de

Occurrence of different classes of perfluorinated compounds in Greek wastewater treatment plants and determination of their solid–water distribution coefficients

International Nuclear Information System (INIS)

Arvaniti, Olga S.; Ventouri, Elpida I.; Stasinakis, Athanasios S.; Thomaidis, Nikolaos S.

2012-01-01

Highlights: ► Eighteen PFCs were determined in wastewater and sludge samples using LC–MS/MS. ► PFPeA, PFOA and PFOS were the dominating compounds in both WWTPs. ► No significant decrease or even increase of most PFCs was noticed in effluents. ► Distribution coefficients of PFCs were calculated for different types of sludge. ► Sorption potential was affected by the target compound and the type of sludge. - Abstract: The concentrations of eighteen perfluorinated compounds (PFCs: C5–C14 carboxylates, C4, C6–C8 and C10 sulfonates and 3 sulfonamides) were determined in wastewater and sludge samples originating from two different wastewater treatment plants (WWTPs). The analytes were extracted by solid phase extraction (dissolved phase) or sonication followed by solid phase extraction (solid phase). Qualitative and quantitative analyses were performed by LC–MS/MS. According to the results, perfluoropentanoic acid (PFPeA), perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were dominant in wastewater and sludge samples from both plants. The average concentrations in the raw and treated wastewater ranged up to 75.7 ng L −1 (perfluorotridecanoic acid, PFTrDA) and 76.0 ng L −1 (PFPeA), respectively. Concentrations of most PFCs were higher in effluents than in influents, indicating their formation during wastewater treatment processes. In sewage sludge, the average concentrations ranged up to 6.7 ng g −1 dry weight (PFOS). No significant seasonal variations in PFCs concentrations were observed, while higher concentrations of PFOA, PFOS and perfluorononanoic acid (PFNA) were determined in the WWTP receiving municipal and industrial wastewater. Significantly different distribution coefficient (K d ) values were determined for different PFCs and different type of sludge, ranging between 169 L kg −1 (PFHxS) to 12,922 L kg −1 (PFDA).

The application of glutamic acid alpha-decarboxylase for the valorization of glutamic acid

NARCIS (Netherlands)

Lammens, T.M.; Biase, De Daniela; Franssen, M.C.R.; Scott, E.L.; Sanders, J.P.M.

2009-01-01

Glutamic acid is an important constituent of waste streams from biofuels production. It is an interesting starting material for the synthesis of nitrogen containing bulk chemicals, thereby decreasing the dependency on fossil fuels. On the pathway from glutamic acid to a range of molecules, the

Are levels of perfluoroalkyl substances in soil related to urbanization in rapidly developing coastal areas in North China?

Science.gov (United States)

Meng, Jing; Wang, Tieyu; Wang, Pei; Zhang, Yueqing; Li, Qifeng; Lu, Yonglong; Giesy, John P

2015-04-01

Concentrations of 13 perfluoroalkyl substances (PFASs) were quantified in 79 surface soil samples from 17 coastal cities in three provinces and one municipality along the Bohai and Yellow Seas. The ∑PFASs concentrations ranged from less than limitation of quantification (LOQ) to 13.97 ng/g dry weight (dw), with a mean of 0.98 ng/g dw. The highest concentration was observed along the Xiaoqing River from Shandong province, followed by that from the Haihe River in Tianjin (10.62 ng/g dw). Among four regions, ∑PFASs concentrations decreased in the order of Tianjin, Shandong, Liaoning and Hebei, which was consistent with levels of urbanization. Fluorine chemical industries allocated in Shandong and Liaoning played important roles in terms of point emission and contamination of PFASs, dominated by perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Intensive anthropogenic activities involved in urbanization possibly resulted in increasing releases of PFASs from industrial and domestic sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phenolic compounds and fatty acids from acorns (Quercus spp.), the main dietary constituent of free-ranged Iberian pigs.

Science.gov (United States)

Cantos, Emma; Espín, Juan Carlos; López-Bote, Clemente; de la Hoz, Lorenzo; Ordóñez, Juan A; Tomás-Barberán, Francisco A

2003-10-08

The aim of the present work was to identify and quantify the phenolic compounds and fatty acids in acorns from Quercus ilex, Quercus rotundifolia, and Quercus suber. The concentration of oleic acid was >63% of total fatty acids in all cases, followed by palmitic and linoleic acids at similar concentrations (12-20%). The concentrations of alpha-tocopherol in Q. rotundifolia, Q. ilex, and Q. suber were 19, 31, and 38 mg/kg of dry matter (DM), respectively, whereas the concentrations of gamma-tocopherol were 113, 66, and 74 mg/kg of DM, respectively. Thirty-two different phenolic compounds were distinguished. All of them were gallic acid derivatives, in the form of either galloyl esters of glucose, combinations of galloyl and hexahydroxydiphenoyl esters of glucose, tergallic O- or C-glucosides, or ellagic acid derivatives. Several tergallic acid C-glucosides were also present in the extracts obtained from Q. suber. Acorns from Q. ilex and Q. rotundifolia showed similar polyphenol patterns mainly with gallic acid-like spectra. Chromatograms of Q. suber showed mainly polyphenols with ellagic acid-like spectra. Valoneic acid dilactone was especially abundant in Q. suber skin. The contribution of skin to the total phenolics of the acorn was relatively small in Q. rotundifolia and Q. ilex but relatively high in Q. suber. Skin extracts from Q. suber, Q. rotundifolia, and Q. ilex showed 1.3, 1.4, and 1.0 antioxidant efficiencies, respectively (compared to that of butylhydroxyanisole). Endosperm extracts showed lower capacity to prevent lipid peroxidation than skin extracts.

Hypercholesterolemia with consumption of PFOA-laced Western diets is dependent on strain and sex of mice

Directory of Open Access Journals (Sweden)

Sandra L. Rebholz

Full Text Available Perfluorooctanoic acid (PFOA is a man-made surfactant with a number of industrial applications. It has a long half-life environmentally and biologically. Past studies suggest a direct relationship between plasma cholesterol and PFOA serum concentrations in humans and an inverse one in rodents fed standard rodent chow, making it difficult to examine mechanisms responsible for the potential PFOA-induced hypercholesterolemia and altered sterol metabolism. To examine dietary modification of PFOA-induced effects, C57BL/6 and BALB/c mice were fed PFOA in a fat- and cholesterol-containing diet. When fed these high fat diets, PFOA ingestion resulted in marked hypercholesterolemia in male and female C57BL/6 mice and less robust hypercholesterolemia in male BALB/c mice. The PFOA-induced hypercholesterolemia appeared to be the result of increased liver masses and altered expression of genes associated with hepatic sterol output, specifically bile acid production. mRNA levels of genes associated with sterol input were reduced only in C57BL/6 females, the mice with the greatest increase in plasma cholesterol levels. Strain-specific PFOA-induced changes in cholesterol concentrations in mammary tissues and ovaries paralleled changes in plasma cholesterol levels. mRNA levels of sterol-related genes were reduced in ovaries of C57BL/6 but not in BALB/c mice and not in mammary tissues. Our data suggest that PFOA ingestion leads to hypercholesterolemia in mice fed fat and cholesterol and effects are dependent upon the genetic background and gender of the mice with C57BL/6 female mice being most responsive to PFOA. Keywords: Perfluorooctanoic acid, C8, PFC, PFAS, Cholesterol, Dietary fat

Fatty acid composition of hemp seed oils from different locations in Turkey

Energy Technology Data Exchange (ETDEWEB)

Kiralan, M.; Gul, V.; Metin Kara, S.

2010-07-01

Recent interest in hemp seed as a source of food has largely focused on its oil content and fatty acid profile. The oil content and fatty acid composition (15 fatty acids) of twenty one different hemp seed samples of domestic origin from north-western Turkey were monitored. The samples were obtained from seed wholesalers and local spice shops and are of unknown genetic origin. The oil content of the hemp seeds ranged between 29.6 to 36.5%. Out of the 15 detected fatty acids, the omega-6 linoleic acid (18:2n-6) was predominant and fluctuated from 55.4 to 56.9%, while the omega-3 a-linolenic (18:3n-3) acid ranged from 16.5 to 20.4% and the omega-9 oleic acid (18:1n-9) ranged from 11.4 to 15.9%. Of the minor fatty acids, the highest concentrations were found for {gamma}-linolenic acid (18:3n-6), range 0.6-1.1%, followed by stearidonic acid (18:4n-3), range 0.3-0.5%. These results show that hemp seed grown in north-western Turkey provides a well balanced and rich source of dietary omega-6 and -3 essential fatty acids and appears to be a potentially valuable source of food. (Author) 31 refs.

Perfluoroalkyl acids in surface seawater from the North Pacific to the Arctic Ocean: Contamination, distribution and transportation.

Science.gov (United States)

Li, Lei; Zheng, Hongyuan; Wang, Tieyu; Cai, Minghong; Wang, Pei

2018-03-16

The bioaccumulative, persistent and toxic properties of long-chain perfluoroalkyl acids (PFAAs) resulted in strict regulations on PFAAs, especially in developed countries. Consequently, the industry manufacturing of PFAAs shifts from long-chain to short-chain. In order to better understand the pollution situation of PFAAs in marine environment under this new circumstance, the occurrence of 17 linear PFAAs was investigated in 30 surface seawater samples from the North Pacific to Arctic Ocean (123°E to 24°W, 32 to 82°N) during the sixth Chinese Arctic Expedition in 2014. Total concentrations of PFAAs (∑PFAAs) were between 346.9 pg per liter (pg/L) to 3045.3 pg/L. The average concentrations of ∑PFAAs decreased in the order of East China Sea (2791.4 pg/L, n = 2), Sea of Japan (East Sea) (832.8 pg/L, n = 6), Arctic Ocean (516.9 pg/L, n = 7), Chukchi Sea (505.2 pg/L, n = 4), Bering Sea (501.2 pg/L, n = 8) and Sea of Okhotsk (417.7 pg/L, n = 3). C4 to C9 perfluoroalkyl carboxylic acids (PFCAs) were detected in more than 80% of the surface water samples. Perfluorobutanoic acid (PFBA) was the most prevalent compound and perfluorooctanoic acid (PFOA) was the second abundant homolog. The concentration of individual PFAAs in the surface seawater of East China Sea was much higher than other sampling seas. As the spatial distribution of PFAAs in the marine environment was mainly influenced by the river inflow from the basin countries, which proved the large input from China. Furthermore, the marginal seas of China were found with the greatest burden of PFOA comparing the pollution level in surface seawater worldwide. PFBA concentration in the surrounding seas of China was also high, but distributed more evenly with an obvious increase in recent years. This large-scale monitoring survey will help the improvement and development of PFAAs regulations and management, where production shift should be taken into consideration. Copyright �

Hyporheic exchange and fulvic acid redox reactions in an alpine stream/wetland ecosystem, Colorado front range

Science.gov (United States)

Miller, Matthew P.; McKnight, Diane M.; Cory, R.M.; Williams, Mark W.; Runkel, Robert L.

2006-01-01

The influence of hyporheic zone interactions on the redox state of fulvic acids and other redox active species was investigated in an alpine stream and adjacent wetland, which is a more reducing environment. A tracer injection experiment using bromide (Br-) was conducted in the stream system. Simulations with a transport model showed that rates of exchange between the stream and hyporheic zone were rapid (?? ??? 10-3 s -1). Parallel factor analysis of fluorescence spectra was used to quantify the redox state of dissolved fulvic acids. The rate coefficient for oxidation of reduced fulvic acids (?? = 6.5 ?? 10-3 s -1) in the stream indicates that electron-transfer reactions occur over short time scales. The rate coefficients for decay of ammonium (?? = 1.2 ?? 10-3 s-1) and production of nitrate (?? = -1.0 ?? 10-3 s-1) were opposite in sign but almost equal in magnitude. Our results suggest that fulvic acids are involved in rapid electron-transfer processes in and near the stream channel and may be important in determining ecological energy flow at the catchment scale. ?? 2006 American Chemical Society.

Proton pump inhibitors reduce the size and acidity of the acid pocket in the stomach.

Science.gov (United States)

Rohof, Wout O; Bennink, Roelof J; Boeckxstaens, Guy E

2014-07-01

The gastric acid pocket is believed to be the reservoir from which acid reflux events originate. Little is known about how changes in position, size, and acidity of the acid pocket contribute to the therapeutic effect of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD). Thirty-six patients with GERD (18 not taking PPIs, 18 taking PPIs; 19 men; age, 55 ± 2.1 y) were analyzed by concurrent high-resolution manometry and pH-impedance monitoring after a standardized meal. The acid pocket was visualized using scintigraphy after intravenous administration of (99m)technetium-pertechnetate. The size of the acid pocket was measured and its position was determined, relative to the diaphragm, using radionuclide markers on a high-resolution manometry catheter. At the end of the study, the acid pocket was aspirated, and its pH level was measured. The number of reflux episodes was comparable between patients on and off PPIs, but the number of acid reflux episodes was reduced significantly in patients on PPIs. In patients on PPIs, the acid pocket was smaller and more frequently located below the diaphragm. The mean pH of the acid pocket was significantly lower in patients not taking PPIs (n = 6) than in those who were (n = 16) (0.9; range, 0.7-1.2 vs 4.0; range, 1.6-5.9; P pH of acid pockets correlated significantly with the lowest pH values measured for refluxate (r = 0.72; P < .01). Based on analyses of acid pockets in patients with GERD, the acid pocket appears to be a reservoir from which reflux occurs when patients are receiving PPIs. PPIs might affect the size, acidity, or position of the acid pocket, which contributes to the efficacy in patients with GERD. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

The use of approximation formulae in calculations of acid-base equilibria-II: salts of mono- and diprotic acids.

Science.gov (United States)

Narasaki, H

1980-02-01

The pH of solutions of salts of mono- and diprotic acids is calculated by use of approximation formulae and the theoretically exact equations. The regions for useful application of the approximation formulae (error monoprotic acids, areas are symmetrically equal to those of the acids. For salts of diprotic acids the ranges generally depend on K(2)/K(1).

Contribution of precursor compounds to the release of per- and polyfluoroalkyl substances (PFASs) from waste water treatment plants (WWTPs).

Science.gov (United States)

Eriksson, Ulrika; Haglund, Peter; Kärrman, Anna

2017-11-01

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs, precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well. Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids (PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters (PAPs) were 15-20ng/g dry weight, the sum of fluorotelomer sulfonic acids (FTSAs) was 0.8-1.3ng/g, and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2ng/g. Persistent PFSAs and PFCAs were detected at 1.9-3.9ng/g and 2.4-7.3ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%, respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment. Copyright © 2017. Published by Elsevier B.V.

Extraction characteristics of trivalent lanthanides and actinides in mixtures of dinonylnaphthalenesulfonic acid and carboxylic acids

International Nuclear Information System (INIS)

West, M.H.

1983-03-01

Dinonylnaphthalenesulfonic acid (HDNNS) has been shown to be an effective liquid cation exchanger for the extraction of metal ions. This extractant has proven to be successful in the extraction of trivalent lanthanides and actinides in the pH range of 2.0 to 3.0, although it shows little selectivity for individual ions because of its strong acid character. In an effort to improve the selectivity of HDNNS between trivalent lanthanides and actinides, carboxylic acids were added to the organic phase and the effects on the extraction characteristics of HDNNS were investigated. Three carboxylic acids - nonanoic, cyclohexanecarboxylic, and cyclohexanebutyric - were studied with the following metals: Am(III), Cm(III), Ce(III), Eu(III), and Tm(III). The distributions of the metal ions were studied holding the HDNNS concentration constant while varying the carboxylic acid concentrations over a range of 1.0 x 10 -5 M to 1.0 M. Results indicated that the greatest enhancement of the extraction occurred at a carboxylic acid concentration of 1.0 x 10 -2 M with negative effects occurring at 0.5 M and 1.0 M. The effects on the extraction of the trivalent lanthanides and actinides were interpreted in terms of the structural differences of the carboxylic acids, the effect of the carboxylic acids on the HDNNS extraction mechanism, and the ionic properties of the metals studied

The browning kinetics of the non-enzymatic browning reaction in L-ascorbic acid/basic amino acid systems

Directory of Open Access Journals (Sweden)

Ai-Nong YU

Full Text Available Abstract Under the conditions of weak basis and the reaction temperature range of 110-150 °C, lysine, arginine and histidine were reacted with L-ascorbic acid at equal amount for 30-150 min, respectively and the formation of browning products was monitored with UV–vis spectrometry. The kinetic characteristics of their non-enzymatic browning reaction were investigated. The study results indicated that the non-enzymatic browning reaction of these three amino acids with L-ascorbic acid to form browning products was zero-order reaction. The apparent activation energies for the formation of browning products from L-ascorbic acid/lysine, L-ascorbic acid/arginine and L-ascorbic acid/histidine systems were 54.94, 50.08 and 35.31kJ/mol. The activation energy data indicated the degree of effects of reaction temperature on non-enzymatic browning reaction. Within the temperature range of 110-150 °C, the reaction rate of L-ascorbic acid/lysine system was the fastest one, followed by that of the L-ascorbic acid/arginine system. The reaction rate of L-ascorbic acid/histidine system was the slowest one. Based on the observed kinetic data, the formation mechanisms of browning products were proposed.

Citric Acid Alternative to Nitric Acid Passivation

Science.gov (United States)

Lewis, Pattie L. (Compiler)

2013-01-01

The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

PCI-GC-MS-MS approach for identification of non-amino organic acid and amino acid profiles.

Science.gov (United States)

Luan, Hemi; Yang, Lin; Ji, Fenfen; Cai, Zongwei

2017-03-15

Alkyl chloroformate have been wildly used for the fast derivatization of metabolites with amino and/or carboxyl groups, coupling of powerful separation and detection systems, such as GC-MS, which allows the comprehensive analysis of non-amino organic acids and amino acids. The reagents involving n-alkyl chloroformate and n-alcohol are generally employed for providing symmetric labeling terminal alkyl chain with the same length. Here, we developed an asymmetric labeling strategy and positive chemical ionization gas chromatography-tandem mass spectrometry (PCI-GC-MS-MS) approach for determination of non-amino organic acids and amino acids, as well as the short chain fatty acids. Carboxylic and amino groups could be selectively labelled by propyl and ethyl groups, respectively. The specific neutral loss of C 3 H 8 O (60Da), C 3 H 5 O 2 (74Da) and C 4 H 8 O 2 (88Da) were useful in the selective identification for qualitative analysis of organic acids and amino acid derivatives. PCI-GC-MS-MS using multiple reaction monitoring (MRM) was applied for semi-quantification of typical non-amino organic acids and amino acids. This method exhibited a wide range of linear range, good regression coefficient (R 2 ) and repeatability. The relative standard deviation (RSD) of targeted metabolites showed excellent intra- and inter-day precision (chloroformate derivatization. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrolytic nature of aqueous sulfuric acid. 2. Acidity.

Science.gov (United States)

Fraenkel, Dan

2012-09-27

In part 1 of this study, I reported that the Debye-Hückel limiting law and the smaller-ion shell (SiS) model of strong electrolyte solutions fit nicely with the experimental mean ionic activity coefficient (γ(±)) of aqueous sulfuric acid as a function of concentration and of temperature when the acid is assumed to be a strong 1-3 electrolyte. Here, I report that the SiS-derived activity coefficient of H(+), γ(H(+)), of the 1-3 acid is comparable to that of aqueous HCl. This agrees with titration curves showing, as well-known, that sulfuric acid in water is parallel in strength to aqueous HCl. The calculated pH is in good accord with the Hammett acidity function, H(0), of aqueous sulfuric acid at low concentration, and differences between the two functions at high concentration are discussed and explained. This pH-H(0) relation is consistent with the literature showing that the H(0) of sulfuric acid (in the 1-9 M range) is similar to those of HCl and the other strong mineral monoprotic acids. The titration of aqueous sulfuric acid with NaOH does not agree with the known second dissociation constant of 0.010 23; rather, the constant is found to be ~0.32 and the acid behaves upon neutralization as a strong diprotic acid practically dissociating in one step. A plausible reaction pathway is offered to explain how the acid may transform, upon base neutralization, from a dissociated H(4)SO(5) (as 3H(+) and HSO(5)(3-)) to a dissociated H(2)SO(4) even though the equilibrium constant of the reaction H(+) + HSO(5)(3-) ↔ SO(4)(2-) + H(2)O, at 25 °C, is 10(-37) (part 1).

Selective fluorescent detection of aspartic acid and glutamic acid employing dansyl hydrazine dextran conjugate.

Science.gov (United States)

Nasomphan, Weerachai; Tangboriboonrat, Pramuan; Tanapongpipat, Sutipa; Smanmoo, Srung

2014-01-01

Highly water soluble polymer (DD) was prepared and evaluated for its fluorescence response towards various amino acids. The polymer consists of dansyl hydrazine unit conjugated into dextran template. The conjugation enhances higher water solubility of dansyl hydrazine moiety. Of screened amino acids, DD exhibited selective fluorescence quenching in the presence of aspartic acid (Asp) and glutamic acid (Glu). A plot of fluorescence intensity change of DD against the concentration of corresponding amino acids gave a good linear relationship in the range of 1 × 10(-4) M to 25 × 10(-3) M. This establishes DD as a potential polymeric sensor for selective sensing of Asp and Glu.

Measurement and modeling of density and viscosity of n-octanol-kerosene-phosphoric acid solutions in a temperature range 293.15-333.15 K

Science.gov (United States)

Ye, Changwen; Pei, Xiangjun; Liu, J. C.

2016-12-01

Densities and viscosities have been measured for the n-octanol + aviation kerosene (AK) + phosphoric acid (H3PO4) system with the mass fraction of H3PO4 in the range from w = 0 to 0.26 and in the temperature of 293.15-333.15 K. According to the experimental data, the measured viscosities were found well correlated with the temperature and mass fraction of H3PO4, which were fitted to regression equations. The result shows that the dilution effect of AK is obvious under the same temperature and mass fraction of H3PO4.

Molecular pharmacology of homologues of ibotenic acid at cloned metabotropic glutamic acid receptors

DEFF Research Database (Denmark)

Bräuner-Osborne, Hans; Nielsen, B; Krogsgaard-Larsen, P

1998-01-01

We have studied the effects of the enantiomers of 2-amino-3-(3-hydroxyisoxazol-5-yl)propionic acid (homoibotenic acid, HIBO) and analogues substituted with a methyl, bromo or butyl group in the four position of the ring at cloned metabotropic glutamate (mGlu) receptors expressed in Chinese hamster...... ovary (CHO) cells. In contrast to the parent compound ibotenic acid, which is a potent group I and II agonist, the (S)-forms of homoibotenic acid and its analogues are selective and potent group I antagonists whereas the (R)-forms are inactive both as agonists and antagonists at group I, II, and III m......Glu receptors. Interestingly, (S)-homoibotenic acid and the analogues display equal potency at both mGlu1alpha and mGlu5a with Ki values in the range of 97 to 490 microM, (S)-homoibotenic acid and (S)-2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid [(S)-4-butylhomoibotenic acid] displaying the lowest...

Development of anti-scale poly(aspartic acid-citric acid) dual polymer systems for water treatment.

Science.gov (United States)

Nayunigari, Mithil Kumar; Gupta, Sanjay Kumar; Kokkarachedu, Varaprasad; Kanny, K; Bux, F

2014-01-01

The formation of calcium sulphate and calcium carbonate scale poses major problems in heat exchangers and water cooling systems, thereby affecting the performance of these types of equipment. In order to inhibit these scale formations, new types of biodegradable water soluble single polymer and dual poly(aspartic acid-citric acid) polymers were developed and tested. The effectiveness of single polymer and four different compositions of poly aspartic acid and citric acid dual polymer systems as scale inhibitors were evaluated. Details of the synthesis, thermal stability, scale inhibition and the morphological characterization of single and dual polymers are presented in this scientific paper. It was found that the calcium sulphate scale inhibition rate was in the range 76.06-91.45%, while the calcium carbonate scale inhibition rate observed was in the range 23.37-30.0% at 65-70 °C. The finding suggests that the water soluble dual polymers are very effective in sulphate scale inhibition in comparison of calcium carbonate scale inhibition.

Construction of Bifunctional Co/H-ZSM-5 Catalysts for the Hydrodeoxygenation of Stearic Acid to Diesel-range Alkanes.

Science.gov (United States)

Wu, Guangjun; Zhang, Nan; Dai, Weili; Guan, Naijia; Li, Landong

2018-04-27

Bifunctional Co/H-ZSM-5 zeolites were prepared by surface organometallic chemistry grafting route, namely by the stoichiometric reaction between cobaltocene and the Brønsted acid sites in zeolites, and applied to the model reaction of stearic acid catalytic hydrodeoxygenation. Cobalt species existed in the form of isolated Co2+ ions at exchange positions after grafting, transformed to CoO species on the surface of zeolite and stabilized inside zeolite channels upon calcination in air, and finally reduced to metallic cobalt species of homogeneous clusters of ca. 1.5 nm by hydrogen. During this process, the Brønsted acid sites of H-ZSM-5 zeolites could be preserved with acid strength slightly reduced. The as-prepared bifunctional catalyst exhibited a ~16 times higher activity in stearic acid hydrodeoxygenation (2.11 gSAgcat-1h-1) than the reference catalyst (0.13 gSAgcat-1h-1) prepared by solid-state ion exchange, and a high C18/C17 ratio of ~24 was achieved as well. The remarkable hydrodeoxygenation performance of bifunctional Co/H-ZSM-5 could be explained from the effective synergy between the uniformed metallic cobalt clusters and the Brønsted acid sites in H-ZSM-5 zeolite. The simplified reaction network and kinetics of stearic acid hydrodeoxygenation catalyzed by the as-prepared bifunctional Co/H-ZSM-5 zeolites were also investigated. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A radioimmunoassay for abscisic acid

International Nuclear Information System (INIS)

Walton, D.; Dashek, W.; Galson, E.

1979-01-01

We have developed a radioimmunoassay (RIA) for abscisic acid (ABA) in the 0.1 ng to 2.5 ng range. Antibodies were obtained from rabbits immunized with ABA bound via its carboxyl group to bovine serum albumin. Cross-reactivity studies indicate that ABA esters are completely cross-reactive with ABA, while trans, trans abscisic acid (t-ABA) phaseic acid (PA) and dihydrophaseic acid (DPA) have much lower but significant cross-reactivities. Purification methods which reduce the levels of cross-reacting substances are described. (orig.) 891 AJ/orig. 892 MKO [de

Long-range Transport Modeling System and its Application over the Northeast Asia

Directory of Open Access Journals (Sweden)

Il-Soo Park

2006-06-01

Full Text Available A Comprehensive Acid Deposition Modeling (CADM was developed at the National Institute of Environmental Research (NIER and Yonsei University in South Korea in order to simulate the long-range transboundary air pollutants and regional acid deposition processes over the Northeast Asia. The modeling system CADM is composed of a real-time numerical weather forecasting model (RAMS and an Eulerian air pollution transport/dispersion/deposition model including gas- and aqueous-phase atmospheric chemical processes for the real-time acquisition of model results and prediction of acidic pollutants. The main objective of CADM is to facilitate an efficient assessment tools by providing the explicit information on the acidic deposition processes. This paper introduces the components of CADM, and describes the comprehensive atmospheric modeling system including atmospheric chemistry for the simulation of acidic processes over the Eastern Asia. The presently developed modeling system CADM has been used to simulate long-range transport over the Northeast Asian region during the spring season from March 5 to 15 2002. For the model validation, the simulated results are compared with both aircraft measurements and surface monitoring observations, and discussed for its operational consideration in Korea

Trans Fatty Acids in Bakery Products from 14 European Countries: The TRANSFAIR Study

NARCIS (Netherlands)

Erp van - Baart, M.-A.; Couet, C.; Cuadrado, C.; Kafatos, A.; Stanley, J.; Poppel, G. van

1998-01-01

The fatty acid composition of bakery products from 14 European countries was analyzed with particular emphasis ontransfatty acids. The proportion oftransfatty acids in cookies and biscuits ranged from <1 to 28%.Transfatty acids content in sweet pastry ranged from practically 0 to 33%. Croissants and

Pasture, multi-enzymes, benzoic acid and essential oils positively influence performance, intestinal organ weight and egg quality in free-range laying hens.

Science.gov (United States)

Iqbal, Z; Roberts, J; Perez-Maldonado, R A; Goodarzi Boroojeni, F; Swick, R A; Ruhnke, I

2018-04-01

1. The objective of this study was to investigate the effect of range type, multi-enzyme applications, and a combination of benzoic acid (BA) and essential oils (EO) on the productive performance, organ weight and egg quality of free-range laying hens. 2. Three hundred laying hens were evaluated for the short-term (6 weeks) and long-term (12 weeks) effects of range type (G = no pasture, P = pasture) and feed additives (T1 = control; T2 = betaglucanase/pectinase/protease; T3 = BA/EO). Body weight, feed intake (FI), feed conversion ratio (FCR), egg production (EP), digestive organ weight, and egg quality (EQ) were evaluated. Data were analysed using SPSS 2.2 in a 2×2×3 factorial arrangement. 3. Hens that ranged on pasture were significantly heavier (2043 g vs. 1996 g; p ranged on gravel. Hens fed T2 were significantly heavier (2050 g) compared to hens fed T1 (2005 g) or T3 (2008 g). Organ weights (gizzard, liver and pancreas) were significantly heavier in hens ranged on pasture (16.8 g/kg BW, 22.3 g/kg BW and 1.89 g/kg BW, respectively) compared to hens ranged on gravel (14.2 g/kg BW, 21.7 g/kg BW and 1.83 g/kg BW, respectively). Over time, body weight (1970-2070 g; p < 0.001) and egg weight (59.5-62.8 g; p < 0.001) increased, FI (123-120 g; p = 0.024) was reduced and FCR (2.36-2.10; p = 0.002) improved 4. In conclusion, hens housed on pasture and fed multi-enzyme supplemented diets had significantly heavier body weight and produced heavier eggs with darker yolk colour. Pasture intake and enzyme supplementation increased digestive organ weight significantly.

Study of Acid Rain in Tikrit City

Directory of Open Access Journals (Sweden)

Khaled H. Latef

2013-04-01

Full Text Available A study of the degree of acidity  for the precipitation in four different sites in Tikrit city was done  for the period from 1-February to 1-April/2007 which is the period of rains in this year.      Chemical tests included (pH as the direct indicator of the degree of acidity ,and the concentration of sulphates (SO4-2 and nitrates ( NO3- as indirect indicator.      The (pH range was (5.56-6.4 which indicates the presence of acid rain in the area under study . (SO4-2 concentrations range was (88-223mg/l while  ( NO3- concentrations range was (80-170mg/l.      The wind velocity ,temperature, and humidity during the sample collection period ranged (2.25-4m/s, (1-260C, (22%-90% respectively

Methodology of analysis of very weak acids by isotachophoresis with electrospray-ionization mass-spectrometric detection: Anionic electrolyte systems for the medium-alkaline pH range.

Science.gov (United States)

Malá, Zdena; Gebauer, Petr

2018-01-15

This work describes for the first time a functional electrolyte system setup for anionic isotachophoresis (ITP) with electrospray-ionization mass-spectrometric (ESI-MS) detection in the neutral to medium-alkaline pH range. So far no application was published on the analysis of very weak acids by anionic ITP-MS although there is a broad spectrum of potential analytes with pK a values in the range 5-10, where application of this technique promises interesting gains in both sensitivity and specificity. The problem so far was the lack of anionic ESI-compatible ITP systems in the mentioned pH range as all typical volatile anionic system components are fully ionized at neutral and alkaline pH and thus too fast to suit as terminators. We propose an original solution of the problem based on the combination of two ITP methods: (i) use of the hydroxyl ion as a natural and ESI-compatible terminator, and (ii) use of configurations based on moving-boundary ITP. The former method ensures effective stacking of analytes by an alkaline terminator of sufficiently low mobility and the latter offers increased flexibility for tuning of the separation window and selectivity according to actual needs. A theoretical description of the proposed model is presented and applied to the design of very simple functional electrolyte configurations. The properties of example systems are demonstrated by both computer simulation and experiments with a group of model analytes. Potential effects of carbon dioxide present in the solutions are demonstrated for particular systems. Experimental results confirm that the proposed methodology is well capable of performing sensitive and selective ITP-MS analyses of very weak acidic analytes (e.g. sulfonamides or chlorophenols). Copyright © 2017 Elsevier B.V. All rights reserved.

Searching for Extraterrestrial Amino Acids in a Contaminated Meteorite: Amino Acid Analyses of the Canakkale L6 Chondrite

Science.gov (United States)

Burton, A. S.; Elsila, J. E.; Glavin, D. P.; Dworkin, J. P.; Ornek, C. Y.; Esenoglu, H. H.; Unsalan, O.; Ozturk, B.

