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Spin filtering

Juan Correa, Luiz F Pinto, Libo Zhao, Ricardo Riguera, Eduardo Fernandez-Megia
A polymer-mediated paramagnetic spin relaxation (PSR) filter is presented for the selective suppression of polymer-interacting species in the 1D and 2D NMR spectra of mixtures. The combined use of Gd3+ and a polymer with a high transverse relaxation enhancement (R2p, which informs on the Gd3+ complexing ability) results in the suppression of any polymer-interacting component in mixtures, irrespective of their R2p. By using poly(acrylic acid) (PAA) as a model system, we demonstrate the selective filtering of typically low R2p species (insensitive to Gd3+), like molecular/polymeric cations and non-ionic polymers that via PAA-recognition (electrostatic/hydrogen bond interactions) come to be exposed to the paramagnetic effect of Gd3+, while leaving unaffected non PAA-interacting species...
October 17, 2018: Chemistry: a European Journal
Christine F Markwalter, Paul L A M Corstjens, Claire M Mammoser, Garrett Camps, Govert J van Dam, David W Wright
Accurate and sensitive point-of-care diagnostic tools are critical for schistosomiasis control and elimination. The existing ultrasensitive lateral flow assay for the detection of Schistosoma circulating anodic antigen (CAA) has demonstrated excellent sensitivity but is time-consuming and requires significant laboratory infrastructure that limits its applicability at the point of care. To address this challenge, we sought to develop an alternative sample preparation method to concentrate CAA from large-volume urine samples requiring little-to-no laboratory equipment...
October 17, 2018: Analyst
Bastian Trepka, Julian Stiegeler, Ilona Wimmer, Mikhail Fonin, Sebastian Polarz
EuO is unique, because it belongs to the few solids combining semiconducting properties (Egap = 1.1 eV) with native ferromagnetism. For future applications of EuO, e.g. as spin-filters or for sensors, one has to learn how defined nanostructures can be prepared. Unlike other ceramic oxides, there are no established soft-chemistry routes (e.g. sol-gel) towards EuO nanomaterials e.g. porous materials. This is due to the labile nature of the oxidation state Eu(+ii). We present a particle-based method leading to a EuO aerogel...
October 12, 2018: Nanoscale
P Zhao, G Chen
Based on the first-principles density functional theory combined with the non-equilibrium Green's function method, we have studied the spin-polarized and thermospin-polarized transport properties of phthalocyanine (Pc) dimer based molecular junction with different transition metal (TM = Mn, Fe, Co, Ni) atoms. Our results show that the spin-polarized and thermospin-polarized transport properties can be effectively tuned by changing the central TM atoms, and only the MnPc dimer system exhibits perfect spin/thermal-spin filtering and sizeable giant magnetoresistance (GMR)/thermal-GMR effects...
October 7, 2018: Journal of Chemical Physics
Lena V Gast, Teresa Gerhalter, Bernhard Hensel, Michael Uder, Armin M Nagel
Double quantum filtered 23 Na MRI with magic angle excitation (DQF-MA) can be used to selectively detect sodium ions located within anisotropic structures such as muscle fibers. It might therefore be a promising tool to analyze the microscopic environment of sodium ions, for example in the context of osmotically neutral sodium retention. However, DQF-MA imaging is challenging due to various signal dependences, on both measurement parameters and external influences. The aim of this work was to examine how B0 in combination with B1 inhomogeneities alter the DQF-MA signal intensity...
October 5, 2018: NMR in Biomedicine
Osamu Takayama, Johneph Sukham, Radu Malureanu, Andrei V Lavrinenko, Graciana Puentes
The photonic spin Hall effect in transmission is a transverse beam shift of the out-coming beam depending on polarization of the incoming beam. The effect can be significantly enhanced by materials with high anisotropy. We report, to the best of our knowledge, the first experimental demonstration of the photonic spin Hall effect in a multilayer hyperbolic metamaterial at visible wavelengths (wavelengths of 520 and 633 nm). The metamaterial is composed of alternating layers of gold and alumina with deeply subwavelength thicknesses, exhibiting extremely large anisotropy...
October 1, 2018: Optics Letters
Shirin Asaadi, Tia Kakko, Alistair W T King, Ilkka Kilpeläinen, Michael Hummel, Herbert Sixta
Cellulose acetate is one of the most important cellulose derivatives. Herein we present a method to access cellulose acetate with a low degree of substitution through a homogeneous reaction in the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH][OAc]). This ionic liquid has also been identified as an excellent cellulose solvent for dry-jet wet fiber spinning. Cellulose was dissolved in [DBNH][OAc] and esterified in situ to be immediately spun into modified cellulose filaments with a degree of substitution (DS) value of 0...
