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Jie-Hua Shi, Yan-Yue Lou, Kai-Li Zhou, Dong-Qi Pan
As a sulfonylurea herbicide, sulfosulfuron is extensively applied in controlling broad-leaves and weeds in agriculture. It may cause a potential risk for human and herbivores health due to its widely application and residue in crops and fruits. The study of the binding characteristics of calf thymus DNA (ct-DNA) with sulfosulfuron was performed through a series of spectroscopic techniques and computer simulation. The experimental results showed sulfosulfuron interacted with ct-DNA through the groove binding...
June 18, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Ramadevi M, Deepesh Panwar, Juby Elsa Joseph, Gaurav Singh Kaira, Mukesh Kapoor
A hitherto unknown low molecular weight form of α-galactosidase (VM-αGal) from germinating black gram (Vigna mungo) seeds was purified to homogeneity (432 U/mg specific activity, 1542-fold purification) using ion-exchange (DEAE-cellulose, CM-sepharose) and affinity (Con-A Sepharose 4B) chromatography. VM-αGal appeared as a single band ~ 45 kDa on SDS-PAGE and showed optimal activity at pH 5 and 55 °C. Hg2+ and SDS completely inhibited VM-αGal activity. The Km, Vmax and catalytic efficiency (kcat /Km ) of VM-αGal for pNPG and raffinose was found to be 0...
June 20, 2018: International Journal of Biological Macromolecules
S Manimaran, K SambathKumar, R Gayathri, K Raja, N Rajkamal, M Venkatachalapathy, G Ravichandran, C Lourdu EdisonRaj
Curcumin is a medicinal agent that exhibits anti-cancer properties and bioactive pigment in Turmeric has a huge therapeutic value. It has a keto-enol moiety that gives rise to many of its chemical properties. A recent study has shown that keto-enol tautomerisation at this moiety is implicated the effect of curcumin. The tautomerisation of curcumin in methanol, acetone and acetonitrile are used in nuclear magnetic resonance (1 H, 13 C) spectroscopy. It was characterized using UV, IR and Raman spectral values...
June 22, 2018: Natural Products and Bioprospecting
Wei Liu, Lin Zhu, Junwei Han, Fen Jiao, Wenqing Qin
Sulfidation is a widely used technology to improve the floatability of oxidized metal minerals or to stabilize the heavy metals in various wastes. The sulfidation mechanism of ZnO with pyrite was detailedly studied by thermodynamic calculation and roasting experiments. The sulfidation behaviors, phase transformations, microscopic morphology and surface properties were investigated by TG-DSC, ICP, XRD, SEM-EDS, and XPS analysis. The results indicate that the nature of the sulfidation is the reaction of ZnO with the gaseous sulfur generated by the decomposition of pyrite...
June 22, 2018: Scientific Reports
Jana Pokorná, Petr Pachl, Elena Karlukova, Jakub Hejdánek, Pavlína Řezáčová, Aleš Machara, Jason Hudlický, Jan Konvalinka, Milan Kožíšek
Neuraminidase is the main target for current influenza drugs. Reduced susceptibility to oseltamivir, the most widely prescribed neuraminidase inhibitor, has been repeatedly reported. The resistance substitutions I223V and S247N, alone or in combination with the major oseltamivir-resistance mutation H275Y, have been observed in 2009 pandemic H1N1 viruses. We overexpressed and purified the ectodomain of wild-type neuraminidase from the A/California/07/2009 (H1N1) influenza virus, as well as variants containing H275Y, I223V, and S247N single mutations and H275Y/I223V and H275Y/S247N double mutations...
June 21, 2018: Viruses
Muhammad Ali, Dario Rangel Shaw, Lei Zhang, Mohamed Fauzi Haroon, Yuko Narita, Abdul-Hamid Emwas, Pascal E Saikaly, Satoshi Okabe
Anaerobic ammonium-oxidizing (anammox) bacteria are well known for their aggregation ability. However, very little is known about cell surface physicochemical properties of anammox bacteria and thus their aggregation abilities have not been quantitatively evaluated yet. Here, we investigated the aggregation abilities of three different anammox bacterial species: "Candidatus Brocadia sinica", "Ca. Jettenia caeni" and "Ca. Brocadia sapporoensis". Planktonic free-living enrichment cultures of these three anammox species were harvested from the membrane bioreactors (MBRs)...