2016-01-01

Amino acids can serve as important markers of cosmochemistry, as their abundances and isomeric and isotopic compositions have been found to vary predictably with changes in parent body chemistry and alteration processes. Amino acids are also of astrobiological interest because they are essential for life on Earth. Analyses of a range of meteorites, including all groups of carbonaceous chondrites, along with H, R, and LL chondrites, ureilites, and a martian shergottite, have revealed that amino acids of plausible extraterrestrial origin can be formed in and persist after a wide range of parent body conditions. However, amino acid analyses of L6 chondrites to date have not provided evidence for indigenous amino acids. In the present study, we performed amino acid analysis on larger samples of a different L6 chondite, Canakkale, to determine whether or not trace levels of indigenous amino acids could be found. The Canakkale meteor was an observed fall in late July, 1964, near Canakkale, Turkey. The meteorite samples (1.36 and 1.09 g) analyzed in this study were allocated by C. Y. Ornek, along with a soil sample (1.5 g) collected near the Canakkale recovery site.

Nucleic Acid Therapy: from humble beginnings a dynamic technology

CSIR Research Space (South Africa)

Millroy, L

2011-02-01

Full Text Available The term “nucleic acid therapy” encompasses a wide range of technologies for the treatment of a range of plant and animal ailments. As the name implies, it makes use of nucleic acid (either DNA or RNA) as a therapeutic agent. There are six branches...

Validation of a multi-analyte HPLC-DAD method for determination of uric acid, creatinine, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid and 2-methylhippuric acid in human urine.

Science.gov (United States)

Remane, Daniela; Grunwald, Soeren; Hoeke, Henrike; Mueller, Andrea; Roeder, Stefan; von Bergen, Martin; Wissenbach, Dirk K

2015-08-15

During the last decades exposure sciences and epidemiological studies attracts more attention to unravel the mechanisms for the development of chronic diseases. According to this an existing HPLC-DAD method for determination of creatinine in urine samples was expended for seven analytes and validated. Creatinine, uric acid, homovanillic acid, niacinamide, hippuric acid, indole-3-acetic acid, and 2-methylhippuric acid were separated by gradient elution (formate buffer/methanol) using an Eclipse Plus C18 Rapid Resolution column (4.6mm×100mm). No interfering signals were detected in mobile phase. After injection of blank urine samples signals for the endogenous compounds but no interferences were detected. All analytes were linear in the selected calibration range and a non weighted calibration model was chosen. Bias, intra-day and inter-day precision for all analytes were below 20% for quality control (QC) low and below 10% for QC medium and high. The limits of quantification in mobile phase were in line with reported reference values but had to be adjusted in urine for homovanillic acid (45mg/L), niacinamide 58.5(mg/L), and indole-3-acetic acid (63mg/L). Comparison of creatinine data obtained by the existing method with those of the developed method showing differences from -120mg/L to +110mg/L with a mean of differences of 29.0mg/L for 50 authentic urine samples. Analyzing 50 authentic urine samples, uric acid, creatinine, hippuric acid, and 2-methylhippuric acid were detected in (nearly) all samples. However, homovanillic acid was detected in 40%, niacinamide in 4% and indole-3-acetic acid was never detected within the selected samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Sorption of perfluoroalkyl substances to two types of minerals.

Science.gov (United States)

Hellsing, Maja S; Josefsson, Sarah; Hughes, Arwel V; Ahrens, Lutz

2016-09-01

The sorption of perfluoroalkyl substances (PFASs) was investigated for two model soil mineral surfaces, alumina (Al2O3) and silica (SiO2), on molecular level using neutron scattering. The PFASs were selected (i.e. perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonic acid (PFOS)) to examine the role of hydrophobic chain length and hydrophilic functional group on their sorption behaviour. All four PFASs were found to sorb to alumina surface (positively charged) forming a hydrated layer consisting of 50% PFASs. The PFAS solubility limit, which decrease with chain length, was found to strongly influence the sorption behaviour. The sorbed PFAS layer could easily be removed by gentle rinsing with water, indicating release upon rainfall in the environment. No sorption was observed for PFOA and PFOS at silica surface (negatively charged), showing electrostatic interaction being the driving force in the sorption process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pulse radiolysis of pyridinecarboxylic acids in aqueous solution

DEFF Research Database (Denmark)

Solar, S.; Getoff, N.; Sehested, K.

1991-01-01

The reactivity of OH, e(aq)- and H radicals towards aqueous carboxypyridines: picolinic acid (2-pyridinecarboxylic acid), PA; isonicotinic acid (4-pyridinecarboxylic acid), i-NA; 2,6-pyridinedicarboxylic acid, 2,6-PDCA; and 3,5-pyridinedicarboxylic acid, 3,5-PDCA was investigated in the pH-range 1...... radical are: 20% for PA, 75% for i-NA, 60% for 2,6-PDCA and 25% for 3,5-PDCA (a yield of 50% has been found earlier for nicotinic acid, NA)....

High Performance Liquid Chromatography Determination of Urinary Hippuric Acid and Benzoic Acid as Indices for Glue Sniffer Urine

OpenAIRE

Abdul Rahim Yacob; Mohamad Raizul Zinalibdin

2010-01-01

A simple method for the simultaneous determination of hippuric acid and benzoic acid in urine using reversed-phase high performance liquid chromatography was described. Chromatography was performed on a Nova-Pak C18 (3.9 x 150 mm) column with a mobile phase of mixed solution methanol: water: acetic acid (20:80:0.2) and UV detection at 254 nm. The calibration curve was linear within concentration range at 0.125 to 6.0 mg/ml of hippuric acid and benzoic acid. The recovery, ...

Hybrid fluorescent nanoparticles fabricated from pyridine-functionalized polyfluorene-based conjugated polymer as reversible pH probes over a broad range of acidity-alkalinity

International Nuclear Information System (INIS)

Cui, Haijun; Chen, Ying; Li, Lianshan; Tang, Zhiyong; Wu, Yishi; Fu, Hongbing; Tian, Zhiyuan

2014-01-01

Conjugated polymer nanoparticles (CPNs) were developed based on a polyfluorene-based conjugated polymer with thiophene units carrying pyridyl moieties incorporated in the backbone of polymer chains (PFPyT). Hybrid CPNs fabricated from PFPyT and an amphiphilic polymer (NP1) displayed pH-sensitive fluorescence emission features in the range from pH 4.8 to 13, which makes them an attractive nanomaterial for wide range optical sensing of pH values. The fluorescence of hybrid CPNs based on chemically close polyfluorene derivatives without pyridyl moieties (NP3), in contrast, remains virtually unperturbed by pH values in the same range. The fluorescence emission features of NP1 underwent fully reversible changes upon alternating acidification/basification of aqueous dispersions of the CPNs and also displayed excellent repeatability. The observed pH sensing properties of NP1 are attributed to protonation/deprotonation of the nitrogen atoms of the pyridine moieties. This, in turn, leads to the redistribution of electron density of pyridine moieties and their participation in the π-conjugation within the polymer main chains. The optically transparent amphiphilic polymers also exerted significant influence on the pH sensing features of the CPNs, likely by acting as proton sponge and/or acid chaperone. (author)

Stimulation of apical sodium-dependent bile acid transporter expands the bile acid pool and generates bile acids with positive feedback properties.

Science.gov (United States)

Rudling, Mats; Bonde, Ylva

2015-01-01

Bile acid synthesis has been considered a prototype for how a physiological process is controlled by end product feedback inhibition. By this feedback inhibition, bile acid concentrations are kept within safe ranges. However, careful examination of published rodent data strongly suggests that bile acid synthesis is also under potent positive feedback control by hydrophilic bile acids. Current concepts on the regulation of bile acid synthesis are derived from mouse models. Recent data have shown that mice have farnesoid X receptor (FXR) antagonistic bile acids capable of quenching responses elicited by FXR agonistic bile acids. This is important to recognize to understand the regulation of bile acid synthesis in the mouse, and in particular to clarify if mouse model findings are valid also in the human situation. In addition to classic end product feedback inhibition, regulation of bile acid synthesis in the mouse largely appears also to be driven by changes in hepatic levels of murine bile acids such as α- and β-muricholic acids. This has not been previously recognized. Stimulated bile acid synthesis or induction of the apical sodium-dependent bile acid transporter in the intestine, increase the availability of chenodeoxycholic acid in the liver, thereby promoting hepatic conversion of this bile acid into muricholic acids. Recognition of these mechanisms is essential for understanding the regulation of bile acid synthesis in the mouse, and for our awareness of important species differences in the regulation of bile acid synthesis in mice and humans. 2015 S. Karger AG, Basel.

Development of a LC-MS/MS Method for the Simultaneous Detection of Tricarboxylic Acid Cycle Intermediates in a Range of Biological Matrices

Directory of Open Access Journals (Sweden)

Omar Al Kadhi

2017-01-01

Full Text Available It is now well-established that perturbations in the tricarboxylic acid (TCA cycle play an important role in the metabolic transformation occurring in cancer including that of the prostate. A method for simultaneous qualitative and quantitative analysis of TCA cycle intermediates in body fluids, tissues, and cultured cell lines of human origin was developed using a common C18 reversed-phase column by LC-MS/MS technique. This LC-MS/MS method for profiling TCA cycle intermediates offers significant advantages including simple and fast preparation of a wide range of human biological samples. The analytical method was validated according to the guideline of the Royal Society of Chemistry Analytical Methods Committee. The limits of detection were below 60 nM for most of the TCA intermediates with the exception of lactic and fumaric acids. The calibration curves of all TCA analytes showed linearity with correlation coefficients r2>0.9998. Recoveries were >95% for all TCA analytes. This method was established taking into consideration problems and limitations of existing techniques. We envisage that its application to different biological matrices will facilitate deeper understanding of the metabolic changes in the TCA cycle from in vitro, ex vivo, and in vivo studies.

Perflurooctanoic acid induces developmental cardiotoxicity in chicken embryos and hatchlings

International Nuclear Information System (INIS)

Jiang, Qixiao; Lust, Robert M.; Strynar, Mark J.; Dagnino, Sonia; DeWitt, Jamie C.

2012-01-01

Highlights: ► PFOA exposure thinned right ventricular wall thickness in D19 chicken embryo hearts. ► PFOA exposure induced left ventricle hypertrophy in hearts of hatchling chickens. ► PFOA exposure induced altered cardiac function in hatchling chickens. -- Abstract: Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxisome proliferator activated receptor alpha (PPARα). As the cardiovascular system is crucial for embryonic survival, PFOA-induced effects on the heart may partially explain embryonic mortality. To assess impacts of PFOA exposure on the developing heart in an avian model, we used histopathology and immunohistochemical staining for myosin to assess morphological alterations in 19-day-old chicken embryo hearts after PFOA exposure. Additionally, echocardiography and cardiac myofibril ATPase activity assays were used to assess functional alterations in 1-day-old hatchling chickens following developmental PFOA exposure. Overall thinning and thinning of a dense layer of myosin in the right ventricular wall were observed in PFOA-exposed chicken embryo hearts. Alteration of multiple cardiac structural and functional parameters, including left ventricular wall thickness, left ventricular volume, heart rate, stroke volume, and ejection fraction were detected with echocardiography in the exposed hatchling chickens. Assessment of ATPase activity indicated that the ratio of cardiac myofibril calcium-independent ATPase activity to calcium-dependent ATPase activity was not affected, which suggests that developmental PFOA exposure may not affect cardiac energetics. In summary, structural and functional characteristics of the heart appear to be developmental targets of PFOA, possibly at the level of cardiomyocytes. Additional studies will

Complexity in Acid-Base Titrations: Multimer Formation Between Phosphoric Acids and Imines.

Science.gov (United States)

Malm, Christian; Kim, Heejae; Wagner, Manfred; Hunger, Johannes

2017-08-10

Solutions of Brønsted acids with bases in aprotic solvents are not only common model systems to study the fundamentals of proton transfer pathways but are also highly relevant to Brønsted acid catalysis. Despite their importance the light nature of the proton makes characterization of acid-base aggregates challenging. Here, we track such acid-base interactions over a broad range of relative compositions between diphenyl phosphoric acid and the base quinaldine in dichloromethane, by using a combination of dielectric relaxation and NMR spectroscopy. In contrast to what one would expect for an acid-base titration, we find strong deviations from quantitative proton transfer from the acid to the base. Even for an excess of the base, multimers consisting of one base and at least two acid molecules are formed, in addition to the occurrence of proton transfer from the acid to the base and simultaneous formation of ion pairs. For equimolar mixtures such multimers constitute about one third of all intermolecular aggregates. Quantitative analysis of our results shows that the acid-base association constant is only around six times larger than that for the acid binding to an acid-base dimer, that is, to an already protonated base. Our findings have implications for the interpretation of previous studies of reactive intermediates in organocatalysis and provide a rationale for previously observed nonlinear effects in phosphoric acid catalysis. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Examining confounding by diet in the association between perfluoroalkyl acids and serum cholesterol in pregnancy

Energy Technology Data Exchange (ETDEWEB)

Skuladottir, Margret; Ramel, Alfons [Faculty of Food Science and Nutrition, University of Iceland, Reykjavik (Iceland); Unit for Nutrition Research, Landspitali National University Hospital, Reykjavik (Iceland); Rytter, Dorte [Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus (Denmark); Haug, Line Småstuen; Sabaredzovic, Azemira [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway); Bech, Bodil Hammer [Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus (Denmark); Henriksen, Tine Brink [Pediatric Department, Aarhus University Hospital, Aarhus (Denmark); Olsen, Sjurdur F. [Center for Fetal Programming, Department of Epidemiology Research, Statens Serum Institut, Copenhagen (Denmark); Department of Nutrition, Harvard School of Public Health, Boston, MA (United States); Halldorsson, Thorhallur I., E-mail: tih@hi.is [Faculty of Food Science and Nutrition, University of Iceland, Reykjavik (Iceland); Unit for Nutrition Research, Landspitali National University Hospital, Reykjavik (Iceland); Center for Fetal Programming, Department of Epidemiology Research, Statens Serum Institut, Copenhagen (Denmark)

2015-11-15

Background: Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have consistently been associated with higher cholesterol levels in cross sectional studies. Concerns have, however, been raised about potential confounding by diet and clinical relevance. Objective: To examine the association between concentrations of PFOS and PFOA and total cholesterol in serum during pregnancy taking into considerations confounding by diet. Methods: 854 Danish women who gave birth in 1988–89 and provided a blood sample and reported their diet in week 30 of gestation. Results: Mean serum PFOS, PFOA and total cholesterol concentrations were 22.3 ng/mL, 4.1 ng/mL and 7.3 mmol/L, respectively. Maternal diet was a significant predictor of serum PFOS and PFOA concentrations. In particular intake of meat and meat products was positively associated while intake of vegetables was inversely associated (P for trend <0.01) with relative difference between the highest and lowest quartile in PFOS and PFOA concentrations ranging between 6% and 25% of mean values. After adjustment for dietary factors both PFOA and PFOS were positively and similarly associated with serum cholesterol (P for trend ≤0.01). For example, the mean increase in serum cholesterol was 0.39 mmol/L (95%CI: 0.09, 0.68) when comparing women in the highest to lowest quintile of PFOA concentrations. In comparison the mean increase in serum cholesterol was 0.61 mmol/L (95%CI: 0.17, 1.05) when comparing women in the highest to lowest quintile of saturated fat intake. Conclusion: In this study associations between PFOS and PFOA with serum cholesterol appeared unrelated to dietary intake and were similar in magnitude as the associations between saturated fat intake and serum cholesterol. - Highlights: • PFOS and PFOA have consistently been linked with raised serum cholesterol • Clinical relevance remains uncertain and confounding by diet has been suggested • The aim of this study was to address these issues in

Examining confounding by diet in the association between perfluoroalkyl acids and serum cholesterol in pregnancy

International Nuclear Information System (INIS)

Skuladottir, Margret; Ramel, Alfons; Rytter, Dorte; Haug, Line Småstuen; Sabaredzovic, Azemira; Bech, Bodil Hammer; Henriksen, Tine Brink; Olsen, Sjurdur F.; Halldorsson, Thorhallur I.

2015-01-01

Background: Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have consistently been associated with higher cholesterol levels in cross sectional studies. Concerns have, however, been raised about potential confounding by diet and clinical relevance. Objective: To examine the association between concentrations of PFOS and PFOA and total cholesterol in serum during pregnancy taking into considerations confounding by diet. Methods: 854 Danish women who gave birth in 1988–89 and provided a blood sample and reported their diet in week 30 of gestation. Results: Mean serum PFOS, PFOA and total cholesterol concentrations were 22.3 ng/mL, 4.1 ng/mL and 7.3 mmol/L, respectively. Maternal diet was a significant predictor of serum PFOS and PFOA concentrations. In particular intake of meat and meat products was positively associated while intake of vegetables was inversely associated (P for trend <0.01) with relative difference between the highest and lowest quartile in PFOS and PFOA concentrations ranging between 6% and 25% of mean values. After adjustment for dietary factors both PFOA and PFOS were positively and similarly associated with serum cholesterol (P for trend ≤0.01). For example, the mean increase in serum cholesterol was 0.39 mmol/L (95%CI: 0.09, 0.68) when comparing women in the highest to lowest quintile of PFOA concentrations. In comparison the mean increase in serum cholesterol was 0.61 mmol/L (95%CI: 0.17, 1.05) when comparing women in the highest to lowest quintile of saturated fat intake. Conclusion: In this study associations between PFOS and PFOA with serum cholesterol appeared unrelated to dietary intake and were similar in magnitude as the associations between saturated fat intake and serum cholesterol. - Highlights: • PFOS and PFOA have consistently been linked with raised serum cholesterol • Clinical relevance remains uncertain and confounding by diet has been suggested • The aim of this study was to address these issues in

Lewis Acidic Ionic Liquids.

Science.gov (United States)

Brown, Lucy C; Hogg, James M; Swadźba-Kwaśny, Małgorzata

2017-08-21

Until very recently, the term Lewis acidic ionic liquids (ILs) was nearly synonymous with halometallate ILs, with a strong focus on chloroaluminate(III) systems. The first part of this review covers the historical context in which these were developed, speciation of a range of halometallate ionic liquids, attempts to quantify their Lewis acidity, and selected recent applications: in industrial alkylation processes, in supported systems (SILPs/SCILLs) and in inorganic synthesis. In the last decade, interesting alternatives to halometallate ILs have emerged, which can be divided into two sub-sections: (1) liquid coordination complexes (LCCs), still based on halometallate species, but less expensive and more diverse than halometallate ionic liquids, and (2) ILs with main-group Lewis acidic cations. The two following sections cover these new liquid Lewis acids, also highlighting speciation studies, Lewis acidity measurements, and applications.

Comparison of some aqueous chemical dosimeters for absorbed doses of less than 1000 rads. [Benzoic--salicylic acid, terephtalic--2-hydroxyterephtabe acid, ferrous sulfate--benzoic acid--xylenol orange, and standard Fricke dosimeter

Energy Technology Data Exchange (ETDEWEB)

Matthews, R W [Australian Atomic Energy Commission Research Establishment, Lucas Heights; Barker, N T; Sangster, D F

1978-01-01

This report gives the results of an investigation into the relative merits of the systems: benzoic-salicylic acid, terephthalic-2-hydroxyterephthalic acid, the more recent ferrous sulphate-benzoic acid-xylenol orange (FBX), and the standard Fricke dosimeter, for the measurement of absorbed doses under identical irradiation conditions, in the range 10 to 1000 rads.

Investigating Students' Reasoning about Acid-Base Reactions

Science.gov (United States)

Cooper, Melanie M.; Kouyoumdjian, Hovig; Underwood, Sonia M.

2016-01-01

Acid-base chemistry is central to a wide range of reactions. If students are able to understand how and why acid-base reactions occur, it should provide a basis for reasoning about a host of other reactions. Here, we report the development of a method to characterize student reasoning about acid-base reactions based on their description of…

Influence of glutamic acid enantiomers on C-mineralization.

Science.gov (United States)

Formánek, Pavel; Vranová, Valerie; Lojková, Lea

2015-02-01

Seasonal dynamics in the mineralization of glutamic acid enantiomers in soils from selected ecosystems was determined and subjected to a range of treatments: ambient x elevated CO2 level and meadow x dense x thinned forest environment. Mineralization of glutamic acid was determined by incubation of the soil with 2 mg L- or D-glutamic acid g(-1) of dry soil to induce the maximum respiration rate. Mineralization of glutamic acid enantiomers in soils fluctuates over the course of a vegetation season, following a similar trend across a range of ecosystems. Mineralization is affected by environmental changes and management practices, including elevated CO2 level and thinning intensity. L-glutamic acid metabolism is more dependent on soil type as compared to metabolism of its D-enantiomer. The results support the hypothesis that the slower rate of D- compared to L- amino acid mineralization is due to different roles in anabolism and catabolism of the soil microbial community. © 2014 Wiley Periodicals, Inc.

Amino Acids and Chirality

Science.gov (United States)

Cook, Jamie E.

2012-01-01

Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

Structure of polyacrylic acid and polymethacrylic acid solutions: a small angle neutron scattering study

Energy Technology Data Exchange (ETDEWEB)

Moussaid, A. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France)); Schosseler, F. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France)); Munch, J.P. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France)); Candau, S.J. (Lab. d' Ultrasons et de Dynamique des Fluides Complexes, Univ. Louis Pasteur, 67 - Strasbourg (France))

1993-04-01

The intensity scattered from polyacrylic acid and polymethacrylic acid solutions has been measured by small angle neutron scattering experiments. The influence of polymer concentration, ionization degree, temperature and salt content has been investigated. Results are in qualitative agreement with a model which predicts the existence of microphases in the unstable region of the phase diagram. Quantitative comparison with the theory is performed by fitting the theoretical structure factor to the experimental data. For a narrow range of ionization degrees nearly quantitative agreement with the theory is found for the polyacrylic acid system. (orig.).

Structure of polyacrylic acid and polymethacrylic acid solutions : a small angle neutron scattering study

Science.gov (United States)

Moussaid, A.; Schosseler, F.; Munch, J. P.; Candau, S. J.

1993-04-01

The intensity scattered from polyacrylic acid and polymethacrylic acid solutions has been measured by small angle neutron scattering experiemnts. The influence of polymer concentration, ionization degree, temperature and salt content has been investigated. Results are in qualitative agreement with a model which predicts the existence of microphases in the unstable region of the phase diagram. Quantitative comparison with the theory is performed by fitting the theoretical structure factor to the experimental data. For a narrow range of ionizaiton degrees nearly quantitative agreement with the theory is found for the polyacrylic acide system.

Lactic acid levels in pleural fluid from patients with bacterial pleuritis.

OpenAIRE

Riley, T V

1985-01-01

Pleural fluid lactic acid estimations were carried out on 60 samples by gas-liquid chromatography. Lactic acid levels in 12 patients with bacterial pleural infection were statistically significantly higher (mean, 287 mg/dl; range, 135 to 482 mg/dl) than in 18 patients with malignancy (mean, 71 mg/dl; range, 24 to 157 mg/dl) and 30 other patients with pleural effusions (mean, 19 mg/dl; range, 10 to 57 mg/dl). The determination of pleural fluid lactic acid may help in differentiating between em...

Interaction of milk whey protein with common phenolic acids

Science.gov (United States)

Zhang, Hao; Yu, Dandan; Sun, Jing; Guo, Huiyuan; Ding, Qingbo; Liu, Ruihai; Ren, Fazheng

2014-01-01

Phenolics-rich foods such as fruit juices and coffee are often consumed with milk. In this study, the interactions of α-lactalbumin and β-lactoglobulin with the phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, and coumalic acid) were examined. Fluorescence, CD, and FTIR spectroscopies were used to analyze the binding modes, binding constants, and the effects of complexation on the conformation of whey protein. The results showed that binding constants of each whey protein-phenolic acid interaction ranged from 4 × 105 to 7 × 106 M-n and the number of binding sites n ranged from 1.28 ± 0.13 to 1.54 ± 0.34. Because of these interactions, the conformation of whey protein was altered, with a significant reduction in the amount of α-helix and an increase in the amounts of β-sheet and turn structures.

Geochemistry and microbial community composition across a range of acid mine drainage impact and implications for the Neoarchean-Paleoproterozoic transition

Science.gov (United States)

Havig, Jeff R.; Grettenberger, Christen; Hamilton, Trinity L.

2017-06-01

Streams impacted by acid mine drainage (AMD, also known as acid rock drainage) represent local environmental and ecological disasters; however, they may also present an opportunity to study microbial communities in environments analogous to past conditions. Neoarchean continents had streams and rivers replete with detrital pyrites. Following the emergence of oxygenic photosynthesis, Cyanobacteria colonized streams and rivers on continental surfaces. The combination of labile detrital pyrite grains and locally produced O2 generated by Cyanobacteria produced ideal conditions for pyrite oxidation similar to that found at modern AMD-impacted sites. To explore the connection of modern sites to ancient conditions, we sampled sites that exhibited a range of AMD-impact (e.g., pH from 2.1 to 7.9 [Fe2+] up to 5.2 mmol/L [SO42-] from 0.3 to 52.4 mmol/L) and found (i) nearly all analytes correlated to sulfate concentration; (ii) all sites exhibited the predominance of a single taxon most closely related to Ferrovum myxofaciens, an Fe-oxidixing betaproteoabacterium capable of carbon and nitrogen fixation, and (iii) signs of potential inorganic carbon limitation and nitrogen cycling. From these findings and building on the work of others, we present a conceptual model of continental surfaces during the Neoarchean and Paleoproterozoic linking local O2 production to pyrite oxidation on continental surfaces to sulfate production and delivery to nearshore environments. The delivery of sulfate drives sulfate reduction and euxinia—favoring anoxygenic photosynthesis over cyanobacterial O2 generation in near-continent/shelf marine environments.

Separation and determination of the enantiomers of lactic acid and 2-hydroxyglutaric acid by chiral derivatization combined with GC-MS.

Science.gov (United States)

Ding, Xuemei; Lin, Shuhai; Weng, Hongbo; Liang, Jianying

2018-03-30

Lactic acid and 2-hydroxyglutaric acid are chiral metabolites that have two distinct d and l enantiomers with distinct biochemical properties. Perturbations of single enantiomeric form have been found to be closely related to certain diseases. The ability to differentiate the d and l enantiomers is therefore important for these disease studies. Herein, we describe a method for the separation and determination of lactic acid and 2-hydroxyglutaric acid enantiomers by chiral derivatization (with l-menthol and acetyl chloride) combined with gas chromatography and mass spectrometry. The two pairs of enantiomers mentioned above exhibited linear calibration curves with correlation coefficient (R 2 ) exceeding 0.99. The measured data were accurate in the acceptable recovery range of 88.17-102.30% with inter-day and intra-day precisions (relative standard deviations) in the 4.23-17.26% range. The limits of detection for d- lactic acid, l-lactic acid, d-2-hydroxyglutaric acid and l-2-hydroxyglutaric acid were 0.13, 0.11, 1.12 and 1.16 μM, respectively. This method was successfully applied to analyze mouse plasma. The d-lactic acid levels in type 2 diabetes mellitus mouse plasma were observed to be significantly higher (P lactic acid may serve as an indicator for type 2 diabetes mellitus. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Oil and fatty acid composition of peanut cultivars grown in Pakistan

International Nuclear Information System (INIS)

Hassan, F.; Ahmed, M.

2012-01-01

Quality and flavor of edible peanuts and its products are affected by fatty acid composition of oil. The information related to chemical composition of Peanut grown in the country are scarce, therefore, the present investigation was designed to determine the oil and fatty acid composition of some commonly grown peanut cultivars in Pakistan. Seven Peanut cultivars were grown during 2008 in randomized complete block design replicated thrice. The tested cultivars differed significantly for oil content which ranged from 49.83 to 53.06% on dry weight basis, thus showing differences of 7% among cultivars. The saturated fatty acids (Palmetic and Stearic acid) in different cultivars ranged between 9.95 to 10.79% and 1.63 to 2.19%, respectively. Differences among cultivars for oleic acid exhibited significance which ranged between 49.34 to 54.83%. Similarly, cultivars differed statistically for linoleic ac id which showed a range of 28.99 to 34.23%, thus depicted difference of 7%. Significant differences among tested cultivars may be attributed to the place of origin of particular cultivar. An inverse relationship was exhibited between oleic and linoleic acid, similar to other edible oils. (author)

Acid-fast Smear and Histopathology Results Provide Guidance for the Appropriate Use of Broad-Range Polymerase Chain Reaction and Sequencing for Mycobacteria.

Science.gov (United States)

Miller, Kennon; Harrington, Susan M; Procop, Gary W

2015-08-01

New molecular diagnostic tests are attractive because of the potential they hold for improving diagnostics in microbiology. The value of these tests, which is often assumed, should be investigated to determine the best use of these potentially powerful tools. To investigate the usefulness of broad-range polymerase chain reaction (PCR), followed by sequencing, in mycobacterial infections. We reviewed the test performance of acid-fast bacilli (AFB) PCR and traditional diagnostic methods (histopathology, AFB smear, and culture). We assessed the diagnostic effect and cost of the unrestricted ordering of broad-range PCR for the detection and identification of mycobacteria in clinical specimens. The AFB PCR was less sensitive than culture and histopathology and was less specific than culture, AFB smear, and histopathology. During 18 months, $93 063 was spent on 183 patient specimens for broad-range PCR and DNA sequencing for mycobacteria to confirm one culture-proven Mycobacterium tuberculosis infection that was also known to be positive by AFB smear and histopathology. In this cohort, there was a false-negative AFB PCR for M tuberculosis and a false-positive AFB PCR for Mycobacterium lentiflavum . Testing of AFB smear-negative specimens from patients without an inflammatory response supportive of a mycobacterial infection is costly and has not been proven to improve patient care. Traditional diagnostics (histopathology, AFB smear, and culture) should remain the primary methods for the detection of mycobacteria in clinical specimens.

Bile acids in treatment of ocular disease

OpenAIRE

Boatright, Jeffrey H.; Nickerson, John M.; Moring, Anisha G.; Pardue, Machelle T.

2009-01-01

Bear bile has been included in Asian pharmacopeias for thousands of years in treatment of several diseases, ranging from sore throat to hemorrhoids. The hydrophilic bile acids tauroursodeoxycholic acid (TUDCA) and ursodeoxycholic acid (UDCA) are the major bile acids of bear bile. Both of these are available as synthetic formulations and are approved by the health administrations of several countries for treatment of cirrhosis and gallstones. This review briefly covers the use of bear bile in ...

Whither Acid Rain?

Directory of Open Access Journals (Sweden)

Peter Brimblecombe

2000-01-01

Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

Acid Evolution of Escherichia coli K-12 Eliminates Amino Acid Decarboxylases and Reregulates Catabolism.

Science.gov (United States)

He, Amanda; Penix, Stephanie R; Basting, Preston J; Griffith, Jessie M; Creamer, Kaitlin E; Camperchioli, Dominic; Clark, Michelle W; Gonzales, Alexandra S; Chávez Erazo, Jorge Sebastian; George, Nadja S; Bhagwat, Arvind A; Slonczewski, Joan L

2017-06-15

catabolism. IMPORTANCE Experimental evolution of an enteric bacterium under a narrow buffered range of acid pH leads to loss of genes that enhance fitness above or below the buffered pH range, including loss of enzymes that may raise external pH in the absence of buffer. Prominent modes of evolutionary change involve IS-mediated insertions and deletions that knock out key regulators. Over generations of acid stress, catabolism undergoes reregulation in ways that differ for each evolving strain. Copyright © 2017 American Society for Microbiology.

Potential role of sea spray generation in the atmospheric transport of perfluorocarboxylic acids.

Science.gov (United States)

Webster, Eva; Ellis, David A

2010-08-01

The observed environmental concentrations of perfluorooctanoic acid (PFOA) and its conjugate base (PFO) in remote regions such as the Arctic have been primarily ascribed to the atmospheric transport and degradation of fluorotelomer alcohols (FTOHs) and to direct PFO transport in ocean currents. These mechanisms are each capable of only partially explaining observations. Transport within marine aerosols has been proposed and may explain transport over short distances but will contribute little over longer distances. However, PFO(A) has been shown to have a very short half-life in aqueous aerosols and thus sea spray was proposed as a mechanism for the generation of PFOA in the gas phase from PFO in a water body. Using the observed PFO concentrations in oceans of the Northern Hemisphere and estimated spray generation rates, this mechanism is shown to have the potential for contributing large amounts of PFOA to the atmosphere and may therefore contribute significantly to the concentrations observed in remote locations. Specifically, the rate of PFOA release into the gas phase from oceans in the Northern Hemisphere is calculated to be potentially comparable to global stack emissions to the atmosphere. The subsequent potential for atmospheric degradation of PFOA and its global warming potential are considered. Observed isomeric ratios and predicted atmospheric concentrations due to FTOH degradation are used to elucidate the likely relative importance of transport pathways. It is concluded that gas phase PFOA released from oceans may help to explain observed concentrations in remote regions. The model calculations performed in the present study strongly suggest that oceanic aerosol and gas phase field monitoring is of vital importance to obtain a complete understanding of the global dissemination of PFCAs. Copyright 2010 SETAC

Amino acid racemisation dating

International Nuclear Information System (INIS)

Murray-Wallace, C.V.

