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https://www.readbyqxmd.com/read/28226538/sheathless-and-high-throughput-sorting-of-paramagnetic-microparticles-in-a-magneto-hydrodynamic-microfluidic-device
#1
Vikash Kumar, Pouya Rezai, Vikash Kumar, Pouya Rezai, Vikash Kumar, Pouya Rezai
Sorting of microorganisms and particles from a mixture is critical for numerous biotechnological and medical applications. Several sorting methods such as pinched flow fractionation (PFF), optical sorting, dielectrophoresis, acoustic separation, magnetophoresis and deterministic lateral displacement (DLD) have been reported in literature. But most of these methods lack ideal characteristics of a sorter such as ability to process at high throughput, simple design, non-complicated fabrication method, sheathless operation and high purity in separation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225611/magneto-structural-correlations-in-pseudotetrahedral-forms-of-the-co-sph-4-2-complex-probed-by-magnetometry-mcd-spectroscopy-advanced-epr-techniques-and-ab-initio-electronic-structure-calculations
#2
Elizaveta A Suturina, Joscha Nehrkorn, Joseph M Zadrozny, Junjie Liu, Mihail Atanasov, Thomas Weyhermüller, Dimitrios Maganas, Stephen Hill, Alexander Schnegg, Eckhard Bill, Jeffrey R Long, Frank Neese
The magnetic properties of pseudotetrahedral Co(II) complexes spawned intense interest after (PPh4)2[Co(SPh)4] was shown to be the first mononuclear transition-metal complex displaying slow relaxation of the magnetization in the absence of a direct current magnetic field. However, there are differing reports on its fundamental magnetic spin Hamiltonian (SH) parameters, which arise from inherent experimental challenges in detecting large zero-field splittings. There are also remarkable changes in the SH parameters of [Co(SPh)4](2-) upon structural variations, depending on the counterion and crystallization conditions...
February 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28225600/kinetics-and-mechanism-of-ultrasonic-activation-of-persulfate-an-in-situ-epr-spin-trapping-study
#3
Zongsu Wei, Frederick A Villamena, Linda K Weavers
Ultrasound (US) was shown to activate persulfate (PS) providing an alternative activation method to base or heat as an in-situ chemical oxidation (ISCO) method. The kinetics and mechanism of ultrasonic activation of PS were examined in aqueous solution using an in-situ electron paramagnetic resonance (EPR) spin trapping technique and radical trapping with probe compounds. Using the spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), hydroxyl radical (•OH) and sulfate radical anion (SO4•‒) were measured from ultrasonic activation of persulfate (US-PS)...
February 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28224152/charge-transfer-complexes-of-metal-free-phthalocyanine-radical-anions-with-decamethylmetallocenium-cations-cp-2co-h2pc%C3%AB-%C3%A2-solvent-and-cp-2cr-h2pc%C3%AB-%C3%A2-4c6h4cl2
#4
Dmitri V Konarev, Salavat S Khasanov, Manabu Ishikawa, Akihiro Otsuka, Hideki Yamochi, Gunzi Saito, Rimma N Lyubovskaya
Charge transfer complexes (Cp*2Co(+))(H2Pc˙(-))·0.5C6H4Cl2·0.7C6H5CN·0.3C6H14 (1) and (Cp*2Cr(+))(H2Pc˙(-))·4C6H4Cl2 (2) have been obtained as single crystals. Both complexes contain metal-free phthalocyanine (Pc) radical anions and decamethylmetallocenium cations. Reduction of the Pc macrocycle leads to the appearance of new bands at 1026-1030 nm in the NIR range and blue shifts of both Soret and Q-bands of H2Pc in the spectra of 1 and 2. The geometry of the Pc macrocycles supports the formation of H2Pc˙(-) by the alternation of shorter and longer C-N(imine) bonds in the macrocycles in 2...
