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Environmental chemistry

Yu-Feng Liang, Ning Jiao
The selective oxidation of organic molecules is a fundamentally important component of modern synthetic chemistry. In the past decades, direct oxidative C-H and C-C bond functionalization has proved to be one of the most efficient and straightforward methods to synthesize complex products from simple and readily available starting materials. Among these oxidative processes, the use of molecular oxygen as a green and sustainable oxidant has attracted considerable attention because of its highly atom-economical, abundant, and environmentally friendly characteristics...
June 21, 2017: Accounts of Chemical Research
David K DeForest, Robert C Santore, Adam C Ryan, Brian G Church, M Jasim Chowdhury, Kevin V Brix
The US Environmental Protection Agency's (USEPA's) current ambient water quality criteria (AWQC) for lead (Pb) in freshwater were developed in 1984. The criteria are adjusted for hardness, but more recent studies have demonstrated that other parameters, especially dissolved organic carbon (DOC) and pH, have a much stronger influence on Pb bioavailability. These recent studies have been used to support development of a biotic ligand model (BLM) for Pb in freshwater, such that acute and chronic Pb toxicity can be predicted over a wide range of water chemistry conditions...
June 21, 2017: Environmental Toxicology and Chemistry
Shamim Mia, Feike A Dijkstra, Balwant Singh
Biochar, a form of pyrogenic carbon, can contribute to agricultural and environmental sustainability by increasing soil reactivity. In soils, biochar could change its role over time through alterations in its surface chemistry. However, a mechanistic understanding of the aging process and its role in ionic nutrient adsorption and supply remain unclear. Here, we aged a wood biochar (550 °C) by chemical oxidation with 5-15% H2O2 and investigated the changes in surface chemistry and the adsorption behavior of ammonium and phosphate...
June 20, 2017: Environmental Science & Technology
Shan Wang, Liang Yue, Zohar Shpilt, Alessandro Cecconello, Jason S Kahn, Jean-Marie Lehn, Itamar Willner
Mimicking complex cellular dynamic chemical networks being up-regulated or down-regulated by external triggers is one of the challenges in system chemistry. Constitutional dynamic networks, CDNs, composed of exchangeable components that respond to environmental triggers by self-adaption, provide general means to mimic biosystems. We use the structural and functional information encoded in nucleic acid nanostructures to construct effector (input)-triggered constitutional dynamic networks that reveal adaptable catalytic properties...
June 19, 2017: Journal of the American Chemical Society
María Pedrero, Susana Campuzano, José M Pingarrón
The determination of organic and inorganic environmental and food pollutants is a key matter of concern in analytical chemistry due to their effects as a serious threat to human health. Focusing on this issue, several methodologies involving the use of nanostructured electrochemical platforms have been recently reported in the literature. Among these methods, those employing the use of quantum dots (QDs) stand out because of features such as signal amplification, good reproducibility and selectivity, and the possibility for multiplexed detection, and because they preserve the outstanding characteristics of electrochemical methodologies with respect to simplicity, ease-of-use, and cost-effective instrumentation...
June 16, 2017: Journal of AOAC International
Magdalena M Ślączka-Wilk, Elżbieta Włodarczyk, Aleksandra Kaleniecka, Paweł K Zarzycki
There is increasing interest in the development of simple analytical systems enabling the fast screening of target components in complex samples. A number of newly invented protocols are based on quasi separation techniques involving microfluidic paper-based analytical devices and/or micro total analysis systems. Under such conditions, the quantification of target components can be performed mainly due to selective detection. The main goal of this paper is to demonstrate that miniaturized planar chromatography has the capability to work as an efficient separation and quantification tool for the analysis of multiple targets within complex environmental samples isolated and concentrated using an optimized SPE method...
June 16, 2017: Journal of AOAC International
Juan J Villaverde, Carmen López-Goti, Manuel Alcamí, Al Mokhtar Lamsabhi, José L Alonso-Prados, Pilar Sandín-España
BACKGROUND: The scientific community and regulatory bodies worldwide, currently promote the development of non-experimental tests that produce reliable data for pesticide risk assessment. The use of standard quantum chemistry methods could allow the development of tools to perform a first screening of compounds to be considered for the experimental studies, improving the risk assessment. This fact results in a better distribution of resources and in better planning, allowing a more exhaustive study of the pesticides and their metabolic products...
