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Sangyun Lee, Heather B Mayes, Jessica M J Swanson, Gregory A Voth
The ClC family of transmembrane proteins functions throughout nature to control the transport of Cl- ions across biological membranes. ClC-ec1 from Escherichia coli is an antiporter, coupling the transport of Cl- and H+ ions in opposite directions and driven by the concentration gradients of the ions. Despite keen interest in this protein, the molecular mechanism of the Cl-/H+ coupling has not been fully elucidated. Here, we have used multiscale simulation to help identify the essential mechanism of the Cl-/H+ coupling...
October 26, 2016: Journal of the American Chemical Society
Viviane Coutinho Meneguzzi, Claudiney Biral Dos Santos, Gustavo Rocha Leite, Blima Fux, Aloísio Falqueto
Cutaneous leishmaniasis (CL) is caused by a protozoan of the genus Leishmania and is transmitted by sand flies. The state of Espírito Santo (ES), an endemic area in southeast Brazil, has shown a considerably high prevalence in recent decades. Environmental niche modelling (ENM) is a useful tool for predicting potential disease risk. In this study, ENM was applied to sand fly species and CL cases in ES to identify the principal vector and risk areas of the disease. Sand flies were collected in 466 rural localities between 1997 and 2013 using active and passive capture...
2016: PloS One
Martin Skov, Frank V de Paoli, Ole B Nielsen, Thomas H Pedersen
INTRODUCTION: In myotonia congenita, loss of ClC-1 Cl(-) -channel function results in skeletal muscle hyperexcitability and myotonia. Anti-myotonic treatment has typically targeted the voltage gated sodium channel in skeletal muscle (Nav1.4). This study explored whether 3 sodium channel modulating anti-epileptics can reduce myotonia in isolated rat and human muscle. METHODS: Dissected muscles were rendered myotonic by ClC-1 channel inhibition. The ability of the drugs to suppress myotonia was then assessed from sub-clinical to maximal clinical concentrations...
October 26, 2016: Muscle & Nerve
V A Yurkiv, V I Melikhov, V S Shubin
We studied the effects of ionophores on activity of Na(+),Cl(-)(HCO 3(-) )-ATPase. The most significant effect on the activity of this enzyme was produced by protonophore 2,4-dinitrophenol. The effect of this drug largely depended on the cation and anion composition and pH of the incubation medium and its pH. Activity of Na(+),Cl(-)(HCO 3(-) )-ATPase increased at neutral and weakly alkaline pH and decreased at pH below 6.5-6.7. In control animals (without histamine injection) with very weak or absent Na(+),Cl(-)(HCO 3(-) )-ATPase activity, the observed effect of the protonophore on ATPase activity was also virtually absent...
October 26, 2016: Bulletin of Experimental Biology and Medicine
Cristine E A Carneiro, Antonio C Stabile, Frederico P Gomes, Antonio C S da Costa, Cássia T B V Zaia, Dimas A M Zaia
Probably one of the most important roles played by minerals in the origin of life on Earth was to pre-concentrate biomolecules from the prebiotic seas. There are other ways to pre concentrate biomolecules such as wetting/drying cycles and freezing/sublimation. However, adsorption is most important. If the pre-concentration did not occur-because of degradation of the minerals-other roles played by them such as protection against degradation, formation of polymers, or even as primitive cell walls would be seriously compromised...
October 25, 2016: Origins of Life and Evolution of the Biosphere
May Garrett, Timothy Taylor, Diane R Mould, Michael A Amantea, Ying Chen, Antonella Ingrosso, Yazdi K Pithavala
PURPOSE: Axitinib, a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptors 1-3, is approved for second-line treatment of advanced renal cell carcinoma. Axitinib is partially metabolized by cytochrome P450 1A2, which is induced by chronic heavy smoking. The effect of smoking on axitinib pharmacokinetics was evaluated in a non-small-cell lung cancer (NSCLC) patient population with a large number of active and ex-smokers. METHODS: Data were pooled from six clinical studies-serial pharmacokinetics from two healthy volunteer studies (n = 58) and sparse pharmacokinetics from four NSCLC studies (n = 152)-for a nonlinear mixed effects modeling (NONMEM v7...
October 25, 2016: Cancer Chemotherapy and Pharmacology
Martina Zangheri, Fabio Di Nardo, Mara Mirasoli, Laura Anfossi, Augusto Nascetti, Domenico Caputo, Giampiero De Cesare, Massimo Guardigli, Claudio Baggiani, Aldo Roda
A novel and disposable cartridge for chemiluminescent (CL)-lateral flow immunoassay (LFIA) with integrated amorphous silicon (a-Si:H) photosensors array was developed and applied to quantitatively detect human serum albumin (HSA) in urine samples. The presented analytical method is based on an indirect competitive immunoassay using horseradish peroxidase (HRP) as a tracer, which is detected by adding the luminol/enhancer/hydrogen peroxide CL cocktail. The system comprises an array of a-Si:H photosensors deposited on a glass substrate, on which a PDMS cartridge that houses the LFIA strip and the reagents necessary for the CL immunoassay was optically coupled to obtain an integrated analytical device controlled by a portable read-out electronics...
