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Aikaterini Spiliotopoulou, Richard Martin, Lars-Flemming Pedersen, Henrik R Andersen
The aim of this study was to investigate the potential of fluorescence spectroscopy to be used as an ozone dosage determination tool in recirculating aquaculture systems (RASs), by studying the relationship between fluorescence intensities and dissolved organic matter (DOM) degradation by ozone, in order to optimise ozonation treatment. Water samples from six different Danish facilities (two rearing units from a commercial trout RAS, a commercial eel RAS, a pilot RAS and two marine water aquariums) were treated with different O3 dosages (1...
December 24, 2016: Water Research
M Elizabeth Chacón Villalba, Carlos A Franca, Jorge A Güida
The solid state photolysis of sodium, silver and thallium hyponitrite (M2N2O2, M=Na, Ag, Tl) salts and a binuclear complex of cobalt bridged by hyponitrite ([Co(NH3)5-N(O)-NO-Co(NH3)5](4+)) were studied by irradiation with visible and UV light in the electronic absorption region. The UV-visible spectra for free hyponitrite ion and binuclear complex of cobalt were interpreted in terms of Density Functional Theory calculations in order to explain photolysis behavior. The photolysis of each compound depends selectively on the irradiation wavelength...
January 10, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Yaolan Niu, Kan Li, Diwen Ying, Yalin Wang, Jinping Jia
Adsorbents synthesized with biopolymer have been widely used in the removal of toxic metal ions. Novel high-efficiency, recyclable, and low-cost adsorbents have received more and more attention. Chitosan and cellulose are the most abundant biopolymers in nature. Composite modified adsorbent (CSTEC) was synthesized as novel fibrous materials for the adsorption of Cu(2+) and Pb(2+) ions from water in this study. The functional fiber was characterized to investigate the surface appearance, functional groups, crystallinity, and thermal stability...
January 10, 2017: Bioresource Technology
Renato Nallin Montagnolli, Paulo Renato Matos Lopes, Jaqueline Matos Cruz, Marina Turini Claro, Gabriela Mercuri Quiterio, Ederio Dino Bidoia
The type and concentration of perfluorinated compounds (PFCs) can induce different types of enzymes and promote alternate patterns of BTEX transformation. However, it is not known how the presence of active fluorocarbon-degrading microbial populations affects the transformation of BTEX. In addition to chemical analysis at the molecular level, our research approached the aqueous film forming fire-fighting foams (AFFF) and BTEX co-contamination at a large-scale with respirometers to quantify the total microbial metabolism of soil via CO2 output levels...
December 30, 2016: Chemosphere
Meifang Cai, Murray B McBride, Kaiming Li, Zhian Li
Soils historically contaminated in urban and orchard environments by Pb and As were amended separately with organic matter, soluble Ca phosphate, and Fe oxide to determine whether these materials could lower Pb or As bioaccessibility. After 5 years of equilibration in the laboratory, the amended soils and control were tested for bioaccessibility using the standard physiologically based extraction test (PBET). Bioaccessibilities of Pb and As were not substantially reduced relative to the unamended controls after the 5-year period by any of the soil amendments...
January 11, 2017: Chemosphere
Xiaoli Tan, Ge Liu, Huiyang Mei, Ming Fang, Xuemei Ren, Changlun Chen
Unraveling the formation process of Ni precipitates at molecular scale is important for understanding the fate and mobility of Ni species in the real environment. Dissolved Si presents in the natural environment ubiquitously, which can alter Ni sorption as well as incorporation into neoformed precipitates. Batch experiments show that the dissolved Si leads to a rapid increase in the Ni sorption rate and interferes with the formation of Ni precipitates. The results of diffuse reflectance spectroscopy (DRS) and extended X-ray absorption fine structure (EXAFS) spectroscopy analyses suggest that the nucleation of a (Ni,Al) phyllosilicate phase involves a kaolinite-like local structure...
January 16, 2017: Chemosphere
Akram Alhussein, Sofiane Achache, Regis Deturche, Frederic Sanchette, Cesar Pulgarin, John Kiwi, Sami Rtimi
This article presents the evidence for the significant effect of copper accelerating the bacterial inactivation on Ti-Nb-Ta-Zr (TNTZ) sputtered films on glass up to a Cu content of 8.3 at.%. These films were deposited by dc magnetron co-sputtering of an alloy target Ti-23Nb-0.7Ta-2Zr (at.%) and a Cu target. The fastest bacterial inactivation of E. coli on this later TNTZ-Cu surface proceeded within ∼75min. The films deposited by magnetron sputtering are chemically homogenous. The film roughness evaluated by atomic force spectroscopy (AFM) on the TNTZ-Cu 8...