1999-01-01

The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject

Quantitative determination of carboxylic acids, amino acids, carbohydrates, ethanol and hydroxymethylfurfural in honey by (1)H NMR.

Science.gov (United States)

del Campo, Gloria; Zuriarrain, Juan; Zuriarrain, Andoni; Berregi, Iñaki

2016-04-01

A method using (1)H NMR spectroscopy has been developed to quantify simultaneously thirteen analytes in honeys without previous separation or pre-concentration steps. The method has been successfully applied to determine carboxylic acids (acetic, formic, lactic, malic and succinic acids), amino acids (alanine, phenylalanine, proline and tyrosine), carbohydrates (α- and β-glucose and fructose), ethanol and hydroxymethylfurfural in eucalyptus, heather, lavender, orange blossom, thyme and rosemary honeys. Quantification was performed by using the area of the signal of each analyte in the honey spectra, together with external standards. The regression analysis of the signal area against concentration plots, used for the calibration of each analyte, indicates a good linearity over the concentration ranges found in honeys, with correlation coefficients higher than 0.985 for the thirteen quantified analytes. The recovery studies give values over the 93.7-105.4% range with relative standard deviations lower than 7.4%. Good precision, with relative standard deviations over the range of 0.78-5.21% is obtained. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radiocarbon variability of fatty acids in semi-urban aerosol samples

International Nuclear Information System (INIS)

Matsumoto, Kohei; Uchida, Masao; Kawamura, Kimitaka; Shibata, Yasuyuki; Morita, Masatoshi

2004-01-01

We analyzed radiocarbon and the stable carbon isotope ratio for individual monocarboxylic (fatty) acids in an aerosol sample (QFF 2138) and compared the results with data of the aerosol sample taken in another year. The fatty acid concentration distribution of aerosol sample QFF 2138 showed a bimodal pattern with maxima at C 16 and C 26 . Stable carbon isotope ratios of the fatty acids ranged from -30.8 per mille to -23.0 per mille which indicates the animal and/or marine algae origins for C 16 -C 19 fatty acids and mainly terrestrial C 3 plant origins for C >20 fatty acids. Δ 14 C values for fatty acids ranged from -89.7 per mille to +83.5 per mille. Compared with QFF1969, we found that the Δ 14 C values of fatty acids exhibited a wide diversity and Δ 14 C values for each fatty acid in QFF 2138 were largely different from those of QFF 1969

Conformation of poly(γ-glutamic acid) in aqueous solution.

Science.gov (United States)

Muroga, Yoshio; Nakaya, Asami; Inoue, Atsuki; Itoh, Daiki; Abiru, Masaya; Wada, Kaori; Takada, Masako; Ikake, Hiroki; Shimizu, Shigeru

2016-04-01

Local conformation and overall conformation of poly(γ-DL-glutamic acid) (PγDLGA) and poly(γ-L-glutamic acid) (PγLGA) in aqueous solution was studied as a function of degree of ionization ε by (1) H-NMR, circular dichroism, and potentiometric titration. It was clarified that their local conformation is represented by random coil over an entire ε range and their overall conformation is represented by expanded random-coil in a range of ε > ε(*) , where ε(*) is about 0.3, 0.35, 0.45, and 0.5 for added-salt concentration of 0.02M, 0.05M, 0.1M, and 0.2M, respectively. In a range of ε acidic media. © 2015 Wiley Periodicals, Inc.

Copper(I) mediated cross-coupling of amino acid derived organozinc reagents with acid chlorides

DEFF Research Database (Denmark)

Hjelmgaard, Thomas; Tanner, David Ackland

2006-01-01

This paper describes the development of a straightforward experimental protocol for copper-mediated cross-coupling of amino acid derived beta-amido-alkylzinc iodides 1 and 3 with a range of acid chlorides. The present method uses CuCN center dot 2LiCl as the copper source and for organozinc reagent...... 1 the methodology appears to be limited to reaction with more stable acid chlorides, providing the desired products in moderate yields. When applied to organozinc reagent 3, however, the protocol is more general and provides the products in good yields in all but one of the cases tested....

Using hair, nail and urine samples for human exposure assessment of legacy and emerging per- and polyfluoroalkyl substances.

Science.gov (United States)

Wang, Yuan; Shi, Yali; Vestergren, Robin; Zhou, Zhen; Liang, Yong; Cai, Yaqi

2018-09-15

Non-invasive samples present ethical and practical benefits for investigating human exposure to hazardous contaminants, but analytical challenges and difficulties to interpret the results limit their application in biomonitoring. Here we investigated the potential for using hair, nail and urine samples as a measure of internal exposure to an array of legacy and emerging per- and polyfluoroalkyl substances (PFASs) in two populations with different exposure conditions. Paired urine-serum measurements of PFASs from a group of highly exposed fishery employees displayed strong correlations for PFASs with three to eight perfluorinated carbons (ρ > 0.653; p < 0.01). Consistent statistical correlations and transfer ratios in nails and hair from both populations demonstrated that these non-invasive samples can be used as a measure of internal exposure to perfluorooctane sulfonic acid and C8 chlorinated polyfluoralkyl ether sulfonic acid (C8 Cl-PFESA). Contrastingly, the infrequent detections and/or lack of consistent transfer ratios for perfluorooctanoic acid, perfluorononanoic acid and short-chain PFASs in hair and nail samples indicate passive uptake from the external environment rather than uptake and internal distribution. Collectively, the study supports the use of urine samples as a valid measure of internal exposure for a range of short- and medium-chain PFASs, while the validity of nail and hair samples as a measure of internal exposure may vary for different PFASs and populations. The ubiquitous detection of C8 Cl-PFESA in all sample matrices from both populations indicates widespread exposure to this contaminant of emerging concern in China. Copyright © 2018 Elsevier B.V. All rights reserved.

Perfluoroalkylated substances (PFAS) affect neither estrogen and androgen receptor activity nor steroidogenesis in human cells in vitro.

Science.gov (United States)

Behr, Anne-Cathrin; Lichtenstein, Dajana; Braeuning, Albert; Lampen, Alfonso; Buhrke, Thorsten

2018-07-01

The perfluoroalkylated substances (PFAS) perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are used for the fabrication of water- and dirt-repellent surfaces. The use of PFOS and PFOA was restricted due to their reprotoxic properties and their environmental persistence. Therefore, industry switches to alternative PFAS, however, in contrast to PFOA and PFOS only few toxicological data are available for their substitutes. The molecular mechanism(s) underlying reproductive toxicity of PFOA and PFOS are largely unknown. Here, the endocrine properties of PFOA, PFOS, and of six substitutes including perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluorobutanoic acid (PFBA), ammonium perfluoro(2-methyl-3-oxahexanoate) (PMOH), and 3H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP) were examined in vitro by using human cell lines such as MCF-7, H295R, LNCaP and MDA-kb2. PFOA, PFOS and PMOH enhanced 17β-estradiol-stimulated estrogen receptor β activity, and PFOS, PMOH, PFHxA and PFBA enhanced dihydrotestosterone-stimulated androgen receptor activity. In the H295R steroidogenesis assay, PFOA and PFOS slightly enhanced estrone secretion, and progesterone secretion was marginally increased by PFOA. All these effects were only observed at concentrations above 10 μM, and none of the PFAS displayed any effect on any of the molecular endocrine endpoints at concentrations of 10 μM or below. Thus, as the blood serum concentrations of the different PFAS in the general Western population are in the range of 10 nM or below, the results suggest that PFAS might not exert endocrine effects in humans at exposure-relevant concentrations according to the molecular endpoints examined in this study. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of Fatty Acid and Amino Acid Compositions in Okra (Abelmoschus esculentus Grown in Different Geographical Locations

Directory of Open Access Journals (Sweden)

Rokayya Sami

2013-01-01

Full Text Available Okra has different uses as a food and a remedy in traditional medicine. Since it produces many seeds, distribution of the plant is also quite easy. Although seed oil yield is low (4.7%, since the linoleic acid composition of the seed oil is quiet high (67.5%, it can still be used as a source of (UNSAT unsaturated fatty acids. In this study, samples of okra grown in four different locations were analyzed to measure fatty acid and amino acid compositions. The content of the lipid extraction ranged from 4.34% to 4.52% on a dry weight basis. Quantitatively, the main okra fatty acids were palmitic acid (29.18–43.26%, linoleic acid (32.22–43.07%, linolenic acid (6.79–12.34%, stearic acid (6.36–7.73%, oleic acid (4.31–6.98%, arachidic acid (ND–3.48%, margaric acid (1.44–2.16%, pentadecylic acid (0.63–0.92%, and myristic acid (0.21–0.49%. Aspartic acid, proline, and glutamic acids were the main amino acids in okra pods, while cysteine and tyrosine were the minor amino acids. Statistical methods revealed how the fatty acid and amino acid contents in okra may be affected by the sampling location.

Immunotoxicity in green mussels under perfluoroalkyl substance (PFAS) exposure: Reversible response and response model development.

Science.gov (United States)

Liu, Changhui; Gin, Karina Yew-Hoong

2018-04-01

The immunotoxicity of 4 commonly detected perfluoroalkyl substances (PFASs), namely, perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) was investigated by measuring biomarkers of the immune profile of green mussels, Perna viridis. The biomarkers included neutral red retention, phagocytosis, and spontaneous cytotoxicity, all of which were tested on mussel hemocytes. Hemocytes are an important component of the invertebrate immune system. We found that exposure to PFASs could lead to reduced hemocyte cell viability and suppress immune function by up to 50% of normal performance within the experimental exposure range. The results indicate that PFASs have an immunotoxic potential and thus could pose severe health risks to aquatic organisms. The reported immunotoxicity is likely to result from the compounds' direct and indirect interactions with the hemocyte membrane, and therefore likely to affect the functionality of these cells. The immunotoxic response was found to be related to the organism's burden of PFASs, and was reversible when the compounds were removed from the test organisms. Based on this relationship, models using an organism's PFAS concentration and bioaccumulation factor (BAF) as the independent variables were established to quantify PFAS-induced immunotoxicity. The models help us to gain a better understanding of the toxic mechanism of PFASs, and provide a tool to evaluate adverse effects for the whole group of compounds with one mathematical equation. Environ Toxicol Chem 2018;37:1138-1145. © 2018 SETAC. © 2018 SETAC.

PFOS, PFNA, and PFOA sub-lethal exposure to embryonic zebrafish have different toxicity profiles in terms of morphometrics, behavior and gene expression.

Science.gov (United States)

Jantzen, Carrie E; Annunziato, Kate A; Bugel, Sean M; Cooper, Keith R

2016-06-01

Polyfluorinated compounds (PFC) are a class of anthropogenic, persistent and toxic chemicals. PFCs are detected worldwide and consist of fluorinated carbon chains of varying length, terminal groups, and industrial uses. Previous zebrafish studies in the literature as well as our own studies have shown that exposure to these chemicals at a low range of concentrations (0.02-2.0μM; 20-2000ppb) resulted in chemical specific developmental defects and reduced post hatch survival. It was hypothesized that sub-lethal embryonic exposure to perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), or perfluorooctanoic acid (PFOA) would result in different responses with regard to morphometric, behavior, and gene expression in both yolk sac fry and larval zebrafish. Zebrafish were exposed to PFOS, PFOA, and PFNA (0.02, 0.2, 2.0μM) for the first five days post fertilization (dpf) and analyzed for morphometrics (5 dpf, 14 dpf), targeted gene expression (5 dpf, 14 dpf), and locomotive behavior (14 dpf). All three PFCs commonly resulted in a decrease in total body length, increased tfc3a (muscle development) expression and decreased ap1s (protein transport) expression at 5dpf, and hyperactive locomotor activity 14 dpf. All other endpoints measured at both life-stage time points varied between each of the PFCs. PFOS, PFNA, and PFOA exposure resulted in significantly altered responses in terms of morphometric, locomotion, and gene expression endpoints, which could be manifested in field exposed teleosts. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of amino acids and amino acid derivatives on crystallization of hemoglobin and ribonuclease A

International Nuclear Information System (INIS)

Ito, Len; Kobayashi, Toyoaki; Shiraki, Kentaro; Yamaguchi, Hiroshi

2008-01-01

The effect of the addition of amino acids and amino acid derivatives on the crystallization of hemoglobin and ribonuclease A has been evaluated. The results showed that certain types of additives expand the concentration conditions in which crystals are formed. Determination of the appropriate conditions for protein crystallization remains a highly empirical process. Preventing protein aggregation is necessary for the formation of single crystals under aggregation-prone solution conditions. Because many amino acids and amino acid derivatives offer a unique combination of solubility and stabilizing properties, they open new avenues into the field of protein aggregation research. The use of amino acids and amino acid derivatives can potentially influence processes such as heat treatment and refolding reactions. The effect of the addition of several amino acids, such as lysine, and several amino acid derivatives, such as glycine ethyl ester and glycine amide, on the crystallization of equine hemoglobin and bovine pancreatic ribonuclease A has been examined. The addition of these amino acids and amino acid derivatives expanded the range of precipitant concentration in which crystals formed without aggregation. The addition of such additives appears to promote the crystallization of proteins

Effect of amino acids and amino acid derivatives on crystallization of hemoglobin and ribonuclease A

Energy Technology Data Exchange (ETDEWEB)

Ito, Len, E-mail: len@ksc.kwansei.ac.jp; Kobayashi, Toyoaki [School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Shiraki, Kentaro [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Yamaguchi, Hiroshi [School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

2008-05-01

The effect of the addition of amino acids and amino acid derivatives on the crystallization of hemoglobin and ribonuclease A has been evaluated. The results showed that certain types of additives expand the concentration conditions in which crystals are formed. Determination of the appropriate conditions for protein crystallization remains a highly empirical process. Preventing protein aggregation is necessary for the formation of single crystals under aggregation-prone solution conditions. Because many amino acids and amino acid derivatives offer a unique combination of solubility and stabilizing properties, they open new avenues into the field of protein aggregation research. The use of amino acids and amino acid derivatives can potentially influence processes such as heat treatment and refolding reactions. The effect of the addition of several amino acids, such as lysine, and several amino acid derivatives, such as glycine ethyl ester and glycine amide, on the crystallization of equine hemoglobin and bovine pancreatic ribonuclease A has been examined. The addition of these amino acids and amino acid derivatives expanded the range of precipitant concentration in which crystals formed without aggregation. The addition of such additives appears to promote the crystallization of proteins.

Use of preservative-free hyaluronic acid (Hylabak® for a range of patients with dry eye syndrome: experience in Russia

Directory of Open Access Journals (Sweden)

Brzhesky VV

2014-06-01

Full Text Available Vladimir Vsevolodovich Brjesky,1 Yury Fedorovich Maychuk,2 Alexey Vladimirovich Petrayevsky,3 Peter Gerrievich Nagorsky41Department of Ophthalmology, Pediatric State Medical Academy, Saint Petersburg, 2Moscow Research Institute of Eye Diseases, Moscow, 3Department of Ophthalmology, Volgograd State Medical University, Volgograd, 4Novosibirsk Branch of the Federal State Institute MNTK Eye Microsurgery, Novosibirsk, Russian Federation, RussiaAbstract: Artificial tear preparations are important in the management of dry eye syndrome. We present the findings from four recently published studies conducted in Russia assessing Hylabak® (marketed as Hyabak® in Europe, a preservative-free hyaluronic acid preparation, for the treatment of dry eye syndrome. All studies had an open, noncomparative design, but one compared the findings with those from 25 patients treated with Tear Naturale® in previous studies. A total of 134 children and adults were enrolled, and the etiologies of dry eye syndrome included contact lens use, intensive office work, adenovirus eye infection, postmenopausal status, persistent meibomian blepharitis, Sjögren's syndrome, phacoemulsification with intraocular lens implantation, and refractive surgery. The patients were treated with Hylabak for 2 weeks to 2 months. All studies showed that Hylabak resulted in marked improvement as assessed by subjective sensations/complaints, Schirmer's test, Norn’s test, impression cytology and biomicroscopy, staining, and tear osmolarity. Greater benefits were also reported compared with Tear Naturale, including a faster onset of action. Hylabak was well tolerated. In conclusion, Hylabak provided rapid and safe relief from the signs and symptoms of dry eye syndrome, as well as improvement in objective measures, in a wide range of patients.Keywords: dry eye, eye drops, artificial tears, hyaluronic acid, Hylabak®, preservative-free

Composition and content analysis of sugars and organic acids for 45 grape cultivars from northeast region of china

International Nuclear Information System (INIS)

Zaozhu, G.N.; Jia, Z.; Zhihu, R.; Zuhui, Z.; Quan, G.; Hongyan, G.; Xiuwu, G.

2017-01-01

The qualitative and quantitative analysis of sugars and acids of grape cultivars from northeast region of China was carried out for quality evaluation and variety improvement of grape. Analysis of major sugars and organic acids for 45 grape berries was carried out using High Performance Liquid Chromatography (HPLC). The result showed that glucose and fructose were the major sugars, beside that, some grape cultivars also contained sucrose. The quantity of glucose and fructose was almost equal in most of grape berries. A significant positive correlation existed between them, glucose content ranged from 53.24 mg/ml to 124.18mg/ml and fructose content ranged from 48.39 mg/ml to118.84 mg/ml. Tartaric acid, malic acid, citric acid and oxalic acid were organic acids and tartaric acid was the main constituent in most grape berries and its concentration was higher than the other organic acids. However, in some grape cultivars, malic acid and citric acid were two highest organic acids while oxalic acid content was the lowest and even in some cultivars it could not be detected. Tartaric acid ranged from 1.28mg/ml to 6.82 mg/ml, malic acid ranged from 0.09mg/ml to 3.95 mg/ml, citric acid ranged from 0.08mg/ml to 4.43 mg/ml, oxalic acid ranged from mg/ml to 0.370 mg/ml. Thirty-four grape cultivars out of 45 cultivars accounted more than 50% tartic acid of the total organic acid contents. However, in cultivars Bixiang Wuhe and Shennong Jinhuanghou citric acid was the main organic acid. Malic acid and citric acid were significantly positively related with total acid. In 43 grape cultivars, the soluble sugars were glucose and fructose. Besides glucose and fructose, sucrose was also observed in cultivars of LN33 and Cayuga white. (author)

Haloacetic acids in the aquatic environment. Part I: macrophyte toxicity

International Nuclear Information System (INIS)

Hanson, Mark L.; Solomon, Keith R.

2004-01-01

Haloacetic acids (HAAs) are contaminants of aquatic ecosystems with numerous sources, both anthropogenic and natural. The toxicity of HAAs to aquatic plants is generally uncharacterized. Laboratory tests were conducted with three macrophytes (Lemna gibba, Myriophyllum sibiricum and Myriophyllum spicatum) to assess the toxicity of five HAAs. Myriophyllum spp. has been proposed as required test species for pesticide registration in North America, but few studies have been conducted under standard test conditions. The HAAs in the present experiments were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). MCA was the most toxic to Myriophyllum spp. with EC 50 values ranging from 8 to 12.4 mg/l depending on the endpoint, followed by DCA (EC 50 range 62-722.5 mg/l), TCA (EC 50 range 49.5-1702.6 mg/l), CDFA (EC 50 range 105.3 to >10,000 mg/l) and with TFA (EC 50 range 222.1 to 10,000 mg/l) the least toxic. Generally, L. gibba was less sensitive to HAA toxicity than Myriophyllum spp., with the difference in toxicity between them approximately threefold. The range of toxicity within Myriophyllum spp. was normally less than twofold. Statistically, plant length and node number were the most sensitive endpoints as they had the lowest observed coefficients of variation, but they were not the most sensitive to HAA toxicity. Toxicological sensitivity of endpoints varied depending on the measure of effect chosen and the HAA, with morphological endpoints usually an order of magnitude more sensitive than pigments for all plant species. Overall, mass and root measures tended to be the most sensitive indicators of HAA toxicity. The data from this paper were subsequently used in an ecological risk assessment for HAAs and aquatic plants. The assessment found HAAs to be of low risk to aquatic macrophytes and the results are described in the second manuscript of this series

Synthesis of Renewable Diesel Range Alkanes by Hydrodeoxygenation of Palmitic Acid over 5% Ni/CNTs under Mild Conditions

Directory of Open Access Journals (Sweden)

Yanan Duan

2017-03-01

Full Text Available Recently, the catalytic upgrading of bio-oil to renewable diesel has been attracting more and more attention. In the current paper, carbon nanotube (CNT-supported nickel catalysts, namely, 5% Ni/CNTs, were prepared for liquid hydrocarbon production through the deoxygenation of palmitic acid, the model compound of bio-oil under a mild condition of 240 °C reaction temperature and 2 MPa H2 pressure. The experimental results revealed that the main reaction product was pentadecane (yield of 89.64% at an optimum palmitic acid conversion of 97.25% via the hydrodecarbonylation (HDC process. The deoxygenation mechanism for palmitic acid conversion was also investigated. This study provides technical parameters and a theoretical basis for further industrialization in the bio-oil upgrading process.

Research and performance evaluation on an HA integrated acid system for sandstone acidizing

Directory of Open Access Journals (Sweden)

Liqiang Zhao

2018-03-01

Full Text Available When the conventional sandstone acidizing technologies are adopted, many slugs are needed in the injection of prepad fluid, treatment fluid and postpad fluid, and consequently the production and operation suffers inconveniences and difficulties. In view of this, a kind of HA integrated acid system which is mainly composed of organic polybasic acids (HA+HCl + HF and an efficient organic solvent was developed in this paper based on the idea of integrated acid replacing ''multiple steps'' and high efficiency and intensification. Via this HA integrated acid system, the complicated blockage in sandstone reservoirs can be removed effectively. Then, experiments were carried out on this system to evaluate its performance in terms of its retardance, organic blockage dissolution, chelating and precipitation inhibition. It is indicated that this new system can not only realize the acidizing of conventional integrated acid, but also present a good retarding performance by controlling H+ multi-stage ionization step by step and by forming silica acid-aluminum phosphonate film on the surface of clay minerals; that via this new HA integrated acid system, the organic blockage can be removed efficiently; and that it is wider in pH solution range than conventional APCs (aminopolycarboxyliates chelants, stronger in chelating capacity of Ca2+, Mg2+ and Fe3+ than conventional chelants (e.g. EDTA, NTA and DTPA, and better in precipitation inhibition on metal fluoride, fluosilicic acid alkali metal, fluoaluminic acid alkali metal and hydroxide than multi-hydrogen acid, fluoboric acid and mud acid systems. These research results provide a technical support for the plugging removal in high-temperature deep oil and gas reservoirs. Keywords: Organic polybasic acid, Integrated acid, Retardance, Chelating, Precipitation, Acidizing, Sandstone, Reservoir

PRODUCTION OF TRIFLUOROACETIC ACID COMPOUNDS

Science.gov (United States)

Haworth, W.N.; Stacey, M.

1949-08-30

A process is described for the preparation of trifluoroacetic acid. Acetone vapor diluted wlth nitrogen and fluorine also diluted with nltrogen are fed separately at a temperature of about 210 deg C into a reaction vessel containing a catalyst mass selected from-the group consisting of silver and gold. The temperature in the reaction vessel is maintained in the range of 200 deg to 250 deg C. The reaction product, trifluoroacetyl fluoride, is absorbed in aqueous alkali solution. Trifluoroacetic acid is recovered from the solution by acidification wlth an acid such as sulfuric followed by steam distillation.

Tailored fatty acid synthesis via dynamic control of fatty acid elongation

Energy Technology Data Exchange (ETDEWEB)

Torella, JP; Ford, TJ; Kim, SN; Chen, AM; Way, JC; Silver, PA

2013-07-09

Medium-chain fatty acids (MCFAs, 4-12 carbons) are valuable as precursors to industrial chemicals and biofuels, but are not canonical products of microbial fatty acid synthesis. We engineered microbial production of the full range of even-and odd-chain-length MCFAs and found that MCFA production is limited by rapid, irreversible elongation of their acyl-ACP precursors. To address this limitation, we programmed an essential ketoacyl synthase to degrade in response to a chemical inducer, thereby slowing acyl-ACP elongation and redirecting flux from phospholipid synthesis to MCFA production. Our results show that induced protein degradation can be used to dynamically alter metabolic flux, and thereby increase the yield of a desired compound. The strategy reported herein should be widely useful in a range of metabolic engineering applications in which essential enzymes divert flux away from a desired product, as well as in the production of polyketides, bioplastics, and other recursively synthesized hydrocarbons for which chain-length control is desired.

Tailored fatty acid synthesis via dynamic control of fatty acid elongation

Science.gov (United States)

Torella, Joseph P.; Ford, Tyler J.; Kim, Scott N.; Chen, Amanda M.; Way, Jeffrey C.; Silver, Pamela A.

2013-01-01

Medium-chain fatty acids (MCFAs, 4–12 carbons) are valuable as precursors to industrial chemicals and biofuels, but are not canonical products of microbial fatty acid synthesis. We engineered microbial production of the full range of even- and odd-chain–length MCFAs and found that MCFA production is limited by rapid, irreversible elongation of their acyl-ACP precursors. To address this limitation, we programmed an essential ketoacyl synthase to degrade in response to a chemical inducer, thereby slowing acyl-ACP elongation and redirecting flux from phospholipid synthesis to MCFA production. Our results show that induced protein degradation can be used to dynamically alter metabolic flux, and thereby increase the yield of a desired compound. The strategy reported herein should be widely useful in a range of metabolic engineering applications in which essential enzymes divert flux away from a desired product, as well as in the production of polyketides, bioplastics, and other recursively synthesized hydrocarbons for which chain-length control is desired. PMID:23798438

Cholesterol and fatty acids profile of Brazilian commercial chicken giblets.

Science.gov (United States)

Pereira, Nádia Rosa; Muniz, Edvani Curti; Matsushita, Makoto; Evelázio de Souza, Nilson

2002-06-01

This study was carried out to determine the chemical composition, cholesterol contents and fatty acids profile of Brazilian commercial chicken giblets. The analysis were performed in gizzard, liver and heart in natura and also in cooked gizzard, fried liver and roasted heart. Fat and cholesterol contents ranged from 0.88% and 72.68 mg/100 g, in cooked gizzard, to 22.19% and 213.18 mg/100 g, in roasted heart. As the fat content gets higher, so does the cholesterol content. Palmitic (C16:0) and stearic acids (C18:0) were the predominant saturated fatty acids (SFA). The C16:0 ranged from 6.39% in cooked gizzard to 18.51% in fried liver. The C18:0 level ranged from 6.62% in roasted heart to 19.19% in cooked gizzard. Linoleic acid (C18:2 omega 6) was the predominant polyunsaturated fatty acid (PUFA). The data revealed that the three different analysed giblets presented a good PUFA/SFA ratio, with values of 1.11, 1.14 and 1.40 for cooked gizzard, fried liver and roasted heart, respectively.

Simultaneous estimation of a binary mixture of a weak acid and a strong acid by volumetric titration and pH measurement

International Nuclear Information System (INIS)

Karmakar, Sanat; Mallika, C.; Kamachi Mudali, U.

2012-01-01

High level liquid waste (HLLW) generated in the aqueous reprocessing of spent nuclear fuels for the separation of uranium and plutonium by PUREX process, comprises the fission and corrosion products in 4 M nitric acid. Reduction in waste volume is accomplished by destroying the acidity of the waste solution from 4 to less than 2 M by treating it with formaldehyde and subsequent concentration by evaporation. In the denitration by HCHO, nitric acid in the waste solution is reduced to NOx and water via nitrous acid as the intermediate product: whereas formaldehyde is oxidized to formic acid which is converted to CO 2 and H 2 O subsequently. The reaction is highly exothermic and the release of all gaseous products may lead to uncontrollable process conditions. Hence, for the safe operation, it is desirable to estimate the concentration of residual formic acid as well as nitric acid in the product stream as a function of time. The acidity in the feed solution is 4 M and the concentration of HNO 3 in the product solution is in the range 1- 4 M. Since the formic acid generated during the reaction will be consumed immediately, the concentration of residual acid will be in the range 0.05-0.5 M. A simultaneous titration method based on pH measurement and volumetric analysis has been developed in the present work for the quantitative determination of the weak acid (HCOOH)with known pKa value and the strong acid (HNO 3 ) in the binary mixture

EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA); Scientific Opinion on Dietary Reference Values for fats, including saturated fatty acids, polyunsaturated fatty acids, monounsaturated fatty acids, trans fatty acids, and cholesterol

DEFF Research Database (Denmark)

Tetens, Inge

This Opinion of the EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA) deals with the setting of Dietary Reference Values (DRVs) for fats. A lower bound of the reference intake range for total fat of 20 energy % (E%) and an upper bound of 35 E% are proposed. Fat intake in infants can......-linolenic acid (ALA) of 0.5 E%; not to set an UL for ALA; to set an AI of 250 mg for eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) for adults; to set an AI of 100 mg DHA for infants (>6 months) and young children...... gradually be reduced from 40 E% in the 6-12 month period to 35-40 E% in the 2nd and 3rd year of life. For specific fatty acids the following is proposed: saturated fatty acid (SFA) and trans fatty acid intake should be as low as possible; not to set any DRV for cis-monounsaturated fatty acids......; not to formulate a DRV for the intake of total cis-polyunsaturated fatty acids (PUFA); not to set specific values for the n-3/n-6 ratio; to set an Adequate Intake (AI) of 4 E% for linoleic acid (LA); not to set any DRV for arachidonic acid; not to set an UL for total or any of the n-6 PUFA; to set an AI for alpha...

Randomised clinical trial: a dose-ranging study of vonoprazan, a novel potassium-competitive acid blocker, vs. lansoprazole for the treatment of erosive oesophagitis.

Science.gov (United States)

Ashida, K; Sakurai, Y; Nishimura, A; Kudou, K; Hiramatsu, N; Umegaki, E; Iwakiri, K; Chiba, T

2015-09-01

The potassium-competitive acid blocker vonoprazan (VPZ) has potent acid-inhibitory effects and may offer clinical advantages over conventional therapy for acid-related disorders. To investigate the efficacy and safety of VPZ in patients with erosive oesophagitis (EO). In this multicentre, randomised, double-blind, parallel-group, dose-ranging study, patients ≥20 years with endoscopically confirmed EO [Los Angeles (LA) grades A-D] received VPZ 5, 10, 20 or 40 mg, or lansoprazole (LPZ) 30 mg once daily for 8 weeks. The primary endpoint was the proportion of healed EO subjects as shown by endoscopy at week 4. A total of 732 subjects received VPZ or LPZ. The proportion of healed EO subjects at week 4 was 92.3%, 92.5%, 94.4%, 97.0% and 93.2%, respectively, with VPZ 5, 10, 20 and 40 mg and LPZ 30 mg. All VPZ doses were non-inferior to LPZ when adjusted for baseline LA grades A/B and C/D. Among those with LA grades C/D, the proportions of healed EO subjects were 87.3%, 86.4%, 100%, 96.0% and 87.0%, respectively, with VPZ 5, 10, 20 and 40 mg and LPZ 30 mg. The incidence of adverse events was similar across the groups. Vonoprazan was effective and non-inferior to LPZ in healing EO. VPZ 20 mg or higher was highly efficacious for severe EO (LA grades C/D). VPZ was associated with no safety concern during this 8-week study, while there was a dose-dependent increase in serum gastrin. Once-daily VPZ 20 mg is the recommended clinical dose for treating EO. © 2015 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.

THERMAL DEGRADATION OF THERMOTROPIC LIQUID CRYSTALLINE TERPOLYESTERS BASED ON VANILLIC ACID, p-HYDROXYBENZOIC ACID AND POLY(ETHYLENE TEREPHTHALATE)

Institute of Scientific and Technical Information of China (English)

LI Xingui; HUANG Meirong; GUAN Guihe; SUN Tong

1993-01-01

Nine thermotropic liquid crystalline terpolyesters based on vanillic acid(V), p-hydroxybenzoic acid(H) and poly(ethylene terephthalate)(E) were investigated by thermogravimetry to ascertain their thermostability and the kinetic parameters for thermal degradation. Overall activation energy data of the degradation had been calculated over the range 5～70% weight loss. The temperatures and the activation energy of the degradation lie in the ranges of 384～394 ℃ at a heating rate of 1 ℃/min and 176～205 KJ/mol at the weight loss of 5%, respectively, which suggests that the terpolyesters have good thermostability.

Occurrence of perfluorinated alkyl substances in sediment from estuarine and coastal areas of the East China Sea.

Science.gov (United States)

Yan, Hong; Zhang, Chaojie; Zhou, Qi; Yang, Shouye

2015-02-01

Perfluorinated alkyl substances (PFAS) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. The occurrence and spatial variation of PFAS were investigated through collection of riverine and marine sediments from estuarine and coastal areas of the East China Sea. Among them, perfluorooctanesulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), and perfluorooctanoic acid (PFOA) were the three predominant PFAS with the highest detection frequencies in the sediment. PFOS up to 32.4 ng g(-1) dw and ∑PFAS up to 34.8 ng g(-1) dw were detected. Compared to other studies, high levels of PFOS were found in sediments from the East China Sea. PFHpA was also detected at higher frequency and concentration than those of other studies, which suggests point sources in this area. Concentrations of PFAS in riverine sediments were much higher than in marine sediments. Analysis of spatial variations presented overall decreasing trends of PFAS from inshore to offshore areas.

