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https://www.readbyqxmd.com/read/28346991/an-integrated-assessment-framework-for-the-analysis-of-multiple-pressures-in-aquatic-ecosystems-and-the-appraisal-of-management-options
#1
A Pistocchi, A Udias, B Grizzetti, E Gelati, P Koundouri, R Ludwig, A Papandreou, I Souliotis
The contribution illustrates an integrated assessment framework aimed at evaluating the relationships between multiple pressures and water body status for the purposes of river basin management. The framework includes the following steps. (1) Understanding how the different pressures affect the status of water bodies. This entails the characterization of biophysical state variables and the definition of a causal relationship between pressures and status. Therefore this step involves interaction between experts bearing ecological understanding and experts providing models to represent the effect of pressures...
January 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28346937/in-crystal-reaction-cycle-of-a-toluene-bound-diiron-hydroxylase
#2
Justin F Acheson, Lucas J Bailey, Thomas C Brunold, Brian G Fox
Electrophilic aromatic substitution is one of the most important and recognizable classes of organic chemical transformation. Enzymes create the strong electrophiles that are needed for these highly energetic reactions by using O2, electrons, and metals or other cofactors. Although the nature of the oxidants that carry out electrophilic aromatic substitution has been deduced from many approaches, it has been difficult to determine their structures. Here we show the structure of a diiron hydroxylase intermediate formed during a reaction with toluene...
March 27, 2017: Nature
https://www.readbyqxmd.com/read/28346905/modeling-the-terrestrial-n-processes-in-a-small-mountain-catchment-through-inca-n-a-case-study-in-taiwan
#3
Meng-Chang Lu, Chung-Te Chang, Teng-Chiu Lin, Lih-Jih Wang, Chiao-Ping Wang, Ting-Chang Hsu, Jr-Chuan Huang
Riverine dissolved inorganic nitrogen (DIN) is an important indicator of trophic status of aquatic ecosystems. High riverine DIN export in Taiwan, ~3800kg-Nkm(-2)yr(-1), which is ~18 times higher than the global average, urges the need of thorough understanding of N cycling processes. We applied INCA-N (Integrated Nitrogen Catchment Model) to simulate riverine DIN export and infer terrestrial N processes using weekly rainwater and streamwater samples collected at the Fushan Experimental Forest (FEF) of northern Taiwan...
March 24, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28346902/in-situ-synthesis-of-cobalt-ferrites-embedded-hollow-n-doped-carbon-as-an-outstanding-catalyst-for-elimination-of-organic-pollutants
#4
Tao Zeng, Mingdong Yu, Haiyan Zhang, Zhiqiao He, Xiaole Zhang, Jianmeng Chen, Shuang Song
Using polydopamine-metal ions complex as precursor, hollow mesoporous N-doped carbon microspheres encapsulating spinel ferrites nanocrystals (HM-NC/CoFe2O4) were facilely prepared with the aim of creating a novel heterogeneous catalyst for sulfate radical-based oxidation of organic contaminants. The surface morphology, structure and composition of HM-NC/CoFe2O4 catalyst were thoroughly investigated. The applicability of the catalyst was systematically assessed through numerous controlled trials, several operating parameters, as well as different model pollutants by means of peroxymonosulfate (PMS) activation...
March 24, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28346901/boundary-work-for-implementing-adaptive-management-a-water-sector-application
#5
Blal Adem Esmail, Davide Geneletti, Christian Albert
Boundary work, defined as effort to mediate between knowledge and action, is a promising approach for facilitating knowledge co-production for sustainable development. Here, we investigate a case study of knowledge co-production, to assess the applicability of boundary work as a conceptual framework to support implementing adaptive management in the water sector. We refer to a boundary work classification recently proposed by Clark et al., (2016), based on three types of knowledge uses, i.e. enlightenment, decision-, and negotiation-support, and three types of sources, i...
