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Jing-Sing Yang, Sheng-Lun Lin, Ta-Chang Lin, Yee-Lin Wu, Lin-Chi Wang, Guo-Ping Chang-Chien
This study examines the emissions of polychlorinated diphenyl ethers (PCDEs) during the start-up processes of a municipal solid waste incinerator (MSWI). Both normal and modified emission control start-ups were tested. Fifteen samples were taken from the flue gas with increasing furnace temperature. Peak PCDE concentrations of 1.48-10.3 ng/Nm(3) were observed at 8-11 h after the start of combustion, when the furnace temperature was in the range of 267-440 °C, that also needed for PCDD/F formation by de novo synthesis...
December 15, 2015: Journal of Hazardous Materials
Li Qin, Mingbao Feng, Xuesheng Zhang, Liansheng Wang, Zunyao Wang
Polychlorinated diphenyl ethers (PCDEs) are a group of halogenated aromatic compounds and serious environmental pollutants. In the present study, sediment and water samples from eight sites in Nanjing section of the Yangtze River were characterized with 15 congeners of PCDEs. Concentrations and distributions of these PCDEs in water phase and sediments were analyzed by GC/MS. Results demonstrated that ∑PCDE concentrations were higher in the low water period (1.15-1.80 μg/L) than those in the high water period (0...
June 2015: Environmental Science and Pollution Research International
Mohammednoor Altarawneh, Bogdan Z Dlugogorski
This study presents a detailed mechanistic account of the formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from polychlorinated diphenyl ethers (PCDEs). It applies the recently developed meta hybrid M06-2X functional and deploys the 2,2'-dichlorodiphenylether (2,2'-DCDE) molecule as a representative model compound for all PCDEs congeners. We find that, exceedingly high activation enthalpies prevent the direct formation of PCDFs from PCDEs via unimolecular elimination of HCl or Cl2...
November 2014: Chemosphere
Se Wang, Ce Hao, Zhanxian Gao, Jingwen Chen, Jieshan Qiu
Polychlorinated diphenyl ethers (PCDEs) are a focus of current environmental concern as a group of ubiquitous potential persistent organic pollutants. There are still significant gaps in our knowledge concerning the photolysis mechanisms of PCDEs. In this study, the direct photolysis mechanisms of PCDEs were investigated by density functional theory. The direct photolysis of PCDEs has three potential reaction pathways including photodechlorination, C-O bond photodissociation, and PCDFs formation. Taking a representative PCDE (i...
September 2014: Chemosphere
Wenxia Liu, Lianfeng Shen, Fawen Zhang, Wenbin Liu, Minghui Zheng, Xitian Yang
Polychlorinated diphenyl ether (PCDE) has attracted great attention recently as an important type of environmental pollutant. The influence of iron and copper oxides on formation of PCDEs was investigated using laboratory-scale flow reactors under air and under nitrogen at 350 °C, a temperature corresponding to the post-combustion zone of a municipal solid waste incinerator. The results show that the 2,2',3,4,4',5,5',6-otachlorodiphenyl ether (OCDE) formed from the condensation of pentachlorophenol (PCP) and 1,2,4,5-tetrachlorobenzene (Cl4Bz) is the predominant congener formed on the SiO2/Fe2O3 surface with and without oxygen...
August 2013: Environmental Science and Pollution Research International
Thomas Danne, Sylvia Lion, Lazlo Madaczy, Henk Veeze, Fillipe Raposo, Imre Rurik, Bärbel Aschemeier, Olga Kordonouri
'SWEET' is an acronym standing for 'Better control in pediatric and adolescent diabeteS: Working to crEate CEnTers of Reference (CORs)' and is based on a partnership of established national and European diabetes organizations such as International Diabetes Federation, Federation of European Nurses in Diabetes, and Primary Care Diabetes Europe (PCDE, A three-level classification of centers has been put forward. In addition to centers for local care, SWEET collaborating centers on their way to being a COR have been defined...
September 2012: Pediatric Diabetes
Sang-Kyu Jung, Vinuselvi Parisutham, Seong Hun Jeong, Sung Kuk Lee
A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E...