July 2, 2018: ACS Sustainable Chemistry & Engineering
Junjian Zheng, Kaili Yan, Zhichao Wu, Mingxian Liu, Zhiwei Wang
Removal of sulfanilic acid (SA) from water is an urgent but still challenging task. Herein, we developed a low pressure electrochemical membrane filtration (EMF) system for SA decontamination using RuO2 -TiO2 @Ti/PVDF composite membrane to serve as not only a filter but also an anode. Results showed that efficient removal of SA was achieved in this EMF system. At a charging voltage of 1.5 V and a electrolyte concentration of 15 mM, flow-through operation with a hydraulic retention time (HRT) of 2 h led to a high SA removal efficiency (80...
2018: Frontiers in Chemistry
Marceo V W Zibetti, Azadeh Sharafi, Ricardo Otazo, Ravinder R Regatte
PURPOSE: Use compressed sensing (CS) for 3D biexponential spin-lattice relaxation time in the rotating frame (T1ρ ) mapping of knee cartilage, reducing the total scan time and maintaining the quality of estimated biexponential T1ρ parameters (short and long relaxation times and corresponding fractions) comparable to fully sampled scans. METHODS: Fully sampled 3D-T1ρ -weighted data sets were retrospectively undersampled by factors 2-10. CS reconstruction using 12 different sparsifying transforms were compared for biexponential T1ρ -mapping of knee cartilage, including temporal and spatial wavelets and finite differences, dictionary from principal component analysis (PCA), k-means singular value decomposition (K-SVD), exponential decay models, and also low rank and low rank plus sparse models...
September 19, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Anshuman Pandey, James W Gregory
Imaging of pressure-sensitive paint (PSP) for pressure measurement on moving surfaces is problematic due to the movement of the object within the finite exposure time of the imager, resulting in the blurring of the blade edges. The blurring problem is particularly challenging when high-sensitivity PSP with a long lifetime is used, where the long luminescence time constant of exponential light decay following a burst of excitation light energy results in blurred images. One method to ameliorate this effect is image deconvolution using a point spread function (PSF) based on an estimation of the luminescent time constant...
September 13, 2018: Sensors
Barnali Bhattacharya, Rajkumar Mondal, Utpal Sarkar
Density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism are used to investigate the effects of substitutional doping by nitrogen and sulfur on transport properties of AGNR-pentalene-AGNR nanojunction. A considerable spin filtering capability in a wide bias range is observed for all systems, which may have potential application in spintronics devices. Moreover, all model devices exhibit a negative differential effect with considerable peak-to-valley ratio. Thus, our findings provide a way to produce multifunctional spintronic devices based on nitrogen and sulfur doped pentalene-AGNR nanojunctions...
September 12, 2018: Journal of Molecular Modeling
Volodymyr V Maslyuk, Rafael Gutierrez, Arezoo Dianat, Vladimiro Mujica, Gianaurelio Cuniberti
Chirality-induced spin selectivity (CISS) is a recently discovered effect, whose precise microscopic origin has not yet been fully elucidated; it seems, however, clear that spin-orbit interaction plays a pivotal role. Various model Hamiltonian approaches have been proposed, suggesting a close connection between spin selectivity and filtering and helical symmetry. However, first-principles studies revealing the influence of chirality on the spin polarization are missing. To clearly demonstrate the influence of the helical conformation on the spin polarization properties, we have carried out spin-dependent Density-Functional Theory (DFT) based transport calculations for a model molecular system...
September 20, 2018: Journal of Physical Chemistry Letters
Wei-Qing Wang, Ole Nørregaard Jensen, Ian Max Møller, Kim H Hebelstrup, Adelina Rogowska-Wrzesinska
Background: Sample preparation is a critical process for proteomic studies. Many efficient and reproducible sample preparation methods have been developed for mass spectrometry-based proteomic analysis of human and animal tissues or cells, but no attempt has been made to evaluate these protocols for plants. We here present an LC-MS/MS-based proteomics study of barley leaf aimed at optimization of methods to achieve efficient and unbiased trypsin digestion of proteins prior to LC-MS/MS based sequencing and quantification of peptides...
2018: Plant Methods
Lin Shao, Hengyi Xu, Ning Xu
We study the transport properties of the silicene nanoribbons subject to periodically driving electric and exchange fields. The multiple barriers made up of corresponding fields reshape the DC conductance by imposing pronounced both Fabry-Perot- and Fano-type resonances accompanied with high spin polarizations. In particular, a transport gap can be generated by the electric barriers with an appropriate strength, which is absent in the case of the barriers of the exchange field. The effects of the hybrid barriers including both electric and exchange fields, however, are not simply a mixture of two individual barriers, while depend on the relative phase of the time-varied barriers...