January 15, 2017: Colloids and Surfaces. B, Biointerfaces
Kristie D Cox Augustyn, Michael R Jackson, Marilyn Schuman Jorns
Hydrogen sulfide (H2S) is an endogenously synthesized signaling molecule that is enzymatically metabolized in mitochondria. The metabolism of H2S maintains optimal concentrations of the gasotransmitter and produces sulfane sulfur (S(0))-containing metabolites that may be functionally important in signaling. Sulfide:quinone oxidoreductase (SQOR) catalyzes the initial 2-electron oxidation of H2S to S(0) using coenzyme Q as electron acceptor in a reaction that requires a third substrate to act as the acceptor of S(0)...
January 20, 2017: Biochemistry
Peter N Chalmers, Markus A Wimmer, Nikhil N Verma, Brian J Cole, Anthony A Romeo, Gregory L Cvetanovich, Michael L Pearl
CONTEXT: The overhand pitch is one of the fastest known human motions and places enormous forces and torques on the upper extremity. Shoulder and elbow pain and injury are common in high-level pitchers. A large body of research has been conducted to understand the pitching motion. EVIDENCE ACQUISITION: A comprehensive review of the literature was performed to gain a full understanding of all currently available biomechanical and clinical evidence surrounding pitching motion analysis...
January 1, 2017: Sports Health
Lin Liu, Andrey G Cherstvy, Ralf Metzler
What are the physical laws of the diffusive search of proteins for their specific binding sites on DNA in the presence of the macromolecular crowding in cells? We performed extensive computer simulations to elucidate the protein target search on DNA. The novel feature is the viscoelastic non-Brownian protein bulk diffusion recently observed experimentally. We examine the influence of the protein-DNA binding affinity and the anomalous diffusion exponent on the target search time. In all cases an optimal search time is found...
January 20, 2017: Journal of Physical Chemistry. B
Marta Ximenis, Emilio Bustelo, Andrés G Algarra, Manel Vega, Carmen Rotger, Manuel G Basallote, Antonio Costa
The hydrolytic degradation of squaramides and squaramic acids, the product of partial hydrolysis of squaramides, has been evaluated by UV spectroscopy at 37°C in the pH range 3-10. Under these conditions, the compounds are kinetically stable over long time periods (>100 d). At pH > 10, the hydrolysis of the squaramate anions shows first-order dependence on both squaramate and OH-. At the same temperature and [OH-], the hydrolysis of squaramides usually displays biphasic spectral changes (A → B → C kinetic model) with formation of squaramates as detectable reaction intermediates...
January 20, 2017: Journal of Organic Chemistry
Xiaoyu Gao, Eleanor Spielman-Sun, Sónia Morais Rodrigues, Elizabeth A Casman, Gregory V Lowry
We assess the effect of CuO nanoparticle (NP) concentration and soil aging time on the extractability of Cu from a standard sandy soil (Lufa 2.1). The soil was dosed with CuO NP or Cu(NO3)2 at 10 mg Cu kg-1 soil (mg/kg) or 100 mg/kg total copper, then extracted using either 0.01M CaCl2 or 0.005M DTPA (pH 7.6) extraction fluids at selected times over 31 days. For 100 mg/kg CuO NP, the amount of DTPA-extractable Cu in soil increased from 3 wt% immediately after mixing to 38 wt% after 31 days. In contrast, the extractability of Cu(NO3)2 was highest initially, decreasing with time...
January 20, 2017: Environmental Science & Technology
Wupeng Yan, Everett M Stone, Yan Jessie Zhang
Enzyme therapeutics that can degrade L-methionine (L-Met) are of great interest as numerous malignancies are exquisitely sensitive to L-Met depletion. To exhaust the pool of the methionine in human serum, we previously engineered an L-Met degrading enzyme based on the human cystathionine-γ-lyase scaffold (hCGL-NLV) in order to circumvent immunogenicity and stability issues observed in the preclinical application of bacterial derived methionine-γ-lyases (MGL). To gain further insights into structure/activity relationships governing the chemistry of the hCGL-NLV lead molecule, we undertook a biophysical characterization campaign that captured crystal structures (2...
January 20, 2017: Biochemistry
Xu Huang, Xuezhang Xiao, Wei Zhang, Xiulin Fan, Liuting Zhang, Changjun Cheng, Shouquan Li, Hongwei Ge, Qidong Wang, Lixin Chen
Magnesium hydride (MgH2) exhibits long-term stability and has recently been developed as a safe alternative to store hydrogen in the solid state, due to its high capacity of 7.6 wt% H2 and low cost compared to other metal hydrides. However, the high activation energy and poor kinetics of MgH2 lead to inadequate hydrogen storage properties, resulting in low energy efficiency. Nano-catalysis is deemed to be the most effective strategy in improving the kinetics performance of hydrogen storage materials. In this work, robust and efficient architectures of carbon-wrapped transition metal (Co/C, Ni/C) nanoparticles (8-16 nm) were prepared and used as catalysts in the MgH2 system via ball milling to improve its de/rehydrogenation kinetics...
