Read by QxMD icon Read


Iciar Uriarte, Cristóbal Pérez, Elena Caballero-Mancebo, Francisco J Basterretxea, Alberto Lesarri, José A Fernández, Emilio J Cocinero
Nicotinoids are agonists of the acetylcholine receptor (nAChR) and play important biochemical and pharmacological roles. Here we report on the structural and conformational landscape of cotinine, and compare its molecular properties with the nicotine prototype, from which it only differs in the addition of a carbonyl group. The investigation of cotinine included a theoretical survey of the effects of rotamerization of the pyridine moiety, the puckering of the pyrrolidinone ring and the internal rotation of the methyl group...
February 17, 2017: Chemistry: a European Journal
Bo Zhang, Sabah M M Abu-Khumra, Abdellah Aibout, Anthony J Horsewill
In NMR the polarisation of the Zeeman system may be routinely probed and manipulated by applying resonant rf pulses. As with spin-1/2 nuclei, at low temperature the quantum tunnelling states of a methyl rotor are characterised by two energy levels and it is interesting to consider how these tunnelling states might be probed and manipulated in an analogous way to nuclear spins in NMR. In this paper experimental procedures based on magnetic field-cycling NMR are described where, by irradiating methyl tunnelling sidebands, the polarisations of the methyl tunnelling systems are measured and manipulated in a prescribed fashion...
February 14, 2017: Journal of Chemical Physics
Nezha Bouhafs, François Lique, Alexandre Faure, Aurore Bacmann, Jun Li, Hua Guo
We present quantum close-coupling calculations for the rotational excitation of the interstellar amidogen radical NH2 due to collisions with H2 molecules. The calculations are based on a recent, high-accuracy full-dimensional NH4 potential energy surface adapted for rigid-rotor scattering calculations. The collisional cross section calculations are performed for all transitions among the first 15 energy levels of both ortho- and para-NH2 and for total energies up to 1500 cm(-1). Both para- and ortho-H2 colliding partners are considered...
February 14, 2017: Journal of Chemical Physics
Yangyang Yang, Ryu Tashiro, Yuki Suzuki, Tomoko Emura, Kumi Hidaka, Hiroshi Sugiyama, Masayuki Endo
Various DNA-based nanodevices have been developed on the nanometer scale using light as regulation input. However, the programmed controllability is still a major challenge for these artificial nanodevices. Herein, we demonstrate a rotary DNA nanostructure in which the rotations are controlled by light. A bar-shaped DNA rotor, fabricated as a stiff double-crossover molecule, was placed on the top of a rectangular DNA tile. The photoresponsive oligonucleotides modified with azobenzenes were employed as switching motifs to release/trap the rotor at specific angular position on DNA tile by switching photoirradiations between ultraviolet and visible light...
February 15, 2017: Chemistry: a European Journal
Hiroki Iida, Kenji Ohmura, Ryuta Noda, Soichiro Iwahana, Hiroshi Katagiri, Naoki Ousaka, Taku Hayashi, Yuh Hijikata, Stephan Irle, Eiji Yashima
Novel double helices covalently-bridged by cyclic boronate esters were synthesized from complementary dimers with a m-terphenyl backbone joined by a chiral or achiral phenylene linker bearing diethyl boronates and diols, respectively. The X-ray crystallographic analysis and variable-temperature NMR and circular dichroism measurements, along theoretical calculations, revealed that the double helices function as a "molecular rotor" in which the cyclic boronate ester units rotate, yielding two stable rotamers at low temperatures...
February 14, 2017: Chemistry, An Asian Journal
Masaki Kobayashi
A complex-valued Hopfield neural network (CHNN) is a multistate model of a Hopfield neural network. It has the disadvantage of low noise tolerance. Meanwhile, a symmetric CHNN (SCHNN) is a modification of a CHNN that improves noise tolerance. Furthermore, a rotor Hopfield neural network (RHNN) is an extension of a CHNN. It has twice the storage capacity of CHNNs and SCHNNs, and much better noise tolerance than CHNNs, although it requires twice many connection parameters. In this brief, we investigate the relations between CHNN, SCHNN, and RHNN; an RHNN is uniquely decomposed into a CHNN and SCHNN...
February 2, 2017: IEEE Transactions on Neural Networks and Learning Systems
Hitoshi Ube, Yoshihiro Yasuda, Hiroyasu Sato, Mitsuhiko Shionoya
Metal ions can serve as a centre of molecular motions due to their coordination geometry, reversible bonding nature and external stimuli responsiveness. Such essential features of metal ions have been utilized for metal-mediated molecular machines with the ability to motion switch via metallation/demetallation or coordination number variation at the metal centre; however, motion switching based on the change in coordination geometry remain largely unexplored. Herein, we report a Pt(II)-centred molecular gear that demonstrates control of rotor engagement and disengagement based on photo- and thermally driven cis-trans isomerization at the Pt(II) centre...
