Ammonia, Oral - Problem Formulation

Project ID

2358

Category

IRIS

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March 13, 2015, 11:16 a.m.

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Journal Article

Abstract  During clathrin-mediated endocytosis (CME), actin assembly provides force to drive vesicle internalization. Members of the Wiskott-Aldrich syndrome protein (WASP) family play a fundamental role stimulating actin assembly. WASP family proteins contain a WH2 motif that binds globular actin (G-actin) and a central-acidic motif that binds the Arp2/3 complex, thus promoting the formation of branched actin filaments. Yeast WASP (Las17) is the strongest of five factors promoting Arp2/3-dependent actin polymerization during CME. It was suggested that this strong activity may be caused by a putative second G-actin-binding motif in Las17. Here, we describe the in vitro and in vivo characterization of such Las17 G-actin-binding motif (LGM) and its dependence on a group of conserved arginine residues. Using the yeast two-hybrid system, GST-pulldown, fluorescence polarization and pyrene-actin polymerization assays, we show that LGM binds G-actin and is necessary for normal Arp2/3-mediated actin polymerization in vitro. Live-cell fluorescence microscopy experiments demonstrate that LGM is required for normal dynamics of actin polymerization during CME. Further, LGM is necessary for normal dynamics of endocytic machinery components that are recruited at early, intermediate and late stages of endocytosis, as well as for optimal endocytosis of native CME cargo. Both in vitro and in vivo experiments show that LGM has relatively lower potency compared to the previously known Las17 G-actin-binding motif, WH2. These results establish a second G-actin-binding motif in Las17 and advance our knowledge on the mechanism of actin assembly during CME.

Journal Article

Abstract  To investigate the distributions, degree, and possible sources of polycyclic aromatic hydrocarbons (PAHs) in bed sediments from four rivers of Xinxiang, 18 sediment samples were analyzed. The concentrations ranged from 4.45 × 10(3) to 29.0 × 10(3) ng/g for ∑15PAHs (sum of US Environmental Protection Agency (EPA) priority PAHs apart from naphthalene (Nap)) and 3.37 × 10(3) to 23.5 × 10(3) ng/g for ∑7carPAHs (including benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenzo[a,h]anthracene (DBA), and indeno[1,2,3-cd]pyrene (InP)) with average concentrations of 10.7 × 10(3) and 7.99 × 10(3) ng/g, respectively. Compared with those from other rivers in China, sediments from four rivers of Xinxiang were severely polluted with PAHs. Pearson correlation analysis showed that ∑15PAHs concentrations had a significant positive correlation with black carbon content. Four- to six-ring PAHs accounted for 83.4 % of total PAHs, which indicated that the main source of PAHs in the studied area could be pyrogenic contamination. Source apportionment using PCA/MLR and UNMIX revealed that coal and biomass combustion contributed 64.4-67.1 %, gasoline vehicle 23.2-27.2 %, and diesel vehicle 5.70-12.4 % of the total PAHs, respectively. The effects range low/effects range median (ERL/ERM) values showed that there was a high level of toxicity risk for BaA. The ecological risk assessment by mean effects range median quotients (mERMQ) revealed a medium ecological risk of ∑15PAHs in sediments from four rivers of Xinxiang, manifesting that a close attention should be paid to pollution of PAHs in the studied area.

Journal Article

Abstract  Recent advances in toxicogenomics present an opportunity to develop new in vitro testing methodologies to identify human carcinogens. We have investigated microRNA expression responses to the treatment of human liver HepaRG cells with the human genotoxic carcinogens aflatoxin B1 (AFB1) and benzo[a]pyrene (B[a]P), and the structurally similar compounds aflatoxin B2 (AFB2) and benzo[e]pyrene (B[e]P) that exhibit minimal carcinogenic potential. We demonstrate that treatment of HepaRG cells with AFB1 or B[a]P resulted in specific changes in the expression of miRNAs as compared with their non-carcinogenic analogues, particularly in a marked over-expression of miR-410. An additional novel finding is the dose- and time-dependent inhibition of miR-122 in AFB1-treated HepaRG cells. Mechanistically, the AFB1-induced down-regulation of miR-122 was attributed to inhibition of the HNF4A/miR-122 regulatory pathway. These results demonstrate that HepaRG cells can be used to investigate miRNA responses to xenobiotic exposure, and illustrate the existence of early non-genotoxic events, in addition to a well-established genotoxic mode of action changes, in the mechanism of AFB1 and B[a]P carcinogenicity.

