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Tomasz Molcan, Sylwia Swigonska, Karina Orlowska, Kamil Myszczynski, Anna Nynca, Agnieszka Sadowska, Monika Ruszkowska, Jan Pawel Jastrzebski, Renata E Ciereszko
Polychlorinated dibenzo-p-dioxins (PCDDs) are widespread by-products of human industrial activity. They accumulate in tissues of animals and humans, exerting numerous adverse effects on different systems. In living organisms, dioxins are metabolized by enzymes of the cytochrome P450 family, including CYP1A1. Particular dioxin congeners differ in their toxicity level and ability to undergo biodegradation. Since the molecular mechanisms underlying dioxin susceptibility or resistance to biodegradation are unknown, in the present study the molecular interactions between five selected dioxins and porcine CYP1A1 protein were investigated...
October 23, 2016: Chemosphere
Xanthi D Andrianou, Stephanie Gängler, Andra Piciu, Pantelis Charisiadis, Christina Zira, Kyriacos Aristidou, Doina Piciu, Russ Hauser, Konstantinos C Makris
Although the increasing prevalence of thyroid nodular disease (TND) has been partially attributed to the more frequent usage of improved diagnostics, environmental factors, such as exposures to thyroid-disrupting chemicals may contribute to TND and altered thyroid function. We investigated the association between exposures to bisphenol A (BPA), its chlorinated derivatives (ClxBPA), and bisphenol F (BPF) with TND and thyroid measures in adult women. A case-control study in Cyprus and Romania (n = 212) was conducted, where cases were those with thyroid nodules (diameter >3mm), and controls without nodules...
2016: PloS One
Jonathan Mellor, Emily Kumpel, Ayse Ercumen, Julie B Zimmerman
Anthropogenic climate change will likely increase diarrhea rates for communities with inadequate water, sanitation or hygiene facilities including those with intermittent water supplies. Current approaches to study these impacts typically focus on the effect of temperature on all-cause diarrhea while excluding precipitation and diarrhea etiology while not providing actionable adaptation strategies. We develop a partially mechanistic, systems approach to estimate future diarrhea prevalence and design adaptation strategies...
October 26, 2016: Environmental Science & Technology
Mohamad S Goodarzi, Hossein Saghafifar
A new method is presented to measure chlorine concentration more accurately than conventional method in exhaust gases of a jet-type singlet oxygen generator. One problem in this measurement is the existence of micrometer-sized droplets. In this article, an empirical method is reported to eliminate the effects of the droplets. Two wavelengths from a fiber coupled LED are adopted and the measurement is made on both selected wavelengths. Chlorine is measured by the two-wavelength more accurately than the one-wavelength method by eliminating the droplet term in the equations...
September 2016: Review of Scientific Instruments
Ching-Yin Chou, Yuan-Pern Lee
The addition reactions of chlorine atom with isobutene (i-C4H8) in solid para-hydrogen (p-H2) were investigated with infrared (IR) absorption spectra. When a p-H2 matrix containing Cl2 and isobutene was irradiated with ultraviolet light at 365 nm, intense lines in a set at 534.5, 1001.0, 1212.9, 1366.0, 2961.6, and 2934.7 cm(-1), and several weaker others due to the 1-chloro-2-methyl-2-propyl radical, (⋅)C(CH3)2CH2Cl, and those in a second set including intense ones at 642.7, 799.2, 1098.2, 1371.8, and 3027...
October 7, 2016: Journal of Chemical Physics
Ji Hoon Kang, Kyung Bin Song
An aqueous chlorine dioxide (ClO₂) treatment combined with highly activated calcium oxide (CaO) and mild heat inactivated naturally existing bacteria and Escherichia coli O157:H7 inoculated on fresh-cut kale. Kale samples were treated with different concentrations of ClO₂ (10, 30, and 50 ppm), CaO (0.01, 0.05, 0.1, and 0.2%), and mild heat (25, 45, 55, and 65°C) as well with combinations of 30 or 50 ppm ClO₂ and 0.2% CaO at 55°C for 3 min. An increasing concentration of ClO₂ and CaO significantly reduced the microbial population compared to the control...
October 25, 2016: Journal of Microbiology and Biotechnology
Norma Tombesi, Karla Pozo, Mónica Álvarez, Petra Přibylová, Petr Kukučka, Ondřej Audy, Jana Klánová
PCBs and PBDEs (7 and 10 congeners, respectively) were analyzed in four coastal surface sediments collected from the northern shore of Bahía Blanca estuary and in nine soils from different locations of Bahía Blanca city and the surrounding region (Southwest of Buenos Aires Province, Argentina). Sediment samples showed PCBs(Σ7) concentrations ranged from 0.61 to 17.6ngg(-1) (dry weight=dw) and PBDEs(Σ10) from 0.16 to 2.02ngg(-1) dw, whereas in soil samples ranged from 0.04 to 1.67ngg(-1) dw for PCBs(Σ7) and 0...