Delta 12-Fatty Acid Desaturase from Candida parapsilosis Is a Multifunctional Desaturase Producing a Range of Polyunsaturated and Hydroxylated Fatty Acids

Czech Academy of Sciences Publication Activity Database

Buček, Aleš; Matoušková, Petra; Sychrová, Hana; Pichová, Iva; Hrušková-Heidingsfeldová, Olga

2014-01-01

Roč. 9, č. 3 (2014), e93322/1-e93322/10 E-ISSN 1932-6203 R&D Projects: GA TA ČR(CZ) TA01011461 Institutional support: RVO:61388963 ; RVO:67985823 Keywords : yeast Saccharomyces cerevisiae * omega-3 fatty acid desaturase * heterologous expression Subject RIV: CE - Biochemistry Impact factor: 3.234, year: 2014 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0093322

Conversion of beta-methylbutyric acid to beta-hydroxy-beta-methylbutyric acid by Galactomyces reessii.

OpenAIRE

Lee, I Y; Nissen, S L; Rosazza, J P

1997-01-01

beta-Hydroxy-beta-methylbutyric acid (HMB) has been shown to increase strength and lean mass gains in humans undergoing resistance-exercise training. HMB is currently marketed as a calcium salt of HMB, and thus, environmentally sound and inexpensive methods of manufacture are being sought. This study investigates the microbial conversion of beta-methylbutyric acid (MBA) to HMB by cultures of Galactomyces reessii. Optimal concentrations of MBA were in the range of 5 to 20 g/liter for HMB produ...

Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

Energy Technology Data Exchange (ETDEWEB)

Gorrochategui, Eva; Pérez-Albaladejo, Elisabet [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain); Casas, Josefina [Department of Biomedicinal Chemistry, IQAC–CSIC, 08034 Barcelona, Catalonia (Spain); Lacorte, Sílvia, E-mail: slbqam@cid.csic.es [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain); Porte, Cinta, E-mail: cinta.porte@cid.csic.es [Department of Environmental Chemistry, IDAEA–CSIC, 08034 Barcelona, Catalonia (Spain)

2014-06-01

The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

International Nuclear Information System (INIS)

Gorrochategui, Eva; Pérez-Albaladejo, Elisabet; Casas, Josefina; Lacorte, Sílvia; Porte, Cinta

2014-01-01

The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

Development of Acid Resistance Velocity Sensor for Analyzing Acidic Fluid Flow Characteristics

Energy Technology Data Exchange (ETDEWEB)

Choi, Gyujin; Yoon, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

2016-10-15

This study presents the development of an acid resistance velocity sensor that is used for measuring velocity inside a copper sulfate plating bath. First, researchers investigated the acid resistance coating to confirm the suitability of the anti-acid sensor in a very corrosive environment. Then, researchers applied signal processing methods to reduce noise and amplify the signal. Next, researchers applied a pressure-resistive sensor with an operation amplifier (Op Amp) and low-pass filter with high impedance to match the output voltage of a commercial flowmeter. Lastly, this study compared three low-pass filters (Bessel, Butterworth and Chebyshev) to select the appropriate signal process circuit. The results show 0.0128, 0.0023, and 5.06% of the mean square error, respectively. The Butterworth filter yielded more precise results when compared to a commercial flowmeter. The acid resistive sensor is capable of measuring velocities ranging from 2 to 6 m/s with a 2.7% margin of error.

Fabrication of superhydrophobic polyaniline films with rapidly switchable wettability

Science.gov (United States)

Zhou, Xiaoyan; Zhang, Zhaozhu; Men, Xuehu; Yang, Jin; Xu, Xianghui; Zhu, Xiaotao; Xue, Qunji

2011-10-01

A superhydrophobic polyaniline (PANI) film has been fabricated by using a facile one-step spraying method. The PANI was synthesized via in situ doping polymerization in the presence of perfluorooctanoic acid (PFOA) as the dopant. The water contact angle of this superhydrophobic surface reaches to 156°. Both the surface chemical compositions and morphological structures were analyzed. A granular morphology of PANI with a moderate amount of nanofibers was obtained. Moreover, a rapid surface wettability transition between superhydrophobicity and superhydrophilicity can be observed when it is doped with PFOA and de-doped with base. The mechanism for this tunable wettability has been discussed in detail.

Technological and economic potential of poly(lactic acid) and lactic acid derivatives

Energy Technology Data Exchange (ETDEWEB)

Datta, R.; Tsai, S.P.; Bonsignore, P.; Moon, S.H.; Frank, J.R.

1993-10-01

Lactic acid has been an intermediate-volume specialty chemical (world production {approximately}40,000 tons/yr) used in a wide range of food processing and industrial applications. lactic acid h,as the potential of becoming a very large volume, commodity-chemical intermediate produced from renewable carbohydrates for use as feedstocks for biodegradable polymers, oxygenated chemicals, plant growth regulators, environmentally friendly ``green`` solvents, and specially chemical intermediates. In the past, efficient and economical technologies for the recovery and purification of lactic acid from crude fermentation broths and the conversion of tactic acid to the chemical or polymer intermediates had been the key technology impediments and main process cost centers. The development and deployment of novel separations technologies, such as electrodialysis (ED) with bipolar membranes, extractive distillations integrated with fermentation, and chemical conversion, can enable low-cost production with continuous processes in large-scale operations. The use of bipolar ED can virtually eliminate the salt or gypsum waste produced in the current lactic acid processes. In this paper, the recent technical advances in tactic and polylactic acid processes are discussed. The economic potential and manufacturing cost estimates of several products and process options are presented. The technical accomplishments at Argonne National Laboratory (ANL) and the future directions of this program at ANL are discussed.

Development of a bacterial bioassay for atrazine and cyanuric acid detection

Directory of Open Access Journals (Sweden)

Anna eHUA

2015-03-01

Full Text Available The s-triazine herbicides are compounds which can disseminate into soils and water. Due to their toxic effects on living organisms, their concentrations in drinking water are legislated by WHO recommendations. Here we have developed for the first time, to the best of our knowledge, an alternative method for physicochemical quantification using two bioluminescent bacterial biosensors: E. coli SM003 for cyanuric acid detection and E. coli SM004 for both atrazine and cyanuric acid detection. The concentration of cyanuric acid detection for E. coli SM003 ranges from 7.83 µM to 2.89 mM, and for E. coli SM004 ranges from 0.22 µM to 15 µM. Moreover, atrazine detection by E. coli SM004 ranges from 1.08 µM to 15 µM. According to WHO recommendations, the cyanuric acid detection range is sensitive enough to discriminate between polluted and drinking water. Nevertheless, the detection of atrazine by E. coli SM004 is only applicable for high concentrations of contaminants.

Physiological and transcriptional response of Lactobacillus casei ATCC 334 to acid stress.

Science.gov (United States)

Broadbent, Jeff R; Larsen, Rebecca L; Deibel, Virginia; Steele, James L

2010-05-01

This study investigated features of the acid tolerance response (ATR) in Lactobacillus casei ATCC 334. To optimize ATR induction, cells were acid adapted for 10 or 20 min at different pH values (range, 3.0 to 5.0) and then acid challenged at pH 2.0. Adaptation over a broad range of pHs improved acid tolerance, but the highest survival was noted in cells acid adapted for 10 or 20 min at pH 4.5. Analysis of cytoplasmic membrane fatty acids (CMFAs) in acid-adapted cells showed that they had significantly (P L. casei survival at pH 2.5 was improved at least 100-fold by chemical induction of the stringent response or by the addition of 30 mM malate or 30 mM histidine to the acid challenge medium. To our knowledge, this is the first report that intracellular histidine accumulation may be involved in bacterial acid resistance.

Nitrosation and Nitration of Fulvic Acid, Peat and Coal with Nitric Acid.

Directory of Open Access Journals (Sweden)

Kevin A Thorn

Full Text Available Nitrohumic acids, produced from base extraction of coals and peats oxidized with nitric acid, have received considerable attention as soil ammendments in agriculture. The nitration chemistry however is incompletely understood. Moreover, there is a need to understand the reaction of nitric acid with natural organic matter (NOM in general, in the context of a variety of environmental and biogeochemical processes. Suwannee River NOM, Suwannee River fulvic acid, and Pahokee Peat fulvic acid were treated with 15N-labeled nitric acid at concentrations ranging from 15% to 22% and analyzed by liquid and solid state 15N NMR spectroscopy. Bulk Pahokee peat and Illinois #6 coal were also treated with nitric acid, at 29% and 40% respectively, and analyzed by solid state 15N NMR spectroscopy. In addition to nitro groups from nitration of aromatic carbon, the 15N NMR spectra of all five samples exhibited peaks attributable to nitrosation reactions. These include nitrosophenol peaks in the peat fulvic acid and Suwannee River samples, from nitrosation of phenolic rings, and N-nitroso groups in the peat samples, from nitrosation of secondary amides or amines, the latter consistent with the peat samples having the highest naturally abundant nitrogen contents. Peaks attributable to Beckmann and secondary reactions of the initially formed oximes were present in all spectra, including primary amide, secondary amide, lactam, and nitrile nitrogens. The degree of secondary reaction product formation resulting from nitrosation reactions appeared to correlate inversely with the 13C aromaticities of the samples. The nitrosation reactions are most plausibly effected by nitrous acid formed from the reduction of nitric acid by oxidizable substrates in the NOM and coal samples.

Serum Vaccine Antibody Concentrations in Children Exposed to Perfluorinated Compounds

DEFF Research Database (Denmark)

Grandjean, P.; Andersen, E. W.; Budtz-Jorgensen, E.

2012-01-01

whether PFC exposure is associated with antibody response to childhood vaccinations. Design, Setting, and Participants Prospective study of a birth cohort from the National Hospital in the Faroe Islands. A total of 656 consecutive singleton births were recruited during 1999-2001, and 587 participated...... in follow-up through 2008. Main Outcome Measures Serum antibody concentrations against tetanus and diphtheria toxoids at ages 5 and 7 years. Results Similar to results of prior studies in the United States, the PFCs with the highest serum concentrations were perfluorooctane sulfonic acid (PFOS......) and perfluorooctanoic acid (PFOA). Among PFCs in maternal pregnancy serum, PFOS showed the strongest negative correlations with antibody concentrations at age 5 years, for which a 2-fold greater concentration of exposure was associated with a difference of -39% (95% CI, -55% to -17%) in the diphtheria antibody...

Comparison of commercially available radioimmunoassays for the determination of bile acids in serum

Energy Technology Data Exchange (ETDEWEB)

Wildgrube, H.J.; Schiller, W.; Winkler, M.; Weber, J.; Campana, H.; Mauritz, G.

1982-05-01

Three commercially available radioimmunoassays for the determination of bile acids in serum were evaluated with respect to specificity and precision. The SLCG-radioimmunoassay (Abbott) measures only sulphated glycolithocholic acid, the CG-radioimmunoassay (Abbott) measures chiefly cholic acid conjugates, and the CBA-radioimmunoassay (Becton-Dickinson) measures all conjugated bile acids, with an over-response to taurine metabolites. With respect to cross reactions, the performances of the CG-and the CBA-radioimmunoassays differed significantly from those stated by the manufacturers, the former showing a 32% response to taurocholic acid, the latter responding only 118% to taurochenodeoxycholic acid. At physiological concentrations of albumin + globulin, the recovery of defined cholanic acids was 85-101%. Good reproducibility was shown by the CG-radioimmunoassay in the range 0.5-10.9 ..mu..mol/l, by the CBA-radioimmunoassay in the range 1.0-25.0 ..mu..mol/l, and by the SLCG-radioimmunoassay in the range 0.5-3.0 ..mu..mol/l. There were no important differences in the inter- and intra-assay precision of the three methods.

Temporal trends of perfluoroalkyl substances (PFAS) in eggs of coastal and offshore birds: Increasing PFAS levels associated with offshore bird species breeding on the Pacific coast of Canada and wintering near Asia.

Science.gov (United States)

Miller, Aroha; Elliott, John E; Elliott, Kyle H; Lee, Sandi; Cyr, Francois

2015-08-01

Perfluoroalkyl substances (PFAS) such as perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) have become virtually ubiquitous throughout the environment, and, based on laboratory studies, have known toxicological consequences. Various national and international voluntary phase-outs and restrictions on these compounds have been implemented over the last 10 to 15 years. In the present study, we examine trends (1990/1991-2010/2011) in aquatic birds (ancient murrelet, Synthliboramphus antiquus [2009 only]; Leach's storm-petrels, Oceanodroma leucorhoa; rhinoceros auklets, Cerorhinca monocerata; double-crested cormorants, Phalacrocorax auritus; and great blue herons, Ardea herodias). The PFCA, PFSA, and stable isotope (δ(15) N and δ(13) C) data collected from these species from the Pacific coast of Canada, ranging over 20 to 30 years, were used to investigate temporal changes in PFAS coupled to dietary changes. Perfluorooctane sulfonic acid (PFOS), the dominant PFSA compound in all 4 species, increased and subsequently decreased in auklet and cormorant eggs in line with the manufacturing phase-out of PFOS and perfluorooctanoic acid (PFOA), but concentrations continuously increased in petrel eggs and remained largely unchanged in heron eggs. Dominant PFCA compounds varied between the offshore and coastal species, with increases seen in the offshore species and little or variable changes seen in the coastal species. Little temporal change was seen in stable isotope values, indicating that diet alone is not driving observed PFAS concentrations. © 2015 SETAC.

Density, viscosity, and N2O solubility of aqueous amino acid salt and amine amino acid salt solutions

International Nuclear Information System (INIS)

Aronu, Ugochukwu E.; Hartono, Ardi; Svendsen, Hallvard F.

2012-01-01

Highlights: ► Density of amino acid salt and amine amino acid salt. ► Viscosity of amino acid salt and amine amino acid salt. ► Henry’s law constant/N 2 O solubility of amino acid salt and amine amino acid salt. ► Schumpe model. Correlations for density, viscosity, and N 2 O solubility. - Abstract: Physicochemical properties of aqueous amino acid salt (AAS), potassium salt of sarcosine (KSAR) and aqueous amine amino acid salt (AAAS), 3-(methylamino)propylamine/sarcosine (SARMAPA) have been studied. Densities of KSAR were measured for sarcosine mole fraction 0.02 to 0.25 for temperature range 298.15 K to 353.15 K, the viscosities were measured for 0.02 to 0.10 mole fraction sarcosine (293.15 K to 343.15 K) while the N 2 O solubilities were measured from 0.02 to 0.10 mole fraction sarcosine solutions (298.15 K to 363.15 K). Densities of SARMAPA were measured for sarcosine mole fraction 0.02 to 0.23 for temperature range (298.15 K to 353.15 K), viscosities were measured for 0.02 to 0.16 mole fraction sarcosine (293.15 K to 343.15 K) while the N 2 O solubilities were measured from 0.02 to 0.16 mole fraction sarcosine solutions (298.15 K to 343.15 K). Experimental results were correlated well with empirical correlations and N 2 O solubility results for KSAR were predicted adequately by a Schumpe model. The solubilities of N 2 O in AAS and AAAS are significantly lower than values for amines. The solubilities vary as: amine > AAAS > AAS.

Comparison of Fatty Acid Composition in Selected Dietary Supplements Containing Conjugated Linoleic Acid.

Science.gov (United States)

Derewiaka, Dorota; Nestorowicz, Klara; Wołosiak, Rafał

2017-07-04

The market of pharmaceutical products is offering a wide range of supplements. Most of the consumers believe that these products will improve their state of health, but are they getting what they want and what they are paying for? The aim of the study was to evaluate the quality of selected dietary supplements containing conjugated linoleic acid (CLA). All supplements were available in the Warsaw markets and bought from pharmacies. Assessment of the quality of food supplements was achieved by analysis of fatty acid using gas chromatography coupled with a mass spectrometer. On the basis of the investigations carried out, it was found that content of CLA in selected dietary supplements ranged between 282 and 528 mg by weight of a single capsule. The content of bioactive ingredients found in three of the four product supplements assessed was lower than was claimed by the manufacturer.

Acid hydrolysis of Curcuma longa residue for ethanol and lactic acid fermentation.

Science.gov (United States)

Nguyen, Cuong Mai; Nguyen, Thanh Ngoc; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Park, Youn-Je; Kim, Jin-Cheol

2014-01-01

This research examines the acid hydrolysis of Curcuma longa waste, to obtain the hydrolysate containing lactic acid and ethanol fermentative sugars. A central composite design for describing regression equations of variables was used. The selected optimum condition was 4.91% sulphuric acid, 122.68°C and 50 min using the desirability function under the following conditions: the maximum reducing sugar (RS) yield is within the limited range of the 5-hydroxymethylfurfural (HMF) and furfural concentrations. Under the condition, the obtained solution contained 144 g RS/L, 0.79 g furfural/L and 2.59 g HMF/L and was directly fermented without a detoxification step. The maximum product concentration, average productivity, RS conversion and product yield were 115.36 g/L, 2.88 g/L/h, 89.43% and 64% for L-lactic acid; 113.92 g/L, 2.59 g/L/h, 88.31% and 63.29% for D-lactic acid; and 55.03 g/L, 1.38 g/L/h, 42.66 and 30.57%, respectively, for ethanol using a 7-L jar fermenter. Copyright © 2013. Published by Elsevier Ltd.

Perfluoroalkyl and polyfluoroalkyl substances in the lower atmosphere and surface waters of the Chinese Bohai Sea, Yellow Sea, and Yangtze River estuary.

Science.gov (United States)

Zhao, Zhen; Tang, Jianhui; Mi, Lijie; Tian, Chongguo; Zhong, Guangcai; Zhang, Gan; Wang, Shaorui; Li, Qilu; Ebinghaus, Ralf; Xie, Zhiyong; Sun, Hongwen

2017-12-01

Polyfluoroalkyl and perfluoroalkyl substances (PFASs), in the forms of neutral polyfluoroalkyl substances in the gas phase of air and ionic perfluoroalkyl substances in the dissolved phase of surface water, were investigated during a sampling campaign in the Bohai Sea, Yellow Sea, and Yangtze River estuary in May 2012. In the gas phase, the concentrations of neutral ∑PFASs were within the range of 76-551pg/m 3 . Higher concentrations were observed in the South Yellow Sea. 8:2 fluorotelomer alcohol (FTOH) was the predominant compound as it accounted for 92%-95% of neutral ∑PFASs in all air samples. Air mass backward trajectory analysis indicated that neutral ∑PFASs came mainly from the coast of the Yellow Sea, including the Shandong, Jiangsu, and Zhejiang provinces of China, and the coastal region of South Korea. The fluxes of gas phase dry deposition were simulated for neutral PFASs, and neutral ∑PFASs fluxes varied from 0.37 to 2.3pg/m 2 /s. In the dissolved phase of the surface water, concentrations of ionic ∑PFASs ranged from 1.6 to 118ng/L, with the Bohai Sea exhibiting higher concentrations than both the Yellow Sea and the Yangtze River estuary. Perfluorooctanoic acid (PFOA) was the predominant compound accounting for 51%-90% of the ionic ∑PFAS concentrations. Releases from industrial and domestic activities as well as the semiclosed geographical conditions increased the level of ionic ∑PFASs in the Bohai Sea. The spatial distributions of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) were different significantly. The Laizhou Bay was the major source region of PFCAs and the Yangtze River estuary was the major source of PFSAs. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of methods to estimate the essential amino acids requirements of fish from the muscle amino acid profile

Directory of Open Access Journals (Sweden)

Álvaro José de Almeida Bicudo

2014-03-01

Full Text Available Many methods to estimate amino acid requirement based on amino acid profile of fish have been proposed. This study evaluates the methodology proposed by Meyer & Fracalossi (2005 and by Tacon (1989 to estimate amino acids requirement of fish, which do exempt knowledge on previous nutritional requirement of reference amino acid. Data on amino acid requirement of pacu, Piaractus mesopotamicus, were used to validate de accuracy of those methods. Meyer & Fracalossi's and Tacon's methodology estimated the lysine requirement of pacu, respectively, at 13 and 23% above requirement determined using dose-response method. The values estimated by both methods lie within the range of requirements determined for other omnivorous fish species, the Meyer & Fracalossi (2005 method showing better accuracy.

Determination of ursolic acid and ursolic acid lactone in the leaves of Eucalyptus tereticornis by HPLC

International Nuclear Information System (INIS)

Maurya, Anupam; Srivastava, Santosh Kumar

2012-01-01

A simple isocratic HPLC method has been developed for the simultaneous quantification of two bioactive triterpenes, ursolic acid and ursolic acid lactone in E. tereticornis leaves. Samples were analyzed on RP-18 (4.6 x 250 mm, 5 m u m ) column with methanol and water acidified to pH 3.5 with TFA (88:12) at 210 nm. The method was validated and applied for the simultaneous quantification of the individual triterpenes in E. tereticornis extract. The calibration curves were linear over a concentration range of 0.05-0.3 mg mL -1 (r = 0.999 and 0.998, respectively). The limits of detection and quantification were 0.190 and 0.644 μg for ursolic acid, and 0.176 and 0.587 μg for ursolic acid lactone, while the percentage recoveries were 97.32 and 96.23% for ursolic acid and ursolic acid lactone, respectively. This is the first report on the HPLC method of ursolic acid lactone with high precision and accuracy. (author)

Determination of ursolic acid and ursolic acid lactone in the leaves of Eucalyptus tereticornis by HPLC

Energy Technology Data Exchange (ETDEWEB)

Maurya, Anupam; Srivastava, Santosh Kumar [Analytical Chemistry Division, Central Institute of Medicinal and Aromatic Plants, Lucknow (India)

2012-03-15

A simple isocratic HPLC method has been developed for the simultaneous quantification of two bioactive triterpenes, ursolic acid and ursolic acid lactone in E. tereticornis leaves. Samples were analyzed on RP-18 (4.6 x 250 mm, 5 {sup m}u{sup m}) column with methanol and water acidified to pH 3.5 with TFA (88:12) at 210 nm. The method was validated and applied for the simultaneous quantification of the individual triterpenes in E. tereticornis extract. The calibration curves were linear over a concentration range of 0.05-0.3 mg mL{sup -1} (r = 0.999 and 0.998, respectively). The limits of detection and quantification were 0.190 and 0.644 {mu}g for ursolic acid, and 0.176 and 0.587 {mu}g for ursolic acid lactone, while the percentage recoveries were 97.32 and 96.23% for ursolic acid and ursolic acid lactone, respectively. This is the first report on the HPLC method of ursolic acid lactone with high precision and accuracy. (author)

Magnetic Vinylphenyl Boronic Acid Microparticles for Surface Catalytic Performance in Esterification of Propionic Acid with Methanol

Directory of Open Access Journals (Sweden)

Ali Kara

2016-12-01

Full Text Available Magnetic vinylphenyl boronic acid microparticles, poly(ethylene glycol dimethacrylate-vinylphenyl boronic acid [m-poly(EGDMA-VPBA], produced by suspension polymerization, was found to be efficient solid acid catalyst for the esterification of methanol and propionic acid. Characterization techniques such as FT-IR, Elemental analyses, ICP-AES, ESR, SEM and N2 sorption showed that both of Fe3O4 and H2SO4 are bonded to the polymer successfully. Esterification was studied for different molar percentages of H2SO4 at temperature range of 50-70 oC. The apparent activation energy was found to be 27.7 kj.mol-1 for 10% H2SO4 doped m-poly(EGDMA-VPBA. Combining of strong acid H2SO4 with m-poly(EGDMA-VPBA, leads to materials with different functional properties. In addition, H2SO4 species could be introduced into the structure as acid centers, therefore this micro-dimensional catalyst has potential candidate for applications in the catalytic esterifications such as propionic acid with methanol.

Interplay of long-range and short-range Coulomb interactions in an Anderson-Mott insulator

Science.gov (United States)

Baćani, Mirko; Novak, Mario; Orbanić, Filip; Prša, Krunoslav; Kokanović, Ivan; Babić, Dinko

2017-07-01

In this paper, we tackle the complexity of coexisting disorder and Coulomb electron-electron interactions (CEEIs) in solids by addressing a strongly disordered system with intricate CEEIs and a screening that changes both with charge carrier doping level Q and temperature T . We report on an experimental comparative study of the T dependencies of the electrical conductivity σ and magnetic susceptibility χ of polyaniline pellets doped with dodecylbenzenesulfonic acid over a wide range. This material is special within the class of doped polyaniline by exhibiting in the electronic transport a crossover between a low-T variable range hopping (VRH) and a high-T nearest-neighbor hopping (NNH) well below room temperature. Moreover, there is evidence of a soft Coulomb gap ΔC in the disorder band, which implies the existence of a long-range CEEI. Simultaneously, there is an onsite CEEI manifested as a Hubbard gap U and originating in the electronic structure of doped polyaniline, which consists of localized electron states with dynamically varying occupancy. Therefore, our samples represent an Anderson-Mott insulator in which long-range and short-range CEEIs coexist. The main result of the study is the presence of a crossover between low- and high-T regimes not only in σ (T ) but also in χ (T ) , the crossover temperature T* being essentially the same for both observables over the entire doping range. The relatively large electron localization length along the polymer chains results in U being small, between 12 and 20 meV for the high and low Q , respectively. Therefore, the thermal energy at T* is sufficiently large to lead to an effective closing of the Hubbard gap and the consequent appearance of NNH in the electronic transport within the disorder band. ΔC is considerably larger than U , decreasing from 190 to 30 meV as Q increases, and plays the role of an activation energy in the NNH.

Organic acids in naturally colored surface waters

Science.gov (United States)

Lamar, William L.; Goerlitz, D.F.

1966-01-01

Most of the organic matter in naturally colored surface waters consists of a mixture of carboxylic acids or salts of these acids. Many of the acids color the water yellow to brown; however, not all of the acids are colored. These acids range from simple to complex, but predominantly they are nonvolatile polymeric carboxylic acids. The organic acids were recovered from the water by two techniques: continuous liquid-liquid extraction with n-butanol and vacuum evaporation at 50?C (centigrade). The isolated acids were studied by techniques of gas, paper, and column chromatography and infrared spectroscopy. About 10 percent of the acids recovered were volatile or could be made volatile for gas chromatographic analysis. Approximately 30 of these carboxylic acids were isolated, and 13 of them were individually identified. The predominant part of the total acids could not be made volatile for gas chromatographic analysis. Infrared examination of many column chromatographic fractions indicated that these nonvolatile substances are primarily polymeric hydroxy carboxylic acids having aromatic and olefinic unsaturation. The evidence suggests that some of these acids result from polymerization in aqueous solution. Elemental analysis of the sodium fusion products disclosed the absence of nitrogen, sulfur, and halogens.

Characterization of metal/humic acid systems by Capillary Electrophoresis

NARCIS (Netherlands)

Staden JJ van; Hoop MAGT van den; Cleven R; LAC

2000-01-01

Metal-humic acid systems have been characterised applying Capillary Electrophoresis (CE). Appropriate experimental conditions with respect to carrier electrolyte, pH range, salt concentration, humic acid concentration and the applied potential, have been optimised. The influence of multivalent metal

Succinic acid production by escherichia coli under anaerobic fermentation

International Nuclear Information System (INIS)

El Shafey, H.M.; Meleigy, S.A.

2009-01-01

The effect of alteration of growth conditions, addition of different sodium salts, and irradiation by gamma rays on succinic acid production by E. coli was studied. Twenty one isolates were obtained from buffalo's rumen, and anaerobic screening of the isolated bacterial strains showed the abilities of seventeen strains to produce succinic acid. The two bacterial strains having highest succinic acid production were identified as escherichia coli SP9 and SP16, and were selected for further studies. Results showed that growth conditions yielded highest succinic acid production for the two isolates were: 72 hours incubation, 37 degree c incubation temperature, initial ph of the fermentation medium 6.0,and 3% (v/v)inoculum size. Addition of 5 mm of nine different sodium salts to the fermentation medium showed stimulating effect on succinic acid production of the nine tried sodium salts, sodium carbonate was found to have the highest enhancing effect, especially if used at 15 mm concentration. Gamma irradiation doses tried were in the range of (0.25-1.50 kGy). An enhancing effect on succinic acid production was shown in the range of 0.25-0.75 kGy with a maximal production at 0.75 kGy (giving 8.36% increase) for e.coli SP9, and in the range of 0.25-1.00 kGy with a maximal production at 1.0 kGy (7.60% increase) for e.coli SP16. higher gamma doses led to a decrease in the enhancing effect. An overall increase in the succinic acid yield of 79.45% and 94.26% for e. coli SP9 and SP16, respectively, was achieved in implicating all optimized factors for succinic acid production in one time

Evaluation of perfluoroalkyl acid activity using primary mouse and human hepatocytes

International Nuclear Information System (INIS)

Rosen, Mitchell B.; Das, Kaberi P.; Wood, Carmen R.; Wolf, Cynthia J.; Abbott, Barbara D.; Lau, Christopher

2013-01-01

While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is known about the biological activity of other perfluoroalkyl acids (PFAAs) detected in the environment. Using a transient transfection assay developed in COS-1 cells, our group has previously evaluated a variety of PFAAs for activity associated with activation of peroxisome proliferator-activated receptor alpha (PPARα). Here we use primary heptatocytes to further assess the biological activity of a similar group of PFAAs using custom designed Taqman Low Density Arrays. Primary mouse and human hepatoyctes were cultured for 48 h in the presence of varying concentrations of 12 different PFAAs or Wy14,643, a known activator of PPARα. Total RNA was collected and the expression of 48 mouse or human genes evaluated. Gene selection was based on either in-house liver microarray data (mouse) or published data using primary hepatocytes (human). Gene expression in primary mouse hepatocytes was more restricted than expected. Genes typically regulated in whole tissue by PPARα agonists were not altered in mouse cells including Acox1, Me1, Acaa1a, Hmgcs1, and Slc27a1. Cyp2b10, a gene regulated by the constitutive androstane receptor and a transcript normally up-regulated by in vivo exposure to PFAAs, was also unchanged in cultured mouse hepatocytes. Cyp4a14, Ehhadh, Pdk4, Cpt1b, and Fabp1 were regulated as expected in mouse cells. A larger group of genes were differentially expressed in human primary hepatocytes, however, little consistency was observed across compounds with respect to which genes produced a significant dose response making the determination of relative biological activity difficult. This likely reflects weaker activation of PPARα in human versus rodent cells as well as variation among individual cell donors. Unlike mouse cells, CYP2B6 was up-regulated in human hepatocytes by a number of PFAAs as was PPARδ. Rankings were conducted on the limited

Regional and long-range transport of air pollution

International Nuclear Information System (INIS)

Sandroni, S.

1987-01-01

The Course lectures presented are organised in four sections: atmospheric transport, conversion, deposition of atmospheric trace constituents and associated problems; conventional and sophisticated techniques for atmospheric sounding (e.g., Sodar, Lidar, Cospec, tetroons, instrument-carrying aircraft) and simulation techniques (non-reactive tracers); models available for various applications (long-range episodes, long-term averages, photochemical and deposition processes); a comparison of performances of different models and the linearity problem in the formation of acid deposition

Cross-Sectional Associations of Serum Perfluoroalkyl Acids and Thyroid Hormones in U.S. Adults: Variation According to TPOAb and Iodine Status (NHANES 2007–2008)

Science.gov (United States)

Webster, Glenys M.; Rauch, Stephen A.; Marie, Nathalie Ste; Mattman, Andre; Lanphear, Bruce P.; Venners, Scott A.