2012: Journal of Biomedicine & Biotechnology
Jiaqi Shi, Xuesheng Zhang, Ruijuan Qu, Ying Xu, Zunyao Wang
Twenty-nine congeners of polychlorinated diphenyl sulfide (PCDPS) theoretically possible were synthesized and purified, and their octanol-water partition coefficients (logK(ow)) and high performance liquid chromatography capacity factors (HPLC-logk') were determined. Then the constitutional and structural descriptors were obtained respectively to establish 2D models and comparative molecular similarity indices analysis (CoMSIA) method was used to establish 3D models. All the models were robust and predictive, indicating that the electrostatic effect may be the primary factor influencing the two properties of PCDPS...
August 2012: Chemosphere
Jean-François Beaulieu, Daniel Ménard
The intestinal epithelium is a highly dynamic tissue undergoing constant and rapid renewal. It consists of a functional villus compartment responsible for terminal digestion and nutrient absorption and a progenitor cell compartment located in the crypts that produce new cells. The mechanisms regulating cell proliferation in the crypt, their migration, and differentiation are still incompletely understood. Until recently, normal human intestinal cell models allowing the study of these mechanisms have been lacking...
2012: Methods in Molecular Biology
Grega E Voglar, Domen Leštan
In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085mg kg(-1) of Cd, Pb, Zn, Cu, Ni and As, respectively...
August 30, 2011: Journal of Hazardous Materials
Wenxia Liu, Minghui Zheng, Wenbin Liu, Lirong Gao, Guijin Su, Bing Zhang
Polychlorinated diphenyl ethers (PCDEs) are a focus of current environmental concern. The formation of PCDEs was investigated using laboratory-scale flow reactors under air and under nitrogen at 350°C. The results show the amount of PCDEs formed from the condensation of pentachlorophenol (PCP) and 1,2,4,5-tetrachlorobenzene (1,2,4,5-Cl(4)Bz) was lower with oxygen than without oxygen, and the PCDE homologue distribution was different under both atmospheres. The presence of oxygen influenced the process of PCDE formation from precursors on the fly ash surface...
February 15, 2011: Journal of Hazardous Materials
F William Mauldin, Francesco Viola, William F Walker
Bias and variance errors in motion estimation result from electronic noise, decorrelation, aliasing, and inherent algorithm limitations. Unlike most error sources, decorrelation is coherent over time and has the same power spectrum as the signal. Thus, reducing decorrelation is impossible through frequency domain filtering or simple averaging and must be achieved through other methods. In this paper, we present a novel motion estimator, termed the principal component displacement estimator (PCDE), which takes advantage of the signal separation capabilities of principal component analysis (PCA) to reject decorrelation and noise...
November 2010: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Sierra Rayne, Kaya Forest
The SPARC software program aqueous pK(a) prediction module was validated against corresponding experimental acidity constants for chlorinated and brominated phenols and the limited experimental aqueous pK(a) data sets for monohydroxylated polychlorinated biphenyls (OH-PCBs), polychlorinated diphenyl ethers (OH-PCDEs), and polybrominated diphenyl ethers (OH-PBDEs). pK(a) values were then estimated for all 837 monohydroxylated mono- through nona-halogenated congeners in each of the OH-PCB, OH-PCDE, and OH-PBDE classes, as well as for the monohydroxylated polybrominated biphenyls (OH-PBBs), giving a total of 3348 compounds...
September 2010: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Xu Hui-Ying, Zou Jian-Wei, Hu Gui-Xiang, Wang Wei
Polychlorinated diphenyl ethers (PCDEs) are a group of important persistent organic pollutants. In the present study, geometrical optimization and electrostatic potential calculations have been performed for all 209 PCDE congeners at the HF/6-31G(*) level of theory. A number of statistically-based parameters have been obtained. Linear relationships between gas-chromatographic relative retention time (RRT), n-octanol/water partition coefficient (log K(OW)), 298 K supercooled liquid vapour pressures (log p(L)), aqueous solubilities (logS(w,L)) and the immunotoxicity values (log ED(50)) of PCDEs and the structural descriptors have been established by multiple linear regression method...