June 15, 2017: Pest Management Science
Li-Li Wang, Zhao Chen, Wei-Er Liu, Hua Ke, Sheng-Hua Wang, Wei Jiang
Chiral epoxides are important intermediates in chemistry and biology. The high-throughput screening of asymmetric epoxidation conditions requires fast determination of the absolute configurations and ee values of chiral epoxides. Herein, we report molecular recognition and chiroptical sensing of epoxides in water using endo-functionalized molecular tubes. The absolute configurations and ee values were simultaneously determined by circular dichroism spectroscopy. In addition, real-time monitoring as well as the application to real asymmetric epoxidation was demonstrated...
June 15, 2017: Journal of the American Chemical Society
Rachel E Kerwin, Julie Feusier, Alise Muok, Catherine Lin, Brandon Larson, Daniel Copeland, Jason A Corwin, Matthew J Rubin, Marta Francisco, Baohua Li, Bindu Joseph, Cynthia Weinig, Daniel J Kliebenstein
Despite the growing number of studies showing that genotype × environment and epistatic interactions control fitness, the influences of epistasis × environment interactions on adaptive trait evolution remain largely uncharacterized. Across three field trials, we quantified aliphatic glucosinolate (GSL) defense chemistry, leaf damage, and relative fitness using mutant lines of Arabidopsis thaliana varying at pairs of causal aliphatic GSL defense genes to test the impact of epistatic and epistasis × environment interactions on adaptive trait variation...
June 13, 2017: New Phytologist
Adam Rajsz, Bronisław Wojtuń, Andrzej Bytnerowicz
In environmental research (i.e., plant ecophysiology, environmental microbiology, and environmental chemistry), some assays require incubation of samples at controlled temperature and darkness. Until now, due to a lack of equipment providing such possibility in situ, researchers had to move collected samples to the laboratory for incubation. Obviously, a delayed incubation and the ex situ conditions could seriously affect the assays' results. A good example of analysis where water bath use is needed is the nitrate reductase activity (NRA) in vivo assay where plant tissue samples are incubated in buffer solution at a predetermined temperature...
July 2017: Environmental Monitoring and Assessment
Zhiwei Wang, Xueye Wang, Junyao Zhang, Xueqing Yu, Zhichao Wu
A clear understanding of the factors governing the deposition and release behaviors of engineered nanoparticles (NPs), such as TiO2 NPs, is necessary for predicting their transport and fate in both natural and engineered aquatic environments. In this study, impacts of specific chemistries on TiO2 NP deposition, as a function of TiO2 NP concentration and ionic strength/valence, were investigated using self-assembled monolayers (SAMs) with five different ending chemical functionalities (-CH3, -OH, -COOH, -NH2, and -CONH2)...
June 16, 2017: Environmental Science & Technology
Mary Doherty, Patricia L Yager, Mary Ann Moran, Victoria J Coles, Caroline S Fortunato, Alex V Krusche, Patricia M Medeiros, Jérôme P Payet, Jeffrey E Richey, Brandon M Satinsky, Henrique O Sawakuchi, Nicholas D Ward, Byron C Crump
Spatial and temporal patterns in microbial biodiversity across the Amazon river-ocean continuum were investigated along ∼675 km of the lower Amazon River mainstem, in the Tapajós River tributary, and in the plume and coastal ocean during low and high river discharge using amplicon sequencing of 16S rRNA genes in whole water and size-fractionated samples (0.2-2.0 μm and >2.0 μm). River communities varied among tributaries, but mainstem communities were spatially homogeneous and tracked seasonal changes in river discharge and co-varying factors...
2017: Frontiers in Microbiology
Muhammad Moazzam Naseer, Klaus Jurkschat
The field of anion recognition has developed into an area of tremendous significance over the recent decades due to the role of anions in biological and environmental systems, contributing significantly to the more general domain of supramolecular chemistry. So far, a number of receptors have been designed for anion recognition, synthesized and evaluated, most involving hydrogen bonding donors (urea, amide, pyrrole, imidazolium and hydroxyl groups), π-acidic aryl rings, Lewis acidic metals (boron, tin, aluminium, mercury and uranium) and positively charged polyammonium moieties...
June 5, 2017: Chemical Communications: Chem Comm
Reshma S Nair, Jimna Mohamed Ameer, Malcolm R Alison, Thapasimuthu V Anilkumar
Extracellular matrices of xenogeneic origin have been extensively used for biomedical applications, despite the possibility of heterogeneity in structure. Surface modification of biologically derived biomaterials using nanoparticles is an emerging strategy for improving topographical homogeneity when employing these scaffolds for sophisticated tissue engineering applications. Recently, as a tissue engineering scaffold, cholecyst derived extracellular matrix (C-ECM) has been shown to have several advantages over extracellular matrices derived from other organs such as jejunum and urinary bladder...