Journal Article

Abstract  Phasor plots of the fluorescence intensity decay (plots of the Fourier sine transform versus the Fourier cosine transform, for one or several angular frequencies) are being increasingly used in studies of homogeneous and heterogeneous systems. In this work, the phasor approach is applied to monomer-excimer kinetics. The results obtained allow a clear visualization of the information contained in the decays. The monomer phasor falls inside the universal circle, whereas the excimer phasor lies outside it, but within the double-exponential outer boundary curve. The monomer and excimer phasors, along with those corresponding to the two exponential components of the decays, fall on a common straight line and obey the generalized lever rule. The clockwise trajectories described by both phasors upon monomer concentration increase are identified. The phasor approach allows discussing in a single graphic not only the effect of concentration but also that of rate constants, including the evolution from irreversible kinetics to fast excited-state equilibrium upon a temperature increase. The obtained results are applied to the fluorescence decays of pyrene monomer and excimer in methylcyclohexane at room temperature. A straightforward method of monomer-excimer lifetime data analysis based on linear plots is also introduced.

Journal Article

Abstract  In order to improve the mechanical properties of poly(L-lactide) (PLLA) based implants, a study was made of how far well dispersed multi-walled carbon nanotubes (MWCNTs) within a PLLA matrix were able to positively affect these properties. To this end, pyrene-end-functionalized poly(L-lactide) (py-end-PLLA) was evaluated as a dispersing agent. Transmission electron microscopy (TEM) analyses and mechanical tests of MWCNTs-based materials demonstrated an enhancement of MWCNT dispersion in the PLLA matrix and improved Young's modulus (E) when 4 wt% of py-end-PLLA was used as the dispersing agent. Subsequently, the bioacceptance of PLLA/py-end-PLLA/MWCNTs nanocomposites was evaluated using human bone marrow stromal cells (HBMC) in vitro. The inclusion of py-end-PLLA and MWCNTs supported HBMC adhesion and proliferation. The expression levels of the bone-specific markers indicated that the cells kept their potential to undergo osteogenic differentiation. The results of this study indicate that the addition of MWCNT combined with py-end-PLLA in PLLA/py-end-PLLA/MWCNTs nanocomposites may widen the range of applications of PLLA within the field of bone tissue engineering thanks to their mechanical strength and cytocompatibility.

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Journal Article

Abstract  Label-assisted laser desorption/ionization (LA-LDI) technique has recently been applied to the detection of small molecules through a time of flight (TOF) mass spectrometric measurement. By excluding the external matrix, the mass spectrum becomes much cleaner being free of matrix related peaks and noises. Peaks corresponding to compounds/complexes formed between the analytes and the label are mostly seen in the spectrum. In this paper we report a LA-LDI mass spectrometry based method for detection of amines, including the ones ubiquitous to biological samples like biogenic amines, amino acids, di- and tripeptides using 1-pyrene carboxaldehyde as the LDI label. © The Royal Society of Chemistry 2015.

Journal Article

Abstract  We report herein the synthesis and characterization of two monometallic ruthenium(II) and osmium(II) complexes of composition [(bpy)2M(HImzPPy)] (ClO4)2 derived from pyrenylimidazole-10-pyridin-2-yl-9H-9,11-diazacyclopenta[e]pyrene (HImzPPy) and 2,2'-bipyridine (bpy) ligands. X-ray crystallographic study shows that both crystals belong to the triclinic system having space group P1̅. The photophysical properties of 1 and 2 in acetonitrile indicate that the metal-to-ligand charge-transfer excited state is mainly centered in the [M(bpy)2](2+) moiety of the complexes and slightly affected by the extended conjugation of the pyrenylimidazole moiety. Both complexes display one-electron reversible metal-centered oxidative processes and a number of quasi-reversible reductive processes. The binding affinities of the complexes toward calf-thymus DNA (CT-DNA) were thoroughly studied through different methods such as absorption, emission, excited-state lifetime, circular dichroism, and thermal denaturation of DNA and a relative DNA binding study using ethidium bromide. All of these experiments account for the intercalative nature of both 1 and 2 toward CT-DNA as well as their light-switch behavior. The anion recognition study through different spectroscopic techniques reveals that both complexes act as "turn-on" luminescence sensors for H2PO4(-) and "turn-off" sensors toward F(-) and AcO(-). The imidazole N-H proton of the receptors gets deprotonated with the excessive addition of F(-) and AcO(-), while it interacts with H2PO4(-) through hydrogen-bonding interaction. Theoretical calculations (DFT and TD-DFT) were also performed to understand the photophysical properties of the metalloreceptors.