2015-01-01

Background: Perfluoroalkyl acids (PFASs) are suspected thyroid toxicants, but results from epidemiological studies are inconsistent. Objectives: We examined associations between serum PFASs and thyroid hormones (THs) in a representative, cross-sectional sample of U.S. adults. We hypothesized that people with high thyroid peroxidase antibodies and low iodine would be more susceptible to PFAS-induced thyroid disruption. Methods: Our sample included 1,525 adults (≥ 18 years) from the 2007–2008 NHANES study with available serum PFASs and THs. We examined associations between four serum PFASs [perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctanoate (PFOA), and perfluorooctane sulfonate (PFOS)], and serum THs [free triiodothyronine (fT3), free thyroxine (fT4), fT3/fT4, thyroid-stimulating hormone (TSH), total T3 (TT3), and total T4 (TT4)] using multivariable linear regression. We stratified subjects into four groups by two indicators of thyroid “stress”: thyroid peroxidase antibody (TPOAb ≥ 9 IU/mL) and iodine status (PFAS–TH associations were not modified by high TPOAb or low iodine alone. However, PFHxS and PFOS were negatively associated (p PFAS-associated thyroid disruption in a subset of U.S. adults with high TPOAb (a marker of autoimmune hypothyroidism) and low iodine status, who may represent a vulnerable subgroup. However, the small sample size, cross-sectional design, and possibility of reverse causation are limitations of this work. Citation: Webster GM, Rauch SA, Ste Marie N, Mattman A, Lanphear BP, Venners SA. 2016. Cross-sectional associations of serum perfluoroalkyl acids and thyroid hormones in U.S. adults: variation according to TPOAb and iodine status (NHANES 2007–2008). Environ Health Perspect 124:935–942; http://dx.doi.org/10.1289/ehp.1409589 PMID:26517287

Dose-ranging pilot randomized trial of amino acid mixture combined with physical activity promotion for reducing abdominal fat in overweight adults

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Sasai H

2017-07-01

Full Text Available Hiroyuki Sasai,1–3,* Keisuke Ueda,4,5,* Takehiko Tsujimoto,6,7 Hiroyuki Kobayashi,1 Chiaki Sanbongi,4 Shuji Ikegami,4 Yoshio Nakata1 1Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, 2Japan Society for the Promotion of Science, Chiyoda, Tokyo, 3Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, 4Food Science Research Laboratories, Meiji Co., Ltd., Odawara, Kanagawa, 5Graduate School of Comprehensive Human Sciences, 6Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, 7Faculty of Human Sciences, Shimane University, Matsue, Shimane, Japan *These authors contributed equally to this work Objective: The objective of this study was to determine the effective dose of an amino acid mixture comprising arginine, alanine, and phenylalanine combined with physical activity promotion in reducing abdominal fat among overweight adults.Methods: A 12-week randomized, double-blind, placebo-controlled, dose-ranging, pilot trial was conducted in Mito, Japan, from January through April 2016, and the data were analyzed from May through November 2016. The study participants were 35 overweight adults, aged 20–64 years, with no regular exercise habit. Participants were randomly assigned to high-dose (3,000 mg/d, n=9, medium-dose (1,500 mg/d, n=9, low-dose (750 mg/d, n=8, or placebo (0 mg/d, n=9 groups, and the test beverage containing the amino acid mixture or placebo was administered for 12 weeks. All participants maintained a physically active lifestyle during the study period through monthly physical activity promotion sessions and smartphone-based self-monitoring with wearable trackers. Primary outcomes were changes in abdominal total, subcutaneous, and visceral fat areas, assessed by computed tomography.Results: Of the 35 enrolled participants, 32 completed the 12-week follow-up visit. The intention-to-treat analysis revealed that the changes in abdominal total fat

Aerosol volatility and enthalpy of sublimation of carboxylic acids.

Science.gov (United States)

Salo, Kent; Jonsson, Asa M; Andersson, Patrik U; Hallquist, Mattias

2010-04-08

The enthalpy of sublimation has been determined for nine carboxylic acids, two cyclic (pinonic and pinic acid) and seven straight-chain dicarboxylic acids (C(4) to C(10)). The enthalpy of sublimation was determined from volatility measurements of nano aerosol particles using a volatility tandem differential mobility analyzer (VTDMA) set-up. Compared to the previous use of a VTDMA, this novel method gives enthalpy of sublimation determined over an extended temperature range (DeltaT approximately 40 K). The determined enthalpy of sublimation for the straight-chain dicarboxylic acids ranged from 96 to 161 kJ mol(-1), and the calculated vapor pressures at 298 K are in the range of 10(-6)-10(-3) Pa. These values indicate that dicarboxylic acids can take part in gas-to-particle partitioning at ambient conditions and may contribute to atmospheric nucleation, even though homogeneous nucleation is unlikely. To obtain consistent results, some experimental complications in producing nanosized crystalline aerosol particles were addressed. It was demonstrated that pinonic acid "used as received" needed a further purification step before being suspended as a nanoparticle aerosol. Furthermore, it was noted from distinct differences in thermal properties that aerosols generated from pimelic acid solutions gave two types of particles. These two types were attributed to crystalline and amorphous configurations, and based on measured thermal properties, the enthalpy of vaporization was 127 kJ mol(-1) and that of sublimation was 161 kJ mol(-1). This paper describes a new method that is complementary to other similar methods and provides an extension of existing experimental data on physical properties of atmospherically relevant compounds.

Interactions between cadmium and lead with acidic soils: Experimental evidence of similar adsorption patterns for a wide range of metal concentrations and the implications of metal migration

International Nuclear Information System (INIS)

Pokrovsky, O.S.; Probst, A.; Leviel, E.; Liao, B.

2012-01-01

Highlights: ► Adsorption experiments of Cd and Pb in acid soils (China, France). ► Large pH conditions and large range of metal concentrations were considered. ► Similar dependencies between metals concentration in solution and metal adsorbed on the surface were predicted using Langmuir and Freundlich equations and surface complexation model (SCM). ► No competition between Cd and Pb detected at pH 5. ► Metal adsorption capacity is two orders of magnitude higher than limit value for soil protection. - Abstract: The importance of high- and low-affinity surface sites for cadmium and lead adsorption in typical European and Asian soils was investigated. Adsorption experiments on surface and deep horizons of acidic brown (Vosges, France) and red loess soils (Hunan, China) were performed at 25 °C as a function of the pH (3.5–8) and a large range of metal concentrations in solution (10 −9 –10 −4 mol l −1 ). We studied the adsorption kinetics using a Cd 2+ -selective electrode and desorption experiments as a function of the solid/solution ratio and pH. At a constant solution pH, all samples exhibited similar maximal adsorption capacities (4.0 ± 0.5 μmol/g Cd and 20 ± 2 μmol/g Pb). A constant slope of adsorbed–dissolved concentration dependence was valid over 5 orders of magnitude of metal concentrations. Universal Langmuir and Freundlich equations and the SCM formalism described the adsorption isotherms and the pH-dependent adsorption edge over very broad ranges of metal concentrations, indicating no high- or low-affinity sites for metal binding at the soil surface under these experimental conditions. At pH 5, Cd and Pb did not compete, in accordance with the SCM. The metal adsorption ability exceeded the value for soil protection by two orders of magnitude, but only critical load guarantees soil protection since metal toxicity depends on metal availability.

Relationship between fatty acid composition and biodiesel quality for nine commercial palm oils

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Chanida Lamaisri

2015-08-01

Full Text Available Biodiesel is an alternative fuel consisting of alkyl esters of fatty acids from vegetable oils or animal fats. The fatty acid compositions in the oils used as feedstock can influence quality of the biodiesel. In the present study, oil content and fatty acid composition of mesocarp and kernel oil were examined from nine commercial oil palm Elaeis guineensis cultivars. Saponification number, iodine value and cetane number were calculated from palm oil fatty acid methyl ester compositions. Fruits of tenera oil palm were collected from a farmer’s plantation in Dan Makham Tia District, Kanchanaburi Province in 2009. Variation between cultivars was observed in oil content and fatty acid profile of mesocarp oil rather than kernel oil. The percentage of oil in dry mesocarp ranged from 63.8% to 74.9%. The mesocarp oil composed of 41.5 - 51.6% palmitic acid, 3.58-7.10% stearic acid, 32.8-42.5% oleic acid and 9.3-13.0% linoleic acid. Likewise saponification number, iodine value and cetane number of mesocarp oil fatty acid methyl ester showed more variation among cultivars, ranging from 196.5-198.9, 45.7-54.6 and 61.8-63.6, respectively. While those of kernel oil fatty acid methyl ester showed no different among cultivars, ranging from 229-242, 13.6-16.4 and 65.3-66.5, respectively. The cetane number of fatty acid methyl ester positively correlated with contents of myristic, palmitic and stearic acids in palm oil and saponification number of biodiesel, but negatively correlated with iodine value

Role of long- and short-range hydrophobic, hydrophilic and charged residues contact network in protein’s structural organization

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Sengupta Dhriti

2012-06-01

Full Text Available Abstract Background The three-dimensional structure of a protein can be described as a graph where nodes represent residues and the strength of non-covalent interactions between them are edges. These protein contact networks can be separated into long and short-range interactions networks depending on the positions of amino acids in primary structure. Long-range interactions play a distinct role in determining the tertiary structure of a protein while short-range interactions could largely contribute to the secondary structure formations. In addition, physico chemical properties and the linear arrangement of amino acids of the primary structure of a protein determines its three dimensional structure. Here, we present an extensive analysis of protein contact subnetworks based on the London van der Waals interactions of amino acids at different length scales. We further subdivided those networks in hydrophobic, hydrophilic and charged residues networks and have tried to correlate their influence in the overall topology and organization of a protein. Results The largest connected component (LCC of long (LRN-, short (SRN- and all-range (ARN networks within proteins exhibit a transition behaviour when plotted against different interaction strengths of edges among amino acid nodes. While short-range networks having chain like structures exhibit highly cooperative transition; long- and all-range networks, which are more similar to each other, have non-chain like structures and show less cooperativity. Further, the hydrophobic residues subnetworks in long- and all-range networks have similar transition behaviours with all residues all-range networks, but the hydrophilic and charged residues networks don’t. While the nature of transitions of LCC’s sizes is same in SRNs for thermophiles and mesophiles, there exists a clear difference in LRNs. The presence of larger size of interconnected long-range interactions in thermophiles than mesophiles, even at

Novel alpha-hydroxy phosphonic acids via castor oil

Science.gov (United States)

Hydroxy fatty acids (HFAs) have found a number of uses in today’s market, with uses ranging from materials to pharmaceuticals. Castor oil has served as a versatile HFA; its principle component, ricinoleic acid, can be isolated from castor oil and has been modified extensively for a number of applica...

Interaction of humic acids and humic-acid-like polymers with herpes simplex virus type 1

Science.gov (United States)

Klöcking, Renate; Helbig, Björn

The study was performed in order to compare the antiviral activity against herpes simplex virus type 1 (HSV-1) of synthetic humic-acid-like polymers to that of their low-molecular-weight basic compounds and naturally occurring humic acids (HA) in vitro. HA from peat water showed a moderate antiviral activity at a minimum effective concentration (MEC) of 20 µg/ml. HA-like polymers, i.e. the oxidation products of caffeic acid (KOP), hydrocaffeic acid (HYKOP), chlorogenic acid (CHOP), 3,4-dihydroxyphenylacetic acid (3,4-DHPOP), nordihydroguaretic acid (NOROP), gentisinic acid (GENOP), pyrogallol (PYROP) and gallic acid (GALOP), generally inhibit virus multiplication, although with different potency and selectivity. Of the substances tested, GENOP, KOP, 3,4-DHPOP and HYKOP with MEC values in the range of 2 to 10 µg/ml, proved to be the most potent HSV-1 inhibitors. Despite its lower antiviral potency (MEC 40 µg/ml), CHOP has a remarkable selectivity due to the high concentration of this polymer that is tolerated by the host cells (>640 µg/ml). As a rule, the antiviral activity of the synthetic compounds was restricted to the polymers and was not preformed in the low-molecular-weight basic compounds. This finding speaks in favour of the formation of antivirally active structures during the oxidative polymerization of phenolic compounds and, indirectly, of corresponding structural parts in different HA-type substances.

SYNTHESIS OF FATTY ACID ETHYL ESTER FROM CHICKEN FAT ...

African Journals Online (AJOL)

eobe

synthesis of fatty acid ethyl ester from chicken fat waste using ZnO/SiO fatty acid ethyl ester ... obtained in the range of 56−88%and a second order quadratic polynomial regression model that established the ... Transesterification is a chemical.

Longitudinal acoustic properties of poly(lactic acid) and poly(lactic-co-glycolic acid)

International Nuclear Information System (INIS)

Parker, N G; Povey, M J W; Mather, M L; Morgan, S P

2010-01-01

Acoustics offers rich possibilities for characterizing and monitoring the biopolymer structures being employed in the field of biomedical engineering. Here we explore the rudimentary acoustic properties of two common biodegradable polymers: poly(lactic acid) and poly(lactic-co-glycolic acid). A pulse-echo technique is developed to reveal the bulk speed of sound, acoustic impedance and acoustic attenuation of small samples of the polymer across a pertinent temperature range of 0-70 0 C. The glass transition appears markedly as both a discontinuity in the first derivative of the speed of sound and a sharp increase in the acoustic attenuation. We further extend our analysis to consider the role of ethanol, whose presence is observed to dramatically modify the acoustic properties and reduce the glass transition temperature of the polymers. Our results highlight the sensitivity of acoustic properties to a range of bulk properties, including visco-elasticity, molecular weight, co-polymer ratio, crystallinity and the presence of plasticizers.

Thermal decomposition of the amino acids glycine, cysteine, aspartic acid, asparagine, glutamic acid, glutamine, arginine and histidine.

Science.gov (United States)

Weiss, Ingrid M; Muth, Christina; Drumm, Robert; Kirchner, Helmut O K

2018-01-01

The pathways of thermal instability of amino acids have been unknown. New mass spectrometric data allow unequivocal quantitative identification of the decomposition products. Calorimetry, thermogravimetry and mass spectrometry were used to follow the thermal decomposition of the eight amino acids G, C, D, N, E, Q, R and H between 185 °C and 280 °C. Endothermic heats of decomposition between 72 and 151 kJ/mol are needed to form 12 to 70% volatile products. This process is neither melting nor sublimation. With exception of cysteine they emit mainly H 2 O, some NH 3 and no CO 2 . Cysteine produces CO 2 and little else. The reactions are described by polynomials, AA→ a NH 3 + b H 2 O+ c CO 2 + d H 2 S+ e residue, with integer or half integer coefficients. The solid monomolecular residues are rich in peptide bonds. Eight of the 20 standard amino acids decompose at well-defined, characteristic temperatures, in contrast to commonly accepted knowledge. Products of decomposition are simple. The novel quantitative results emphasize the impact of water and cyclic condensates with peptide bonds and put constraints on hypotheses of the origin, state and stability of amino acids in the range between 200 °C and 300 °C.

Trends of perfluorochemicals in Greenland ringed seals and polar bears: indications of shifts to decreasing trends.

Science.gov (United States)

Rigét, Frank; Bossi, Rossana; Sonne, Christian; Vorkamp, Katrin; Dietz, Rune

2013-11-01

Time-series of perfluorinated alkylated substances (PFASs) in East Greenland polar bears and East and West Greenland ringed seals were updated in order to deduce whether a response to the major reduction in perfluoroalkyl production in the early 2000s had occurred. Previous studies had documented an exponential increase of perfluorooctane sulphonate (PFOS) in liver tissue from both species. In the present study, PFOS was still the far most dominant compound constituting 92% (West Greenland ringed seals), 88% (East Greenland ringed seals) and 85% (East Greenland polar bears). The PFOS concentrations increased up to 2006 with doubling times of approximately 6 years for the ringed seal populations and 14 years in case of polar bears. Since then a rapid decrease has occurred with clearing half-lives of approximately 1, 2 and 4 years, respectively. In polar bears perfluorohexane sulphonate (PFHxS) and perfluorooctane sulphonamide (PFOSA) also showed decreasing trends in recent years as do perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA). For the West Greenland ringed seal population perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), PFDA and PFUnA peaked in the mid 2000s, whereas PFNA, PFDA and PFUnA in the East Greenland population have been stable or increasing in recent years. The peak of PFASs in Greenland ringed seals and polar bears occurred at a later time than in Canadian seals and polar bears and considerably later than observed in seal species from more southern latitudes. We suggest that this could be explained by the distance to emission hot-spots and differences in long-range transport to the Arctic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Electrolytes for methanol-air fuel cells. I. The performance of methanol electro-oxidation catalysts in sulphuric acid and phosphoric acid electrolytes

Energy Technology Data Exchange (ETDEWEB)

Andrew, M.R.; McNicol, B.D.; Short, R.T.; Drury, J.S.

1977-03-01

Phosphoric acid and sulphuric acid have been compared as potential electrolytes for methanol-air fuel cells. The performances of typical electro-oxidation catalysts were measured in both electrolytes over a range of concentrations. With all catalysts the activity falls with increasing acid concentration. While this is to some extent due to the decrease in water activity at higher concentrations it seems that with both acids there is significant poisoning of the catalyst. The results can be explained for both electrolytes by assuming that adsorption of undissociated acid poisons the catalyst surfaces and that the reaction rate on the poisoned surfaces is proportional to the water activity.

Nitric acid adduct formation during crystallization of barium and strontium nitrates and their co-precipitation from nitric acid media

International Nuclear Information System (INIS)

Mishina, N.E.; Zilberman, B.Ya.; Lumpov, A.A.; Koltsova, T.I.; Puzikov, E.A.; Ryabkov, D.V.

2015-01-01

The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate concentration is presented and described by the mass action law, indicating on formation of the adducts with nitric acid. Precipitates of Ba(NO 3 ) 2 and Sr(NO 3 ) 2 crystallized from nitric acid were studied by ISP OES and IR spectroscopy. The data obtained confirmed formation of metastable adducts with nitric acid. IR and X-ray diffraction studies of the mixed salt systems indicated conversion of the mixed salts into (Ba,Sr)(NO 3 ) 2 solid solution of discrete structure in range of total nitrate ion concentration ∼6 mol/L. (author)

Thermal stability of L-ascorbic acid and ascorbic acid oxidase in broccoli (Brassica oleracea var. italica).

Science.gov (United States)

Munyaka, Ann Wambui; Makule, Edna Edward; Oey, Indrawati; Van Loey, Ann; Hendrickx, Marc

2010-05-01

The thermal stability of vitamin C (including l-ascorbic acid [l-AA] and dehydroascorbic acid [DHAA]) in crushed broccoli was evaluated in the temperature range of 30 to 90 degrees C whereas that of ascorbic acid oxidase (AAO) was evaluated in the temperature range of 20 to 95 degrees C. Thermal treatments (for 15 min) of crushed broccoli at 30 to 60 degrees C resulted in conversion of l-AA to DHAA whereas treatments at 70 to 90 degrees C retained vitamin C as l-AA. These observations indicated that enzymes (for example, AAO) could play a major role in the initial phase (that is, oxidation of l-AA to DHAA) of vitamin C degradation in broccoli. Consequently, a study to evaluate the temperature-time conditions that could result in AAO inactivation in broccoli was carried out. In this study, higher AAO activity was observed in broccoli florets than stalks. During thermal treatments for 10 min, AAO in broccoli florets and stalks was stable until around 50 degrees C. A 10-min thermal treatment at 80 degrees C almost completely inactivated AAO in broccoli. AAO inactivation followed 1st order kinetics in the temperature range of 55 to 65 degrees C. Based on this study, a thermal treatment above 70 degrees C is recommended for crushed vegetable products to prevent oxidation of l-AA to DHAA, the onset of vitamin C degradation. The results reported in this study are applicable for both domestic and industrial processing of vegetables into products such as juices, soups, and purees. In this report, we have demonstrated that processing crushed broccoli in a temperature range of 30 to 60 degrees C could result in the conversion of l-ascorbic acid to dehydroascorbic (DHAA), a very important reaction in regard to vitamin C degradation because DHAA could be easily converted to other compounds that do not have the biological activity of vitamin C.

Occurrence and Determination of Haloacetic Acids in Metro Manila Drinking Water

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Irene B. Rodriguez

2009-12-01

Full Text Available Haloacetic acids are found in chlorinated water with high organic matter content. An analytical method based on a US EPA method for measuring these compounds in water is described. The optimized method used diethyl ether as extraction solvent with sulphuric acid-methanol as esterification agent and subsequent detection by gas chromatography-electron capture detection. Evaluation of this method showed that it was linear in the concentration range of 10 to 150 µg L-1 and the method detection limits were from 17 to 57 µg L-1. Although the method demonstrated low recoveries (16 to 43%, it is useful in the quantitative determination of monochloroacetic acid as well as the qualitative determination of other haloacetic acids in water. Drinking water samples taken from different areas in Metro Manila serviced by the local treatment plants were analysed using the method. Monochloroacetic acid, monobromoacetic acid, and bromochloroacetic acid were detected in these samples. Monochloroacetic acid was quantified and found in concentrations ranging from 19 to 157 µg L-1. In most of the water samples, the concentration of monochloroacetic acid exceeded the US EPA maximum allowable total concentration of 60 µg L-1 for the five haloacetic acids (monochloro-, dichloro-, trichloro-, monobromo-, and dibromoacetic acids in drinking water. This initial study established the occurrence of potentially harmful haloacetic acids in the local drinking water supplies.

HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHIC DETERMINATION OF CAFFEIC ACID AND ROSMARINIC ACID FROM THE LEAVES OF Orthosiphon stamineus

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M. Amzad Hossain

2010-06-01

Full Text Available This paper presents the studies performed on extraction of Orthosiphon stamineus, Benth by using different solvent for the identification and quantification of the caffeic acid derivatives such as caffeic acid  and rosmarinic acid which confers to the leaves of this plant with remarkable pharmaceutical properties. High performance thin-layer chromatographic (HPTLC allows the identification and the quantification of more than 20 samples in the same chromatographic run. The analysis of the samples requires 15-30 min compared with more than 2 h using a typical HPLC method. Using the techniques of the HPTLC and the UV-VIS spectra we have found that the extraction of this herb plant contain, the caffeic acid and rosmarinic acid ranging between 0.029% up to 0.506% and up to 0.24% to 2.24% respectively.     Keywords: Caffice acid derivatives, quantification, Malaysian Orthosiphon stamineus, HPTLC

Fatty acid biosynthesis VII. Substrate control of chain-length of products synthesised by rat liver fatty acid synthetase

DEFF Research Database (Denmark)

Hansen, Heinz Johs. Max; Carey, E.M.; Dils, R.

1970-01-01

- 1. Gas-liquid and paper chromatography have been used to determine the chain-lengths of fatty acids synthesised by purified rat liver fatty acid synthetase from [1-14C]acetyl-CoA, [1,3-14C2]malonyl-CoA and from [1-14C]acetyl-CoA plus partially purified rat liver acetyl-CoA carboxylase. - 2....... A wide range (C4:0–C18:0) of fatty acids was synthesised and the proportions were modified by substrate concentrations in the same manner as for purified rabbit mammary gland fatty acid synthetase. - 3. The relative amount of radioactivity incorporated from added acetyl-CoA and malonyl-CoA depended...... of long-chain fatty acids was synthesised from carboxylated acetyl-CoA than from added malonyl-CoA. - 5. It is suggested that acetyl-CoA carboxylase may carboxylate acetate bound to fatty acid synthetase....

Acidic deposition along the Appalachian Trail corridor and its effects on acid-sensitive terrestrial and aquatic resources

Science.gov (United States)

Lawrence, Gregory B.; Sullivan, Timothy J.; Burns, Douglas A.; Bailey, Scott W.; Cosby, Bernard J.; Dovciak, Martin; Ewing, Holly A.; McDonnell, Todd C.; Minocha, Rakesh; Riemann, Rachel; Quant, Juliana; Rice, Karen C.; Siemion, Jason; Weathers, Kathleen C.

2015-01-01

The Appalachian National Scenic Trail (AT), a unit of the National Park Service (NPS), spans nearly 2,200 miles from Georgia to Maine, encompassing a diverse range of ecosystems. Acidic deposition (acid rain) threatens the AT’s natural resources. Acid rain is a result of sulfur (S) and nitrogen (N) compounds produced from fossil fuel combustion, motor vehicles, and agricultural practices. The AT is particularly vulnerable to S and N because it passes along ridgetops that receive higher levels of acid rain than lower valley terrain, and these ridges are often underlain by bedrock with minimal ability to buffer acidic inputs. Further, there are numerous S and N emission sources across the region. In the environment, acidic deposition can lower the pH of streams and soils which can ultimately affect fish, invertebrates, and vegetation that inhabit these areas. To address this concern, the MegaTransect Deposition Effects Study evaluated the condition and sensitivity of the AT corridor with respect to acidic deposition, and defined air pollution thresholds (critical and target loads) and recovery rates. Findings indicate that additional S emission

Decarboxylative Trifluoromethylation of Aliphatic Carboxylic Acids.

Science.gov (United States)

Kautzky, Jacob A; Wang, Tao; Evans, Ryan W; MacMillan, David W C

2018-05-14

Herein we disclose an efficient method for the conversion of carboxylic acids to trifluoromethyl groups via the combination of photoredox and copper catalysis. This transformation tolerates a wide range of functionality including heterocycles, olefins, alcohols, and strained ring systems. To demonstrate the broad potential of this new methodology for late-stage functionalization, we successfully converted a diverse array of carboxylic acid-bearing natural products and medicinal agents to the corresponding trifluoromethyl analogues.

Synthesis, biological distribution and radiation dosimetry of Te-123m analogues of hexadecenoic acid

International Nuclear Information System (INIS)

Basmadjian, G.P.; Ice, R.D.; Mills, S.L.

1982-01-01

The synthesis and biological distribution of four Te-123m analogues of hexadecenoic acid in rats, rabbits and dogs were described for use as possible myocardial imaging agents. The heart-to-blood ratios ranged from 0.13 for 3-telluranonadecenoic acid in rats at 5 mins to 6.25 for 18-methyl-17-tellura-9-nonadecenoic acid in dogs at 24 hrs. The biological half-life of the Te-123m labelled fatty acids ranged from 26 to 583 hrs in the hearts of the test animals. These Te-123m fatty acids were retained in the heart longer than radioiodinated fatty acids and have acceptable absorbed doses to the various target organs. (U.K.)

The transfer of alkanoic acids from dodecane to water

International Nuclear Information System (INIS)

Sagert, N.H.; Quinn, M.J.; Dixon, R.S.

1981-01-01

A rotating diffusion cell was used to study the transfer of five alkanoic acids from dodecane to water under conditions of known interfacial area and hydrodynamics. hd The acids studied were acetic, butanoic, hexanoic, 2-methylbutanoic and 2,2-dimethylpropanoic acids. Small interfacial resistances to mass transfer were noted, the mass transfer coefficients for interfacial transfer being in the range 2.6 to 4.7 μm/s at 25 0 C. This small range means that the effects of the length and structure of the alkane chain on the resistance to mass transfer are minimal. A study of the temperature dependence of the resistance to mass transfer at the interface showed that the resistance is largely entropic rather than enthalpic. (author)

Perfluorinated compounds in infiltrated river rhine water and infiltrated rainwater in coastal dunes.

Science.gov (United States)

Eschauzier, Christian; Haftka, Joris; Stuyfzand, Pieter J; de Voogt, Pim

2010-10-01

Different studies have shown that surface waters contain perfluorinated compounds (PFCs) in the low ng/L range. Surface waters are used to produce drinking water and PFCs have been shown to travel through the purification system and form a potential threat to human health. The specific physicochemical properties of PFCs cause them to be persistent and some of them to be bioaccumulative and toxic in the environment. This study investigates the evolvement of PFC concentrations in Rhine water and rainwater during dune water infiltration processes over a transect in the dune area of the western part of The Netherlands. The difference between infiltrated river water and rainwater in terms of PFC composition was investigated. Furthermore, isomer profiles were investigated. The compound perfluorobutanesulfonate (PFBS) was found at the highest concentrations of all PFCs investigated, up to 37 ng/L in infiltrated river water (71 ± 13% of ΣPFCs). This is in contrast with the predominant occurrence of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) reported in literature. The concentrations of PFBS found in infiltrated river Rhine water were significantly higher than those in infiltrated rainwater. For perfluorohexanesulfonate (PFHxS) the opposite was found: infiltrated rainwater contained more than infiltrated river water. The concentrations of PFOA, perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), PFBS, PFOS, and PFHxS in infiltrated river water showed an increasing trend with decreasing age of the water. The relative contribution of the branched PFOA and PFOS isomers to total concentrations of PFOA and PFOS showed a decreasing trend with decreasing age of the water.

Markers of anthropogenic contamination: A validated method for quantification of pharmaceuticals, illicit drug metabolites, perfluorinated compounds, and plasticisers in sewage treatment effluent and rain runoff.

Science.gov (United States)

Wilkinson, John L; Swinden, Julian; Hooda, Peter S; Barker, James; Barton, Stephen

2016-09-01

An effective, specific and accurate method is presented for the quantification of 13 markers of anthropogenic contaminants in water using solid phase extraction (SPE) followed by high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Validation was conducted according to the International Conference on Harmonisation (ICH) guidelines. Method recoveries ranged from 77 to 114% and limits of quantification between 0.75 and 4.91 ng/L. A study was undertaken to quantify the concentrations and loadings of the selected contaminants in 6 sewage treatment works (STW) effluent discharges as well as concentrations in 5 rain-driven street runoffs and field drainages. Detection frequencies in STW effluent ranged from 25% (ethinylestradiol) to 100% (benzoylecgonine, bisphenol-A (BPA), bisphenol-S (BPS) and diclofenac). Average concentrations of detected compounds in STW effluents ranged from 3.62 ng/L (ethinylestradiol) to 210 ng/L (BPA). Levels of perfluorinated compounds (PFCs) perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) as well as the plasticiser BPA were found in street runoff at maximum levels of 1160 ng/L, 647 ng/L and 2405 ng/L respectively (8.52, 3.09 and 2.7 times more concentrated than maximum levels in STW effluents respectively). Rain-driven street runoff may have an effect on levels of PFCs and plasticisers in receiving rivers and should be further investigated. Together, this method with the 13 selected contaminants enables the quantification of various markers of anthropogenic pollutants: inter alia pharmaceuticals, illicit drugs and their metabolites from humans and improper disposal of drugs, while the plasticisers and perfluorinated compounds may also indicate contamination from industrial and transport activity (street runoff). Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

Science.gov (United States)

Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

2002-11-01

The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

Extraterrestrial Amino Acids Identified in Metal-Rich CH and CB Carbonaceous Chondrites from Antarctica

Science.gov (United States)

Burton, Aaron S.; Elsila, Jamie E.; Hein, Jason E.; Glavin, Daniel P.; Dworkin, Jason P.

2013-01-01

Carbonaceous chondrites contain numerous indigenous organic compounds and could have been an important source of prebiotic compounds required for the origin of life on Earth or elsewhere. Extraterrestrial amino acids have been reported in five of the eight groups of carbonaceous chondrites and are most abundant in CI, CM, and CR chondritesbut are also present in the more thermally altered CV and CO chondrites. We report the abundance, distribution, and enantiomeric and isotopic compositions of simple primary amino acids in six metal-rich CH and CB carbonaceous chondrites that have not previously been investigated for amino acids: Allan Hills (ALH) 85085 (CH3), Pecora Escarpment(PCA) 91467 (CH3), Patuxent Range (PAT) 91546 (CH3), MacAlpine Hills (MAC) 02675(CBb), Miller Range (MIL) 05082 (CB), and Miller Range (MIL) 07411 (CB). Amino acid abundances and carbon isotopic values were obtained by using both liquid chromatography time-of-flight mass spectrometry and fluorescence, and gas chromatography isotope ratiomass spectrometry. The (delta D, delta C-13, delta N-15) ratios of multiple amino acids fall outside of the terrestrial range and support their extraterrestrial origin. Extracts of CH chondrites were found to be particularly rich in amino acids (1316 parts per million, ppm) while CB chondrite extracts had much lower abundances (0.22 ppm). The amino acid distributions of the CH and CB chondrites were distinct from the distributions observed in type 2 and 3 CM and CR chondrites and contained elevated levels of beta-, gamma-, and delta-amino acids compared to the corresponding alpha-amino acids, providing evidence that multiple amino acid formation mechanisms were important in CH and CB chondrites.

Why is hydrofluoric acid a weak acid?

Science.gov (United States)

Ayotte, Patrick; Hébert, Martin; Marchand, Patrick

2005-11-08

The infrared vibrational spectra of amorphous solid water thin films doped with HF at 40 K reveal a strong continuous absorbance in the 1000-3275 cm(-1) range. This so-called Zundel continuum is the spectroscopic hallmark for aqueous protons. The extensive ionic dissociation of HF at such low temperature suggests that the reaction enthalpy remains negative down to 40 K. These observations support the interpretation that dilute HF aqueous solutions behave as weak acids largely due to the large positive reaction entropy resulting from the structure making character of the hydrated fluoride ion.

Levels of uric acid in erectile dysfunction of different aetiology.

Science.gov (United States)

Barassi, Alessandra; Corsi Romanelli, Massimiliano Marco; Pezzilli, Raffaele; Dozio, Elena; Damele, Clara Anna Linda; Vaccalluzzo, Liborio; Di Dario, Marco; Goi, Giancarlo; Papini, Nadia; Massaccesi, Luca; Colpi, Giovanni Maria; Melzi d'Eril, Gian Vico

2018-01-12

Erectile dysfunction is a common disease characterized by endothelial dysfunction. The aetiology of ED is often multifactorial but evidence is being accumulated in favor of the proper function of the vascular endothelium that is essential to achieving and maintaining penile erection. Uric acid itself causes endothelial dysfunction via decreased nitric oxide production. This study aims to evaluate the serum uric acid (SUA) levels in 180 ED patients, diagnosed with the International Index of Erectile Function-5 (IIEF-5) and 30 non-ED control. Serum uric acid was analyzed with a commercially available kit using ModularEVO (Roche, Monza, Italy). Within-assay and between-assay variations were 3.0% and 6.0%, respectively. Out of the ED patients, 85 were classified as arteriogenic (A-ED) and 95 as non-arteriogenic (NA-ED) with penile-echo-color-Doppler. Uric acid levels (median and range in mg/dL) in A-ED patients (5.8, 4.3-7.5) were significantly higher (p uric acid levels in patients with mild A-ED (IIEF-5 16-20) and severe/complete A-ED (IIEF-5 ≤ 10) that were 5.4 (range 4.3-6.5) mg/dL and 6.8 (range 6.4-7.2) mg/dL, respectively. There was no difference between the levels of uric acid in patients with different degree of NA-ED. Our findings reveal that SUA is a marker of ED but only of ED of arteriogenic aetiology.