February 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28223532/identification-of-productive-and-futile-encounters-in-an-electron-transfer-protein-complex
#5
Witold Andrałojć, Yoshitaka Hiruma, Wei-Min Liu, Enrico Ravera, Masaki Nojiri, Giacomo Parigi, Claudio Luchinat, Marcellus Ubbink
Well-defined, stereospecific states in protein complexes are often in exchange with an ensemble of more dynamic orientations: the encounter states. The structure of the stereospecific complex between cytochrome P450cam and putidaredoxin was solved recently by X-ray diffraction as well as paramagnetic NMR spectroscopy. Other than the stereospecific complex, the NMR data clearly show the presence of additional states in the complex in solution. In these encounter states, populated for a small percentage of the time, putidaredoxin assumes multiple orientations and samples a large part of the surface of cytochrome P450cam...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28222609/bambusuril-as-a-one-electron-donor-for-photoinduced-electron-transfer-to-methyl-viologen-in-mixed-crystals
#6
Tomas Fiala, Lucie Ludvíková, Dominik Heger, Jan Švec, Tomáš Slanina, L'ubica Vetráková, Michal Babiak, Marek Nečas, Petr Kulhánek, Petr Klán, Vladimir Sindelar
Methyl viologen hexafluorophosphate (MV(2+)·2PF6(-)) and dodecamethylbambus[6]uril (BU6) form crystals in which the layers of viologen dications alternate with those of a 1:2 supramolecular complex of BU6 and PF6(-). This arrangement allows for a one-electron reduction of MV(2+) ions upon UV irradiation to form MV(+•) radical cations within the crystal structure with half-lives of several hours in air. The mechanism of this photoinduced electron transfer in the solid state and the origin of the long-lived charge-separated state were studied by steady-state and transient spectroscopies, cyclic voltammetry, and electron paramagnetic resonance spectroscopy...
February 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28221040/magnetic-fullerene-dna-hyaluronic-acid-nanovehicles-with-magnetism-reduction-dual-responsive-triggered-release
#7
Ling Wang, Yitong Wang, Jingcheng Hao, Shuli Dong
We create the dual-responsive nanovehicle that can effectively combine and abundantly utilize magnetic and glutathione (GSH)-reductive triggers to control the drug delivery and achieve more intelligent and powerful targeting. In the nanovehicles, paramagnetic fullerene (C60@CTAF) was prepared via one-step modification of fullerene with magnetic surfactant CTAF by hydrophobic interaction for the first time. The perfect conjugation of C60 and CTAF increased the solubility or dispersity of fullerenes and qualify CTAF with more powerful assembly capability with DNA...
February 21, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28220925/slow-relaxation-of-the-magnetization-observed-in-an-antiferromagnetically-ordered-phase-for-scm-based-two-dimensional-layered-compounds
#8
Koichi Kagesawa, Yuki Nishimura, Hiroki Yoshida, Brian K Breedlove, Masahiro Yamashita, Hitoshi Miyasaka
Two-dimensional layered compounds with different counteranions, [{Mn(salen)}4C6](BF4)2·2(CH3OH) (1) and [{Mn(salen)}4C6](PF6)2·2(CH3OH) (2) (salen(2-) = N,N'-bis(salicylideneiminato), C6(2-) = C6H12(COO)2(2-)), were synthesized by assembling [Mn(salen)(H2O)]X (X(-) = BF4(-) and PF6(-)) and C6H12(CO2(-))2 (C6(2-)) in a methanol/2-propanol medium. The compounds have similar structures, which are composed of Mn(salen) out-of-plane dimers bridged by μ(4)-type C6(2-) ions, forming a brick-wall-type network of [-{Mn2}-OCO-] chains alternately connected via C6H12 linkers of C6(2-) moieties...
February 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28220818/labeling-adipose-derived-stem-cell-sheet-by-ultrasmall-super-paramagnetic-fe3o4-nanoparticles-and-magnetic-resonance-tracking-in-vivo
#9
Shukui Zhou, Ting Yin, Qingsong Zou, Kaile Zhang, Guo Gao, Joseph G Shapter, Peng Huang, Qiang Fu
Cell sheet therapy has emerged as a potential therapeutic option for reparation and reconstruction of damaged tissues and organs. However, an effective means to assess the fate and distribution of transplanted cell sheets in a serial and noninvasive manner is still lacking. To investigate the feasibility of tracking Adipose derived stem cells (ADSCs) sheet in vivo using ultrasmall super-paramagnetic Fe3O4 nanoparticles (USPIO), canine ADSCs were cultured and incubated with USPIO and 0.75 μg/ml Poly-L-Lysine (PLL) for 12 h...
February 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28220538/on-bead-combinatorial-synthesis-and-imaging-of-europium-iii-based-paracest-agents-aids-in-identification-of-chemical-features-that-enhance-cest-sensitivity
#10
Jaspal Singh, Vineeta Rustagi, Shanrong Zhang, A Dean Sherry, D Gomika Udugamasooriya
The rate of water exchange between the inner-sphere of a paramagnetic ion and bulk water is an important parameter in determining the magnitude of the chemical exchange saturation transfer signal from paramagnetic CEST agents (paraCEST). This is governed by various geometric, steric, and ligand field factors created by macrocyclic ligands surrounding the paramagnetic metal ion. Our previous on-bead combinatorial studies of di-peptoid-europium(III)-DOTA-tetraamide complexes revealed that negatively charged groups in the immediate vicinity of the metal center strongly enhances the CEST signal...