May 26, 2017: Colloids and Surfaces. B, Biointerfaces
Elizabeth R Jones, Christopher J Martyniuk, Jeffrey M Morris, Michelle O Krasnec, Robert J Griffitt
The 2010 Deepwater Horizon (DWH) oil spill caused the release of 4.9 million barrels of crude oil into the Gulf of Mexico, followed by the application of 2.9 million L of the dispersant, Corexit™ to mitigate the spread of oil. The spill resulted in substantial shoreline oiling, potentially exposing coastal organisms to polyaromatic hydrocarbon (PAH) and dispersant contaminants. To investigate molecular effects in fish following exposure to environmentally relevant concentrations of DWH oil and dispersants, we exposed adult sheepshead minnows (Cyprinodon variegatus) to two concentrations of high-energy water-accommodated fraction (HEWAF), chemically enhanced water-accommodated fraction (CEWAF) or Corexit 9500™ for 7 and 14days...
May 26, 2017: Comparative Biochemistry and Physiology. Part D, Genomics & Proteomics
Hansell Gonzalez-Raymat, Guangliang Liu, Carolina Liriano, Yanbin Li, Yongguang Yin, Jianbo Shi, Guibin Jiang, Yong Cai
Elemental mercury (Hg(0)) has different behavior in the environment compared to other pollutants due to its unique properties. It can remain in the atmosphere for long periods of time and so can travel long distances. Through air-surface (e.g., vegetation or ocean) exchange (dry deposition), Hg(0) can enter terrestrial and aquatic systems where it can be converted into other Hg species. Despite being ubiquitous and playing a key role in Hg biogeochemical cycling, Hg(0) behavior in the environment is not well understood...
May 31, 2017: Environmental Pollution
W B F Jalil, A Pentón-Madrigal, A Mello, F A Carneiro, R M Soares, L S Baptista, J P Sinnecker, L A S de Oliveira
Superparamagnetic magnetite nanoparticles have been synthesized by a highly reproducible polyvinyl alcohol (PVA)-based modified sol-gel process using water as the only solvent. The synthesis method has proven to be effective, time and cost saving and environmental friendly, resulting in PVA-coated magnetite nanoparticles as direct product from the synthesis, without any special atmosphere or further thermal treatment. X-ray diffraction and transmission electron microscopy revealed that the biocompatible PVA-coating prevents the nanoparticle agglomeration, giving rise to spherical crystals with sizes of 6...
September 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Chloe E Emerson, Helena C Reinardy, Nicholas R Bates, Andrea G Bodnar
Increasing atmospheric carbon dioxide (CO2) has resulted in a change in seawater chemistry and lowering of pH, referred to as ocean acidification. Understanding how different organisms and processes respond to ocean acidification is vital to predict how marine ecosystems will be altered under future scenarios of continued environmental change. Regenerative processes involving biomineralization in marine calcifiers such as sea urchins are predicted to be especially vulnerable. In this study, the effect of ocean acidification on regeneration of external appendages (spines and tube feet) was investigated in the sea urchin Lytechinus variegatus exposed to ambient (546 µatm), intermediate (1027 µatm) and high (1841 µatm) partial pressure of CO2 (pCO2) for eight weeks...
May 2017: Royal Society Open Science
Feiyang Liu, Piaoping Tang, Ruihua Ding, Lujuan Liao, Lisheng Wang, Mian Wang, Jianyi Wang
A glycosylation strategy based on click chemistry was employed to develop a naphthalimide-based Fe(3+) fluorescent probe with low cytotoxicity and good water-solubility. The selectivity and sensitivity to Fe(3+) of three synthesized naphthalimide-based fluorescent probes follows a Nap-PZ < Nap-OH < Nap-Glc trend, because Nap-PZ was modified with a good water-soluble group. The cytotoxicity follows a Nap-PZ > Nap-OH > Nap-Glc trend, because the exposed toxic group of Nap-PZ was shielded by a good biocompatible group...
June 13, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
T Karl, M Graus, M Striednig, C Lamprecht, A Hammerle, G Wohlfahrt, A Held, L von der Heyden, M J Deventer, A Krismer, C Haun, R Feichter, J Lee
Nitrogen oxide (NOx) pollution is emerging as a primary environmental concern across Europe. While some large European metropolitan areas are already in breach of EU safety limits for NO2, this phenomenon does not seem to be only restricted to large industrialized areas anymore. Many smaller scale populated agglomerations including their surrounding rural areas are seeing frequent NO2 concentration violations. The question of a quantitative understanding of different NOx emission sources is therefore of immanent relevance for climate and air chemistry models as well as air pollution management and health...
May 30, 2017: Scientific Reports
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