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Ling Han, Ruixiang Zheng, Michele R Richards, Ming Tan, Elena N Kitova, Xi Jiang, John S Klassen
Human noroviruses (HuNoVs) are a major cause of acute gastroenteritis. Many HuNoVs recognize histo-blood group antigens (HBGAs) as cellular receptors or attachment factors for infection. It was recently proposed that HuNoV recognition of HBGAs involves a cooperative, multistep binding mechanism that exploits both known and, previously, unknown glycan binding sites. In this study, binding measurements, implemented using electrospray ionization mass spectrometry (ESI-MS), were performed on homodimers of the protruding domain (P dimers) of the capsid protein of three HuNoV strains [Saga (GII...
March 19, 2018: Glycobiology
Ji She, Jiangtao Guo, Qingfeng Chen, Weizhong Zeng, Youxing Jiang, Xiao-Chen Bai
The organellar two-pore channel (TPC) functions as a homodimer, in which each subunit contains two homologous Shaker-like six-transmembrane (6-TM)-domain repeats. TPCs belong to the voltage-gated ion channel superfamily and are ubiquitously expressed in animals and plants. Mammalian TPC1 and TPC2 are localized at the endolysosomal membrane, and have critical roles in regulating the physiological functions of these acidic organelles. Here we present electron cryo-microscopy structures of mouse TPC1 (MmTPC1)-a voltage-dependent, phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2 )-activated Na+ -selective channel-in both the apo closed state and ligand-bound open state...
March 21, 2018: Nature
Mingda Zheng, Yingying Wang, Chenge Wang, Wei Wei, Shuang Ma, Xiaohan Sun, Jiang He
A simple and selective colorimetric sensor based on citrate capped silver nanoparticles (Cit-AgNPs) is proposed for the detection of Thiophanate-methyl (TM) with high sensitivity and selectivity. The method based on the color change of Cit-AgNPs from yellow to cherry red with the addition of TM to Cit-AgNPs that caused a red-shift on the surface plasmon resonance (SPR) band from 394nm to 525nm due to the hydrogen-bonding and substitution. The density functional theory (DFT) method was also calculated the interactions between the TM and citrate ions...
March 13, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Dan Fraenkel
In the past few decades, emf (E) measurements using improved electrochemical cells have afforded the derivation of mean ionic activity coefficients (γ± 's) of very dilute solutions of binary electrolytes, within the 10-6 - 10-3 molar range (Malatesta et al., J. Sol. Chem. 1994, 23, 11). Such measurements are especially important for highly charged electrolytes whose behavior at very low concentration is not yet fully understood, and whose γ± values, derived from E data, have been claimed by Malatesta and coworkers to exhibit "negative deviations" from the Debye-Hückel (DH) limiting law...
March 21, 2018: Journal of Chemical Theory and Computation
Yanbing Zhai, Siyu Liu, Lijuan Gao, Lili Hu, Wei Xu
With improved performances, miniature mass spectrometers are becoming suitable for more practical applications. At the same time, the coupling of an approximate ionization source is essential in terms of minimizing sample preparation and broadening the range of samples that could be analyzed. In this study, an atmospheric pressure laserspray ionization (AP-LSI) source was coupled with our home developed miniature ion trap mass spectrometer. The whole system is compact in size, and biological samples could be directly analyzed with minimum sample preparation...
March 21, 2018: Analytical Chemistry
Nuket Kartal Temel, Ramazan Gürkan
A novel ultrasound assisted-cloud point extraction method was developed for preconcentration and determination of V(V) in beverage samples. After complexation by pyrogallol in presence of safranin T at pH 6.0, V(V) ions as ternary complex are extracted into the micellar phase of Triton X-114. The complex was monitored at 533 nm by spectrophotometry. The matrix effect on the recovery of V(V) from the spiked samples at 50 μg L-1 was evaluated. In optimized conditions, the limits of detection and quantification of the method, respectively, was 0...
March 2018: Acta Chimica Slovenica
Shima Rahim Pouran, Abolfazl Bayrami, Mohammad Saleh Shafeeyan, Abdul Aziz Abdul Raman, Wan Mohd Ashri Wan Daud
Oxidative treatment of a cationic dye solution, methylene blue, was investigated using magnetite nanoparticles and goethite in heterogeneous Fenton-like reaction, and ferrous ions in homogeneous Fenton-reaction. The aim was to compare the degradation efficiencies of the studied catalysts for decolorization of methylene blue solution as the model organic pollutant. Response surface methodology (RSM) was applied to determine the optimal operational conditions for magnetite/H2O2 and goethite/H2O2 systems. The [H2O2] of 0...