Molecularly imprinted titania nanoparticles for selective recognition and assay of uric acid

Science.gov (United States)

Mujahid, Adnan; Khan, Aimen Idrees; Afzal, Adeel; Hussain, Tajamal; Raza, Muhammad Hamid; Shah, Asma Tufail; uz Zaman, Waheed

2015-06-01

Molecularly imprinted titania nanoparticles are su ccessfully synthesized by sol-gel method for the selective recognition of uric acid. Atomic force microscopy is used to study the morphology of uric acid imprinted titania nanoparticles with diameter in the range of 100-150 nm. Scanning electron microscopy images of thick titania layer indicate the formation of fine network of titania nanoparticles with uniform distribution. Molecular imprinting of uric acid as well as its subsequent washing is confirmed by Fourier transformation infrared spectroscopy measurements. Uric acid rebinding studies reveal the recognition capability of imprinted particles in the range of 0.01-0.095 mmol, which is applicable in monitoring normal to elevated levels of uric acid in human blood. The optical shift (signal) of imprinted particles is six times higher in comparison with non-imprinted particles for the same concentration of uric acid. Imprinted titania particles have shown substantially reduced binding affinity toward interfering and structurally related substances, e.g. ascorbic acid and guanine. These results suggest the possible application of titania nanoparticles in uric acid recognition and quantification in blood serum.

CCN activation experiments with adipic acid: effect of particle phase and adipic acid coatings on soluble and insoluble particles

Directory of Open Access Journals (Sweden)

S. S. Hings

2008-07-01

Full Text Available Slightly soluble atmospherically relevant organic compounds may influence particle CCN activity and therefore cloud formation. Adipic acid is a frequently employed surrogate for such slightly soluble organic materials. The 11 published experimental studies on the CCN activity of adipic acid particles are not consistent with each other nor do they, in most cases, agree with the Köhler theory. The CCN activity of adipic acid aerosol particles was studied over a significantly wider range of conditions than in any previous single study. The work spans the conditions of the previous studies and also provides alternate methods for producing "wet" (deliquesced solution droplets and dry adipic acid particles without the need to produce them by atomization of aqueous solutions. The experiments suggest that the scatter in the previously published CCN measurements is most likely due to the difficulty of producing uncontaminated adipic acid particles by atomization of solutions and possibly also due to uncertainties in the calibration of the instruments. The CCN activation of the small (d_m<150 nm initially dry particles is subject to a deliquescence barrier, while for the larger particles the activation follows the Köhler curve. Wet adipic acid particles follow the Köhler curve over the full range of particle diameters studied. In addition, the effect of adipic acid coatings on the CCN activity of both soluble and insoluble particles has also been studied. When a water-soluble core is coated by adipic acid, the CCN-hindering effect of particle phase is eliminated. An adipic acid coating on hydrophobic soot yields a CCN active particle. If the soot particle is relatively small (d_core≤102 nm, the CCN activity of the coated particles approaches the deliquescence line of adipic acid, suggesting that the total size of the particle determines CCN activation and the soot core acts as a scaffold.

Tissue uptake, distribution and elimination of {sup 14}C-PFOA in zebrafish (Danio rerio)

Energy Technology Data Exchange (ETDEWEB)

Ulhaq, Mazhar [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Sundström, Maria [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Larsson, Pia; Gabrielsson, Johan [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Bergman, Åke [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Norrgren, Leif [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Örn, Stefan, E-mail: Stefan.Orn@slu.se [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden)

2015-06-15

Highlights: • Bioconcentration of PFOA at steady-state was approximately 20–30 times. • High concentrations were observed in bile and intestines implying enterohepatic circulation. • PFOA accumulated in oocytes indicating maternal transfer. - Abstract: Perfluorooctanoic acid (PFOA) is a long-chain perfluorinated chemical that has been shown to be non-degradable and persistent in the environment. Laboratory studies on bioconcentration and compound-specific tissue distribution in fish can be valuable for prediction of the persistence and environmental effects of the chemicals. In the present study male and female zebrafish (Danio rerio) were continuously exposed to 10 μg/L of radiolabeled perfluorooctanoic acid ({sup 14}C-PFOA) for 40 days, after which the exposed fish were transferred to fresh clean water for another 80 days wash-out period. At defined periodic intervals during the uptake and wash-out, fish were sampled for liquid scintillation counting and whole body autoradiography to profile the bioconcentration and tissue distribution of PFOA. The steady-state concentration of {sup 14}C-PFOA in the zebrafish was reached within 20–30 days of exposure. The concentration-time course of {sup 14}C-PFOA displayed a bi-exponential decline during washout, with a terminal half-life of approximately 13–14 days. At steady-state the bioconcentration of {sup 14}C-PFOA into whole-body fish was approximately 20–30 times greater than that of the exposure concentration, with no differences between females and males. The bioconcentration factors for liver and intestine were approximately 100-fold of the exposure medium, while in brain, ovary and gall bladder the accumulation factors were in the range 15–20. Whole-body autoradiograms confirmed the highest labeling of PFOA in bile and intestines, which implies enterohepatic circulation of PFOA. The {sup 14}C-PFOA was also observed in maturing vitellogenic oocytes, suggesting chemical accumulation via yolk proteins

Formic and Acetic Acid Observations over Colorado by Chemical Ionization Mass Spectrometry and Organic Acids' Role in Air Quality

Science.gov (United States)

Treadaway, V.; O'Sullivan, D. W.; Heikes, B.; Silwal, I.; McNeill, A.

2015-12-01

Formic acid (HFo) and acetic acid (HAc) have both natural and anthropogenic sources and a role in the atmospheric processing of carbon. These organic acids also have an increasing importance in setting the acidity of rain and snow as precipitation nitrate and sulfate concentrations have decreased. Primary emissions for both organic acids include biomass burning, agriculture, and motor vehicle emissions. Secondary production is also a substantial source for both acids especially from biogenic precursors, secondary organic aerosols (SOAs), and photochemical production from volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). Chemical transport models underestimate organic acid concentrations and recent research has sought to develop additional production mechanisms. Here we report HFo and HAc measurements during two campaigns over Colorado using the peroxide chemical ionization mass spectrometer (PCIMS). Iodide clusters of both HFo and HAc were recorded at mass-to-charge ratios of 173 and 187, respectively. The PCIMS was flown aboard the NCAR Gulfstream-V platform during the Deep Convective Clouds and Chemistry Experiment (DC3) and aboard the NCAR C-130 during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The DC3 observations were made in May and June 2012 extending from the surface to 13 km over the central and eastern United States. FRAPPE observations were made in July and August 2014 from the surface to 7 km over Colorado. DC3 measurements reported here are focused over the Colorado Front Range and complement the FRAPPE observations. DC3 HFo altitude profiles are characterized by a decrease up to 6 km followed by an increase either back to boundary layer mixing ratio values or higher (a "C" shape). Organic acid measurements from both campaigns are interpreted with an emphasis on emission sources (both natural and anthropogenic) over Colorado and in situ photochemical production especially ozone precursors.

Mass flows of perfluorinated compounds (PFCs) in central wastewater treatment plants of industrial zones in Thailand.

Science.gov (United States)

Kunacheva, Chinagarn; Tanaka, Shuhei; Fujii, Shigeo; Boontanon, Suwanna Kitpati; Musirat, Chanatip; Wongwattana, Thana; Shivakoti, Binaya Raj

2011-04-01

Perfluorinated compounds (PFCs) are fully fluorinated organic compounds, which have been used in many industrial processes and have been detected in wastewater and sludge from municipal wastewater treatment plants (WWTPs) around the world. This study focused on the occurrences of PFCs and PFCs mass flows in the industrial wastewater treatment plants, which reported to be the important sources of PFCs. Surveys were conducted in central wastewater treatment plant in two industrial zones in Thailand. Samples were collected from influent, aeration tank, secondary clarifier effluent, effluent and sludge. The major purpose of this field study was to identify PFCs occurrences and mass flow during industrial WWTP. Solid-phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis. Total 10 PFCs including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluoropropanoic acid (PFPA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonate (PFHxS), perfluoronanoic acid (PFNA), perfluordecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA) were measured to identify their occurrences. PFCs were detected in both liquid and solid phase in most samples. The exceptionally high level of PFCs was detected in the treatment plant of IZ1 and IZ2 ranging between 662-847ngL(-1) and 674-1383ngL(-1), respectively, which greater than PFCs found in most domestic wastewater. Due to PFCs non-biodegradable property, both WWTPs were found ineffective in removing PFCs using activated sludge processes. Bio-accumulation in sludge could be the major removal mechanism of PFCs in the process. The increasing amount of PFCs after activated sludge processes were identified which could be due to the degradation of PFCs precursors. PFCs concentration found in the effluent were very high comparing to those in river water of the area. Industrial activity could be the one of major sources of PFCs

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid

Institute of Scientific and Technical Information of China (English)

Yuan; Bu; Wenle; Dai; Nan; Li; Xinran; Zhao; Xia; Zuo

2013-01-01

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid has been investigated by cyclic voltammetry,linear polarization and chronoamperometry.The graphene nanopowder modified electrode was prepared using the drop coating method,which displayed excellent electrocatalytic activity towards the oxidation of dopamine and uric acid compared with the bare glassy carbon electrode in phosphate buffer solution at pH=7.0.Linear responses for dopamine and uric acid were obtained in the ranges of3.3μmol/L to 249.1μmol/L and 6.7μmol/L to 386.3μmol/L with detection limits of 1.5μmol/L and 2.7μmol/L(S/N=3),respectively.The response time was less than 2 s in case of dopamine and 3 s in case of uric acid,respectively.The results demonstrated that the graphene nanopowder had potential for detecting dopamine and uric acid.

Activity of earthworm in Latosol under simulated acid rain stress

Science.gov (United States)

Jia-En Zhang; Jiayu Yu; Ying Ouyang

2015-01-01

Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period....

Pore-expanded SBA-15 sulfonic acid silicas for biodiesel synthesis.

Science.gov (United States)

Dacquin, J P; Lee, A F; Pirez, C; Wilson, K

2012-01-07

Here we present the first application of pore-expanded SBA-15 in heterogeneous catalysis. Pore expansion over the range 6-14 nm confers a striking activity enhancement towards fatty acid methyl ester (FAME) synthesis from triglycerides (TAG), and free fatty acid (FFA), attributed to improved mass transport and acid site accessibility. This journal is © The Royal Society of Chemistry 2012

Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, 2

International Nuclear Information System (INIS)

Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

1984-01-01

The desorption of uranium from the granular titanium-activated carbon composite adsorbent (concentration of uranium: 25.5 mg/1-Ad), which adsorbed uranium from natural sea water, was examined by the column process with acidic eluent at room temperature. The column operation was able to be carried out without destruction of the granular adsorbent by the generation of the carbon dioxide, and free from disturbance of the eluent flow by precipitate of calcium sulfate dihydrate with sulfuric acid eluent. The amount of acid consumption by the adsorbent was 0.87 eq/1-Ad. The alkaline earth metals were eluted in the range of elution volume below 2 1/1-Ad, whereas uranium, iron, and titanium were eluted above 2 1/1-Ad. Therefore, uranium was separable from the alkaline earth metals which were adsorbed in the most quantity in the adsorbent. In the range of elution volume 2 to 12 1/1-Ad, the percentage of desorbed uranium and the concentration ratio of uranium were 80 %, 680 with 0.5 N sulfuric acid, and 59 %, 490 with 0.5 N hydrochloric acid, respectively. The percentage of dissolved titanium (DTI) was 0.3 % with 0.5 N sulfuric acid, 0.26 % with 0.5 N hydrochloric acid in the same range. (author)

Electrospun Poly(lactic acid-co-glycolic acid) Scaffolds for Skin Tissue Engineering

Science.gov (United States)

Kumbar, Sangamesh G.; Nukavarapu, Syam Prasad; James, Roshan; Nair, Lakshmi S.; Laurencin, Cato T.

2008-01-01

Electrospun fiber matrices composed of scaffolds of varying fiber diameters were investigated for potential application of severe skin loss. Few systematic studies have been performed to examine the effect of varying fiber diameter electrospun fiber matrices for skin regeneration. The present study reports the fabrication of poly[lactic acid-co-glycolic acid] (PLAGA) matrices with fiber diameters of 150–225, 200–300, 250–467, 500–900, 600–1200, 2500–3000 and 3250–6000 nm via electrospinning. All fiber matrices found to have a tensile modulus from 39.23 ± 8.15 to 79.21 ± 13.71 MPa which falls in the range for normal human skin. Further, the porous fiber matrices have porosity between 38–60 % and average pore diameters between 10–14µm. We evaluated the efficacy of these biodegradable fiber matrices as skin substitutes by seeding them with human skin fibroblasts (hSF). Human skin fibroblasts acquired a well spread morphology and showed significant progressive growth on fiber matrices in the 350–1100 nm diameter range. Collagen type III gene expression was significantly up-regulated in hSF seeded on matrices with fiber diameters in the range of 350–1100 nm. Based on the need, the proposed fiber skin substitutes can be successfully fabricated and optimized for skin fibroblast attachment and growth. PMID:18639927

Ion-neutral Clustering of Bile Acids in Electrospray Ionization Across UPLC Flow Regimes

Science.gov (United States)

Brophy, Patrick; Broeckling, Corey D.; Murphy, James; Prenni, Jessica E.

2018-02-01

Bile acid authentic standards were used as model compounds to quantitatively evaluate complex in-source phenomenon on a UPLC-ESI-TOF-MS operated in the negative mode. Three different diameter columns and a ceramic-based microfluidic separation device were utilized, allowing for detailed descriptions of bile acid behavior across a wide range of flow regimes and instantaneous concentrations. A custom processing algorithm based on correlation analysis was developed to group together all ion signals arising from a single compound; these grouped signals produce verified compound spectra for each bile acid at each on-column mass loading. Significant adduction was observed for all bile acids investigated under all flow regimes and across a wide range of bile acid concentrations. The distribution of bile acid containing clusters was found to depend on the specific bile acid species, solvent flow rate, and bile acid concentration. Relative abundancies of each cluster changed non-linearly with concentration. It was found that summing all MS level (low collisional energy) ions and ion-neutral adducts arising from a single compound improves linearity across the concentration range (0.125-5 ng on column) and increases the sensitivity of MS level quantification. The behavior of each cluster roughly follows simple equilibrium processes consistent with our understanding of electrospray ionization mechanisms and ion transport processes occurring in atmospheric pressure interfaces. [Figure not available: see fulltext.

Acid tolerance in Salmonella typhimurium induced by culturing in the presence of organic acids at different growth temperatures.

Science.gov (United States)

Alvarez-Ordóñez, Avelino; Fernández, Ana; Bernardo, Ana; López, Mercedes

2010-02-01

The influence of growth temperature and acidification of the culture medium up to pH 4.25 with acetic, citric, lactic and hydrochloric acids on the growth and subsequent acid resistance at pH 3.0 of Salmonella typhimurium CECT 443 was studied. The minimum pH value which allowed for S. typhimurium growth within the temperature range of 25-37 degrees C was 4.5 when the pH was reduced using citric and hydrochloric acids, and 5.4 and 6.4 when lactic acid and acetic acid were used, respectively. At high (45 degrees C) or low (10 degrees C) temperatures, the growth pH boundary was increased about 1 pH unit. The growth temperature markedly modified the acid resistance of the resulting cells. In all cases, D-values were lower for cells grown at 10 degrees C and significantly increased with increasing growth temperature up to 37 degrees C, at which D-values obtained were up to 10 times higher. Cells grown at 45 degrees C showed D-values similar to those found for cells grown at 25 degrees C. The growth of cells in acidified media, regardless of the pH value, caused an increase in their acid resistance at the four incubation temperatures, although the magnitude of the Acid Tolerance Response (ATR) observed depended on the growth temperature. Acid adapted cultures at 10 degrees C showed D-values ranging from 5.75 to 6.91 min, which turned out to be about 2 times higher than those corresponding to non-acid adapted cultures, while higher temperatures induced an increase in D-values of at least 3.5 times. Another finding was that, while at 10 and 45 degrees C no significant differences among the effect of the different acids tested in inducing an ATR were observed, when cells were grown at 25 and 37 degrees C citric acid generally turned out to be the acid which induced the strongest ATR. Results obtained in this study show that growth temperature is an important factor affecting S. typhimurium acid resistance and could contribute to find new strategies based on intelligent

The role of organic acids exuded from roots in phosphorus nutrition and aluminium tolerance in acidic soils

Energy Technology Data Exchange (ETDEWEB)

Hocking, P J; Randall, P J; Delhaize, E [CSIRO Plant Industry, Canberra (Australia); Keerthisinghe, G [International Atomic Energy Agency, Vienna (Austria)

2000-06-01

Soil acidity is a major problem of large areas of arable land on a global scale. Many acid soils are low in plant-available phosphorus (P) or are highly P-fixing, resulting in poor plant growth. In addition, aluminium (Al) is soluble in acid soils in the toxic Al{sup 3+} form, which also reduces plant growth. There is considerable evidence that both P deficiency and exposure to Al{sup 3+} stimulate the efflux of organic acids from roots of a range of species. Organic acids such as citrate, malate and oxalate are able to desorb or solubilise fixed soil P, making it available for plant uptake. Organic acids also chelate Al{sup 3+} to render it non-toxic, and are, therefore, involved in Al tolerance mechanisms. In this review, we discuss the literature on the role of organic acids exuded from roots in improving plant P uptake and Al-tolerance in acid soils. Research is now attempting to understand how P deficiency or exposure to Al{sup 3+} activates or induces organic acid efflux at the molecular level, with the aim of improving P acquisition and Al tolerance by conventional plant breeding and by genetic engineering. At the agronomic level, it is desirable that existing crop and pasture plants with enhanced soil-P uptake and tolerance to Al due to organic acid exudation are integrated into farming systems. (author)

The role of organic acids exuded from roots in phosphorus nutrition and aluminium tolerance in acidic soils

International Nuclear Information System (INIS)

Hocking, P.J.; Randall, P.J.; Delhaize, E.; Keerthisinghe, G.

2000-01-01

Soil acidity is a major problem of large areas of arable land on a global scale. Many acid soils are low in plant-available phosphorus (P) or are highly P-fixing, resulting in poor plant growth. In addition, aluminium (Al) is soluble in acid soils in the toxic Al 3+ form, which also reduces plant growth. There is considerable evidence that both P deficiency and exposure to Al 3+ stimulate the efflux of organic acids from roots of a range of species. Organic acids such as citrate, malate and oxalate are able to desorb or solubilise fixed soil P, making it available for plant uptake. Organic acids also chelate Al 3+ to render it non-toxic, and are, therefore, involved in Al tolerance mechanisms. In this review, we discuss the literature on the role of organic acids exuded from roots in improving plant P uptake and Al-tolerance in acid soils. Research is now attempting to understand how P deficiency or exposure to Al 3+ activates or induces organic acid efflux at the molecular level, with the aim of improving P acquisition and Al tolerance by conventional plant breeding and by genetic engineering. At the agronomic level, it is desirable that existing crop and pasture plants with enhanced soil-P uptake and tolerance to Al due to organic acid exudation are integrated into farming systems. (author)

Influence of oilseed supplement ranging in n-6/n-3 ratio on fatty acid composition and Δ5-, Δ6-desaturase protein expression in steer muscles.

Science.gov (United States)

Turner, T D; Mitchell, A; Duynisveld, J; Pickova, J; Doran, O; McNiven, M A

2012-12-01

This study investigated effects of roasted or extruded oilseed supplementation ranging in n-6/n-3 ratios from 0.3 to 5.0 on the fatty acid composition and expression of delta-5 desaturase (Δ5d) and Δ6-desaturase (Δ6d) protein in commercial steer cheek (m. masseter) and diaphragm (pars costalis diaphragmatis) muscles. In general, the n-6/n-3 ratio of the diet had a subsequent effect on the muscle n-6/n-3 ratio (P muscle 18:2n-6 and 18:3n-3 content relating to proportion of dietary soya bean and linseed (P muscle the Δ5d protein expression had a stronger association with the desaturase products rather than the precursors. The relationship between Δ5d protein expression and the muscle LC n-6/n-3 ratio was negative in both muscles (P muscle 18:2n-6 and 18:3n-3 deposition, whereas the Δ5d and Δ6d protein expression had some influence on the polar lipid LC-PUFA profile. Results reaffirm that processed oilseeds can be used to increase the proportion of fatty acids potentially beneficial for human health, by influencing the formation of LC-PUFA and reducing the n-6/n-3 ratio.

Comparative radiosensitivity of amino acids during γ-radiolysis in aqueous solutions

International Nuclear Information System (INIS)

Duzhenkova, N.A.; Savich, A.V.

1977-01-01

The radiosensitivity of amino acids contained in proteins has been compared. The γ-radiolysis of aqueous solutions of amino acids has studied over a wide range of concentrations in the presence of air, the dose rate being 60 rad/sec, and the dose, 100 krad. Radiation-chemical yields of amino acid decay and ammonia accumulation are given. An increase in yields with amino acid concentration has been established. Assumptions concerning some peculiarities of the amino acid decay mechanism are made

Thermodynamic study on the adsorption of strontium on polyantimonic acid exchanger

International Nuclear Information System (INIS)

Li Mingyu; Chen Jing; Wang Jianchen; Zhao Jing

2007-01-01

The adsorption of strontium on the polyantimonic acid adsorbent was studied. The equilibrium data for the adsorption of strontium on polyantimonic acid exchanger from aqueous solutions were obtained and correlated with Langmuir-type and Freundlich-type isotherm equation within the temperature range of 293-323 K and the experimental concentration range. Freundlich adsorption isotherms and the isosteric enthalpy indicate that the adsorption of strontium on polyantimonic acid is an endothermic process from aqueous solutions. The enthalpy, free energy, and entropy of adsorption were calculated. The results indicate that the adsorption process is a complex interaction of physical and chemical processes. The adsorption behaviors were reasonably explained. (authors)

γ radiation dosimetry in Mega rad range using sugar solution

International Nuclear Information System (INIS)

Venkataramani, R.; Mehta, S.K.; Soman, S.D.

1976-01-01

The formation of malonaldehyde under γ irradiation of solid sucrose and aqueous sucrose, fructose and arabinose solutions has been studied in the Mega rad range. Malonaldehyde (MA) concentration was estimated spectrophotometrically after complexing with 2-thio-barbituric acid. The effect of free radical scavengers (KI and N 2 O) on the yield of MA was investigated. Of the systems studied a 5% aqueous sucrose solution gave a proportional response of MA formation with dose in 0.2 to 5 Mega rad range. A 5% aqueous solution of sucrose prepared from sucrose irradiated in solid state also gave a smooth response of MA yield with dose from 8 to 30 Mega rad. The aqueous and solid sucrose systems together can be conveniently used for dosimetry in the range of 0.2 30 Mega rad. (author)

gamma. radiation dosimetry in Mega rad range using sugar solution

Energy Technology Data Exchange (ETDEWEB)

Venkataramani, R; Mehta, S K; Soman, S D [Bhabha Atomic Research Centre, Bombay (India). Health Physics Div.

1976-09-01

The formation of malonaldehyde under ..gamma.. irradiation of solid sucrose and aqueous sucrose, fructose and arabinose solutions has been studied in the Mega rad range. Malonaldehyde (MA) concentration was estimated spectrophotometrically after complexing with 2-thio-barbituric acid. The effect of free radical scavengers (KI and N/sub 2/O) on the yield of MA was investigated. Of the systems studied a 5% aqueous sucrose solution gave a proportional response of MA formation with dose in 0.2 to 5 Mega rad range. A 5% aqueous solution of sucrose prepared from sucrose irradiated in solid state also gave a smooth response of MA yield with dose from 8 to 30 Mega rad. The aqueous and solid sucrose systems together can be conveniently used for dosimetry in the range of 0.2 30 Mega rad.

Spectra-structure correlations of saturated and unsaturated medium-chain fatty acids. Near-infrared and anharmonic DFT study of hexanoic acid and sorbic acid.

Science.gov (United States)

Grabska, Justyna; Beć, Krzysztof B; Ishigaki, Mika; Wójcik, Marek J; Ozaki, Yukihiro

2017-10-05

Quantum chemical reproduction of entire NIR spectra is a new trend, enabled by contemporary advances in the anharmonic approaches. At the same time, recent increase of the importance of NIR spectroscopy of biological samples raises high demand for gaining deeper understanding of NIR spectra of biomolecules, i.e. fatty acids. In this work we investigate saturated and unsaturated medium-chain fatty acids, hexanoic acid and sorbic acid, in the near-infrared region. By employing fully anharmonic density functional theory (DFT) calculations we reproduce the experimental NIR spectra of these systems, including the highly specific spectral features corresponding to the dimerization of fatty acids. Broad range of concentration levels from 5·10 -4 M in CCl 4 to pure samples are investigated. The major role of cyclic dimers can be evidenced for the vast majority of these samples. A highly specific NIR feature of fatty acids, the elevation of spectral baseline around 6500-4000cm -1 , is being explained by the contributions of combination bands resulting from the vibrations of hydrogen-bonded OH groups in the cyclic dimers. Based on the high agreement between the calculated and experimental NIR spectra, a detailed NIR band assignments are proposed for hexanoic acid and sorbic acid. Subsequently, the correlations between the structure and NIR spectra are elucidated, emphasizing the regions in which clear and universal traces of specific bands corresponding to saturated and unsaturated alkyl chains can be established, thus demonstrating the wavenumber regions highly valuable for structural identifications. Copyright © 2017 Elsevier B.V. All rights reserved.

Fatty acid omega-oxidation as a rescue pathway for fatty acid oxidation disorders in humans

NARCIS (Netherlands)

Wanders, Ronald J. A.; Komen, Jasper; Kemp, Stephan

2011-01-01

Fatty acids (FAs) can be degraded via different mechanisms including alpha-, beta- and omega-oxidation. In humans, a range of different genetic diseases has been identified in which either mitochondrial FA beta-oxidation, peroxisomal FA beta-oxidation or FA alpha-oxidation is impaired. Treatment

[Trace analysis of aristolochic acid A].

Science.gov (United States)

Liu, Yalin; Gao, Huimin; Wang, Zhimin; Zhang, Qiwei

2010-12-01

A HPLC method for limit detection of aristolochic acid A in the Chinese herbs containing aristolochic acid or suspected-containing aristolochic acid and their preparations was established. The samples were analyzed on an Alltima C18 column eluted with methanol-water-acetic acid (68:32:1.5) as the mobile phase. Flow rate was at 1.0 mL x min(-1) and the detection wavelength was at 390 nm. The calibration curve was linear over the range from 0.016 to 0.51 g (r = 0.9993) and LOD was 4 ng. The average recovery was 101.2% with RSD of 2.01%. The procedures of sample preparation were systematically investigated. The contents of aristolochic acid A in Radix et Rhizoma Asari bought from market or drugstore were fluctuated from 3.1 to 26.6 microg x g(-1) and 3 of 11 samples accorded with the quality requirement of current Chinese Pharmacopoeia. Among 15 batches samples of Chinese medicaments, only one sample was found to contain aristolochic acid A. The present investigation shows that the method is sensitive and repeatable and it could be used for the limit detection of aristolochic acid A in the Chinese herbal medicines containing trace amount of aristolochic acid A or suspected-containing aristolochic acid A and their preparations.

Association between Serum Unmetabolized Folic Acid Concentrations and Folic Acid from Fortified Foods.

Science.gov (United States)

Palchetti, Cecília Zanin; Paniz, Clóvis; de Carli, Eduardo; Marchioni, Dirce M; Colli, Célia; Steluti, Josiane; Pfeiffer, Christine M; Fazili, Zia; Guerra-Shinohara, Elvira Maria

2017-01-01

To investigate the association between serum unmetabolized folic acid (UMFA) concentrations and folic acid from fortified foods and nutrients known as dietary methyl-group donors (folate, methionine, choline, betaine and vitamins B2, B6 and B12) in participants exposed to mandatory fortification of wheat and maize flours with folic acid. Cross-sectional study carried out with 144 healthy Brazilian participants, both sexes, supplement nonusers. Serum folate, UMFA, vitamin B12 and total plasma homocysteine (tHcy) were biochemically measured. Dietary intake was assessed by 2 non-consecutive 24-hour dietary recalls (24-HRs) and deattenuated energy-adjusted nutrient data were used for statistical analysis. Ninety eight (68.1%) participants were women. Median (interquartile range) age was 35.5 (28.0-52.0) years. Elevated serum folate concentrations (>45 nmol/L) were found in 17 (11.8%), while folate deficiency ( 1 nmol/L (90th percentile). UMFA concentrations were positively correlated with folic acid intake and negatively correlated to choline, methionine and vitamin B6 intakes. Participants in the lowest quartile of UMFA concentrations had lower dietary intake of total folate (DFEs) and folic acid, and higher dietary intake of methionine, choline and vitamin B6 than participants in the highest quartile of UMFA. Folic acid intake (OR [95% CI] = 1.02 [1.01-1.04)] and being a male (OR [95% CI] = 0.40 [0.19-0.87) were associated with increased and reduced odds for UMFA concentrations > 0.55 nmol/L (median values), respectively. UMFA concentrations were directly influenced by folic acid intake from fortified foods in a healthy convenience sample of adult Brazilians exposed to mandatory flour fortification with folic acid.

A cross-sectional study on trans-fatty acids and risk markers of CHD among middle-aged men representing a broad range of BMI

DEFF Research Database (Denmark)

Nielsen, Birgit M.; Nielsen, Marie M.; Jakobsen, Marianne U.

2011-01-01

Intake of trans-fatty acids (TFA), especially industrially produced TFA (I-TFA), has been associated with the risk of CHD through influence on serum lipid levels. Other causal pathways remain less investigated. In the present cross-sectional study of middle-aged men representing a broad range...... of BMI, the association between intake of TFA, I-TFA and ruminant TFA (R-TFA) and obesity-associated risk markers of CHD was assessed. The study comprised 393 Danish men (median age 49 years) with a median BMI of 28·4 kg/m2. Intake of TFA was estimated based on 7 d dietary records, whereas outcomes...... pressure and insulin homeostasis. Among middle-aged men with a generally low intake of TFA, neither I-TFA nor R-TFA was significantly related to obesity-associated risk markers of CHD. The decreased average intake of I-TFA in Denmark since 1995 is suggested to effectively prevent occurrence of the adverse...

Chemical Composition and Fatty Acid Content of Some Spices and Herbs under Saudi Arabia Conditions

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Fahad Mohammed Al-Jasass

2012-01-01

Full Text Available Some Saudi herbs and spices were analyzed. The results indicated that mustard, black cumin, and cress seeds contain high amount of fat 38.45%, 31.95% and 23.19%, respectively, as compared to clove (16.63%, black pepper (5.34% and fenugreek (4.51% seeds. Cress, mustard, black cumin and black pepper contain higher protein contents ranging from 26.61 to 25.45%, as compared to fenugreek (12.91% and clove (6.9%. Crude fiber and ash content ranged from 6.36 to 23.6% and from 3.57 to 7.1%, respectively. All seeds contain high levels of potassium (ranging from 383 to 823 mg/100g, followed by calcium (ranging from 75 to 270 mg/100g, Magnesium (ranged from 42 to 102 mg/100g and iron (ranged from 20.5 to 65 mg/100g. However, zinc, manganese and copper were found at low levels. The major fatty acids in cress and mustard were linolenic acid (48.43% and erucic acid (29.81%, respectively. The lenoleic acid was the major fatty acid in black cumin, fenugreek, black pepper and clove oils being 68.07%, 34.85%, 33.03% and 44.73%, respectively. Total unsaturated fatty acids were 83.24, 95.62, 86.46, 92.99, 81.34 and 87.82% for cress, mustard, black cumin, fenugreek, black pepper and clove, respectively. The differences in the results obtained are due to environmental factors, production areas, cultivars used to produce seeds and also due to the different methods used to prepare these local spices.

Study on fatty acids composition of lipid class in fish oil, proximate analysis and calorie value of kijar in Iran

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Ali Aberoumand

2017-01-01

Full Text Available 14.00 This aim of this research was to determine fatty acids and raw proximate composition and calorie value of fish Kijar in Iran. The fatty acids and proximate composition Kijar was determined. The established AOAC (Association of Official Agricultural Chemist, USA methods were followed for composition bio chemical of fish. Mean moisture, fat, protein, ash, carbohydrate contents and calorie value of raw fish were 70.81%, 5.88%, 17.80%, 3.41%, 2.1% and 132.52 kcal, respectively. Among fatty acids, palmitic acid was a major fatty acid while stearic acid was the other major constituent. Unsaturated monoenoic fatty acids (oleic and palmitoleic acids were major constituents. Important unsaturated fatty acids such as EPA and DHA, were also identified. percentage composition of fatty acids in the lipid classes of oil of Saurida undosquamis which the saturated fatty acids ranges from 58% to 72.14%. Palmitic acid is predominant and its composition ranges 38.64% to 48.98% while stearic acid ranges from 11.35% to 19.50%. Among unsaturated fatty acids, monoenoic are the major fatty acids. Oleic acid ranges from 12.15% to 27.48%. It is concluded that fish kijar found as health seafood for Iranian southern peoples form point of view of nutritional values and valuable fatty acids. Therefore it is recommended people put this fish in diet basket and it consumed three times in the week. Normal 0 false false false EN-US X-NONE AR-SA

Proximate and fatty acid composition of some commercially important fish species from the Sinop region of the Black Sea.

