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quantum magnetic analyser

Sabrin Ibrahim, Gamal Mohamed, Rwaida Al Haidari, Amal El-Kholy, Mohamed Zayed
Background: Marine organisms are established to be a wealthy source of bioactive compounds with diverse chemical structures and bioactivities. Acanthostrongylophora ingens is known to be rich with pyrimidine b-carboline and manzamine-type alkaloids. The goal of the present work is to isolate and identify new alkaloids from A. ingens as well as to assess the cytotoxic potential of these metabolites towards various cancer cell lines. Methods: The crude MeOH extract of the sponge was separated by vacuum liquid chromatography (VLC), using n-hexane , EtOAc, and MeOH...
April 2018: Pharmacognosy Magazine
Stephen Liddle, Erli Lu, Ashley Wooles, Mathew Gregson, Philip Cobb
Reaction of the uranium silyl-phosphino-carbene complex [U{C(SiMe3)(PPh2)}(BIPM)(μ-Cl)Li(TMEDA)(μ-TMEDA)0.5]2 (1, BIPM = C(PPh2NSiMe3)2; TMEDA = Me2NCH2CH2NMe2) with the rhodium chloride compound [Rh(μ-Cl)(COD)]2 (COD = cyclo-octadiene) affords the unprecedented heterotrimetallic UIV-RhI2 complex [U(Cl)2{C(PPh2NSiMe3)(PPh[C6H4]NSiMe3)}{Rh(COD)}{Rh(CH(SiMe3)(PPh2)}] (2). Complex 2 exhibits one, very short, uranium-rhodium distance that is by some margin the shortest uranium-rhodium bond on record, one of the shortest absolute uranium-metal distances generally, and the shortest actinide-transition metal bond in terms of formal shortness ratio...
April 17, 2018: Angewandte Chemie
Victor Fleurov, Victor Kagalovsky, Igor V Lerner, Igor Valery Yurkevich
We revise a phase diagram for the sliding Luttinger liquid (SLL) of coupled one-dimensional quantum wires packed in two- or three-dimensional arrays in the absence of a magnetic field. We analyse whether physically justifiable (reasonable) inter-wire interactions, i.e. either the screened Coulomb or ``Coulomb-blockade" type interactions, stabilise the SLL phase. Calculating the scaling dimensions of the most relevant perturbations (the inter-wire single-particle hybridisation, charge-density wave, and superconducting inter-wire couplings), we find that their combination always destroys the SLL phase for the repulsive intra-wire interaction...
March 26, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Maryam Daneshpour, Behzad Karimi, Kobra Omidfar
miRNAs are among the novel biomarkers that can be evaluated for sensitive and early cancer diagnosis. In the present study, an electrochemical nanobiosensor has been fabricated to detect two gastric cancer (GC) related miRNAs simultaneously. By employing Au nanoparticles- and CdSe@CdS quantum dots-contained magnetic nanocomposites as electrochemical labels along with the polythiophene/reduced graphene oxide-modified carbon electrodes, this dual signal nanobiosensor showed a considerable performance in quantifying miR-106a (a GC oncogenic miRNA) and let-7a (a GC tumor suppressor miRNA)...
March 13, 2018: Biosensors & Bioelectronics
K Shrestha, V Marinova, B Lorenz, C W Chu
We present a systematic quantum oscillations study on a metallic, p-type Bi2 Te3 topological single crystal in magnetic fields up to B  =  7 T. The maxima/minima positions of oscillations measured at different tilt angles align to one another when plotted as a function of the normal component of magnetic field, confirming the presence of the 2D Fermi surface. Additionally, the Berry phase, β  =  0.4  ±  0.05 obtained from the Landau level fan plot, is very close to the theoretical value of 0...
May 10, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
D G Costa, Rodrigo B Capaz, R Falconi, S Strikos, M ElMassalami
According to an earlier Abrikosov model, a positive, nonsaturating, linear magnetoresistivity (LMR) is expected in clean, low-carrier-density metals when measured at very low temperatures and under very high magnetic fields. Recently, a vast class of materials were shown to exhibit extraordinary high LMR but at conditions that deviate sharply from the above-mentioned Abrikosov-type conditions. Such deviations are often considered within either classical Parish-Littlewood scenario of random-conductivity network or within a quantum scenario of small-effective mass or low carriers at tiny pockets neighboring the Fermi surface...
March 6, 2018: Scientific Reports
Jun-Liang Liu, Yan-Cong Chen, Ming-Liang Tong
Toward promising candidates of quantum information processing, the rapid development of lanthanide-based single-molecule magnets (Ln-SMMs) highlights design strategies in consideration of the local symmetry of lanthanide ions. In this review, crystal-field theory is employed to demonstrate the electronic structures according to the semiquantitative electrostatic model. Then, specific symmetry elements are analysed for the elimination of transverse crystal fields and quantum tunnelling of magnetization (QTM)...