February 8, 2017: Nature Communications
M Bitter, V Milner
We experimentally demonstrate coherent control of a quantum system, whose dynamics is chaotic in the classical limit. Interaction of diatomic molecules with a periodic sequence of ultrashort laser pulses leads to the dynamical localization of the molecular angular momentum, a characteristic feature of the chaotic quantum kicked rotor. By changing the phases of the rotational states in the initially prepared coherent wave packet, we control the rotational distribution of the final localized state and its total energy...
January 20, 2017: Physical Review Letters
N Paul, A Corsi, A Obertelli, P Doornenbal, G Authelet, H Baba, B Bally, M Bender, D Calvet, F Château, S Chen, J-P Delaroche, A Delbart, J-M Gheller, A Giganon, A Gillibert, M Girod, P-H Heenen, V Lapoux, J Libert, T Motobayashi, M Niikura, T Otsuka, T R Rodríguez, J-Y Roussé, H Sakurai, C Santamaria, N Shimizu, D Steppenbeck, R Taniuchi, T Togashi, Y Tsunoda, T Uesaka, T Ando, T Arici, A Blazhev, F Browne, A M Bruce, R Carroll, L X Chung, M L Cortés, M Dewald, B Ding, F Flavigny, S Franchoo, M Górska, A Gottardo, A Jungclaus, J Lee, M Lettmann, B D Linh, J Liu, Z Liu, C Lizarazo, S Momiyama, K Moschner, S Nagamine, N Nakatsuka, C Nita, C R Nobs, L Olivier, Z Patel, Zs Podolyák, M Rudigier, T Saito, C Shand, P-A Söderström, I Stefan, R Orlandi, V Vaquero, V Werner, K Wimmer, Z Xu
The first measurement of the low-lying states of the neutron-rich ^{110}Zr and ^{112}Mo was performed via in-beam γ-ray spectroscopy after one proton removal on hydrogen at ∼200  MeV/nucleon. The 2_{1}^{+} excitation energies were found at 185(11) keV in ^{110}Zr, and 235(7) keV in ^{112}Mo, while the R_{42}=E(4_{1}^{+})/E(2_{1}^{+}) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions...
January 20, 2017: Physical Review Letters
Shengjun Shi, Huaiyin Xiong, Yingxiang Liu, Weishan Chen, Junkao Liu
A new type of multiple-degree-of-freedom (multi-DOF) ultrasonic motor was developed aiming at high output torque and compact structure. To reach this purpose, a ring type composite stator was proposed with four driving feet uniformly arranged in the inner circumference of the ring stator. The stator employs two orthogonal axial bending modes and a radial bending mode, by exciting two of them simultaneously, to generate elliptic trajectories on driving feet tips and to push sphere rotor around x, y and z axis respectively...
January 5, 2017: Ultrasonics
Małgorzata Bojczuk, Dorota Żyżelewicz, Paweł Hodurek
Countercurrent chromatography, based on liquid-liquid partitioning, has many technological variants. One of them is centrifugal partition chromatography, introduced by Wataru Murayama and Kanichi Nunogaki in 1982. This technique, like other countercurrent chromatography techniques, is based on the phenomenon of liquid-liquid partitioning between two immiscible liquid phases, that stay at equilibrium. But the significant difference between this technique and others is the retention mechanism of stationary phase...
January 31, 2017: Journal of Separation Science
M Rida Mokhtari, Brahim Cherki, Amal Choukchou Braham
This paper propose an hierarchical controller based on a new disturbance observer with finite time convergence (FTDO) to solve the path tracking of a small coaxial-rotor-typs Unmanned Aerial Vehicles (UAVs) despite of unknown aerodynamic efforts. The hierarchical control technique is used to separate the flight control problem into an inner loop that controls attitude and an outer loop that controls the thrust force acting on the vehicle. The new disturbance observer with finite time convergence is intergated to online estimate the unknown uncertainties and disturbances and to actively compensate them in finite time...
January 27, 2017: ISA Transactions
Marisol Ibarra-Rodriguez, Blanca M Muñoz-Flores, H V Rasika Dias, Mario Sanchez, Alberto Gómez-Treviño, Rosa Santillan, Norberto Farfan, Victor Manuel Jimenez-Perez
Here we report the design, synthesis, and characterization of two new fluorescent molecular rotors of boron derived from Schiff bases: (2,4,8,10-tetra-tert-butyl-6-phenyldibenzo[d,h][1,3,6,2]dioxazaboronine 3 and 1,4-bis(2,4,8,10-tetra-tert-butyldibenzo[d,h][1,3,6,2]dioxazaboronin-6-yl)benzene 4, as well as the free ligand 2-{[(3,5-di-t-butyl-2-hydroxyphenyl)imino]methyl}-4,6-di-t-butyl-phenol 1. All compounds were fully characterized by NMR (1H, 11B, and 13C), IR, UV/vis, fluorescence spectroscopy, and high resolution mass spectrometry...