February 21, 2017: Magnetic Resonance in Chemistry: MRC
https://www.readbyqxmd.com/read/28218836/magnetic-and-hfepr-studies-of-exchange-coupling-in-a-series-of-%C3%AE-cl-dicobalt-complexes
#11
Jia-Jia Liu, Shang-Da Jiang, Petr Neugebauer, Joris van Slageren, Yanhua Lan, Wolfgang Wernsdorfer, Bing-Wu Wang, Song Gao
We report three dinuclear cobalt(II) complexes, [Co(L)Cl2]2 (L = bpy, mbpy, and dmpbt), that are bridged solely by chloride ions. High-field electron paramagnetic resonance and magnetometric measurements were applied to investigate the magnetic intramolecular Co-Co interactions. Simulation results based on the multispin model reveal that the complexes are weakly ferromagnetically coupled and that the isotropic exchange coupling constants differ slightly for the three complexes. Moreover, the competing effects of zero-field splitting and magnetic coupling on the temperature-dependent magnetic susceptibility were analyzed...
February 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28218831/new-possibilities-for-magnetic-control-of-chemical-and-biochemical-reactions
#12
Anatoly Buchachenko, Ronald G Lawler
Chemistry is controlled by Coulomb energy; magnetic energy is lower by many orders of magnitude and may be confidently ignored in the energy balance of chemical reactions. The situation becomes less clear, however, when reaction rates are considered. In this case, magnetic perturbations of nearly degenerate energy surface crossings may produce observable, and sometimes even dramatic, effects on reactions rates, product yields, and spectroscopic transitions. A case in point that has been studied for nearly five decades is electron spin-selective chemistry via the intermediacy of radical pairs...
February 20, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28218529/antibacterial-paramagnetic-quinones-from-actinoallomurus
#13
Marianna Iorio, João Cruz, Matteo Simone, Alice Bernasconi, Cristina Brunati, Margherita Sosio, Stefano Donadio, Sonia I Maffioli
Four metabolites, designated paramagnetoquinone A, B, C, and D (1-4), were isolated from three strains belonging to the actinomycete genus Actinoallomurus. Compounds 1 and 2 showed potent antibacterial activity with MIC values lower than 0.015 μg/mL against Gram-positive pathogens, including antibiotic-resistant strains. Since compounds 1 and 2 were NMR-silent due to the presence of an oxygen radical, structure elucidation was achieved through a combination of derivatizations, oxidations, and analysis of (13)C-labeled compounds...
February 20, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28215401/nickel-salen-supported-paramagnetic-nanoparticles-for-6-his-target-recombinant-protein-affinity-purification
#14
Zahra Rashid, Ramin Ghahremanzadeh, Mohammad-Reza Nejadmoghaddam, Mahboobeh Nazari, Mohammad-Reza Shokri, Hossein Naeimi, Amir-Hassan Zarnani
In this research, a simple, efficient, inexpensive, rapid and high yield method for the purification of 6×histidine-tagged recombinant protein was developed. For this purpose, manganese ferrite magnetic nanoparticles (MNPs) were synthesized through a co-precipitation method and then they were conveniently surface-modified with tetraethyl orthosilicate (TEOS) in order to prevent oxidation and form high density of hydroxyl groups. Next, the salen ligand was prepared from condensation reaction of salicylaldehyde and 3-aminopropyl (trimethoxy) silane (APTMS) in 1:1 molar ratio; followed by complexation with Ni(OAc)2...
February 13, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28214939/selective-determination-of-sulfonamides-from-environmental-water-based-on-magnetic-surface-molecularly-imprinting-technology
#15
Yang Xu, Qi Zhao, Liyan Jiang, Zhengqiang Li, Yanhua Chen, Lan Ding
In the study, a simple and selective method based on magnetic separation technology is presented for the extraction of sulfonamides (SAs) from environmental water, followed by liquid chromatography-tandem mass spectrometry. In this method, magnetic surface molecularly imprinted polymers (Fe3O4@SiO2@MIPs) with super-paramagnetic property and high selectivity toward SAs were developed as magnetic adsorbents. The Fe3O4@SiO2@MIPs were then applied to the selective extraction of SAs from environmental water. The extraction and enrichment were accomplished simultaneously in a single step by simply stirring the mixture of adsorbents and water samples...