Science.gov (United States)

Kocatepe, Demet; Turan, Hülya

2012-06-01

The proximate and fatty acid compositions of the commercially important fish species (Engraulis encrasicolus, Alosa alosa, Belone belone, Scorpaena porcus, Pomatomus saltatrix, Mullus barbatus) from the Sinop region of the Black Sea were examined. The fat contents ranged from 1.26% (for scorpion fish) to 18.12% (for shad). The protein contents were min 14.54% (for red mullet) and maximum 20.26% (for belone). The fatty acid compositions of the fish ranged from 27.83 to 35.91% for saturated fatty acids, 19.50-33.80% for monounsaturated fatty acids and 15.25-40.02% for polyunsaturated fatty acids. Among the saturated fatty acids, palmitic acid (16:0) (17.75-22.20%) was the dominant fatty acid for all the fish species. As a second saturated fatty acid, myristic acid (14:0) was observed in four of the fish species and its content ranged from 4.72 to 7.31%. Whereas, for the other two fish species, the second saturated fatty acid was stearic acid (18:0) ranging between 4.54 and 10.64%. Among the monounsaturated fatty acids, those occurring in the highest proportions were oleic acid (18:1n-9c) (11.67-22.45%) and palmitoleic acid (16:1) (4.50-9.40%). Docosahexaenoic acid (22:6n-3) (5.41-28.52%), eicosapentaenoic acid (20:5n-3) (4.68-11.06) and linoleic acid (18:2n-6) (1.38-3.49%) were dominant polyunsaturated fatty acids, respectively. All the species, in particular the belone, the anchovy and the shad had high levels of the n-3 series.

Stability range of MoC (hp2). II. Thermodynamic properties of generalized Lewis acid-base intermetallics

International Nuclear Information System (INIS)

Koukouvetakis, J.

1988-01-01

The γ-MoC phase with the hexagonal WC structure was prepared without the presence of metal stabilizers at temperatures below 1000 degree C. This phase was found to be thermodynamically stable at low temperatures and decomposed to Mo 2 C and graphite at 1400 K. Using equilibrium and thermodynamic data, the thermodynamic quantities of this phase were calculated. Oxide equilibration and solid-state galvanic cell experiments were used to study thermodynamic properties of binary Lewis acid-base stabilized transition-metal alloys. The activity of vanadium was determined in alloys of vanadium with platinum-group metals such as Rh, Pd, and Ir at 1000 degree C. The activities of titanium in titanium-iridium alloys and of niobium in Nb 3 Ir were determined at 1400 degree C. The ternary phase diagram of V-Pd-O at 1000 degree C was obtained. Based on the vanadium-palladium results, a partial titration curve of palladium by vanadium was constructed. The excess partial molar Gibbs free energy of vanadium at infinite dilution was found to be -36.4 kcal mol -1 at 1000 degree C. Results are in agreement with the predictions of Brewer's theory of transition-metal alloy acid-base behavior

Lung and chest wall impedances in the dog in normal range of breathing: effects of pulmonary edema.

Science.gov (United States)

Barnas, G M; Stamenović, D; Lutchen, K R

1992-09-01

We evaluated the effect of pulmonary edema on the frequency (f) and tidal volume (VT) dependences of respiratory system mechanical properties in the normal ranges of breathing. We measured resistance and elastance of the lungs (RL and EL) and chest wall of four anesthetized-paralyzed dogs during sinusoidal volume oscillations at the trachea (50-300 ml, 0.2-2 Hz), delivered at a constant mean airway pressure. Measurements were made before and after severe pulmonary edema was produced by injection of 0.06 ml/kg oleic acid into the right atrium. Chest wall properties were not changed by the injection. Before oleic acid, EL increased slightly with increasing f in each dog but was independent of VT. RL decreased slightly and was independent of VT from 0.2 to 0.4 Hz, but above 0.4 Hz it tended to increase with increasing flow, presumably due to the airway contribution. After oleic acid injection, EL and RL increased greatly. Large negative dependences of EL on VT and of RL on f were also evident, so that EL and RL after oleic acid changed two- and fivefold, respectively, within the ranges of f and VT studied. We conclude that severe pulmonary edema changes lung properties so as to make behavior VT dependent (i.e., nonlinear) and very frequency dependent in the normal range of breathing.

Polarographic determination of stability constants of Eu(III) complexes with acrylic acid and crotonic acid

Energy Technology Data Exchange (ETDEWEB)

Rao, A L.J.; Makhan, S [Punjabi Univ., Patiala (India). Dept. of Chemistry

1979-07-01

Compositions and formation constants of Eu(III) complexes with acrylic acid and crotonic acid have been studied polarographically. The reductions are reversible and diffusion-controlled. The plot of Esub(1/2) versus -log Csub(x) is linear in the case of Eu(III)-acrylic acid system. The change in number of ligands bound to europium during reduction was found to be approximately equal to 1 and ratio of dissociation constants of Eu(III) and Eu(II) was found to be 40.76 x 10sup(-2). In the case of Eu(III)-crotonic acid system, composition and formation constants have been calculated by the method of Deford and Hume. Crotonic acid forms two complex species with europium (..beta../sub 1/, 60; ..beta../sub 2/, 4.2x10sup(+2)). The percentage distribution of various complex species as a function of ligand concentration has been calculated in the case of Eu(III)-crotonic acid system. A polarographic method for the determination of micro amounts of Eu(III) in the presence of diverse ions has been developed. Under optimum conditions Eu(III) in the concentration range 4x10sup(-4)-2x10sup(-3)M can be successfully determined in various mixtures.

Vitamin B2 content determination in liver paste by using acid and acid-enzyme hydrolysis

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Basić Zorica

2007-01-01

Full Text Available Background/Aim. Vitamin B2 is available in foodstuff in the form of coenzyme and in free form. For its content determination a few procedures should be performed (deliberation from a complex, extraction of free and deliberated form and detection, identification and quantification. There is a particular problem in determination of vitamin B2 in the meat products. For a determination of total vitamin B2 content in liver paste two preparation procedures are compared: acid and acid-enzymatic hydrolysis. The aim of this study thus, was to compare the effectiveness of these two different procedures for vitamin B2 content determination in liver paste. Methods. High pressure liquid chromatography (HPLC method with fluorescence detector, as specific and adequately sensitive for the foodstuff of a complex composition with a natural vitamin content, was used for determination of vitamin B2 in liver paste. Acid hydrolysis was performed with the application 0.1 M hydrochloric acid in a pressure cooker, and enzymatic hydrolysis was performed with the 10% takadiastase on 45 ºC within four hours. Ten samples of liver paste from the supply of the Serbian Army were examined. Separation was performed on the analytical column Nucleosil 50−5 C18 with mobile phase 450 ml CH3OH + 20 ml 5 mM CH3COONH4, and detection on the fluorescent detector with the variable wave length. Both methods were validated: examining a detection limit, quantification limit, specificity (because of a possible B2 vitamin interference with reagents, linearity of a peak area and standard concentration of B2 vitamin ratio in the range from 0.05 μg/ml to 2 μg/ml, precision for the 0.05 μg/ml concentration and recovery. Results. All the previously examined parameters validated both methods as specific, precise and reproductive, with a high recovery (98.5% for acid and 98.2% for acid - enzymatic hydrolysis, as well as linearity in a range that significantly superseded the expected content in

Amino Acid Transporters and Release of Hydrophobic Amino Acids in the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120

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Rafael Pernil

2015-04-01

Full Text Available Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of amino acid uptake, and three ABC-type transporters for amino acids have been previously characterized. Seven new loci encoding predicted amino acid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in amino acid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic amino acid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/amino acid:cation symporter (DAACS family whose inactivation resulted in an increased uptake of a broad range of amino acids. An assay to study amino acid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB was observed when transport system N-I (a hydrophobic amino acid ABC-type transporter was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

Fatty acid composition indicating diverse habitat use in coral reef fishes in the Malaysian South China Sea.

Science.gov (United States)

Arai, Takaomi; Amalina, Razikin; Bachok, Zainudin

2015-02-22

In order to understand feeding ecology and habitat use of coral reef fish, fatty acid composition was examined in five coral reef fishes, Thalassoma lunare, Lutjanus lutjanus, Abudefduf bengalensis, Scarus rivulatus and Scolopsis affinis collected in the Bidong Island of Malaysian South China Sea. Proportions of saturated fatty acids (SAFA) ranged 57.2% 74.2%, with the highest proportions in fatty acids, the second highest was monounsaturated fatty acids (MUFA) ranged from 21.4% to 39.0% and the proportion of polyunsaturated fatty acids (PUFA) was the lowest ranged from 2.8% to 14.1%. Each fatty acid composition differed among fishes, suggesting diverse feeding ecology, habitat use and migration during the fishes' life history in the coral reef habitats. Diets of the coral fish species might vary among species in spite of that each species are living sympatrically. Differences in fatty acid profiles might not just be considered with respect to the diets, but might be based on the habitat and migration.

Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

Science.gov (United States)

Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

2016-05-01

To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments.

Mitochondrial uncouplers with an extraordinary dynamic range.

Science.gov (United States)

Lou, Phing-How; Hansen, Birgit S; Olsen, Preben H; Tullin, Søren; Murphy, Michael P; Brand, Martin D

2007-10-01

We have discovered that some weak uncouplers (typified by butylated hydroxytoluene) have a dynamic range of more than 10(6) in vitro: the concentration giving measurable uncoupling is less than one millionth of the concentration causing full uncoupling. They achieve this through a high-affinity interaction with the mitochondrial adenine nucleotide translocase that causes significant but limited uncoupling at extremely low uncoupler concentrations, together with more conventional uncoupling at much higher concentrations. Uncoupling at the translocase is not by a conventional weak acid/anion cycling mechanism since it is also caused by substituted triphenylphosphonium molecules, which are not anionic and cannot protonate. Covalent attachment of the uncoupler to a mitochondrially targeted hydrophobic cation sensitizes it to membrane potential, giving a small additional effect. The wide dynamic range of these uncouplers in isolated mitochondria and intact cells reveals a novel allosteric activation of proton transport through the adenine nucleotide translocase and provides a promising starting point for designing safer uncouplers for obesity therapy.

Frictional response of fatty acids on steel.

Science.gov (United States)

Sahoo, Rashmi R; Biswas, S K

2009-05-15

Self-assembled monolayers of fatty acids were formed on stainless steel by room-temperature solution deposition. The acids are covalently bound to the surface as carboxylate in a bidentate manner. To explore the effect of saturation in the carbon backbone on friction in sliding tribology, we study the response of saturated stearic acid (SA) and unsaturated linoleic acid (LA) as self-assembled monolayers using lateral force microscopy and nanotribometry and when the molecules are dispersed in hexadecane, using pin-on-disc tribometry. Over a very wide range (10 MPa-2.5 GPa) of contact pressures it is consistently demonstrated that the unsaturated linoleic acid molecules yield friction which is significantly lower than that of the saturated stearic acid. It is argued, using density functional theory predictions and XPS of slid track, that when the molecular backbone of unsaturated fatty acids are tilted and pressed strongly by a probe, in tribological contact, the high charge density of the double bond region of the backbone allows coupling with the steel substrate. The interaction yields a low friction carboxylate soap film on the substrate. The saturated fatty acid does not show this effect.

Extraction of uranium from aqueous solution by phosphonic acid-imbedded polyurethane foam

International Nuclear Information System (INIS)

Katragadda, S.; Gesser, H.D.; Chow, A.

1997-01-01

Phenylphosphonic acid was imbedded into the matrix of the polyurethane foam during the fabrication process of the polymer. The extraction of uranium by phosphonic acid-imbedded polyurethane foam and blank polyurethane (i.e., foam without phosphonic acid functional groups) was investigated. Phosphonic acid-imbedded foam showed superior extractability of uranium from solutions with pH = 7.0 ± 1.5 over a wide range of temperatures. (author)

Simultaneous detection of ascorbic acid, uric acid and homovanillic acid at copper modified electrode

International Nuclear Information System (INIS)

Selvaraju, T.; Ramaraj, R.

2007-01-01

The copper was deposited on glassy carbon (GC) and indium tin oxide (ITO) electrodes by electrochemical method. The copper structures on electrode were characterized by atomic force microscope, X-ray diffractometeric pattern and differential pulse voltammetric studies. Optimal conditions for uniform growth of copper structures on the electrode were established. Voltammetric sensor was fabricated using the copper deposited GC electrode for the simultaneous detection and determination of uric acid (UA) and homovanillic acid (HVA) in the presence of excess concentrations of ascorbic acid (AA). The voltammetric signals due to AA and UA oxidation were well separated with a potential difference of 400 mV and AA did not interfere with the measurement of UA and HVA at the GC/Cu electrode. Linear calibration curves were obtained in the concentration range 1-40 μM for AA and 20-50 μM for UA at physiological pH and a detection limit of 10 nM of UA in the presence of 10-fold excess concentrations of AA was achieved. The simultaneous detection of submicromolar concentrations of AA, UA and HVA was achieved at the GC/Cu electrode. The practical utility of the present GC/Cu modified electrode was demonstrated by measuring the AA content in Vitamin C tablet, UA content in human urine and blood serum samples with satisfactory results

A limited LCA of bio-adipic acid: manufacturing the nylon-6,6 precursor adipic acid using the benzoic acid degradation pathway from different feedstocks.

Science.gov (United States)

van Duuren, J B J H; Brehmer, B; Mars, A E; Eggink, G; Dos Santos, V A P Martins; Sanders, J P M

2011-06-01

A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, toluene, or phenol from lignin to cis, cis-muconic acid, which is subsequently converted to adipic acid through hydrogenation. Apart from the impact of usage of petrochemical and biomass-based feedstocks, the environmental impact of the final concentration of cis, cis-muconic acid in the fermentation broth was studied using 1.85% and 4.26% cis, cis-muconic acid. The LCA focused on the cumulative energy demand (CED), cumulative exergy demand (CExD), and the CO(2) equivalent (CO(2) eq) emission, with CO(2) and N(2) O measured separately. The highest calculated reduction potential of CED and CExD were achieved using phenol, which reduced the CED by 29% and 57% with 1.85% and 4.26% cis, cis-muconic acid, respectively. A decrease in the CO(2) eq emission was especially achieved when the N(2) O emission in the combined biological and chemical process was restricted. At 4.26% cis, cis-muconic acid, the different carbon backbone feedstocks contributed to an optimized reduction of CO(2) eq emissions ranging from 14.0 to 17.4 ton CO(2) eq/ton adipic acid. The bulk of the bioprocessing energy intensity is attributed to the hydrogenation reactor, which has a high environmental impact and a direct relationship with the product concentration in the broth. Copyright © 2011 Wiley Periodicals, Inc.

Molecularly imprinted polyaniline-ferrocene-sulfonic acid-Carbon dots modified pencil graphite electrodes for chiral selective sensing of D-Ascorbic acid and L-Ascorbic acid: A clinical biomarker for preeclampsia

International Nuclear Information System (INIS)

Pandey, Indu; Jha, Shashank Shekhar

2015-01-01

Highlights: • Pencil graphite electrode was non-covalently functionalized by C-dots. • Electrochemically synthesized ferrocene-sulfonic acid doped PANI film was used as chiral recognition element. • Electrochemical chiral sensing of L-ascorbic acid and D-ascorbic acid was carried out. • L-ascorbic acid determination was done in aqueous, biological and pharmaceutical samples at nM level. - Abstract: A simple and novel method is proposed for chiral separation of L-ascorbic acid and D-ascorbic acid in human cerebrospinal fluids and blood plasma samples. Electro-polymerized molecularly imprinted poly-aniline ferrocenesulfonic acid-C-dots modified pencil graphite electrodes was successfully applied for separation and quantification of D-/L-ascorbic acid in aqueous and some biological samples. Parameters, important to control the performance of the electrochemical sensor were investigated and optimized, including the effects of pH, monomer- template ratios, electropolymerization cycles and scan rates. The molecularly imprinted film exhibited a high chiral selectivity and sensitivity towards D-ascorbic acid and L-ascorbic acid respectively. The surface morphologies and electrochemical properties of the proposed sensor were characterized by scanning electron microscopy, cyclic voltammetry, difference pulse voltammetry, chrono-amperometry and electrochemical impedance spectroscopy. L-ascorbic acid selective sensor shows excellent selectivity towards the L-ascorbic acid in comparison to D- ascorbic acid vice versa for D- ascorbic acid selective sensor. Under optimal conditions the linear range of the calibration curve for L- ascorbic acid and D- ascorbic acid was 6.0–165.0 nM and 6.0–155.0 nM, with the detection limit of 0.001 nM and 0.002 nM. Chiral detection of L-ascorbic acid was successfully carried out in pharmaceuticals and human plasma samples (pregnant women and non pregnant women) via proposed sensor with good selectivity and sensitivity.

Association of Perfluoroalkyl Substances, Bone Mineral Density, and Osteoporosis in the U.S. Population in NHANES 2009-2010.

Science.gov (United States)

Khalil, Naila; Chen, Aimin; Lee, Miryoung; Czerwinski, Stefan A; Ebert, James R; DeWitt, Jamie C; Kannan, Kurunthachalam

2016-01-01

Perfluoroalkyl substances (PFASs), including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA), are detectable in the serum of 95% of the U.S. Considering the role of PFASs as endocrine disruptors, we examined their relationships with bone health. The association between serum PFAS concentration and bone mineral density at total femur (TFBMD), femoral neck (FNBMD), lumbar spine (LSBMD), and physician-diagnosed osteoporosis was assessed in 1,914 participants using data from the National Health and Nutritional Examination Survey 2009-2010. The mean age of the participants was 43 years. Men had higher serum PFAS concentrations than women (p PFAS concentrations were associated with lower bone mineral density, which varied according to the specific PFAS and bone site assessed. Most associations were limited to women. Osteoporosis in women was also associated with PFAS exposure, based on a small number of cases. Khalil N, Chen A, Lee M, Czerwinski SA, Ebert JR, DeWitt JC, Kannan K. 2016. Association of perfluoroalkyl substances, bone mineral density, and osteoporosis in the U.S. population in NHANES 2009-2010. Environ Health Perspect 124:81-87; http://dx.doi.org/10.1289/ehp.1307909.

A Taiwanese food frequency questionnaire correlates with plasma docosahexaenoic acid but not with plasma eicosapentaenoic acid levels: questionnaires and plasma biomarkers.

Science.gov (United States)

Chien, Kuo-Liong; Lee, Meei-Shyuan; Tsai, Yi-Tsen; Chen, Pey-Rong; Lin, Hung-Ju; Hsu, Hsiu-Ching; Lee, Yuan-The; Chen, Ming-Fong

2013-02-16

Little evidence is available for the validity of dietary fish and polyunsaturated fatty acid intake derived from interviewer-administered questionnaires and plasma docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) concentration. We estimated the correlation of DHA and EPA intake from both questionnaires and biochemical measurements. Ethnic Chinese adults with a mean (± SD) age of 59.8 (±12.8) years (n = 297) (47% women) who completed a 38-item semi-quantitative food-frequency questionnaire and provided a plasma sample were enrolled. Plasma fatty acids were analyzed by capillary gas chromatography. The Spearmen rank correlation coefficients between the intake of various types of fish and marine n-3 fatty acids as well as plasma DHA were significant, ranging from 0.20 to 0.33 (P food frequency questionnaire, were correlated with the percentages of these fatty acids in plasma, and in particular with plasma DHA. Plasma DHA levels were correlated to dietary intake of long-chain n-3 fatty acids.

Analytical application of aminohydroxamic acids

International Nuclear Information System (INIS)

Fadl Elmoula, Abd ELfatah Abdella

2000-11-01

Anthranilic hydroxamic acid was prepared by coupling of methylanthranilate (prepared by esterification of anthranilic acid with methyl alcohol using the fisher-speir method) with freshly prepared hydroxylamine. The lignad was characterized by the usual reaction of hydroxamic acid with acidic V(V) and Fe(III) solutions that gives blood-red colour in amyl alcohol and deep-violet colour in aqueous solution, respectively. The absorbance of Fe(III)-hydroxamic acids complexes increases with increase of pH. In this study, the effect of pH on the absorbance of Fe(III)-anthranilic hydroxamic acid was in accordance with this trend. The maximum absorbance was obtained at pH 5.0 at maximum wavelength of 482 nm. For Cu(II)-anthranilic hydroxamic acid complex, the use of acidic basic pH lead to precipitation of Cu(II)-ligand complex. But when using buffer pH (acetic acid/sodium acetate) a clear green colour of Cu(II)-ligand complex was obtained. The maximum wavelength of 390 nm. V(V)-anthranilic hydroxamic acid complex was extracted in acidic medium in amyl alcohol at pH 2.0 because in aqueous solution V(V)-anthranilic hydroxamic acid complex has not clear colour. It was observed the the maximum extraction in acidic medium decrease sharply with the increasing of pH value. The maximum wavelength for maximum absorbance was recorded at 472 nm. V(V) interfered with determination of Fe(III)) above concentration of 2 ppm, whereas Cu(II) interferes slightly with the determination of Fe(III) ions even at a high concentration of the Cu(II) ions. Both Cu(II) and Ni(II) do not interfere with the determination of V(V) ions even at high concentrations, Fe(III) ion produced slight interference, while Mo(VI) ions have a pronounced interference. Both V(V) and Fe(III) ions interfered markedly with the determination of Cu(II) ions, and made impractical under conditions. However, the calibration curves for the three metal ions produced a practical linear dynamic range.(Author)

Citric acid as multifunctional agent in blowing films of starch/PBAT

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Patrícia Salomão Garcia

2011-09-01

Full Text Available Citric acid was used as a compatibilizer in the production of starch and PBAT films plasticized with glycerol and processed by blow extrusion. Films produced were characterized by WVP, mechanical properties, FT-IR-ATR and SEM. WPV ranged from 3.71 to 12.73×10-11 g m-1 s-1 Pa-1, while tensile strength and elongation at break ranged from 1.81 to 7.15 MPa and from 8.61 to 23.63%, respectively. Increasing the citric acid concentration improved WVP and slightly decreased film resistance and elongation. The films micrographs revealed a more homogeneous material with the addition of citric acid. However, the infrared spectra revealed little about cross-linking esterification reaction

Phlebotomy treatment for elimination of perfluoroalkyl acids in a highly exposed family: a retrospective case-series.

Directory of Open Access Journals (Sweden)

Stephen J Genuis

Full Text Available BACKGROUND: Perfluoroalkyl acids (PFAAs are a family of commonly used synthetic chemicals that have become widespread environmental contaminants. In human serum, perfluorohexane sulfonate (PFHxS, perflurooctane sulfonate (PFOS, and perfluorooctanoate (PFOA are most frequently detected, in part owing to their long elimination half-lives of between 3.8 yrs (PFOA and 8.5 yrs (PFHxS. These PFAAs also cross the placenta and have been associated with developmental toxicity, and some are considered likely human carcinogens. Interventions to eliminate PFAAs in highly contaminated individuals would reduce future health risks, but minimal research has been conducted on methods to facilitate accelerated human clearance of these persistent substances. METHODS: Six patients with elevated serum concentrations from a single family were treated by intermittent phlebotomy over a 4-5 year period at intervals similar to, or less frequent than what is done for routine blood donation at Canadian Blood Services. The apparent elimination half-life (HLapp for PFHxS, PFOS, and PFOA in this treated population was calculated in each patient and compared to the intrinsic elimination half-lives (HLin from a literature reference population of untreated fluorochemical manufacturing plant retirees (n = 26, age >55 yrs. RESULTS: For all three PFAAs monitored during phlebotomy, HLapp in each of the family members (except the mother, who had a low rate of venesection was significantly shorter than the geometric mean HL measured in the reference population, and in some cases were even shorter compared to the fastest eliminator in the reference population. CONCLUSION: This study suggests significantly accelerated PFAA clearance with regular phlebotomy treatment, but the small sample size and the lack of controls in this clinical intervention precludes drawing firm conclusions. Given the minimal risks of intermittent phlebotomy, this may be an effective and safe clinical

Destruction of nitric acid in purex process streams by formaldehyde treatment

International Nuclear Information System (INIS)

Kumar, S.V.; Nadkarni, M.N.; Mayankutty, P.C.; Pillai, N.S.; Shinde, S.S.

1974-01-01

Efficiency of destruction of nitric acid in purex process streams with formaldehyde has been studied as a function of initial acidity, uranium concentration, rate of addition of formaldehyde and temperature in the range 6 - 0.5M acid. Guidelines are suggested for the accurate calculations of the volume of formaldehyde needed to effect the required change of acidity at 100degC. Sodium nitrite has been established as a 'key' to initiate the reaction and water as an effective scrubber for collecting the acid fumes emanating from the reaction vessel. (author)

Introduction to fatty acids and lipids.

Science.gov (United States)

Burdge, Graham C; Calder, Philip C

2015-01-01

The purpose of this article is to describe the structure, function and metabolism of fatty acids and lipids that are of particular importance in the context of parenteral nutrition. Lipids are a heterogeneous group of molecules that share the common property of hydrophobicity. Lipids range in structure from simple short hydrocarbon chains to more complex molecules, including triacylglycerols, phospholipids and sterols and their esters. Lipids within each class may differ structurally. Fatty acids are common components of complex lipids, and these differ according to chain length and the presence, number and position of double bonds in the hydrocarbon chain. Structural variation among complex lipids and among fatty acids gives rise to functional differences that result in different impacts upon metabolism and upon cell and tissue responses. Fatty acids and complex lipids exhibit a variety of structural variations that influence their metabolism and their functional effects. © 2015 S. Karger AG, Basel.

PERACETIC ACID PRETREATMENT OF ALFALFA STEM AND ASPEN BIOMASS

OpenAIRE

Lei Xu,; Ulrike W. Tschirner

2011-01-01

Alfalfa stems and ground aspen were exposed to peracetic acid (0.5 to 9% on biomass) at temperatures ranging from 40 to 100° C and reaction times from 1 to 5 hours. Glucose release as a percentage of total cellulose content was determined using subsequent standard enzymatic hydrolysis. Statistical analysis confirmed that aspen showed a strong response to peracetic acid addition rate. 9% peracetic acid removed 14% of the original lignin and increased the rate of glucose release from 23% to 44%...

Insulin response of the glucose and fatty acid metabolism in dry dairy cows across a range of body condition scores.

Science.gov (United States)

De Koster, J; Hostens, M; Van Eetvelde, M; Hermans, K; Moerman, S; Bogaert, H; Depreester, E; Van den Broeck, W; Opsomer, G

2015-07-01

The objective of the present research was to determine the insulin response of the glucose and fatty acid metabolism in dry dairy cows with a variable body condition score (BCS). Ten pregnant Holstein Friesian dairy cows (upcoming parity 2 to 5) were selected based on BCS at the beginning of the study (2mo before expected parturition date). During the study, animals were monitored weekly for BCS and backfat thickness and in the last 2wk, blood samples were taken for determination of serum nonesterified fatty acid (NEFA) concentration. Animals underwent a hyperinsulinemic euglycemic clamp test in the third week before the expected parturition date. The hyperinsulinemic euglycemic clamp test consisted of 4 consecutive insulin infusions with increasing insulin doses: 0.1, 0.5, 2, and 5mIU/kg per minute. For each insulin infusion period, a steady state was defined as a period of 30min where no or minor changes of the glucose infusion were necessary to keep the blood glucose concentration constant and near basal levels. During the steady state, the glucose infusion rate [steady state glucose infusion rate (SSGIR) in µmol/kg per minute] and NEFA concentration [steady state NEFA concentration (SSNEFA) in mmol/L] were determined and reflect the insulin response of the glucose and fatty acid metabolism. Dose response curves were created based on the insulin concentrations during the steady state and the SSGIR or SSNEFA. The shape of the dose response curves is determined by the concentration of insulin needed to elicit the half maximal effect (EC50) and the maximal SSGIR or the minimal SSNEFA for the glucose or fatty acid metabolism, respectively. The maximal SSGIR was negatively associated with variables reflecting adiposity of the cows (BCS, backfat thickness, NEFA concentration during the dry period, and absolute weight of the different adipose depots determined after euthanasia and dissection of the different depots), whereas the EC50 of the glucose metabolism was

Volumetric properties of itaconic acid aqueous solutions

International Nuclear Information System (INIS)

Nisenbaum, Alexander; Apelblat, Alexander; Manzurola, Emanuel

2012-01-01

Highlights: ► Densities of itaconic acid aqueous solutions in a wide range of concentrations and temperatures. ► The apparent molar volumes and the cubic expansion coefficients. ► The derivatives of isobaric heat capacities with respect to pressure. ► Changes in the structure of water when itaconic acid is dissolved. - Abstract: Densities of itaconic acid aqueous solutions were measured at 5 K intervals from T = (278.15 to 343.15) K. From the determined densities, the apparent molar volumes, the cubic expansion coefficients and the second derivatives of volume with respect to temperature which are interrelated with the derivatives of isobaric heat capacities with respect to pressure were evaluated. These derivatives were qualitatively correlated with the changes in the structure of water when itaconic acid is dissolved in it.

Modelling of thermal degradation kinetics of ascorbic acid in ...

African Journals Online (AJOL)

Ascorbic acid (vitamin C) loss in thermally treated pawpaw and potato was modelled mathematically. Isothermal experiments in the temperature range of 50 -80 oC for the drying of pawpaw and 60 -100 oC for the blanch-drying of potato were utilized to determine the kinetics of ascorbic acid loss in both fruit and vegetable.

Trans fatty acids in dietary fats and oils from 14 European countries : the TRANSFAIR study

NARCIS (Netherlands)

Aro, A.; Amelsvoort, J. van; Becker, W.; Erp-Baart, M.A. van; Kafatos, A.; Leth, T.; Poppel, G. van

1998-01-01

The fatty acid composition of dietary fats and oils from 14 European countries was analyzed with particular emphasis on isomerictransfatty acids. The proportion oftransfatty acids in typical soft margarines and low-fat spreads ranged between 0.1 and 17% of total fatty acids and that

Influence of triethyl phosphate on phosphatase activity in shooting range soil: Isolation of a zinc-resistant bacterium with an acid phosphatase.

Science.gov (United States)

Story, Sandra; Brigmon, Robin L

2017-03-01

Phosphatase-mediated hydrolysis of organic phosphate may be a viable means of stabilizing heavy metals via precipitation as a metal phosphate in bioremediation applications. We investigated the effect of triethyl phosphate (TEP) on soil microbial-phosphatase activity in a heavy-metal contaminated soil. Gaseous TEP has been used at subsurface sites for bioremediation of organic contaminants but not applied in heavy-metal contaminated areas. Little is known about how TEP affects microbial activity in soils and it is postulated that TEP can serve as a phosphate source in nutrient-poor groundwater and soil/sediments. Over a 3-week period, TEP amendment to microcosms containing heavy-metal contaminated soil resulted in increased activity of soil acid-phosphatase and repression of alkaline phosphatase, indicating a stimulatory effect on the microbial population. A soil-free enrichment of microorganisms adapted to heavy-metal and acidic conditions was derived from the TEP-amended soil microcosms using TEP as the sole phosphate source and the selected microbial consortium maintained a high acid-phosphatase activity with repression of alkaline phosphatase. Addition of 5mM zinc to soil-free microcosms had little effect on acid phosphatase but inhibited alkaline phosphatase. One bacterial member from the consortium, identified as Burkholderia cepacia sp., expressed an acid-phosphatase activity uninhibited by high concentrations of zinc and produced a soluble, indigo pigment under phosphate limitation. The pigment was produced in a phosphate-free medium and was not produced in the presence of TEP or phosphate ion, indicative of purple acid-phosphatase types that are pressed by bioavailable phosphate. These results demonstrate that TEP amendment was bioavailable and increased overall phosphatase activity in both soil and soil-free microcosms supporting the possibility of positive outcomes in bioremediation applications. Copyright © 2016. Published by Elsevier Inc.

Gallic Acid: Review of the Methods of Determination and Quantification.

Science.gov (United States)

Fernandes, Felipe Hugo Alencar; Salgado, Hérida Regina Nunes

2016-05-03

Gallic acid (3,4,5 trihydroxybenzoic acid) is a secondary metabolite present in most plants. This metabolite is known to exhibit a range of bioactivities including antioxidant, antimicrobial, anti-inflammatory, and anticancer. There are various methods to analyze gallic acid including spectrometry, chromatography, and capillary electrophoresis, among others. They have been developed to identify and quantify this active ingredient in most biological matrices. The aim of this article is to review the available information on analytical methods for gallic acid, as well as presenting the advantages and limitations of each technique.