October 25, 2016: Analytical and Bioanalytical Chemistry
Yi-Qing Zhong, Hui-Qiong Xiao, Xiao-Yi Yi
Treatment of the 2,5-bis(2'-pyridyl)pyrrolato (PDP(-)) anion with {Ru(COD)Cl2}n in THF readily yielded [Ru(PDP)(COD)Cl] (1) in almost quantitative yield. Anion metathesis of 1 in organic solvent by NO3(-) and OTf(-) (OTf(-) = triflato) gave [Ru(PDP)(COD)(NO3)] (2) and [Ru(PDP)(COD)(OTf)] (3), and in aqueous solution by BF4(-) and PF6(-) afforded aqueous complexes [Ru(PDP)(COD)(H2O)](BF4) (4+·BF4(-)) and [Ru(PDP)(COD)(H2O)](PF6) (4+·PF6(-)), respectively. Treatment of 1 with PhICl2 in CH2Cl2 afforded 5 with halogenated pyrrole...
October 26, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Florence Auberon, Opeyemi Joshua Olatunji, Gaëtan Herbette, Diamondra Raminoson, Cyril Antheaume, Beatriz Soengas, Frédéric Bonté, Annelise Lobstein
We report the first phytochemical study of the neotropical orchid Cyrtopodium paniculatum. Eight new compounds, including one phenanthrene 1, one 9,10-dihydro-phenanthrene 2, one hydroxybenzylphenanthrene 3, two biphenanthrenes 4-5, and three 9,10 dihydrophenanthrofurans 6-8, together with 28 known phenolic compounds, mostly stilbenoids, were isolated from the CH₂Cl₂ extract of its leaves and pseudobulbs. The structures of the new compounds were established on the basis of extensive spectroscopic methods...
October 24, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Nicholas M Dalesio, Craig W Hendrix, Douglas Hale McMichael, Carol B Thompson, Carlton K K Lee, Huy Pho, Rafael S Arias, Rachael Rzasa Lynn, Jeffrey Galinkin, Myron Yaster, Robert H Brown, Alan R Schwartz
BACKGROUND: Obesity causes multiorgan dysfunction, specifically metabolic abnormalities in the liver. Obese patients are opioid-sensitive and have high rates of respiratory complications after surgery. Obesity also has been shown to cause resistance to leptin, an adipose-derived hormone that is key in regulating hunger, metabolism, and respiratory stimulation. We hypothesized that obesity and leptin deficiency impair opioid pharmacokinetics (PK) independently of one another. METHODS: Morphine PK were characterized in C57BL/6J wild-type (WT), diet-induced obese (DIO), and leptin-deficient (ob/ob) mice, and in ob/ob mice given leptin-replacement (LR) therapy...
October 24, 2016: Anesthesia and Analgesia
M Koselski, A Olszewska, A Hordyjewska, T Małecka-Massalska, K Trebacz
Patch clamp recordings carried out in the inside-out configuration revealed activity of three kinds of channels: nonselective cation channels, small-conductance K(+) channels, and large-conductance anion channels. The nonselective cation channels did not distinguish between Na(+) and K(+). The unitary conductance of these channels reached 28 pS in a symmetrical concentration of 200 mM NaCl. A lower value of this parameter was recorded for the small-conductance K(+) channels and in a 50-fold gradient of K(+) (200 mM/4 mM) it reached 8 pS...
October 26, 2016: Physiological Research
Fengyan Wang, Kopin Liu
A complete set of four polarization-dependent differential cross sections in the reactions of Cl + aligned-CHD3(v1=1,jK)→DCl(v=0)+CHD2(v1=1) is reported here for two different, rotationally polarized states with j = 1: specifically the jK=10 state prepared via the R(0) excitation and the 1±1 state via Q(1). In stark contrast to the complicated situation of the HCl(v) + CD3(v = 0) channel reported in Paper-I, the stereo-requirement of this isotopic channel for both polarized reactants appears quite straightforward and consistent with a direct rebound mechanism...