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Journal Article

Abstract  In this study, we designed and investigated pH-responsive nanoparticles based on different ratios of monomers with primary, secondary or tertiary amino groups. For this purpose, copolymers of methyl methacrylate (MMA) with different compositions of amino methacrylates (2-(dimethylamino)ethyl methacrylate (DMAEMA), 2-(tert-butylamino)ethyl methacrylate (tBAEMA) and 2-aminoethyl methacrylate hydrochloride (AEMA·HCI)) were synthesized using the reversible addition-fragmentation chain transfer (RAFT) polymerization process. The controlled nature of the radical polymerization was demonstrated by kinetic studies. All copolymers show low dispersities (D strok signM<1.2) with amino contents between 9 and 21 mol %. For the nanoparticle formation, nanoprecipitation with subsequent solvent evaporation was used. All suspensions were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Different initial conditions of the formulations resulted in differently sized nanoparticles that have monomodal size distributions, relatively narrow polydispersity index (PDI) values and positive zeta potential values. The pH-stability test results demonstrated that, depending on the structure and amount of the amino content, the obtained nanoparticles reveal a reversible pH-response, such as dissolution at acidic pH values. The ability of the nanoparticles to encapsulate guest molecules was confirmed by pyrene fluorescence studies. The cytotoxicity assay results showed that the nanoparticles did not have any significant cytotoxic effect. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2711-2721.

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Journal Article

Abstract  A new π-conjugated copolymer having TTFV and pyrene repeat units was synthesized and found to exhibit reversible redox activity, while the self-aggregation behaviour in solution phase was found to be responsive to external stimuli (solvent and pH). This journal is © The Royal Society of Chemistry 2015.

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Journal Article

Abstract  The synthesis of a monomer containing fourfold hydrogen bonding groups 2-(((6-(6-methyl-4[1H]pyrimidionylureido)hexyl)carbamoyl)oxy)ethyl methacrylate (UPyEMA) and its copolymerization with either n-butyl acrylate, tert-butyl acrylate, or styrene using reversible addition-fragmentation chain transfer (RAFT) polymerization is reported. The copolymers possessed high molecular weight and narrow molecular weight distributions and formed stable organogels in both chloroform and 1,2-dichlorobezene. Critical gelation concentrations were determined and the rheology of the organogels characterized. A novel monomer containing pyrene was prepared, and its polymerization under RAFT control was demonstrated. The pyrene-containing monomer was copolymerized with the polymer organogelators forming fluorescent organogels. It is proposed that these gels are suitable for two-photon upconversion applications. © 2015, Springer-Verlag Berlin Heidelberg.

Journal Article

Abstract  The possibility of controlling the compression extent and the coiling shape of the 1,12-diammoniumdodecane guest is shown by changing the dimensions of the internal space of the host guanidinium 1,3,5,8 pyrene-tetrasulfonate PTS(4-) crystalline capsules by using guanidinium (G(+)), amino-guanidinium (AG(+)), and diaminoguanidinium (A2G(+)) cations.