October 22, 2016: Science of the Total Environment
Sai Zheng, Jia-Chen Shi, Jian-Ying Hu, Wen-Xin Hu, Jing Zhang, Bing Shao
The reaction kinetics and transformation pathways between bisphenol F (BPF) and sodium hypochlorite were investigated at pH values ranging from 6.5 to 8.5 and with different initial concentration ratios. The reaction rate was pH- and free available chlorine (FAC)-dependent: the reaction rate at pH 8.5 was almost 10 times than that at pH 6.5. A total of 40 compounds were tentatively identified as chloro-substituted BPF and polyphenolic compounds by liquid chromatography quadrupole time-of-flight mass spectrometry operating in electrospray ionization mode (LC-ESI-Q-ToF), and 4 main byproducts were confirmed by (1)H and (13)C nuclear magnetic resonance (NMR)...
October 19, 2016: Water Research
Yangyang Chang, Yaohui Bai, Qinghua Ji, Yang Huo, Huijuan Liu, John C Crittenden, Jiuhui Qu
The toxicity of disinfection by-products (DBPs) from a single precursor was studied intensively. Here we examined the genotoxicity when two precursors (tyrosine (Tyr) and benzophenone-4 (BP-4)) were chlorinated together and separately. We sought to examine whether the genotoxicity of the mixture (GCM) could be estimated from the sum of the genotoxicities of the individual precursors (GCI), which were chlorinated separately. We determined the genotoxicity using the SOS/umu test. The results revealed that GCM was not identical to GCI...
October 11, 2016: Journal of Hazardous Materials
Li-Zhi Huang, Hans Christian B Hansen, Kim Daasbjerg
Graphene-based nanomaterials can mediate environmentally relevant abiotic redox reactions of chlorinated aliphatic hydrocarbons. In this study as low amounts as ∼0.007 % of graphene oxide (GO) was found to catalyze the reduction of carbon tetrachloride by layered Fe(II)-Fe(III) hydroxide (Green Rust, GR) in aqueous solutions with chloroform being the reduction product. On the basis of sorption studies of carbon tetrachloride onto the GO surface it is suggested that it is the amphiphilicity of GO, which initiates the reaction by providing a suitable reaction platform for the reagents...
October 18, 2016: Journal of Hazardous Materials
Xiaolan Zeng, Jing Chen, Ruijuan Qu, Xiaoxue Pan, Zunyao Wang
The atmospheric chemical reactions of some polyfluorinated dibenzofurans (PFDFs) and polychlorinated dibenzofurans (PCDFs), initiated by OH radical, were investigated by performing theoretical calculations using density functional theory (DFT) and B3LYP/6-311++G(2df,p) method. The obtained results indicate that OH addition reactions of PFDFs and PCDFs occurring at C1∼4 and CA sites are thermodynamic spontaneous changes and the branching ratio of the PF(C)DF-OH adducts is decided primarily by kinetic factor...
October 21, 2016: Chemosphere
J D Major, M Al Turkestani, L Bowen, M Brossard, C Li, P Lagoudakis, S J Pennycook, L J Phillips, R E Treharne, K Durose
CdTe thin-film solar cells are now the main industrially established alternative to silicon-based photovoltaics. These cells remain reliant on the so-called chloride activation step in order to achieve high conversion efficiencies. Here, by comparison of effective and ineffective chloride treatments, we show the main role of the chloride process to be the modification of grain boundaries through chlorine accumulation, which leads an increase in the carrier lifetime. It is also demonstrated that while improvements in fill factor and short circuit current may be achieved through use of the ineffective chlorides, or indeed simple air annealing, voltage improvement is linked directly to chlorine incorporation at the grain boundaries...
October 24, 2016: Nature Communications
Yong Guo, Ruige Yang, Hui Xu
Introduction of the halogen atom or the acyl group at the C-ring of fraxinellone was investigated. Some unexpected halogenation products were obtained with the different chlorination/bromination reagents, and their possible reaction mechanisms were also proposed. Seven key steric structures of 2a', 2b, 2b', 2c', 3a, 3b, and one isomer (5'α-Cl) of 2a were further confirmed by single-crystal X-ray diffraction. Especially compounds 2a, 2a', 3a and 3c exhibited more potent insecticidal activity than toosendanin...