April 3, 2018: Chemical Society Reviews
J Oitmaa
We investigate ground-state and high-temperature properties of the nearest-neighbour Heisenberg antiferromagnet on the three-dimensional diamond lattice, using series expansion methods. The ground-state energy and magnetization, as well as the magnon spectrum, are calculated and found to be in good agreement with first-order spin-wave theory, with a quantum renormalization factor of about 1.13. High-temperature series are derived for the free energy, and physical and staggered susceptibilities for spin S  =  1/2, 1 and 3/2, and analysed to obtain the corresponding Curie and Néel temperatures...
April 18, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
J Beerwerth, M Storek, D Greim, J Lueg, R Siegel, B Cetinkaya, W Hiller, H Zimmermann, J Senker, R Böhmer
Polycrystalline dimethyl sulfone is studied using central-transition oxygen-17 exchange NMR. The quadrupolar and chemical shift tensors are determined by combining quantum chemical calculations with line shape analyses of rigid-lattice spectra measured for stationary and rotating samples at several external magnetic fields. Quantum chemical computations predict that the largest principal axes of the chemical shift anisotropy and electrical field gradient tensors enclose an angle of about 73°. This prediction is successfully tested by comparison with absorption spectra recorded at three different external magnetic fields...
March 2018: Journal of Magnetic Resonance
Frederik Görg, Michael Messer, Kilian Sandholzer, Gregor Jotzu, Rémi Desbuquois, Tilman Esslinger
Periodic driving can be used to control the properties of a many-body state coherently and to realize phases that are not accessible in static systems. For example, exposing materials to intense laser pulses makes it possible to induce metal-insulator transitions, to control magnetic order and to generate transient superconducting behaviour well above the static transition temperature. However, pinning down the mechanisms underlying these phenomena is often difficult because the response of a material to irradiation is governed by complex, many-body dynamics...
January 24, 2018: Nature
Vasily Lavrentiev, D Chvostova, Alexandr Stupakov, Inna Lavrentieva, J Vacik, Mykhaylo Motylenko, Mykhailo Barchuk, David Rafaja, Alexandr Dejneka
Driving by interplay between plasmonic and magnetic effects in organic composite semiconductors is a challenging task with a huge potential for practical applications. Here, we present the evidences of a quantum plasmon excited in the self-assembled CoxC60 nanocomposite films with x>15 (interval of the Co cluster coalescence) and analysed it using the optical absorption (OA) spectra. In the case of the CoxC60 film with x=16 (LF sample), the quantum plasmon generated by the Co/CoO clusters was found as the 1...
January 25, 2018: Nanotechnology
Qinqin Huang, Yin Wang, Xingxiang Chen, Yimeng Wang, Zhiqiang Li, Shiming Du, Lianrong Wang, Shi Chen
Circulating tumor cells (CTCs) are cancer cells that shed from a primary tumor and circulate in the bloodstream. As a form of "tumor liquid biopsy", CTCs provide important information for the mechanistic investigation of cancer metastasis and the measurement of tumor genotype evolution during treatment and disease progression. However, the extremely low abundance of CTCs in the peripheral blood and the heterogeneity of CTCs make their isolation and characterization major technological challenges. Recently, nanotechnologies have been developed for sensitive CTC detection; such technologies will enable better cell and molecular characterization and open up a wide range of clinical applications, including early disease detection and evaluation of treatment response and disease progression...
2018: Nanotheranostics
P Reith, X Renshaw Wang, H Hilgenkamp
Scanning superconducting quantum interference device microscopy (SSM) is a scanning probe technique that images local magnetic flux, which allows for mapping of magnetic fields with high field and spatial accuracy. Many studies involving SSM have been published in the last few decades, using SSM to make qualitative statements about magnetism. However, quantitative analysis using SSM has received less attention. In this work, we discuss several aspects of interpreting SSM images and methods to improve quantitative analysis...
December 2017: Review of Scientific Instruments
Khadijat O Abdulwahab, Mohammad A Malik, Paul O'Brien, Iñigo J Vitorica-Yrezabal, Grigore A Timco, Floriana Tuna, Richard E P Winpenny
Monodisperse cobalt chromium ferrite (FeCoCrO4 ) nanoparticles have been synthesised using the trimetallic pivalate cluster [CrCoFeO(O2 Ct Bu)6 (HO2 Ct Bu)3 ]. The precursor was thermolysed in oleylamine and oleic acid, with diphenyl ether as the solvent at 260 °C. The effect of time and the concentration of the precursor on the stoichiometry of the phase formed and/or the morphology of the nanoparticles was studied. The reaction time was investigated by withdrawing aliquots at different times. No products were formed after 5 minutes and aliquots withdrawn at reaction times of less than 1 hour contain traces of iron oxide (Fe2 O3 ); only cubic cobalt chromium ferrite (FeCoCrO4 ) was obtained after one hour...