February 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28213280/magnetic-lateral-flow-immunoassay-test-strip-development-considerations-for-proof-of-concept-evaluation
#16
R Connolly, R O' Kennedy
Lateral flow immunoassays (LFIA) have grown to become the predominant test device format for the diagnostics and point-of-care industries. The demand for robust and reproducible LFIAs has been facilitated through scale-up production methods using specialized and automated instruments. However, the feasibility of a LFIA device can still be evaluated in a small-scale laboratory setting through controlled manual preparation methods. The advent of super-paramagnetic (SPMP) labels for use in lateral flow has heralded the possibility of highly sensitive and stable LFIAs...
February 14, 2017: Methods: a Companion to Methods in Enzymology
https://www.readbyqxmd.com/read/28212030/revisiting-silicalite-1-nucleation-in-clear-solution-by-electrochemical-impedance-spectroscopy
#17
Gert Brabants, Maxim Hubin, Erwin Konrad Reichel, Bernhard Jakoby, Eric Breynaert, Francis Taulelle, Johan A Martens, Christine E A Kirschhock
EIS was used to detect and investigate nucleation in silicalite-1 clear solutions. Whereas zeolite nucleation was previously assumed to be a step event, inducing a sharp discontinuity around a Si/OH ratio of 1, complex bulk conductivity measurements at elevated temperatures reveal a gradual decay of the conductivity with increased silicon concentrations. Inverse Laplace transformation of the complex conductivity allows to observe the chemical exchange phenomena governing nano-aggregate formation. At low temperatures, the fast exchange between dissociated ions and ion pairs leads to a gradual decay of the conductivity with increasing silicon content...
February 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28211967/generation-of-the-scf3-radical-by-photoredox-catalysis-intra-and-intermolecular-carbotrifluoromethylthiolation-of-alkenes
#18
Guillaume Dagousset, Cédric Simon, Elsa Anselmi, Béatrice Tuccio, Thierry Billard, Emmanuel Magnier
We report herein the first use of N-trifluoromethylthiosaccharin as the source of SCF3 radical under photoredox catalysis. This allowed an efficient and general visible-light-mediated carbotrifluoromethylthiolation of alkenes. Under the optimized conditions using fac-Ir(ppy)3 as the photocatalyst, various N-aryl acrylamides as well as a wide range of substituted styrenes can readily be difunctionalized in an intra- or intermolecular fashion, affording the corresponding SCF3-containing products in good to excellent yield...
February 17, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28211716/direct-identification-of-dilute-surface-spins-on-al_-2-o_-3-origin-of-flux-noise-in-quantum-circuits
#19
S E de Graaf, A A Adamyan, T Lindström, D Erts, S E Kubatkin, A Ya Tzalenchuk, A V Danilov
An on-chip electron spin resonance technique is applied to reveal the nature and origin of surface spins on Al_{2}O_{3}. We measure a spin density of 2.2×10^{17}  spins/m^{2}, attributed to physisorbed atomic hydrogen and S=1/2 electron spin states on the surface. This is direct evidence for the nature of spins responsible for flux noise in quantum circuits, which has been an issue of interest for several decades. Our findings open up a new approach to the identification and controlled reduction of paramagnetic sources of noise and decoherence in superconducting quantum devices...
February 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28211704/observation-of-classical-quantum-crossover-of-1-f-flux-noise-and-its-paramagnetic-temperature-dependence
#20
C M Quintana, Yu Chen, D Sank, A G Petukhov, T C White, Dvir Kafri, B Chiaro, A Megrant, R Barends, B Campbell, Z Chen, A Dunsworth, A G Fowler, R Graff, E Jeffrey, J Kelly, E Lucero, J Y Mutus, M Neeley, C Neill, P J J O'Malley, P Roushan, A Shabani, V N Smelyanskiy, A Vainsencher, J Wenner, H Neven, John M Martinis
By analyzing the dissipative dynamics of a tunable gap flux qubit, we extract both sides of its two-sided environmental flux noise spectral density over a range of frequencies around 2k_{B}T/h≈1  GHz, allowing for the observation of a classical-quantum crossover. Below the crossover point, the symmetric noise component follows a 1/f power law that matches the magnitude of the 1/f noise near 1 Hz. The antisymmetric component displays a 1/T dependence below 100 mK, providing dynamical evidence for a paramagnetic environment...
February 3, 2017: Physical Review Letters
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