Journal Article

Abstract  Light-harvesting complexes collect light energy and deliver it by a cascade of energy and electron transfer processes to the reaction center where charge separation leads to storage as chemical energy. The design of artificial light-harvesting assemblies faces enormous challenges because several antenna chromophores need to be kept in close proximity but self-quenching needs to be avoided. Double stranded DNA as a supramolecular scaffold plays a promising role due to its characteristic structural properties. Automated DNA synthesis allows incorporation of artificial chromophore-modified building blocks, and sequence design allows precise control of the distances and orientations between the chromophores. The helical twist between the chromophores, which is induced by the DNA framework, controls energy and electron transfer and thereby reduces the self-quenching that is typically observed in chromophore aggregates. This Account summarizes covalently multichromophore-modified DNA and describes how such multichromophore arrays were achieved by Watson-Crick-specific and DNA-templated self-assembly. The covalent DNA systems were prepared by incorporation of chromophores as DNA base substitutions (either as C-nucleosides or with acyclic linkers as substitutes for the 2'-deoxyribofuranoside) and as DNA base modifications. Studies with DNA base substitutions revealed that distances but more importantly relative orientations of the chromophores govern the energy transfer efficiencies and thereby the light-harvesting properties. With DNA base substitutions, duplex stabilization was faced and could be overcome, for instance, by zipper-like placement of the chromophores in both strands. For both principal structural approaches, DNA-based light-harvesting antenna could be realized. The major disadvantages, however, for covalent multichromophore DNA conjugates are the poor yields of synthesis and the solubility issues for oligonucleotides with more than 5-10 chromophore modifications in a row. A logical alternative approach is to leave out the phosphodiester bridges between the chromophores and let chromophore-nucleoside conjugates self-assemble specifically along single stranded DNA as template. The self-organization of chromophores along the DNA template based on canonical base pairing would be advantageous because sequence selective base pairing could provide a structural basis for programmed complexity within the chromophore assembly. The self-assembly is governed by two interactions. The chromophore-nucleoside conjugates as guest molecules are recognized via hydrogen bonds to the corresponding counter bases in the single stranded DNA template. Moreover, the π-π interactions between the stacked chromophores stabilize these self-assembled constructs with increasing length. Longer DNA templates are more attractive for self-assembled antenna. The helicity in the stack of porphyrins as guest molecules assembled on the DNA template can be switched by environmental changes, such as pH variations. DNA-templated stacks of ethynyl pyrene and nile red exhibit left-handed chirality, which stands in contrast to similar covalent multichromophore-DNA conjugates with enforced right-handed helicity. With ethynyl nile red, it is possible to occupy every available binding site on the templates. Mixed assemblies of ethynyl pyrene and nile red show energy transfer and thereby provide a proof-of-principle that simple light-harvesting antennae can be obtained in a noncovalent and self-assembled fashion. With respect to the next important step, chemical storage of the absorbed light energy, future research has to focus on the coupling of sophisticated DNA-based light-harvesting antenna to reaction centers.

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Journal Article

Abstract  Solvent effects on the quenching process from the first excited state of 5-(1-pyrenyl)-2′-deoxyuridine (Py-dU) were theoretically examined. Our results suggest that the excited-state electron transfer occurs without the so-called proton-coupled electron transfer process, which supports experimental results. Although there are no remarkable differences observed in the structure and the corresponding S1 excitation energy between the solutions of MeOH and MeCN within a polarizable continuum model, we report here that hydrogen bonds between the explicit MeOH molecule with the dU moiety, whose structure was frequently found in molecular dynamics simulations, result in an enhancement of the electron-transfer rate constant. © 2015 Elsevier B.V.

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Journal Article

Abstract  This study was designed to assess the effect of soil acidification on the extractability of polycyclic aromatic hydrocarbons (PAHs) distributed across various soil organic matter fractions. Phenanthrene, anthracene and pyrene (each at 3.2mgkg-1 soil) were applied to a natural soil and to an artificially acidified soil, and the samples were incubated for 10days. Several solvents were tested for the recovery of PAHs from soil, and n-hexane was the best for extraction efficiency. Soil was treated with hydroxypropyl-β-cyclodextrin (HPCD), pyrophosphate or pyrophosphate-HPCD in sequence followed by the recovery of residual PAHs in n-hexane. Recovery of PAHs by a single-step non-exhaustive n-hexane extraction from acidified soil was significantly less than that from the original non-acidified soil (P=0.023). Based on the sequential extraction, the pool of n-hexane extractable PAHs was classified operationally into four fractions: one portion that is shared with HPCD (HS), one shared with pyrophosphate (PS) and one with both HPCD and pyrophosphate (HPS), and one that is not shared (US). The sum of PAHs recovered from acidified soil was significantly less than that for non-acidified soil when compared for PS fractions (5.37 and 14.42%, respectively, with P=0.003) or US fractions (47.76 and 54.00%, respectively, P<0.001). In contrast, soil acidification increased the sum of PAHs recovered in HS (from 4.29% (non-acidic) to 5.39% (acidified), P=0.014) and HPS fractions (from 23.8% (non-acidic) to 30% (acidified), P<0.001). The results suggest that soil acidification reduces the pool of PAHs that is accessible exclusively by organic solvents, but increases the fraction that can be extracted with HPCD or pyrophosphate or both. Spectroscopic analysis (Fourier transform infrared spectroscopy and ultraviolet-visible analysis) of isolated humic substances reveals their greater aromaticity when extracted from acidified soil, which might explain the larger proportion of surface-adsorbed PAHs in soil organic matter that can be dissolved by an aqueous extractant. © 2016 British Society of Soil Science.