January 2, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Lamia T Abou El-Kassem, Usama W Hawas, Samy K El-Desouky, Radwan Al-Farawati
A new pseudoguaiane-type sesquiterpene named litopharbol (1) was isolated from the methanolic extract of the Red Sea soft coral Litophyton arboreum, along with known sesquiterpenoids alismol (2), alismorientol B (3), teuhetenone A (4), and calamusin I (5); steroid, 24-methyl-cholesta-5,24(28)-diene-3β-ol (6), alkyl glyceryl ether, chimyl alcohol (7); sphingolipid, erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8); and nitrogenous bases, thymine (9) and thymidine (10). The structures were determined on the basis of nuclear magnetic resonance (NMR) spectroscopic (1D and 2D NMR data including heteronuclear single quantum coherence spectroscopy, heteronuclear multiple-bond correlation spectroscopy, and nuclear Overhauser effect spectroscopy) and mass spectrometric analyses...
January 26, 2018: Zeitschrift Für Naturforschung. C, A Journal of Biosciences
Laetitia Nivelle, Jane Hubert, Eric Courot, Nicolas Borie, Jean-Hugues Renault, Jean-Marc Nuzillard, Dominique Harakat, Christophe Clément, Laurent Martiny, Dominique Delmas, Philippe Jeandet, Michel Tarpin
A new resveratrol dimer (1) called labruscol, has been purified by centrifugal partition chromatography of a crude ethyl acetate stilbene extract obtained from elicited grapevine cell suspensions of Vitis labrusca L. cultured in a 14-liter stirred bioreactor. One dimensional (1D) and two dimensional (2D) nuclear magnetic resonance (NMR) analyses including ¹H, (13)C, heteronuclear single-quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), and correlation spectroscopy (COSY) as well as high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS) were used to characterize this compound and to unambiguously identify it as a new stilbene dimer, though its relative stereochemistry remained unsolved...
November 9, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Chip J Smith, Durgesh V Wagle, Hugh M O'Neill, Barbara R Evans, Sheila N Baker, Gary A Baker
To fully leverage the advantages of ionic liquids for many applications, it is necessary to immobilize or encapsulate the fluids within an inert, robust, quasi-solid-state format that does not disrupt their many desirable, inherent features. The formation of ionogels represents a promising approach; however, many earlier approaches suffer from solvent/matrix incompatibility, optical opacity, embrittlement, matrix-limited thermal stability, and/or inadequate ionic liquid loading. We offer a solution to these limitations by demonstrating a straightforward and effective strategy toward flexible and durable ionogels comprising bacterial cellulose supports hosting in excess of 99% ionic liquid by total weight...
October 23, 2017: ACS Applied Materials & Interfaces
N R Bernier, L D Tóth, A Koottandavida, M A Ioannou, D Malz, A Nunnenkamp, A K Feofanov, T J Kippenberg
Nonreciprocal microwave devices are ubiquitous in radar and radio communication and indispensable in the readout chains of superconducting quantum circuits. Since they commonly rely on ferrite materials requiring large magnetic fields that make them bulky and lossy, there has been significant interest in magnetic-field-free on-chip alternatives, such as those recently implemented using the Josephson nonlinearity. Here, we realize reconfigurable nonreciprocal transmission between two microwave modes using purely optomechanical interactions in a superconducting electromechanical circuit...
September 19, 2017: Nature Communications
Gijs van Erven, Ries de Visser, Donny W H Merkx, Willem Strolenberg, Peter de Gijsel, Harry Gruppen, Mirjam A Kabel
Understanding the mechanisms underlying plant biomass recalcitrance at the molecular level can only be achieved by accurate analyses of both the content and structural features of the molecules involved. Current quantification of lignin is, however, majorly based on unspecific gravimetric analysis after sulfuric acid hydrolysis. Hence, our research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric (13)C lignin was used as internal standard (IS) for lignin quantification via analytical pyrolysis coupled to gas chromatography with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS)...
October 17, 2017: Analytical Chemistry
Nobuhiro Matsumoto, Takuya Shimosaka
The purities of two high-purity organic compounds with a nitroxyl radical moiety were quantified based on their free-radical content using the effective magnetic-moment method. Magnetic moments were measured and X-band electron paramagnetic resonance (EPR) spectra were obtained using a superconducting quantum interference device and X-band EPR spectrometer, respectively, over a wide temperature range of near-room temperature to near-liquid-helium temperature. Concerning measurements of effective g-values using an EPR spectrometer, both the sweep direction and sweep speed were taken into account to obtain accurate g-values...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
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