March 2018: Acta Chimica Slovenica
Lidija Radovanović, Jelena Rogan, Dejan Poleti, V Marko Rodić, Zvonko Jagličić
Two new isostructural M(II) (M = Ni, Co) complexes with 2,2'-dipyridylamine (dipya) and dianion of terephthalic acid (H2tpht), [M(dipya)2(H2O)2](tpht) ∙ 2H2O, have been synthesized by ligand exchange reaction and characterized by single-crystal X-ray diffraction, FTIR spectroscopy, TG/DSC analysis and magnetic measurements. The crystal structures of [M(dipya)2(H2O)2](tpht) ∙ 2H2O consist of discrete complex units in which M(II) adopts deformed octahedral geometries. Two dipya ligands and two water molecules are coordinated to M(II) atom, tpht acts as a counter ion, while additional two water molecules remained uncoordinated...
March 2018: Acta Chimica Slovenica
Kirila Stojnova, Vidka Divarova, Petya Racheva, Kristina Bozhinova, Vanya Lekova
The equilibria of the chelate formation and ion-association in the liquid-liquid extraction system Mo(VI)‒3,5-DNC‒INT‒H2O‒CHCl3 were studied by spectrophotometry. The optimum conditions for the chelate formation and extraction of the ion-associated complex formed between the anionic chelate of Mo(VI)‒3,5-dinitrocatechol (3,5-DNC) and the cation of 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (INT) were established. The validity of Beer's law was checked and some analytical characteristics were calculated...
March 2018: Acta Chimica Slovenica
Dorota Gugała-Fekner
The paper presents the thermodynamic analysis of adenine adsorption on a mercury electrode in an acetate buffer at pH 3 and pH 4. Adsorption energy and constants were determined using the Frumkin isotherm and the virial isotherm. Stronger adsorption in the buffer at pH 3 was observed in comparison to the buffer at pH 4. Using cyclic voltammetry and Faraday impedance measurement, an inhibitory effect of adenine on the kinetics of Zn (II) ion electro-reduction was observed.
March 2018: Acta Chimica Slovenica
Ali Serol Ertürk, Mustafa Ulvi Gürbüz, Metin Tülü, Abdürrezzak Emin Bozdoğan
Different generations (G3-G4) of amine-terminated Jeffamine® T-403 core poly(amidoamine) PAMAM dendrimers (JCPDs) were used as new macromolecular heavy metal chelating agent templates in polymer assisted ultrafiltration (PAUF) for the investigation of their removal ability for some of the divalent metal ions: Cu, Co, Ni, Cd, and Zn from aqueous solutions under competitive conditions. The effects of pH and generation size of JCPDs were also investigated. Extent of binding (EOB) data can be appropriately expressed by a tetradentate coordination for JCPDs at pH 9 where the maximum removal of metal ions was observed...
March 2018: Acta Chimica Slovenica
Agnieszka Drozd, Dominika Wojewska, Manuel David Peris-Díaz, Piotr Jakimowicz, Artur Krężel
Metallothioneins (MTs), small cysteine-rich proteins, present in four major isoforms, are key proteins involved in zinc and copper homeostasis in mammals. To date, only one X-ray crystal structure of a MT has been solved. It demonstrates seven bivalent metal ions bound in two structurally independent domains with M4S11 (α) and M3S9 (β) clusters. Recent discoveries indicate that Zn(ii) ions are bound with MT2 with the range from nano- to picomolar affinity, which determines its cellular zinc buffering properties that are demonstrated by the presence of partially Zn(ii)-depleted MT2 species...
March 21, 2018: Metallomics: Integrated Biometal Science
Simon Heeke, Véronique Hofman, Elodie Long-Mira, Virginie Lespinet, Salomé Lalvée, Olivier Bordone, Camille Ribeyre, Virginie Tanga, Jonathan Benzaquen, Sylvie Leroy, Charlotte Cohen, Jérôme Mouroux, Charles Hugo Marquette, Marius Ilié, Paul Hofman
Background : With the integration of various targeted therapies into the clinical management of patients with advanced lung adenocarcinoma, next-generation sequencing (NGS) has become the technology of choice and has led to an increase in simultaneously interrogated genes. However, the broader adoption of NGS for routine clinical practice is still hampered by sophisticated workflows, complex bioinformatics analysis and medical interpretation. Therefore, the performance of the novel QIAGEN GeneReader NGS system was compared to an in-house ISO-15189 certified Ion PGM NGS platform...