June 12, 2018: Water Research
M Wöhrwag, C Semprebon, A Mazloomi Moqaddam, I Karlin, H Kusumaatmaja
A thermodynamically consistent free energy model for fluid flows comprised of one gas and two liquid components is presented and implemented using the entropic lattice Boltzmann scheme. The model allows a high density ratio, up to the order of O(10^{3}), between the liquid and gas phases, and a broad range of surface tension ratios, covering partial wetting states where Neumann triangles are formed, and full wetting states where complete encapsulation of one of the fluid components is observed. We further demonstrate that we can capture the bouncing, adhesive, and insertive regimes for the binary collisions between immiscible droplets suspended in air...
June 8, 2018: Physical Review Letters
Xunyu Song, Lin Cao, Shuang Cong, Yukun Song, Mingqian Tan
Emergence of endogenous nanoparticles in thermally processed food has aroused much attention due to their unique properties and potential biological impact. The aim of this study was to investigate the presence of fluorescence nanoparticles in roasted chicken breasts, elemental composition, physico-chemical properties and their molecular interaction with human serum albumin (HSA). Transmission electron microscopy analysis revealed that the foodborne nanoparticles from roasted chicken were nearly spherical with an average particle size of 1...
June 22, 2018: Journal of Agricultural and Food Chemistry
Yifu Yu, Yanmei Shi, Bin Zhang
The rational synthesis of advanced nanomaterials with well-defined structures has been intensively studied due to the remarkable properties and intriguing applications of the formed materials. Recently, inorganic-organic hybrids have been widely adopted as precursors for chemical transformations toward the preparation of diverse nanomaterials. Specifically, inorganic and organic species with nano/molecule/atom-scale distribution serve as self-templates and sacrificial agents, respectively, endowing the products with controlled morphologies, band gaps, defects, and spatial architectures...
June 22, 2018: Accounts of Chemical Research
Carolyn E Carr, Irine Khutsishvili, Luis A Marky
Triplex formation occurs via interaction of a third strand with the major groove of double stranded nucleic acid, through Hoogsteen hydrogen bonding. In this work, we use a combination of temperature-dependent UV spectroscopy and differential scanning calorimetry to determine complete thermodynamic profiles for the unfolding of poly(rA)•poly(rU) (Duplex) and poly(rA)•2poly(rU) (Triplex). Our thermodynamic results are in good agreement with the much earlier work of Krakauer and Sturtevant using only UV melting techniques...
June 22, 2018: Journal of Physical Chemistry. B
David R Stevens, Sharon Hammes-Schiffer
The enzyme human DNA polymerase η (Pol η) is critical for bypassing lesions during DNA replication. In addition to the two Mg2+ ions aligning the active site, experiments suggest that a third Mg2+ ion could play an essential catalytic role. Herein the role of this third metal ion is investigated with quantum mechanical/molecular mechanical (QM/MM) free energy simulations of the phosphoryl transfer reaction and a proposed self-activating proton transfer from the incoming nucleotide to the pyrophosphate leaving group...
June 22, 2018: Journal of the American Chemical Society
Luca Cera, Christoph A Schalley
Self-organization in synthetic chemical systems is quickly developing into a powerful strategy for designing new functional materials. As self-organization requires the system to exist far from thermodynamic equilibrium, chemists have begun to go beyond the classical equilibrium self-assembly that is often applied in bottom-up supramolecular synthesis, and to learn about the surprising and unpredicted emergent properties of chemical systems that are characterized by a higher level of complexity and extended reactivity networks...
June 21, 2018: Advanced Materials
Nacer Ferrah
This comparative study investigates pre-concentration/separation procedure for the magnetic solid phase extraction of Hg(II) species by a new green materials: naked magnetic chitosan flakes coated Fe3 O4 micro-particles (NMCFs) and magnetic chitosan flakes coated Fe3 O4 micro-particles embedded ethylenediaminetetraacetic-disodium (MCFs-EDTA-Na2 ) in a batch process. The sorption procedure was optimized by using model solutions containing mercury(II) ions in chloride medium. The influence of experimental parameters like pH, time reaction, initial Hg(II) concentration, and ionic strength was investigated...
June 21, 2018: Environmental Science and Pollution Research International
Liwia Rajpert, Andreas Schäffer, Markus Lenz
The environmental fate of major (e.g. C, N, S, Fe and Mn) and trace (e.g. As, Cr, Sb, Se and U) elements is governed by microbially catalysed reduction-oxidation (redox) reactions. Mesocosms are routinely used to elucidate trace metal fate on the basis of correlations between biogeochemical proxies such as dissolved element concentrations, trace element speciation and dissolved organic matter. However, several redox processes may proceed simultaneously in natural soils and sediments (particularly, reductive Mn and Fe dissolution and metal/metalloid reduction), having a contrasting effect on element mobility...