March 24, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28346898/modelling-of-escherichia-coli-concentrations-in-bathing-water-at-microtidal-coasts
#6
A Palazón, I López, L Aragonés, Y Villacampa, F J Navarro-González
Monitoring of the quality of bathing water in line with the European Commission bathing water directive (Directive 2006/7/EC) is a significant economic expense for those countries with great lengths of coastline. In this study a numerical model based on finite elements is generated whose objective is partially substituting the microbiological analysis of the quality of coastal bathing waters. According to a study of the concentration of Escherichia coli in 299 Spanish Mediterranean beaches, it was established that the most important variables that influence the concentration are: monthly sunshine hours, mean monthly precipitation, number of goat cattle heads, population density, presence of Posidonia oceanica, UV, urbanization level, type of sediment, wastewater treatment ratio, salinity, distance to the nearest discharge, and wave height perpendicular to the coast...
March 24, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28346886/simultaneous-determination-of-amitraz-chlordimeform-formetanate-and-their-main-metabolites-in-human-urine-by-high-performance-liquid-chromatography-tandem-mass-spectrometry
#7
Xue Gao, Yanglan Tan, Hao Guo
A rapid, simple and reliable high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for simultaneous determination of amitraz, chlordimeform, formetanate and their main metabolites, N-(2,4-dimethylphenyl)-N-methyl-formamidine (DMPF), 2,4-dimethylformamidine (DMF), 2,4-dimethylaniline (DMA), 4-chloro-2-methylaniline and 3-hydroxyacetanilide in human urine. The urine samples were mixed with buffer solutions (pH 8) and subsequently cleaned up by solid supported liquid/liquid extraction (SLE)...
March 11, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28346840/fabrication-and-evaluation-of-phytomenadione-as-a-nanostructure-lipid-carrier-for-enhancement-of-bioavailability
#8
Bader Mubarak Aljaeid, Khaled Mohamed Hosny
Owing to its limited aqueous solubility, Phytomenadione (vitamin K) undergoes a low bioavailability (50%) with a large inter-individual variability after oral administration. Therefore, the aim of this work was to incorporate vitamine K into nanostructure lipid carrier systems to improve its aqueous solubility and bioavailability. Phytomenadione was used as a liquid lipid, Precirol ATO5, and Compritol ATO were used as solid lipids, Labrasol and Cremophore EL as water soluble surfactants, Capryol 90 and Lauroglycol as lipid soluble surfactants...
March 27, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/28346827/effects-of-cerium-oxide-and-ferrocene-nanoparticles-addition-as-fuel-borne-catalysts-on-diesel-engine-particulate-emissions-environmental-and-health-implications
#9
Zhi-Hui Zhang, Rajasekhar Balasubramanian
This study systematically examined the potential impacts of doping CeO2 and Fe(C5H5)2 nanoparticles as fuel-borne catalysts (FBCs) to ultralow sulfur diesel (ULSD) fuel on the physical, chemical and toxicological characteristics of diesel particulate matter (DPM). The FBCs-doped fuels are effective in promoting soot oxidation and reducing the DPM mass emissions, but lead to a significant increase in the total particle counts due to the formation of self-nucleated metallic nanoparticles. Compared to undoped ULSD, the FBCs-doped fuels result in higher concentrations of particle-phase polycyclic aromatic hydrocarbons (PAHs) and n-alkanes, higher fractions of organic carbon (OC) and water-soluble organic carbon (WSOC) in particles, show slight alterations in soot nanostructure, reduce soot ignition temperature and activation energy...
March 27, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28346789/resolving-ultrafast-photoinduced-deactivations-in-water-solvated-pyrimidine-nucleosides
#10
Ana J Pepino, Javier Segarra-Martí, Artur Nenov, Roberto Improta, Marco Garavelli
For the first time, ultrafast deactivations of photo-excited water-solvated pyrimidine nucleosides are mapped employing hybrid QM(CASPT2)/MM(AMBER) optimizations that account for explicit solvation, sugar effects and dynamically correlated potential energy surfaces. Low energy S1/S0 ring-puckering and ring-opening conical intersections (CIs) are suggested to drive the ballistic coherent sub-ps (<200fs) decays observed in each pyrimidine, the energetics controlling this processes correlating with the lifetimes observed...