March 21, 2018: Cancers
Michal Hricovíni, Milan Mazúr, Angela Sîrbu, Oleg Palamarciuc, Vladimir B Arion, Vlasta Brezová
X- and Q-band electron paramagnetic resonance (EPR) spectroscopy was used to characterize polycrystalline Cu(II) complexes that contained sodium 5-sulfonate salicylaldehyde thiosemicarbazones possessing a hydrogen, methyl, ethyl, or phenyl substituent at the terminal nitrogen. The ability of thiosemicarbazone proligands to generate superoxide radical anions and hydroxyl radicals upon their exposure to UVA irradiation in aerated aqueous solutions was evidenced by the EPR spin trapping technique. The UVA irradiation of proligands in neutral or alkaline solutions and dimethylsulfoxide (DMSO) caused a significant decrease in the absorption bands of aldimine and phenolic chromophores...
March 21, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Caterina Monini, Micaela Cunha, Etienne Testa, Michaёl Beuve
NanOx is a new biophysical model that aims at predicting the biological effect of ions in the context of hadron therapy. It integrates the fully-stochastic nature of ionizing radiation both at micrometric and nanometric scales and also takes into account the production and diffusion of reactive chemical species. In order to further characterize the new framework, we discuss the meaning and relevance of most of the NanOx parameters by evaluating their influence on the linear-quadratic coefficient α and on the dose deposited to achieve 10% or 1% of cell survival, D 10 % or D 1 % , as a function of LET...
March 21, 2018: Cancers
Tracey Ann Cuin, Ingo Dreyer, Erwan Michard
Fast responses to an external threat depend on the rapid transmission of signals through a plant. Action potentials (APs) are proposed as such signals. Plant APs share similarities with their animal counterparts; they are proposed to depend on the activity of voltage-gated ion channels. Nonetheless, despite their demonstrated role in (a)biotic stress responses, the identities of the associated voltage-gated channels and transporters remain undefined in higher plants. By demonstrating the role of two potassium-selective channels in Arabidopsis thaliana in AP generation and shaping, we show that the plant AP does depend on similar Kv -like transport systems to those of the animal signal...
March 21, 2018: International Journal of Molecular Sciences
Aaron B Christian, Aaron T Schye, Kelvin O White, John Neumeier
The magnetic, thermal, and optical properties of single-crystalline CoTa$_2$O$_6$ and FeTa$_2$O$_6$ are reported. Optical dichroism was observed in CoTa$_2$O$_6$. Magnetic susceptibility $\chi$($T$) measurements reveal long-range antiferromagnetic order with N\'eel temperatures $T_N$ = 6.12(5)~K and 8.11(5)~K, respectively, and anisotropy in $\chi$. The thermal expansion coefficients exhibit significant anisotropy and the influence of the magnetic ions and long-range order. A structural phase transition to orthorhombic occurs below $T_N$ for FeTa$_2$O$_6$...
March 21, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Priyanka A Shah, Pranav S Shrivastav, Pravin G Vanol, Mallika Sanyal
AIM: A simple, selective and sensitive hydrophilic interaction liquid chromatography-MS/MS method is developed for the simultaneous determination of metformin (MET) and teneligliptin (TEN) in human plasma using deuterated internal standards. The mechanism of retention of analytes was studied by varying the proportion of organic diluent, buffer strength, pH of the mobile phase and temperature. RESULTS: The results showed a mixed-mode mechanism comprising of hydrophilic (partition) and electrostatic interaction (ion exchange) for MET and essentially hydrophilic for TEN...
March 21, 2018: Bioanalysis
Styliani Consta, Myong In Oh, Mahmoud Sharawy, Anatoly Malevanets
Macroion-droplet interactions play a critical role in many settings such as ionization techniques of samples in mass spectrometry analysis and atmospheric aerosols. The droplets under investigation are composed of a polar solvent, primarily water, a charged macroion and, possibly, buffer ions. We present highlights of our research on the relation between the charge state of a macroion and the droplet morphologies. We have determined that depending on the charge on the macroion and certain macroscopic properties of the solvent, such as its dielectric constant and surface tension, a droplet may obtain striking conformations such as droplets with extruded tails, ``pearl-necklace'' conformations and multi-point ``star'' shapes...
March 21, 2018: Journal of Physical Chemistry. A
Daniel Ramirez, Yusaku Suto, Nataly Carolina Rosero-Navarro, Akira Miura, Kiyoharu Tadanaga, Franklin Jaramillo
Organic-inorganic hybrid perovskite materials have recently been investigated in a variety of applications, including solar cells, light emitting devices (LEDs), and lasers because of their impressive semiconductor properties. Nevertheless, the perovskite structure has the ability to host extrinsic elements, making its application in the battery field possible. During the present study, we fabricated and investigated the electrochemical properties of three-dimensional (3D) methylammonium lead mixed-halide CH3 NH3 PbI3- x Brx and two-dimensional (2D) propylammonium-methlylammonium lead bromide (CH3 NH3 )2 (CH3 (CH2 )2 NH3 )2 Pb3 Br10 hybrid perovskite thin films as electrode materials for Li-ion batteries...
March 21, 2018: Inorganic Chemistry
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