October 3, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Mustapha Bouhrara, Diana Y Lee, Abinand C Rejimon, Christopher M Bergeron, Richard G Spencer
BACKGROUND: Cerebral blood flow (CBF) is an emerging biomarker for normal aging and neurodegenerative diseases. Arterial spin labeling (ASL) perfusion MRI permits noninvasive quantification of CBF. However, high-quality mapping of CBF from ASL imaging is challenging, largely due to noise. NEW METHOD: We demonstrate the ability of the recently introduced nonlocal estimation of multispectral magnitudes (NESMA) filter to greatly improve determination of CBF estimates from ASL imaging data...
November 1, 2018: Journal of Neuroscience Methods
Si-Cong Zhu, Shun-Jin Peng, Kai-Ming Wu, Cho-Tung Yip, Kai-Lun Yao, Chi-Hang Lam
We investigate the electronic and transport properties of vanadium-doped zigzag blue phosphorus nanoribbons by first-principles quantum transport calculations. We study the spin-dependent transport properties and obtain current-voltage curves showing obvious spin polarization and negative differential behaviors. These interesting transport behaviors can be explained by the band structure of the vanadium-doped zigzag blue phosphorus nanoribbons. The tunnel magnetoresistance and spin-filtering effects under different magnetic configurations originate predominately from the symmetry matching between the band structures of the electrodes...
August 15, 2018: Physical Chemistry Chemical Physics: PCCP
Kanghyun Ryu, Jaewook Shin, Hongpyo Lee, Jun-Hyeong Kim, Dong-Hyun Kim
PURPOSE: To obtain in vivo electrical conductivity images from multi-echo gradient-echo (mGRE) sequence using a zero-TE phase extrapolation algorithm based on the Kalman method. METHODS: For estimation of the zero-TE phase from the mGRE data, an iterative algorithm consisting of a combination of the Kalman filter, Kalman smoother, and expectation maximization was implemented and compared with linear extrapolation methods. Simulations were performed for verification, and phantom and in vivo studies were conducted for validation...
July 29, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Chih-Yu Chen, C D Hu, Yeu-Chung Lin
A gauge invariant effective lagrangian for the fermion axial anomaly is constructed. The dynamical degree of freedom for fermion field is preserved. Using the anomaly lagrangian, the scattering cross section of pair production γγ → e- e+ in Dirac or Weyl semimetal is computed. The result is compared with the corresponding result from Dirac lagrangian. It is found that anomaly lagrangain and Dirac lagrangian exhibit the same E ⋅ B pattern, therefore the E ⋅ B signature may not serve a good indicator of the existence of axial anomaly...
July 26, 2018: Scientific Reports
Sebastian Schmitz, Andrew Kovalchuk, Alejandro Martín-Rodríguez, Jan van Leusen, Natalya V Izarova, Svenja D M Bourone, Yong Ai, Eliseo Ruiz, Ryan C Chiechi, Paul Kögerler, Kirill Yu Monakhov
A series of isostructural dinuclear 3d-4f complexes, isolated as [CuLn(L·SMe)2 (OOCMe)2 (NO3 )]· xMeOH (Ln = Gd 1, Tb 2, Dy 3, and Y 4; x = 0.75-1) and comprising one acetate and two thioether-Schiff base (L·SMe- ) bridging ligands based on 4-(methylthio)aniline and 2-hydroxy-3-methoxybenzaldehyde (HL·SMe = C15 H15 NO2 S), was synthesized and fully characterized. The magnetic properties of the charge-neutral {CuLn} complexes are dominated by ferromagnetic CuII -LnIII exchange interactions. Large-area electron transport studies reveal that the average conductivity of robust, self-assembled {CuLn} monolayers on a gold substrate is significantly lower than that of common alkanethiolates...
August 6, 2018: Inorganic Chemistry
R-Y Yuan, Q-J Yang, Y Guo
Special resonant modes in unique quantum structure can enhance spin and valley filtering effect. Hence we investigated resonant tunneling effect with large incident angles through single electric barrier in monolayer MoS2 junctions consisting of normal/ferromagnetic/normal parts. We found that for large incident angles the spin- and valley-dependent line-type resonances appear in the transmission and conductance spectra, which results in the transmission probabilities of spin-up and spin-down electrons at K and [Formula: see text] valleys being all improved to 100[Formula: see text] but for different special gate voltage...
September 5, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
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