March 27, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28346787/assembly-and-speed-in-ion-exchange-based-modular-phoretic-micro-swimmers
#11
Ran Niu, Denis Botin, Julian Weber, Alexander Reinmüller, Thomas Palberg
We report an experimental study on ion-exchange based modular micro-swimmers in low-salt water. Cationic ion-exchange particles and passive cargo particles assemble into self-propelling complexes, showing self-propulsion at speeds of several microns per second over extended distances and times. We quantify the assembly and speed of the complexes for different combinations of ion exchange particles and cargo particles, substrate types, salt types and concentrations, and cell geometries. Irrespective of experimental boundary conditions, we observe a regular development of the assembly shape with increasing number of cargo...
March 27, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28346785/infrared-spectroscopy-of-ionic-liquids-consisting-of-imidazolium-cations-with-different-alkyl-chain-lengths-and-various-halogen-or-molecular-anions-with-and-without-a-small-amount-of-water
#12
Toshiki Yamada, Yukihiro Tominari, Shukichi Tanaka, Maya Mizuno
Infrared spectroscopy was performed on ionic liquids (ILs) that had imidazolium cations with different alkyl chain lengths and various halogen or molecular anions with and without a small amount of water. The molar concentration normalized absorbance due to +C-H vibrational modes in the range of 3000 to 3200 cm-1 was nearly identical for ILs that had imidazolium cations with different alkyl chain lengths and the same anions. A close correlation was found between the red-shifted +C-H vibrational modes, the chemical shift of +C(2)-H proton, and the energy stabilization of hydrogen-bonding interaction...
March 27, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28346781/metabolism-of-ibuprofen-by-phragmites-australis-uptake-and-phytodegradation
#13
Yujie He, Alette A M Langenhoff, Nora B Sutton, Huub H M Rijnaarts, Marco H Blokland, Feiran Chen, Christian Huber, Peter Schröder
This study explores ibuprofen (IBP) uptake and transformation in the wetland plant species Phragmites australis and the underlying mechanisms. We grew P. australis in perlite under greenhouse conditions and treated plants with 60 µg/l of IBP. Roots and rhizomes (RR), stems and leaves (SL), and liquid samples were collected during 21 days of exposure. Results show that P. australis can take up, translocate, and degrade IBP. IBP was completely removed from the liquid medium after 21 days with a half-life of 2...
March 27, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28346776/proton-exchange-in-a-paramagnetic-chemical-exchange-saturation-transfer-agent-from-experimental-studies-and-ab-initio-metadynamics-simulation
#14
Rodolphe Pollet, Célia S Bonnet, Pascal Retailleau, Philippe Durand, Éva Tóth
The proton-exchange process between water and a carbamate has been studied experimentally and theoretically in a lanthanide-based paramagnetic chemical exchange saturation transfer agent endowed with potential multimodality detection capabilities (optical imaging, or T1 MRI for the Gd(III) analogue). In addition to an in-depth structural analysis by a combined approach (using X-ray crystallography, NMR, and molecular dynamics), our ab initio simulation in aqueous solution sheds light on the reaction mechanism for this proton exchange, which involves structural Grotthuss diffusion...
March 27, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28346761/commentary-information-processing-in-anxiety-and%C3%A2-depression-novel-targets-for-translational-research-a-reflection-on-lau-and-waters-2017
#15
Gal Arad, Yair Bar-Haim
Understanding psychopathology in the context of a developmental cognitive neuroscience approach entails the notion that specific individual differences in information processing can serve as both etiologic and maintaining factors in the development of specific disorders. It is posited that such mechanistic understanding of neurocognitive aberrations during development can then serve focused translational efforts in the form of cognitive bias modification treatments. In the review by Lau and Waters (this issue), an astute developmental model is suggested regarding the role of potential neurocognitive mechanisms in depression and anxiety in youth...