January 20, 2017: Physical Chemistry Chemical Physics: PCCP
Sam D Molenaar, Pradip Saha, Annemerel R Mol, Tom H J A Sleutels, Annemiek Ter Heijne, Cees J N Buisman
Microbial electrosynthesis is a useful form of technology for the renewable production of organic commodities from biologically catalyzed reduction of CO₂. However, for the technology to become applicable, process selectivity, stability and efficiency need strong improvement. Here we report on the effect of different electrochemical control modes (potentiostatic/galvanostatic) on both the start-up characteristics and steady-state performance of biocathodes using a non-enriched mixed-culture inoculum. Based on our results, it seems that kinetic differences exist between the two dominant functional microbial groups (i...
January 19, 2017: International Journal of Molecular Sciences
Deepti Diwan, Kohei Shinkai, Toshihiro Tetsuka, Bin Cao, Hidenao Arai, Tetsuo Koyama, Ken Hatano, Koji Matsuoka
Protein-carbohydrate interactions exhibit myriad intracellular recognition events, so understanding and investigating their specific interaction with high selectivity and strength are of crucial importance. In order to examine the effect of multivalent binding on the specificity of protein-carbohydrate interactions, we synthesized mannose glycosides as a novel type of glycosylated monomer and glycopolymers of polyacrylamide derivatives with α-mannose (α-Man) by radical polymerization and monitored their strength of interaction with concanavalin A (Con A) by surface plasmon resonance (SPR) detection...
January 18, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Rok Kocen, M Gasik, Ana Gantar, Sasa Novak
Along with biocompatibility, bioinductivity and appropriate biodegradation, mechanical properties are also of crucial importance for tissue engineering scaffolds. Hydrogels, such as gellan gum, are usually soft materials, which may benefit from the incorporation of inorganic particles, e.g. bioactive glass, not only due to the acquired bioactivity, but also due to improved mechanical properties. They exhibit complex viscoelastic properties, which can be evaluated in various ways. In this work, to reliably evaluate the effect of the bioactive glass addition on viscoelastic properties of the composite hydrogel, we employed and compared three most commonly used techniques, analyzing their advantages and limitations: monotonic uniaxial unconfined compression, small amplitude oscillatory shear (SAOS) rheology and dynamic mechanical analysis (DMA)...
January 20, 2017: Biomedical Materials
D Banerjee, V Burtsev, D Cooke, P Crivelli, E Depero, A V Dermenev, S V Donskov, F Dubinin, R R Dusaev, S Emmenegger, A Fabich, V N Frolov, A Gardikiotis, S N Gninenko, M Hösgen, V A Kachanov, A E Karneyeu, B Ketzer, D V Kirpichnikov, M M Kirsanov, S G Kovalenko, V A Kramarenko, L V Kravchuk, N V Krasnikov, S V Kuleshov, V E Lyubovitskij, V Lysan, V A Matveev, Yu V Mikhailov, V V Myalkovskiy, V D Peshekhonov, D V Peshekhonov, O Petuhov, V A Polyakov, B Radics, A Rubbia, V D Samoylenko, V O Tikhomirov, D A Tlisov, A N Toropin, A Yu Trifonov, B Vasilishin, G Vasquez Arenas, P Ulloa, K Zhukov, K Zioutas
We report on a direct search for sub-GeV dark photons (A^{'}), which might be produced in the reaction e^{-}Z→e^{-}ZA^{'} via kinetic mixing with photons by 100 GeV electrons incident on an active target in the NA64 experiment at the CERN SPS. The dark photons would decay invisibly into dark matter particles resulting in events with large missing energy. No evidence for such decays was found with 2.75×10^{9} electrons on target. We set new limits on the γ-A^{'} mixing strength and exclude the invisible A^{'} with a mass ≲100  MeV as an explanation of the muon g_{μ}-2 anomaly...
January 6, 2017: Physical Review Letters
Seunggeol Ryu, Prosenjit Sen, Youngsuk Nam, Choongyeop Lee
When a water drop impacts a mesh having submillimeter pores, a part of the drop penetrates through the mesh if the impact velocity is sufficiently large. Here we show that different surface wettability, i.e., hydrophobicity and superhydrophobicity, leads to different water penetration dynamics on a mesh during drop impact. We show, despite the water repellence of a superhydrophobic surface, that water can penetrate a superhydrophobic mesh more easily (i.e., at a lower impact velocity) over a hydrophobic mesh via a penetration mechanism unique to a superhydrophobic mesh...
January 6, 2017: Physical Review Letters
J Braenzel, A A Andreev, F Abicht, L Ehrentraut, K Platonov, M Schnürer
Direct acceleration of electrons in a coherent, intense light field is revealed by a remarkable increase of the electron number in the MeV energy range. Laser irradiation of thin polymer foils with a peak intensity of ∼1×10^{20}  W/cm^{2} releases electron bunches along the laser propagation direction that are postaccelerated in the partly transmitted laser field. They are decoupled from the laser field at high kinetic energies, when a second foil target at an appropriate distance prevents their subsequent deceleration in the declining laser field...
January 6, 2017: Physical Review Letters
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