The method of quantitative determination of iodine in acetic acid

International Nuclear Information System (INIS)

Sukhomlinov, A.B.; Kalinchenko, N.B.

1988-01-01

Method for separate determination of J 2 and J - concentrations in acetic acid is suggested. Iodine concentration in acetic acid is determined by measuring potential of iodine-selective electrode first in the initial solution of acetic acid, where molecular iodine dissociation equals 0.5, and then in acetic acid, with alkali (NaOH) addition up to pH > 3, where molecular iodine dissociation equals 1. Determination is conducted in 5x10 -7 -5x10 -6 mol/l concentration range with relative standard deviation not more than 0.1. 1 fig

Updated national emission of perfluoroalkyl substances (PFASs) from wastewater treatment plants in South Korea.

Science.gov (United States)

Kwon, Hye-Ok; Kim, Hee-Young; Park, Yu-Mi; Seok, Kwang-Seol; Oh, Jeong-Eun; Choi, Sung-Deuk

2017-01-01

A nationwide emission estimate of perfluoroalkyl substances (PFASs) from wastewater treatment plants (WWTPs) is required to understand the source-receptor relationship of PFASs and to manage major types of WWTPs. In this study, the concentrations of 13 PFASs (8 perfluorocarboxylic acids, 3 perfluoroalkane sulfonates, and 2 intermediates) in wastewater and sludge from 81 WWTPs in South Korea were collected. The emission pathways of PFASs were redefined, and then the national emission of PFASs from WWTPs was rigorously updated. In addition to the direct calculations, Monte Carlo simulations were also used to calculate the likely range of PFAS emissions. The total (Σ 13 PFAS) emission (wastewater + sludge) calculated from the direct calculation with mean concentrations was 4.03 ton/y. The emissions of perfluorooctanoic acid (PFOA, 1.19 ton/y) and perfluorooctane sulfonate (PFOS, 1.01 ton/y) were dominant. The Monte Carlo simulations suggested that the realistic national emission of Σ 13 PFASs is between 2 ton/y and 20 ton/y. Combined WWTPs treating municipal wastewater from residential and commercial areas were identified as a major emission source, contributing 65% to the total PFAS emissions. The Han and Nakdong Rivers were the primary contaminated rivers, receiving 89% of the total PFAS discharge from WWTPs. The results and methodologies in this study can be useful to establish a management policy for PFASs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acid deposition in the northern hemisphere

Energy Technology Data Exchange (ETDEWEB)

Longhurst, J.W.S.; Green, S.E.; Lee, D.S.

1987-02-01

Examines the phenomenon of acid deposition: the distribution and magnitude of sources and its actual and potential direct and indirect effects on soils, forests and other vegetation; wildlife, freshwaters, materials and health. The wide range of technological and other controls that are available to reduce the emissions of pollutants contributing to the phenomenon is also examined and includes pre-combustion control of pollutants, removal during combustion and post-combustion control. Also considered are political responses to acidification, acid deposition monitoring in the United Kingdom and the treatment of acidified areas.

Impaired acid neutralization in the duodenum in pancreatic insufficiency.

Science.gov (United States)

Dutta, S K; Russell, R M; Iber, F L

1979-10-01

The influence of severe exocrine pancreatic disease on the acid-neutralizing capacity of the duodenum was studied in five patients with pancreatic insufficiency (PI) and six control subjects using duodenal perfusion-marker technique. Hydrochloric acid (0.1 N containing 1% PEG) was infused at constant rates (1.2, 4.5 and 7.0 ml/min) into the duodenum just distal to the duodenal bulb. Samples were aspirated from the tip of the duodenal perfusion tube located at the ligament of Treitz. All samples were analyzed for volume, pH, titrable acidity, PEG and [14C]PEG (gastric marker) determination. Patients with PI demonstrated significantly diminished ability to neutralize various acid loads as compared to controls who virtually completely neutralized acid loads in the range of maximal gastric acid secretion. Exogenous secretin did not significantly improve percent acid neutralized in PI. These data clearly indicate that patients with PI have significantly impaired ability to neutralize even small loads of acid in the duodenum.

Combinations of mutant FAD2 and FAD3 genes to produce high oleic acid and low linolenic acid soybean oil.

Science.gov (United States)

Pham, Anh-Tung; Shannon, J Grover; Bilyeu, Kristin D

2012-08-01

High oleic acid soybeans were produced by combining mutant FAD2-1A and FAD2-1B genes. Despite having a high oleic acid content, the linolenic acid content of these soybeans was in the range of 4-6 %, which may be high enough to cause oxidative instability of the oil. Therefore, a study was conducted to incorporate one or two mutant FAD3 genes into the high oleic acid background to further reduce the linolenic acid content. As a result, soybean lines with high oleic acid and low linolenic acid (HOLL) content were produced using different sources of mutant FAD2-1A genes. While oleic acid content of these HOLL lines was stable across two testing environments, the reduction of linolenic acid content varied depending on the number of mutant FAD3 genes combined with mutant FAD2-1 genes, on the severity of mutation in the FAD2-1A gene, and on the testing environment. Combination of two mutant FAD2-1 genes and one mutant FAD3 gene resulted in less than 2 % linolenic acid content in Portageville, Missouri (MO) while four mutant genes were needed to achieve the same linolenic acid in Columbia, MO. This study generated non-transgenic soybeans with the highest oleic acid content and lowest linolenic acid content reported to date, offering a unique alternative to produce a fatty acid profile similar to olive oil.

Effects of acid-base imbalance on vascular reactivity

Directory of Open Access Journals (Sweden)

A.C. Celotto

2008-06-01

Full Text Available Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo and those occurring within the intracellular space (pHi, although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent, prostacyclin (PGI2/cAMP-dependent and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.

Spatiotemporal distribution and mass loadings of perfluoroalkyl substances in the Yangtze River of China.

Science.gov (United States)

Pan, Chang-Gui; Ying, Guang-Guo; Zhao, Jian-Liang; Liu, You-Sheng; Jiang, Yu-Xia; Zhang, Qian-Qian

2014-09-15

A systematic investigation into contamination profiles of eighteen perfluoroalkyl substances (PFASs) in both surface water and sediments of Yangtze River was carried out by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in summer and winter of 2013. The total concentrations of the PFASs in the water and sediment of Yangtze River ranged from 2.2 to 74.56 ng/L and 0.05 to 1.44 ng/g dry weights (dw), respectively. The PFAS concentrations were correlated to some selected water quality parameters such as pH, total phosphorus (TP), total nitrogen (TN) and conductivity in water, and some sediment properties, such as total organic carbon (TOC), TP, and TN in sediment. The monitoring results for the water and sediment samples showed no obvious seasonal variations. Among the selected 18 PFASs, perfluorooctanoic acid (PFOA) was the dominant PFAS compound found both in water and sediment for the two seasons with its maximum concentration of 18.03 ng/L in water and 0.72 ng/g in sediment, followed by perfluorobutane sulfonic acid (PFBS) with its maximum concentration of 41.9 ng/L in water in Wuhan, whereas the lowest concentrations of PFASs were observed at Poyang lake. The annual loadings of PFOA, perfluorohexanoic acid (PFHxA), PFBS, perfluorooctane sulfonic acid (PFOS) and the total PFASs in the Yangtze River were 6.8 tons, 2.2 tons, 8.2 tons, 0.88 tons, and 20.7 tons, respectively. Wuhan and Er'zhou of Hubei contributed the most amounts of PFASs into the Yangtze River. A correlation was found between some PFASs, for example PFBS and PFOS, which suggests that both of these PFASs originate from common sources in the region. Copyright © 2014 Elsevier B.V. All rights reserved.

Structural characteristics and properties of the regenerated silk fibroin prepared from formic acid.

Science.gov (United States)

Um, I C; Kweon, H Y; Park, Y H; Hudson, S

2001-08-20

Structural characteristics and thermal and solution properties of the regenerated silk fibroin (SF) prepared from formic acid (FU) were compared with those of SF from water (AU). According to the turbidity and shear viscosity measurement, SF formic acid solution was stable and transparent, no molecular aggregations occurred. The sample FU exhibited the beta-sheet structure, while AU random coil conformation using Fourier transform infrared (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry. The effects of methanol treatment on samples were also examined. According to the measurement of crystallinity (XRD) and crystallinity index (FTIR), the concept of long/short-range ordered structure formation was proposed. Long-range ordered crystallites are predominantly formed for methanol treated SF film while SF film cast from formic acid favors the formation of short-range ordered structure. The relaxation temperatures of SF films measured by dynamic thermomechanical analysis supported the above mechanism due to the sensitivity of relaxation temperature on the short-range order.

Complex formation between glutamic acid and molybdenum (VI)

International Nuclear Information System (INIS)

Gharib, Farrokh; Khorrami, S.A.; Sharifi, Sasan

1997-01-01

Equilibria of the reaction of molybdenum (VI) with L-glutamic acid have been studied in aqueous solution in the pH range 2.5 to 9.5, using spectrophotometric and optical rotation methods at constant ionic strength (0.15 mol dm -3 sodium perchlorate) and temperature 25 ± 0.1 degC. Our studies have shown that glutamic acid forms a mononuclear complex with Mo(VI) of the type MoO 3 L 2- at pH 5.5. The stability constant of this complexation and the dissociation constants of L-glutamic acid have been determined. (author). 17 refs., 2 figs., 4 tabs

High-dose, short-term exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) affects the number of circulating neutrophils differently, but enhances the inflammatory responses of macrophages to lipopolysaccharide (LPS) in a similar fashion.

Science.gov (United States)

Qazi, Mousumi R; Bogdanska, Jasna; Butenhoff, John L; Nelson, B Dean; DePierre, Joseph W; Abedi-Valugerdi, Manuchehr

2009-08-21

Having found previously that high-dose, short-term dietary exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) suppresses adaptive immunity, in the present study we characterize the effects of these fluorochemicals on the innate immune system. Male C57BL/6 mice receiving 0.02% (w/w) PFOS or PFOA in their diet for 10 days exhibited a significant reduction in the numbers of total white blood cells (WBC), involving lymphopenia in both cases, but neutropenia only in response to treatment with PFOA. Moreover, both compounds also markedly reduced the number of macrophages (CD11b(+) cells) in the bone marrow, but not in the spleen or peritoneal cavity. The ex vivo production of tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) by peritoneal macrophages isolated from animals treated with PFOA or PFOS was increased modestly. Moreover, both fluorochemicals markedly enhanced the ex vivo production of these same cytokines by peritoneal and bone marrow macrophages stimulated either in vitro or in vivo with lipopolysaccharide (LPS); whereas there was no such effect on splenic macrophages. The serum levels of these inflammatory cytokines observed in response to in vivo stimulation with LPS were elevated substantially by prior exposure to PFOA, but not by PFOS. None of these parameters of innate immunity were altered in animals receiving a dietary dose of these compounds that was 20-fold lower (0.001%, w/w). These findings reveal that in addition to suppressing adaptive immunity, high-dose, short-term exposure of mice to either PFOS or PFOA augments inflammatory responses to LPS, a potent activator of innate immunity.

Fatty acid composition indicating diverse habitat use in coral reef fishes in the Malaysian South China Sea

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Takaomi Arai

2015-01-01

Full Text Available BACKGROUND: In order to understand feeding ecology and habitat use of coral reef fish, fatty acid composition was examined in five coral reef fishes, Thalassoma lunare, Lutjanus lutjanus, Abudefduf bengalensis, Scarus rivulatus and Scolopsis affinis collected in the Bidong Island of Malaysian South China Sea. RESULTS: Proportions of saturated fatty acids (SAFA ranged 57.2% 74.2%, with the highest proportions in fatty acids, the second highest was monounsaturated fatty acids (MUFA ranged from 21.4% to 39.0% and the proportion of polyunsaturated fatty acids (PUFA was the lowest ranged from 2.8% to 14.1%. Each fatty acid composition differed among fishes, suggesting diverse feeding ecology, habitat use and migration during the fishes' life history in the coral reef habitats. CONCLUSIONS: Diets of the coral fish species might vary among species in spite of that each species are living sympatrically. Differences in fatty acid profiles might not just be considered with respect to the diets, but might be based on the habitat and migration.

Plasma free amino acid kinetics in rainbow trout (Oncorhynchus mykiss) using a bolus injection of 15N-labeled amino acids.

Science.gov (United States)

Robinson, Jacob William; Yanke, Dan; Mirza, Jeff; Ballantyne, James Stuart

2011-02-01

To gain insight into the metabolic design of the amino acid carrier systems in fish, we injected a bolus of (15)N amino acids into the dorsal aorta in mature rainbow trout (Oncorhynchus mykiss). The plasma kinetic parameters including concentration, pool size, rate of disappearance (R(d)), half-life and turnover rate were determined for 15 amino acids. When corrected for metabolic rate, the R(d) values obtained for trout for most amino acids were largely comparable to human values, with the exception of glutamine (which was lower) and threonine (which was higher). R(d) values ranged from 0.9 μmol 100 g(-1) h(-1) (lysine) to 22.1 μmol 100 g(-1) h(-1) (threonine) with most values falling between 2 and 6 μmol 100 g(-1) h(-1). There was a significant correlation between R(d) and the molar proportion of amino acids in rainbow trout whole body protein hydrolysate. Other kinetic parameters did not correlate significantly with whole body amino acid composition. This indicates that an important design feature of the plasma-free amino acids system involves proportional delivery of amino acids to tissues for protein synthesis.

Hydrophobization og the surface fo malachite with some fluorosurfactants. 2,3 no fussokei kaimen kasseizai ni yoru malachite hyomen no sosuika

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, M [National Reserach Institute for Pollution and Resources, Tsukuba (Japan); Wakamatsu, T [Kyoto University, Kyoko (Japan). Faculty of Engineering

1991-10-18

The depleting trends of high-grade ores in recent years make it unavoidable to float ores in fine powder forms. To achieve this, research and development is important on such a recovering agent that can hydrophobize the surfaces of useful ores selectively and powerfully. This paper describes the discussion on three kinds of fluorosurfactant, namely perfluorooctanoic acid, Ftergent-100 and Ftergent-150, whic were used to hydrophobize the surface of malachite, and compared of its utilization possibility as a recovery agent with other surfactants. As a result, it was found that the Ftergent-100, which contains five CF{sub 3}{sup {minus}} in one molecule having extremely low critical surface tension, and the Ftergent-150 can hydrophobize sufficiently the malachite surface and provide good deposition. The region providing good deposition was at a weak-acidic to weak-alkali region in the case of the Ftergent-150. Therefore, both materials are thought they could be used as a recovering agent. 8 refs., 10 figs., 3 tabs.

Preparation and Wetting Behavior of Lyophobic Surface on Zinc Substrate

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HAN Xiang-xiang

2018-03-01

Full Text Available Micro-nano structure on zinc substrate was fabricated through the combination of chemical etching with hydrochloric acid aqueous solution and hydrothermal reaction. After modification with perfluorooctanoic solution, the lyophobic surface was prepared. The phase composition, microstructure, chemical composition, and wettability of the as-obtained surface were investigated by X-ray diffractometer, scanning electron microscope, Fourier transform infrared spectrometer, and contact angle tester. The results show that a layer of ZnO nano-rods grows on the surface of the submicrometer structure, and exhibits good resistance to water impact and stability under the combined action of low surface energy material. When hydrochloric acid concentration is 1.0mol/L and hydrothermal reaction temperature is 95℃, the lyophobic surface possesses the best morphology of ZnO nano-rods. The maximum contact angles of distilled water and peanut oil are 154.65° and 144.65°, respectively, and the sliding angle is less than 10°.

Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed.

Science.gov (United States)

Möller, Axel; Ahrens, Lutz; Surm, Renate; Westerveld, Joke; van der Wielen, Frans; Ebinghaus, Ralf; de Voogt, Pim

2010-10-01

The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of SigmaPFAS were estimated to be approximately 6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Complexing blends of polyacrylic acid-polyethylene glycol and poly(ethylene-co-acrylic acid)-polyethylene glycol as shape stabilized phase change materials

International Nuclear Information System (INIS)

Alkan, Cemil; Günther, Eva; Hiebler, Stefan; Himpel, Michael

2012-01-01

Highlights: ► Complexing groups to PEGs in a polymer could stabilize PEG at different molecular weights. ► Shape stabilized PEGs for thermal energy storage are prepared using compounds with interacting groups. ► Phase change temperature of PEGs could be changed using a complexing copolymer with acid groups. - Abstract: Blends of poly(ethylene glycol) (PEG) at 1000, 6000, and 10,000 g/mole average molecular weights and poly(acrylic acid) (PAA) or poly(ethylene-co-acrylic acid) (EcoA) have been prepared by solution blending and accounted for thermal energy storage properties as shape stabilized polymer blends. The blends have been analyzed using Fourier transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC) techniques. Total thermal energy values of the complexes have been determined by the method of Mehling et al. As a result of the investigation it is found that polymers with acid groups form interpolymer complexes (IPCs) and miscible and immiscible IPC–PEG blends when blended with PEGs. PEGs formed IPCs with PAA and EcoA polymers in solutions and reach to saturation and turns to be blends of IPC and PEG polymer. PEGs in this work bleed out of the blends when its compositions reach to a degree of immiscibility. In the first range where blends are IPCs and in the third range where bleeding of PEG occurs, blends are not feasible for thermal energy storage applications. However, in the second range, the blends are potential materials for passive thermal energy storage applications.

Development and Validation of a HPTLC Method for Simultaneous Estimation of L-Glutamic Acid and γ-Aminobutyric Acid in Mice Brain.

Science.gov (United States)

Sancheti, J S; Shaikh, M F; Khatwani, P F; Kulkarni, Savita R; Sathaye, Sadhana

2013-11-01

A new robust, simple and economic high performance thin layer chromatographic method was developed for simultaneous estimation of L-glutamic acid and γ-amino butyric acid in brain homogenate. The high performance thin layer chromatographic separation of these amino acid was achieved using n-butanol:glacial acetic acid:water (22:3:5 v/v/v) as mobile phase and ninhydrin as a derivatising agent. Quantitation of the method was achieved by densitometric method at 550 nm over the concentration range of 10-100 ng/spot. This method showed good separation of amino acids in the brain homogenate with Rf value of L-glutamic acid and γ-amino butyric acid as 21.67±0.58 and 33.67±0.58, respectively. The limit of detection and limit of quantification for L-glutamic acid was found to be 10 and 20 ng and for γ-amino butyric acid it was 4 and 10 ng, respectively. The method was also validated in terms of accuracy, precision and repeatability. The developed method was found to be precise and accurate with good reproducibility and shows promising applicability for studying pathological status of disease and therapeutic significance of drug treatment.

Fatty acid, tocopherol and squalene contents of Rosaceae seed oils.

Science.gov (United States)

Matthaus, Bertrand; Özcan, Mehmet Musa

2014-12-01

The aim of current study is to establish the composition of these seeds belong to Rosaceae family with respect to fatty acid, tocopherol and squalene content. The oil contents of seeds varied between 3.49 (Cotoneaster bullatus) to 46.15 g/100 g (Prunus tenella). The main fatty acids of seed oils were oleic (6.50 - 67.11 %), linoleic (22.08 - 68.62 %) and 20:1n-7 (0.10 - 61.59 %). As observed, the oils of seed were rich in linoleic and oleic acids. Total tocopherol contents ranged between 7.06 mg/100 g (Prunus tenella) to 165.74 mg/100 g (Potentilla glandulosa ssp. pseudorupestris). The major tocopherols were γ-tocopherol, ranging from 2.08 mg/100 g to 106.01 mg/100 g; α-tocopherol ranging from 2.86 mg100 g to 74.26 mg/100 g and δ-tocopherol ranging used in this experiment were found between 0.02 mg/100 g (Alchemilla caucasica) to o.29 mg/100 g (Cotoneaster simonsii). These results show that Rosaceae seed oils can be a potential saurce of valuable oil which might be useful for the evaluation of dietary information in important food crops and other industrial applications.

Exopolysaccharides produced by lactic acid bacteria

NARCIS (Netherlands)

Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

2016-01-01

A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and

Biotechnological Production of Organic Acids from Renewable Resources.

Science.gov (United States)

Pleissner, Daniel; Dietz, Donna; van Duuren, Jozef Bernhard Johann Henri; Wittmann, Christoph; Yang, Xiaofeng; Lin, Carol Sze Ki; Venus, Joachim

2017-03-07

Biotechnological processes are promising alternatives to petrochemical routes for overcoming the challenges of resource depletion in the future in a sustainable way. The strategies of white biotechnology allow the utilization of inexpensive and renewable resources for the production of a broad range of bio-based compounds. Renewable resources, such as agricultural residues or residues from food production, are produced in large amounts have been shown to be promising carbon and/or nitrogen sources. This chapter focuses on the biotechnological production of lactic acid, acrylic acid, succinic acid, muconic acid, and lactobionic acid from renewable residues, these products being used as monomers for bio-based material and/or as food supplements. These five acids have high economic values and the potential to overcome the "valley of death" between laboratory/pilot scale and commercial/industrial scale. This chapter also provides an overview of the production strategies, including microbial strain development, used to convert renewable resources into value-added products.

A comprehensive study on energy absorption and exposure buildup factors for some essential amino acids, fatty acids and carbohydrates in the energy range 0.015-15 MeV up to 40 mean free path

International Nuclear Information System (INIS)

Kurudirek, Murat; Ozdemir, Yueksel

2011-01-01

The gamma ray energy absorption (EABF) and exposure buildup factors (EBF) have been calculated for some essential amino acids, fatty acids and carbohydrates in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameter geometric progression (G-P) fitting approximation has been used to calculate both EABF and EBF. Variations of EABF and EBF with incident photon energy, penetration depth and weight fraction of elements have been studied. While the significant variations in EABF and EBF for amino acids and fatty acids have been observed at the intermediate energy region where Compton scattering is the main photon interaction process, the values of EABF and EBF appear to be almost the same for all carbohydrates in the continuous energy region. It has been observed that the fatty acids have the largest EABF and EBF at 0.08 and 0.1 MeV, respectively, whereas the maximum values of EABF and EBF have been observed for aminoacids and carbohydrates at 0.1 MeV. At the fixed energy of 1.5 MeV, the variation of EABF with penetration depth appears to be independent of the variations in chemical composition of the amino acids, fatty acids and carbohydrates. Significant variations were also observed between EABF and EBF which may be due to the variations in chemical composition of the given materials.

Examination of Vitamin and Amino Acid Profiles of Gmelina ...

African Journals Online (AJOL)

The study examined the vitamin and amino acid profiles of Unripe Gmelina Whole Fruit (UGWF), Ripe Gmelina Whole Fruit (RGWF) and Ripe Gmelina Fruit Pulp (RGFP). The combined riboflavin, thiamin, niacin, ascorbic acid, vitamins A and E of all the samples ranged from 0.09-0.30 mg/100g, 0.22-0.88 mg/100g, 0.12-0.64 ...

Amino Acid Metabolism in Acute Renal Failure: Influence of Intravenous Essential L-Amino Acid Hyperalimentation Therapy

Science.gov (United States)

Abel, Ronald M.; Shih, Vivian E.; Abbott, William M.; Beck, Clyde H.; Fischer, Josef E.

1974-01-01

A solution of 8 essential I-amino acids and hypertonic dextrose was administered to 5 patients in acute postoperative renal failure in a program of hyperalimentation designed to decrease the patient's catabolic state and to accrue certain metabolic benefits. A sixth patient receiving intravenous glucose alone served as a control. The pretreatment plasma concentrations of amino acids in all 6 patients did not differ significantly from normal; following intravenous essential amino acids at a dose of approximately 12.6 gm/24 hours, no significant elevations out of the normal range of these substances occurred. Since urinary excretion rates did not dramatically increase, urinary loss was excluded as a possible cause for the failure of increase of plasma concentrations. The results suggest that the administration of an intravenous solution of 1-amino acids and hypertonic dextrose is associated with rapid clearance from the blood of these substances and, with a failure of increased urinary excretion, indirect evidence of amino acid utilization for protein synthesis has been obtained. Histidine supplementation in patients with acute renal failure is probably unnecessary based on the lack of significant decreases in histidine concentrations in these patients. PMID:4850497

[Determination of chlorogenic acid, caffeic acid and linarin in Flos Chrysanthemi Indici from different places by RP-hPLC].

Science.gov (United States)

Guo, Qiaosheng; Fang, Hailing; Shen, Haijin

2010-05-01

To evaluate the quality of Flos Chrysanthemi Indici which produced in twenty-two different producing places. Chlorogenic acid and caffeic acid were analyzed on a Shim-pack C8 colunm (4.6 mm x 250 mm, 5 microm) eluted with the mobile phase consisted of acetonitrile-0.5% phosphoric acid( 19:81). The detection wavelength was set at 326 nm. Linarin were eluted with the mobile phase consisted of methanol-water-acetic acid(26: 23: 1). The detection wavelength was set at 334 nm. The column temperature was 25 degrees C. The flow rate was 1.0 mL x min . The linear response ranged within 2.5-50 microg for chlorogenic acid (r = 0.998), 2.5-25 microg for caffeic acid (r = 0.998) and 4.97-41.47 microg for linarin (r = 0.999), respectively. Recoveries were 100.8% with RSD 2.1% for chlorogenic acid, 96.2% with RSD 2.3% for caffeic acid and 103.7% with RSD 1.8% for linarin. There was a significant difference in the content of chlorogenic acid, caffeic acid, linarin among the samples. The content of chlorogenic in the sample from Fengdou Chongqing city was the highest in those from other places. The content of caffeic acid in the all samples is very low. The content of linarin in the samples from Jiangsu province and Anhui province almost reached the national standard in pharmacopoeia.

Folic acid levels in some food staples in Ireland are on the decline: implications for passive folic acid intakes?

Science.gov (United States)

Kelly, F; Gibney, E R; Boilson, A; Staines, A; Sweeney, M R

2016-06-01

Neural tube defects are largely preventable by the maternal periconceptual consumption of folic acid. The aim of this study was to examine the levels of synthetic folic acid in foods and the range of food stuffs with added folic acid available to consumers in Ireland at the current time. Three audits of fortified foods available in supermarkets in the Republic of Ireland were conducted. Researchers visited supermarkets and obtained folic acid levels from nutrition labels in 2004, 2008 and 2013/4. Levels were compared using MS Excel. The profile of foods fortified with folic acid in 2013/4 has changed since 2004. The percentage of foods fortified with folic acid has decreased as has the level of added folic acid in some food staples, such as fat/dairy spreads. Bread, milk and spreads no longer contain as much folic acid as previously (2004 and 2008). This may contribute to a decrease in folate intake and therefore may contribute to an increase in NTD rates. Research on current blood concentrations of folate status markers is now warranted. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The mid-IR Absorption Cross Sections of α- and β-NAT (HNO3 · 3H2O) in the range 170 to 185 K and of metastable NAD (HNO3 · 2H2O) in the range 172 to 182 K

Science.gov (United States)

Iannarelli, R.; Rossi, M. J.

2015-11-01

Growth and Fourier transform infrared (FTIR) absorption in transmission of the title nitric acid hydrates have been performed in a stirred flow reactor (SFR) under tight control of the H2O and HNO3 deposition conditions affording a closed mass balance of the binary mixture. The gas and condensed phases have been simultaneously monitored using residual gas mass spectrometry and FTIR absorption spectroscopy, respectively. Barrierless nucleation of the metastable phases of both α-NAT (nitric acid trihydrate) and NAD (nitric acid dihydrate) has been observed when HNO3 was admitted to the SFR in the presence of a macroscopic thin film of pure H2O ice of typically 1 µm thickness. The stable β-NAT phase was spontaneously formed from the precursor α-NAT phase through irreversible thermal rearrangement beginning at 185 K. This facile growth scheme of nitric acid hydrates requires the presence of H2O ice at thicknesses in excess of approximately hundred nanometers. Absolute absorption cross sections in the mid-IR spectral range (700-4000 cm-1) of all three title compounds have been obtained after spectral subtraction of excess pure ice at temperatures characteristic of the upper troposphere/lower stratosphere. Prominent IR absorption frequencies correspond to the antisymmetric nitrate stretch vibration (ν3(NO3-)) in the range 1300 to 1420 cm-1 and the bands of hydrated protons in the range 1670 to 1850 cm-1 in addition to the antisymmetric O-H stretch vibration of bound H2O in the range 3380 to 3430 cm-1 for NAT.

Mine waters: Acidic to circumneutral

Science.gov (United States)

Nordstrom, D. Kirk

2011-01-01

Acid mine waters, often containing toxic concentrations of Fe, Al, Cu, Zn, Cd, Pb, Ni, Co, and Cr, can be produced from the mining of coal and metallic deposits. Values of pH for acid mine waters can range from –3.5 to 5, but even circumneutral (pH ≈ 7) mine waters can have high concentrations of As, Sb, Mo, U, and F. When mine waters are discharged into streams, lakes, and the oceans, serious degradation of water quality and injury to aquatic life can ensue, especially when tailings impoundments break suddenly. The main acid-producing process is the exposure of pyrite to air and water, which promotes oxidative dissolution, a reaction catalyzed by microbes. Current and future mining should plan for the prevention and remediation of these contaminant discharges by the application of hydrogeochemical principles and available technologies, which might include remining and recycling of waste materials.

Excitatory amino acid neurotoxicity and neurodegenerative disease.

Science.gov (United States)

Meldrum, B; Garthwaite, J

1990-09-01

The progress over the last 30 years in defining the role of excitatory amino acids in normal physiological function and in the abnormal neuronal activity of epilepsy has been reviewed in earlier articles in this series. In the last five years it has become clear that excitatory amino acids also play a role in a wide range of neurodegenerative processes. The evidence is clearest where the degenerative process is acute, but is more controversial for slow degenerative processes. In this article Brian Meldrum and John Garthwaite review in vivo and in vitro studies of the cytotoxicity of amino acids and summarize the contribution of such toxicity to acute and chronic neurodegenerative disorders.

Determination of free acidity in nuclear fuel reprocessing streams by fiber optic aided spectrophotometric technique

International Nuclear Information System (INIS)

Ganesh, S.; Velavendan, P.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

2014-01-01

A fiber optic aided spectrophotometric technique has been developed for the determination of free acidity in nuclear fuel reprocessing streams. The developed method is simple, accurate and applicable to all ranges of nitric acid and heavy metal concentrations relevant to the purex process. The method is based on the formation of yellow colour with an acid-sensitive indicator such as chrome azurol s, the intensity of yellow colour is proportional to the acid concentration. The system obeys Lambert-Beer's law at 455 nm in the range of acidity 1-10 M of nitric acid. The results obtained are reproducible with standard deviation 2% and relative error is less than 3%. The results obtained by the developed technique are in good agreement with those obtained by the standard procedure. This method is adaptable for remote operation and on-line monitoring. (author)

The effect of pH on the erosion of dentine and enamel by dietary acids in vitro.

Science.gov (United States)

West, N X; Hughes, J A; Addy, M

2001-09-01

The reported incidence of tooth erosion caused by acidic soft drinks has been increasingly documented. Citric and phosphoric acids are the two main dietary acids present in these soft drinks. Many variables need to be determined in order to assess risk factors for dental erosion caused by beverage consumption including pH, titratable acidity, pKa, buffering capacity, hence the aim of these in vitro investigations. Methodologies included profiling flat enamel and dentine samples (acidic solutions adjusted with alkali over the available pH range; citric, phosphoric and hydrochloric acid were adjusted with sodium hydroxide and citric acid with trisodium citrate. Tissue loss was calculated by profilometry. Results showed that under these conditions citric acid caused far more erosion over the pH range employed than phosphoric acid for both tissue types. Citric acid compared with hydrochloric acid highlighted dissolution and chelation effects. Phosphoric acid caused minimal erosion over pH 3 for enamel and pH 4 for dentine. These factors could be considered in order to reduce the erosivity of acidic soft drinks.

Capsaicinoids, amino acid and fatty acid profiles in different fruit components of the world hottest Naga king chilli (Capsicum chinense Jacq).

Science.gov (United States)

Ananthan, R; Subhash, K; Longvah, T

2018-01-01

The world hottest Naga king chilli is cultivated and consumed in Northeast India. Capsaicinoids, amino acids and fatty acids were studied in fruit and fruit components of Naga king chilli. Capsaicinoid content was increased in each ripening stage and maximum level was observed at red color fruits. Total protein and fat content of placenta was 19.41 and 20.36% respectively. Capsaicinoids of placenta (7.35±2.241%) was higher followed by seed (3.83±1.358%) and pericarp (2.91±0.667%). Similarly, essential amino acid content was also higher in placenta compared to other components. Amino acid score ranged from 37 to 38 with cystine and methionine as limiting amino acid. Low level of palmitic, stearic and α-linolenic acid and very high level of linoleic acid were found in seeds. Total polyunsaturates of seeds were higher followed by whole fruit. Naga king chilli is unique due to its high capsaicinoid content and it offers potential crop for the future exploitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The role of boric acid in the Phebus-FP tests