April 2017: Journal of Child Psychology and Psychiatry, and Allied Disciplines
https://www.readbyqxmd.com/read/28346743/fabrication-of-a-mechanically-anisotropic-poly-glycerol-sebacate-membrane-for-tissue-engineering
#16
Chi-Nung Hsu, Pei-Yuan Lee, Ho-Yi Tuan-Mu, Chen-Yu Li, Jin-Jia Hu
Poly(glycerol sebacate) (PGS) has been used successfully as a scaffolding material for soft tissue engineering. PGS scaffolds, however, are usually mechanically isotropic, which may restrict their use in tissue repairs as many soft tissues in the body have anisotropic mechanical behaviors. Although various methods have been used to fabricate anisotropic scaffolds, it remains challenging to make anisotropic scaffolds from thermoset PGS. Here a new, simple method to fabricate an anisotropic PGS membrane which can then be used to construct thicker three-dimensional anisotropic scaffolds was developed...
March 27, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28346724/acclimation-of-bloom-forming-and-perennial-seaweeds-to-elevated-pco2-conserved-across-levels-of-environmental-complexity
#17
Dong Xu, C-Elisa Schaum, Fan Lin, Ke Sun, James R Munroe, Xiao W Zhang, Xiao Fan, Lin H Teng, Yi T Wang, Zhi Z Zhuang, Nai H Ye
Macroalgae contribute approximately 15% of the primary productivity in coastal marine ecosystems, fix up to 27.4 Tg of carbon per year, and provide important structural components for life in coastal waters. Despite this ecological and commercial importance, direct measurements and comparisons of the short-term responses to elevated pCO2 in seaweeds with different life-history strategies are scarce. Here, we cultured several seaweed species (bloom-forming/non-bloom-forming/perennial/annual) in the laboratory, in tanks in an in-door mesocosm facility, and in coastal mesocosms under pCO2 levels ranging from 400 μatm to 2000 μatm...
March 27, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28346722/a-simple-tetraminocalix-4-arene-as-a-highly-efficient-catalyst-under-on-water-conditions-through-hydrophobic-amplification-of-weak-hydrogen-bonds
#18
Margherita De Rosa, Pellegrino La Manna, Annunziata Soriente, Carmine Gaeta, Carmen Talotta, Neal Hickey, Silvano Geremia, Placido Neri
The simple tetraminocalix[4]arene 1, bearing weak H-bond donor NH2 groups, is a highly efficient organocatalyst for the Vinylogous Mukaiyama Aldol Reaction (VMAR) of 2-(trimethylsilyloxy)furan 5 with α-ketoesters 6a-l under "on-water conditions", thanks to the hydrophobic amplification of weak interactions. The catalytic efficiency of calixarene catalyst 1 is closely related to its recognition abilities toward the reactants 5 and 6 through a multipoint recognition model. The proposed model provides good explanations for the differences on the reaction rate acceleration and on the stereoselectivity observed with different substrates...
March 27, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28346559/mechanism-of-degradation-of-a-nitrogenous-heterocycle-induced-by-a-reductive-radical-decomposition-of-a-sym-triazine-ring
#19
Gengxin Lyu, Guosheng Shi, Liang Tang, Haiping Fang, Minghong Wu
Cyanuric acid is a major component of many materials and chemicals, and is the most important intermediate in the degradation processes of sym-triazine compounds in the natural environment, as well as being used for water treatment. However, the degradation mechanism of cyanuric acid is still unclear in various advanced oxidation processes (AOPs), where ˙OH is usually regarded as the dominant radical. Here, using a combination of density functional theory calculations and experimental observations, we unexpectedly show that the sym-triazine ring structure is broken efficiently by reductive free radicals - hydrogen radicals (˙H), rather than traditional ˙OH...
March 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28346547/a-controllable-water-signal-transistor
#20
Lili Wu, Xiaoyan Zhou, Hangjun Lu, Qing Liang, Jianlong Kou, Fengmin Wu, Jintu Fan
We performed molecular dynamics simulations to study the regulating ability of water chains confined in a Y-shaped nanochannel. It was shown that a signal at the molecular level could be controlled by two other charge-induced signals when the water chains were confined in a Y-shaped nanochannel, demonstrating promising applications as water signal transistors in nanosignal systems. The mechanism of a water signal transistor is similar to a signal logic device. This remarkable ability to control the water signal is attributed to the strong dipole-ordering of the water chains in the nanochannel...
March 27, 2017: Physical Chemistry Chemical Physics: PCCP
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