June 21, 2018: Applied Microbiology and Biotechnology
Matthias Falmbigl, Igor A Karateev, Iryna S Golovina, Aleksandr V Plokhikh, Thomas C Parker, Alexander L Vasiliev, Jonathan E Spanier
Thin films of ≈50 nm thickness with Ba/Ti-ratios ranging from 0.8 to 1.06 were prepared by depositing alternating layers of Ba(OH)2 and TiO2. Annealing at 750 °C promoted the solid-solid transformation into polycrystalline BaTiO3 films containing a mixture of the perovskite and the hexagonal polymorphs with average crystallite sizes smaller than 14 nm and without impurity phases. This, together with an increase of the cubic lattice parameters for Ba-rich films, suggests an extended metastable solubility range for the perovskite-phase in these nanocrystalline thin films on both sides of the stoichiometric composition...
June 22, 2018: Nanoscale
Anne Bauer, Astrid Jäschke, Sebastian Schöne, Robert Barthen, Juliane März, Katja Schmeide, Michael Patzschke, Berthold Kersting, Karim Fahmy, Jana Oertel, Vinzenz Brendler, Thorsten Stumpf
The environmental aspects of ore processing and waste treatment call for an optimization of applied technologies. There, understanding of the structure and complexation mechanism on a molecular scale is indispensable. Here, the complexation of UVI with a calix[4]arene-based 8-hydroxyquinoline ligand was investigated by applying a wide range of complementary methods. In solution, the formation of two complex species was proven with stability constants of log  ß 1:1 =5.94±0.02 and log  ß 2:1 =6.33±0.01, respectively...
June 2018: ChemistryOpen
S M Shugurov, A I Panin, S I Lopatin
RATIONALE: CeO2 -WO3 and CeO2 -MoO3 catalysts have shown excellent performance in the selective reduction of NOx by ammonia (NH3 -selective catalytic reduction) over a wide temperature range. Strong interaction between CeO2 and WO3 or MoO3 might be the dominant reason for the high activity of these mixed oxides. Studies of ceria-containing gaseous salts involve considerable experimental difficulties, since the transition of such salts to vapor requires high temperatures. To predict the possibility of the existence of gaseous associates formed by cerium and molybdenum (tungsten) oxides it is important to know their thermodynamic characteristics...
June 21, 2018: Rapid Communications in Mass Spectrometry: RCM
Youbing Zhu, Shuili Yu, Bing Zhang, Jianfeng Li, Dongsheng Zhao, Zhengyang Gu, Chao Gong, Guicai Liu
Alkali/surfactant/polymer (ASP) flooding wastewater is highly caustic, and membrane fouling is the main obstacle during ASP ultrafiltration (UF) treatment. To maintain favorable filtration performance, polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) membranes were implemented here, and their antifouling properties and mechanisms were investigated based on the threshold flux theory. Compared with the PVDF membranes, the PTFE membranes exhibited superior antifouling properties with lower reductions in flux and smaller hydraulic resistance, and they presented a nearly identical pseudo-stable fouling rate at a later time point...
June 18, 2018: Science of the Total Environment
Mariacristina Gagliardi, Angelo Bifone
The general misconception that γ-lactones are not thermodynamically polymerizable has limited the development of all γ-lactone-based copolymers. A few studies have reported copolymerization of these five-membered cyclic esters with more reactive monomers, yet a systematic investigation of kinetics and thermodynamics is still lacking. To explore the feasibility of the reaction, we combined equilibrium and non-isothermal syntheses for the copolymerization of γ-valerolactone with ϵ-caprolactone, initiated with methoxy polyethyleneglycol and catalyzed by Tin(II) 2-ethylhexanoate...
2018: PloS One
Salvatore Lombardo, Wim Thielemans
Negatively charged ions readily interact with the surface of positively charged pyridinium-grafted cellulose nanocrystals. In this work we investigated the thermodynamics of these interactions using isothermal titration calorimetry. We investigated the effect of the ionic charge, using carboxylate salts with different valence (1-4), and compared it with sodium sulfate as another delocalized ionic charge. Experiments performed using cellulose nanocrystals with three different degrees of substitution of pyridinium grafts showed that the number of ions adsorbed onto the surface of cellulose nanocrystals is directly linked to the number of grafted cationic functionalities...
June 21, 2018: Physical Chemistry Chemical Physics: PCCP
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