Journal Article

Abstract  Damage to p53 tumor suppressor gene is found in half of all human cancers. Databases integrating studies of large numbers of tumors and cancer cell cultures show that mutation sites of specific p53 codons are correlated with specific types of cancers. If the most frequently damaged p53 codons in vivo correlate with the most frequent chemical damage sites in vitro, predictions of organ-specific cancer risks might result. Herein, we describe LC-MS/MS methodology to reveal codons with metabolite-adducted nucleobases by LC-MS/MS for oligonucleotides longer than 20 base pairs. Specifically, we used a known carcinogen, benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) to determine the most frequently adducted nucleobases within codons. We used a known sequence of 32 base pairs (bp) representing part of p53 exon 7 with 5 possible reactive hot spots. This is the first nucleobase reactivity study of a double stranded DNA p53 fragment featuring more than 20 base pairs with multiple reactive sites. We reacted the 32 bp fragment with benzo[a]pyrene metabolite BPDE that undergoes nucleophilic substitution by DNA bases. Liquid chromatography-mass spectrometry (LC-MS/MS) was used for sequencing of oligonucleotide products from the reacted 32 bp fragment after fragmentation by a restriction endonuclease. Analysis of the adducted p53 fragment compared with unreacted fragment revealed guanines of codons 248 and 244 as most frequently targeted, which are also mutated with high frequency in human tumors. Codon 248 is mutated in non-small cell and small cell lung, head and neck, colorectal and skin cancer, while codon 244 is mutated in small cell lung cancer, all of which involve possible BDPE exposure. Results suggest the utility of this approach for screening of adducted p53 gene by drugs and environmental chemicals to predict risks for organ specific cancers.

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Journal Article

Abstract  The fluorescent probe is constructed by incorporating an α, β-unsaturated pyridinium to a pyrene fluorophore. The chemodosimeter has shown a selective and sensitive response to sulfite anion over other various anions and biological thiol through a Michael addition of the sulfite to the alkene of the probe. Meanwhile, it can be easily observed that the color of the probe for sulfite changes from yellow to colorless by the naked eye, and from yellow to blue under UV lamp immediately after the sulfite is added. © 2015 Elsevier Ltd. All rights reserved.

Journal Article

Abstract  Due to its important biological and clinical roles of polynucleotide kinase (PNK), accurate monitoring of PNK activity and inhibition is highly desirable. Herein, a homogeneous and sensitive fluorescence assay has been proposed for the detection of PNK activity by integrating target recycling signal amplification of DNA toehold strand displacement reaction (TSDR) with gamma-cyclodextrin (γ-CD) enhancement of pyrene excimer. A label-free hairpin DNA1 (H1) and two singly pyrene-labelled DNA, H2 and H3, are designed. Accompanying the occurrence of the efficient enzyme reactions, namely phosphorylation-actuated λ exonuclease reaction, a single-stranded DNA as a trigger DNA (tDNA) of TSDR can be released from H1. Then, tDNA drives circulatory interactions between H2 and H3 to continuously form H2/H3 duplex, resulting in formation of pyrene excimer and a "turn on" fluorescence signal of pyrene excimer. Furthermore, the fluorescence of pyrene excimer is further amplified by introducing gamma-cyclodextrin (γ-CD), which can regulate the space proximity of two pyrene molecules. Thus, TSDR-induced cyclic formation of pyrene excimer and γ-CD enhancement can specifically up-regulate the fluorescence of pyrene excimer for detection of PNK activity, the detection limit is 9.3×10(-5)UmL(-1), which is superior to those of most existing approaches. Moreover, the proposed strategy can also be successfully utilized to study inhibition efficiency of different PNK inhibitors as well. Therefore, a dual amplification approach is provided for nucleic acid phosphorylation related researches.

Journal Article

Abstract  Herein, we have developed a one-pot method for the fabrication of one-dimensional core/shell microrods with tunable shell compositions by the introduction of additives. Crystalline dimethyl melamine hydrochloride was utilized as the core, while melamine derivatives with different functional groups, such as pyrene, thiophene and naphthalene diimide, served as additives to regulate the core morphology and were adsorbed as the shell. The length and width of these one-dimensional structures can be tuned by varying the molar ratio of core and shell molecules as well as their total concentration. Through X-ray diffraction, the detailed molecular arrangements within the core of the microrods were revealed, and the selective effect of additives on specific crystal faces was evaluated. It is anticipated that this work may provide a facile approach for the fabrication of one-dimensional functional materials.