July 2010: Chemosphere
Ylva Persson, Andrei Shchukarev, Lars Oberg, Mats Tysklind
BACKGROUND, AIM, AND SCOPE: The distribution of chlorinated organic contaminants in groundwater and the importance of colloids were studied in groundwater from a sawmill site contaminated by chlorophenol preservatives. MATERIALS AND METHODS: The groundwater was fractionated into three different size ranges: (1) >0.7 microm, (2) 0.4-0.7 microm and (3) 0.2-0.4 microm and the filtered water phase. The concentrations of chlorophenols (CP), chlorinated phenoxy phenols (PCPP), chlorinated diphenyl ethers (PCDE), chlorinated dibenzofurans (PCDF) and chlorinated dibenzo-p-dioxins (PCDD) were determined in each fraction...
September 2008: Environmental Science and Pollution Research International
Jean Louis Pujol, Jean Luc Breton, Radj Gervais, Marie-Laure Tanguy, Elisabeth Quoix, Philippe David, Henri Janicot, Virginie Westeel, Sabine Gameroff, Jean Genève, Dominique Maraninchi
PURPOSE: This randomized, double-blind, placebo-controlled phase III study aimed to determine whether thalidomide prolongs survival of patients with extensive-disease small-cell lung cancer (SCLC). PATIENTS AND METHODS: One hundred nineteen patients received two courses of etoposide, cisplatin, cyclophosphamide, and 4'-epidoxorubicin (PCDE). Responder patients who had recovered from chemotherapy toxicity were randomly assigned to receive four additional PCDE cycles plus thalidomide (400 mg daily) or placebo...
September 1, 2007: Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology
Jaana Koistinen, Jussi V K Kukkonen, Arto Sormunen, Erkki Mannila, Sirpa Herve, Terttu Vartiainen
The bioaccumulation potential and environmental fate of polychlorinated hydroxydiphenyl ethers (HO-PCDEs; polychlorinated phenoxyphenols, PCPP), the major impurities of chlorophenol formulations and their methoxy analogues (MeO-PCDEs; polychlorinated methoxyanisoles, PCPAs) were investigated. Oligochaete worms (Lumbriculus variegatus) exposed to sediment spiked with a model substance of one HO-hexaCDE (4'-HO-PCDE 161) or its methoxy analogue (4'-MeO-PCDE 161) clearly accumulated the test compounds revealing the potential for environmental risk of HO-PCDEs and MeO-PCDEs...
July 2007: Chemosphere
Sofia Frankki, Ylva Persson, Andrei Shchukarev, Mats Tysklind, Ulf Skyllberg
The retention and mobility of hydrophobic organic contaminants (HOCs) in soil is mainly determined by hydrophobic partitioning to dissolved and particulate organic matter (DOM and POM, respectively). The aqueous phase, DOM, and POM fractions were extracted and separated from soils at three sites contaminated with technical chlorophenol formulations. Concentrations of chlorophenols (CP), polychlorinated phenoxyphenols (PCPP), polychlorinated diphenyl ethers (PCDE) and polychlorinated dibenzo-p-dioxins and furans (PCDD/F) were determined...
July 2007: Environmental Pollution
Sofia Frankki, Ylva Persson, Mats Tysklind, Ulf Skyllberg
We determined the distribution of hydrophobic organic contaminants (HOCs) to fractions of natural organic matter in a soil contaminated by chlorophenol wood preservatives more than 30 years ago. The concentration of dissolved organic matter (DOM) was enhanced in soil suspensions by raising pH to 6.8-9.1. After 48 h of desorption/equilibration, the DOM fraction was separated from the particulate organic matter (POM) of the soil by filtration. In the next step, DOM was flocculated by Al-nitrate, and free concentrations of HOCs were determined in the aqueous phase...
November 1, 2006: Environmental Science & Technology
Jose L Domingo, Ana Bocio, Gemma Falcó, Juan M Llobett
In the present study, the concentrations of PBDEs and PCDEs were determined in 14 edible marine species widely consumed by the population of Catalonia (Spain). The daily intake of PBDEs and PCDEs associated with this consumption was also determined. A total of 42 composite samples were analyzed by HRGC/HRMS. The highest PBDE levels (ng/kg wet weight) were found in salmon (2015) followed by mackerel, swordfish, and red mullet (1124, 978, and 769, respectively), while those of PCDEs (ng/kg wet weight) were detected in red mullet (7088) followed by sardine (1829), anchovy (1606), tuna (1292), and mackerel (1031)...
July 15, 2006: Environmental Science & Technology
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