October 24, 2016: Scientific Reports
Eric H Wilson, Sushil K Atreya, Ralf I Kaiser, Paul R Mahaffy
Recent observations of the Martian surface by the Phoenix lander and the Sample Analysis at Mars indicate the presence of perchlorate (ClO4(-)). The abundance and isotopic composition of these perchlorates suggest that the mechanisms responsible for their formation in the Martian environment may be unique in our solar system. With this in mind, we propose a potential mechanism for the production of Martian perchlorate: the radiolysis of the Martian surface by galactic cosmic rays, followed by the sublimation of chlorine oxides into the atmosphere and their subsequent synthesis to form perchloric acid (HClO4) in the atmosphere, and the surface deposition and subsequent mineralization of HClO4 in the regolith to form surface perchlorates...
August 2016: Journal of Geophysical Research. Planets
Yu-Hsuan Chen, Chia-Yu Chang, Wang-Hsien Ding
A simple and effective method for determining short chain chlorinated paraffins (SCCPs) in indoor dust is presented. The method employed a modified vortex-homogenized matrix solid-phase dispersion (VH-MSPD) prior to its detection by gas chromatography - electron-capture negative-ion mass spectrometry (GC-ECNI-MS) operating in the selected-ion-monitoring (SIM) mode. Under the best extraction conditions, 0.1-g of dust sample was dispersed with 0.1-g of silica gel by using vortex (2min) instead of using a mortar and pestle (3min)...
October 19, 2016: Journal of Chromatography. A
Glen Andrew de Vera, Jurg Keller, Wolfgang Gernjak, Howard Weinberg, Maria José Farré
Ozonation is known to generate biodegradable organic matter, which is typically reduced by biological filtration to avoid bacterial regrowth in distribution systems. Post-chlorination generates halogenated disinfection byproducts (DBPs) but little is known about the biodegradability of their precursors. This study determined the effect of ozonation and biofiltration conditions, specifically ozone exposure and empty bed contact time (EBCT), on the control of DBP formation potentials in drinking water. Ozone exposure was varied through addition of H2O2 during ozonation at 1 mgO3/mgDOC followed by biological filtration using either activated carbon (BAC) or anthracite...
October 8, 2016: Water Research
Zhan Zhou, Yuhui Zheng, Cheng Zhang Cheng, Jiajia Wen, Qianming Wang
Here we developed the first case of pyropheophorbide-a-loaded PEGylated-hybrid carbon nanohorns (CNH-Pyro) to study tumor targeting therapy. During incubation with living cells, CNH-Pyro exhibited very intense red emissions. The intracellular imaging results were carried out by flow cytometry based on four different kinds of cell lines (including three adherent cell lines and one suspension cell line). Compared with free pyropheophorbide-a, CNH-Pyro demonstrated enhanced photodynamic tumor ablation efficiency during in vitro experiments due to improved biocompatibility of the hybrid nanomaterial and the photothermal therapy effect derived from carbon-network structure...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Koji Kosaka, Keiko Ohkubo, Michihiro Akiba
The occurrence of six haloacetamides (HAcAms), which are a group of emerging nitrogenous disinfection byproducts, was investigated in drinking water across Japan in September 2015 and February 2016. At least one of the six HAcAms were found in all of the drinking water samples and their total concentrations ranged from 0.3 to 3.8 μg/L. The detection frequencies and concentrations of 2,2-dichloroacetamide (DCAcAm) and 2-bromo-2-chloroacetamide (BCAcAm) were the largest among the targeted HAcAm species. The total HAcAm concentrations in the raw water after chlorination ranged from 0...
October 13, 2016: Water Research
Zhongbing Chen, Jan Vymazal, Peter Kuschk
Three different flow regimes were carried out in a pilot-scale horizontal subsurface flow constructed wetland-treating sulfate rich wastewater contaminated with monochlorobenzene (MCB) and perchloroethene (PCE). The three regimes were continuous flow, 7-day cycle discontinuous flow, and 2.5-day cycle discontinuous flow. The results show that intensifying the tidal regime (2.5-day cycle) significantly enhanced MCB removal before 2 m from the inlet and increasing PCE removal efficiency at 0.5 m. The PCE dechlorination process was promoted with tidal operation, especially under the 2...
October 21, 2016: Environmental Science and Pollution Research International
Gabriel Chia Shi Zhe, Andrew Green, Yuke Tien Fong, Haur Yueh Lee, Sweet Far Ho
Sodium hypochlorite is a clear yellowish solution with a characteristic odour of chlorine and is commonly used as a disinfectant and a bleaching agent. It is used in various healthcare settings for its fast-acting and broad-spectrum antimicrobial activity. It is a known irritant and there are some reports that it can also cause allergic contact dermatitis of type IV hypersensitivity. We report a case of work-related type I hypersensitivity to sodium hypochlorite, presenting with recurrent urticarial rash and a positive prick test reaction to this chemical...
October 21, 2016: BMJ Case Reports
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