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Journal Article

Abstract  An intramolecular oxidative C-C bond formation reaction of a 1,2-bis(pyren-2-yl)benzene derivative gave benzodinaphthopentaphene, a new polycyclic aromatic hydrocarbon. Its expanded it-system induced a bathochromic shift in the absorption spectrum and amphoteric multi redox processes in electrochemistry. Furthermore, the [5]helicene moiety of the molecule induced helical chirality.

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Journal Article

Abstract  A double hydrophilic block copolymer with β-cyclodextrin end-groups was prepared via RAFT polymerization and click reaction. The micelle formation of the polymer has been investigated as a function of temperature and pH values. The release of the encapsulated fluorescent probe pyrene from the polymer can be controlled by variation of temperature and addition of adamantanyl-NH3Cl. This journal is © The Royal Society of Chemistry 2015.

Journal Article

Abstract  Fluorescence excitation emission matrices-parallel factor analysis (EEM-PARAFAC) is a powerful tool for characterizing dissolved organic matter (DOM), and it is applied in a rapidly growing number of studies on drinking water and wastewater treatments. This paper presents an overview of recent findings about the occurrence and behavior of PARAFAC components in drinking water and wastewater treatments, as well as their feasibility for assessing the treatment performance and water quality including disinfection by-product formation potentials (DBPs FPs). A variety of humic-like, protein-like, and unique (e.g., pyrene-like) fluorescent components have been identified, providing valuable insights into the chemical composition of DOM and the effects of various treatment processes in engineered systems. Coagulation/flocculation-clarification preferentially removes humic-like components, and additional treatments such as biological activated carbon filtration, anion exchange, and UV irradiation can further remove DOM from drinking water. In contrast, biological treatments are more effective for protein-like components in wastewater treatments. PARAFAC components have been proven to be valuable as surrogates for conventional water quality parameter, to track the changes of organic matter quantity and quality in drinking water and wastewater treatments. They are also feasible for assessing formations of trihalomethanes and other DBPs and evaluating treatment system performance. Further studies of EEM-PARAFAC for assessing the effects of the raw water quality and variable treatment conditions on the removal of DOM, and the formation potentials of various emerging DBPs, are essential for optimizing the treatment processes to ensure treated water quality.

Journal Article

Abstract  PURPOSE: To investigate the risk of non-Hodgkin lymphoma (NHL) associated with residential carpet dust measurements of polycyclic aromatic hydrocarbons (PAHs).

METHODS: We evaluated the relationship between residential carpet dust PAH concentrations (benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, and indeno(1,2,3-c,d)pyrene, and their sum) and risk of NHL (676 cases, 511 controls) in the National Cancer Institute Surveillance Epidemiology and End Results multicenter case-control study. As a secondary aim, we investigated determinants of dust PAH concentrations. We computed odds ratios (OR) and 95 % confidence interval (CI) for associations between NHL and concentrations of individual and summed PAHs using unconditional logistic regression, adjusting for age, gender, and study center. Determinants of natural log-transformed PAHs were investigated using multivariate least-squares regression.

RESULTS: We observed some elevated risks for NHL overall and B cell lymphoma subtypes in association with quartiles or tertiles of PAH concentrations, but without a monotonic trend, and there was no association comparing the highest quartile or tertile to the lowest. In contrast, risk of T cell lymphoma was significantly increased among participants with the highest tertile of summed PAHs (OR = 3.04; 95 % CI, 1.09-8.47) and benzo(k)fluoranthene (OR = 3.20; 95 % CI, 1.13-9.11) compared with the lowest tertile. Predictors of PAH dust concentrations in homes included ambient air PAH concentrations and the proportion of developed land within 2 km of a residence. Older age, more years of education, and white race were also predictive of higher levels in homes.

CONCLUSION: Our results suggest a potential link between PAH exposure and risk of T cell lymphoma and demonstrate the importance of analyzing risk by NHL histologic type.

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Journal Article

Abstract  3-Thienylacetic acid was converted in six steps into a new spirobi[thieno[2,3-c]pyran] (overall yield: 52%). The spirobi[thieno[2,3-c]pyran] was selectively mono- or dimetalated with butyllithium and then transmetalated with zinc chloride; cross-coupling reaction with various aryl or heteroaryl bromides, including bromo-oligothiophenes, acid chlorides, and 1-bromopyrene, produced the corresponding spiro derivatives in high yields. © Georg Thieme Verlag Stuttgart New York Synthesis 2015.

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