January 30, 2017: Journal of Organic Chemistry
Lyubov' E Shimolina, Maria Angeles Izquierdo, Ismael López-Duarte, James A Bull, Marina V Shirmanova, Larisa G Klapshina, Elena V Zagaynova, Marina K Kuimova
The microscopic viscosity plays an essential role in cellular biophysics by controlling the rates of diffusion and bimolecular reactions within the cell interior. While several approaches have emerged that have allowed the measurement of viscosity and diffusion on a single cell level in vitro, the in vivo viscosity monitoring has not yet been realized. Here we report the use of fluorescent molecular rotors in combination with Fluorescence Lifetime Imaging Microscopy (FLIM) to image microscopic viscosity in vivo, both on a single cell level and in connecting tissues of subcutaneous tumors in mice...
January 30, 2017: Scientific Reports
Nils A Kulak, Philipp E Geyer, Matthias Mann
Recent advances in mass spectrometry (MS)-based proteomics now allow very deep coverage of cellular proteomes. To achieve near-comprehensive identification and quantification, the combination of a first HPLC-based peptide fractionation orthogonal to the online LC-MS/MS step has proven to be particularly powerful. This first dimension is typically performed with mL/min-flow and relatively large column inner diameters, which allows efficient pre-fractionation but typically requires peptide amounts in the mg range...
January 26, 2017: Molecular & Cellular Proteomics: MCP
Muhammad Balouch, Esra Gucuk Ipek, Jonathan Chrispin, Rizma J Bajwa, Tarek Zghaib, Ronald D Berger, Hiroshi Ashikaga, Saman Nazarian, Joseph E Marine, Hugh Calkins, David D Spragg
BACKGROUND: The utility of rotor ablation using commercially available systems as an adjunct to pulmonary vein isolation (PVI) is controversial. Variable results may stem from heterogeneous practice patterns. We investigated whether a prespecified protocol to determine temperospatial rotor stability improved acute and intermediate outcomes following rotor ablation. HYPOTHESIS: Protocolized rotor mapping and ablation, with prespecified metrics to determine temporal rotor stability prior to ablation, will improve short- and long-term PVI/rotor ablation outcomes...
January 25, 2017: Clinical Cardiology
Pinquan Qin, Alexei Andreanov, Hee Chul Park, Sergej Flach
We study the fate of dynamical localization of two quantum kicked rotors with contact interaction, which relates to experimental realizations of the rotors with ultra-cold atomic gases. A single kicked rotor is known to exhibit dynamical localization, which takes place in momentum space. The contact interaction affects the evolution of the relative momentum k of a pair of interacting rotors in a non-analytic way. Consequently the evolution operator U is exciting large relative momenta with amplitudes which decay only as a power law 1/k(4)...
January 24, 2017: Scientific Reports
Pawel Kuklik, Stef Zeemering, Arne van Hunnik, Bart Maesen, Laurent Pison, Dennis Lau, Jos Maessen, Piotr Podziemski, Christian Meyer, Benjamin Schaffer, Harry Crijns, Stephan Willems, Ulrich Schotten
OBJECTIVE: To explore technical challenges of phase singularity mapping during Atrial Fibrillation (AF) using direct contact electrograms. METHODS: AF mapping was performed in high-density epicardial recordings of human paroxysmal (PAF) or persistent (PersAF) (N=20 pts) AF with an array of 16x16 electrodes placed on atrial epicardium. Phase singularity (PS) points were detected using subsets of electrodes forming rings of varying size. RESULTS: PS detection using a 2x2 electrode ring identified 0...
April 15, 2016: IEEE Transactions on Bio-medical Engineering
Jian Liu, Jiamei Jin, Ruinan Ji, Di Chen
In this paper, a novel modal-independent ultrasonic motor with dual stator is proposed, in order to relieve the difficulty of adjustment for coincidence of modal frequencies of a stator for multi-modal coupling type ultrasonic motor (USM). It consists of two stators (an upper stator and a lower stator) and a rotor. The stators are excited the 3rd longitudinal vibration mode, by arranging the location of rotor and two stators, the rotor can realize rotary motion by friction effect with the stators. The rotor is mounted between the maximum deformation location of the upper stator and the nodal line of the lower stator...
January 10, 2017: Ultrasonics
Xiaofeng Zhao, Xiaofeng Xie, Sonika Sharma, Luke T Tolley, Alex Plistil, Hal E Barnett, Martin P Brisbin, Adam C Swensen, John C Price, Paul B Farnsworth, H Dennis Tolley, Stanley D Stearns, Milton L Lee
A compact ultrahigh-pressure nanoflow liquid chromatograph (LC) was developed with the purpose in mind of creating a portable system that could be easily moved to various testing locations or placed in close proximity to other instruments for optimal coupling, such as with mass spectrometry (MS). The system utilized innovative nanoflow pumps integrated with a very low volume stop-flow injector and mixing tee. The system weighed only 5.9 kg (13 lbs) or 4.5 kg (10 lbs) without a controller and could hold up to 1100 bar (16000 psi) of pressure...
January 3, 2017: Analytical Chemistry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"