October 14, 2016: Journal of Chemical Physics
Fengyan Wang, Kopin Liu
When a CHD3 molecule is pumped to the C-H stretching-excited state by absorbing a linearly polarized infrared (IR) photon via the R(0) branch of the v1 = 1←0 transition, the rotational angular momentum j of the prepared state jK=10 preferentially lies in a plane perpendicular to the IR polarization axis εIR. By way of contrast, when the Q(1) branch is used, the state of jK=1±1 is prepared with j aligned along the direction of εIR. Reported here is a detailed study of the title reaction by actively controlling the collision geometries under these two IR-excitation schemes at collision energy Ec = 8...
October 14, 2016: Journal of Chemical Physics
Tuan Anh Pham, Tadashi Ogitsu, Edmond Y Lau, Eric Schwegler
Establishing an accurate and predictive computational framework for the description of complex aqueous solutions is an ongoing challenge for density functional theory based first-principles molecular dynamics (FPMD) simulations. In this context, important advances have been made in recent years, including the development of sophisticated exchange-correlation functionals. On the other hand, simulations based on simple generalized gradient approximation (GGA) functionals remain an active field, particularly in the study of complex aqueous solutions due to a good balance between the accuracy, computational expense, and the applicability to a wide range of systems...
October 21, 2016: Journal of Chemical Physics
Ann-Lauriene Haag, Zeno Schumacher, Peter Grutter
A detailed analysis of the temporal surface stress evolution for potential-driven adsorption of ions is discussed. A gold-coated cantilever is used to simultaneously measure the change in surface stress as well as the current response during an applied potential step. In this electrochemical configuration, the cantilever acts as the working electrode, a platinum wire as the counter electrode, and the Ag/AgCl (sat. KCl) electrode as the reference electrode. To study the time-dependent signal and the sensitivity of the cantilever response, the frequency of the potential step applied to the cantilever is varied from 1 s to 0...
October 21, 2016: Journal of Chemical Physics
Burak Himmetoglu
We present an application of the boosted regression tree algorithm for predicting ground state energies of molecules made up of C, H, N, O, P, and S (CHNOPS). The PubChem chemical compound database has been incorporated to construct a dataset of 16 242 molecules, whose electronic ground state energies have been computed using density functional theory. This dataset is used to train the boosted regression tree algorithm, which allows a computationally efficient and accurate prediction of molecular ground state energies...
October 7, 2016: Journal of Chemical Physics
David Cappelletti, Stefano Falcinelli, Fernando Pirani
Gas phase collisions of a D2 projectile by CF4 and by CCl4 targets have been investigated with the molecular beam technique. The integral cross section, Q, has been measured for both collisional systems in the thermal energy range and oscillations due to the quantum "glory" interference have been resolved in the velocity dependence of Q. The analysis of the measured Q(v) data provided novel information on the anisotropic potential energy surfaces of the studied systems at intermediate and large separation distances...
October 7, 2016: Journal of Chemical Physics
Naoki Ichijo, Kazuyuki Takeda, Kazuhiko Yamada, K Takegoshi
We propose a simple data-analysis scheme to determine the coupling constant and the asymmetry parameter of nuclear quadrupolar interactions in field-swept nuclear magnetic resonance (NMR) for static powder samples. This approach correlates the quadrupolar parameters to the positions of the singularities, which can readily be found out as sharp peaks in the field-swept pattern. Moreover, the parameters can be determined without quantitative acquisition and elaborate calculation of the overall profile of the pattern...
October 7, 2016: Journal of Chemical Physics
Ching-Yin Chou, Yuan-Pern Lee
The addition reactions of chlorine atom with isobutene (i-C4H8) in solid para-hydrogen (p-H2) were investigated with infrared (IR) absorption spectra. When a p-H2 matrix containing Cl2 and isobutene was irradiated with ultraviolet light at 365 nm, intense lines in a set at 534.5, 1001.0, 1212.9, 1366.0, 2961.6, and 2934.7 cm(-1), and several weaker others due to the 1-chloro-2-methyl-2-propyl radical, (⋅)C(CH3)2CH2Cl, and those in a second set including intense ones at 642.7, 799.2, 1098.2, 1371.8, and 3027...
October 7, 2016: Journal of Chemical Physics
István Szabó, Gábor Czakó
We report a detailed quasiclassical trajectory study for the dynamics of the ground-state and CH/CD stretching-excited F(-) + CHD2Cl(vCH/CD = 0, 1) → Cl(-) + CHD2F, HF + CD2Cl(-), and DF + CHDCl(-) SN2, proton-, and deuteron-abstraction reactions using a full-dimensional global ab initio analytical potential energy surface. The simulations show that (a) CHD2Cl(vCH/CD = 1), especially for vCH = 1, maintains its mode-specific excited character prior to interaction, (b) the SN2 reaction is vibrationally mode-specific,...
October 7, 2016: Journal of Chemical Physics
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