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https://www.readbyqxmd.com/read/29332833/a-combination-of-thiol-ene-click-chemistry-and-surface-initiated-atom-transfer-radical-polymerization-fabrication-of-boronic-acid-functionalized-magnetic-graphene-oxide-composite-for-enrichment-of-glycoproteins
#1
Jie Su, Xiwen He, Langxing Chen, Yukui Zhang
An efficient glycoproteins enrichment platform is one of vital preprocessing steps in biomarker research and in particular glycoproteomics. In this work, a well-defined boronic acid functionalized magnetic graphene oxide nanocomposite (Fe3O4-GO@PAAPBA) was synthesized for the selective enrichment of glycoproteins from complex biological samples via a novel strategy based on the "thiol-ene" click chemistry and surface initiated atom transfer radical polymerization (SI-ATRP). The initiator of ATRP was anchored to the surface of substrate through "thiol-ene" click reaction...
April 1, 2018: Talanta
https://www.readbyqxmd.com/read/29331136/zwitterionization-of-glycine-in-water-environment-stabilization-mechanism-and-nmr-spectral-signatures
#2
Danillo Valverde, Zélia Maria da Costa Ludwig, Célia Regina da Costa, Valdemir Ludwig, Herbert C Georg
At physiological conditions, myriads of biomolecules (e.g., amino acids, peptides, and proteins) exist predominantly in the zwitterionic structural form and their biological functions will result in these conditions. However these geometrical structures are inaccessible energetically in the gas phase, and at this point, stabilization of amino-acids in physiological conditions is still under debate. In this paper, the electronic properties of a glycine molecule in the liquid environment were studied by performing a relaxation of the glycine geometry in liquid water using the free energy gradient method combined with a sequential quantum mechanics/molecular mechanics approach...
January 14, 2018: Journal of Chemical Physics
https://www.readbyqxmd.com/read/29330968/correlation-of-dynamic-contrast-enhanced-mri-derived-volume-transfer-constant-with-histological-angiogenic-markers-in-high-grade-gliomas
#3
Ningning Di, Chenjun Yao, Wenna Cheng, Yan Ren, Jianxun Qu, Bin Wang, Zhenwei Yao
INTRODUCTION: To ascertain if the volume transfer constant (Ktrans ) derived from T1 dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) correlates with the immunohistological markers of angiogenesis in high-grade gliomas. METHODS: Fifty-one image-guided biopsy specimens in 34 patients with newly presenting high-grade gliomas (grade III = 16; grade IV = 18) underwent preoperative imaging (conventional imaging and T1 DCE-MRI). We correlated vascular endothelial growth factor (VEGF) expression and the microvessel density (MVD) of MRI-guided biopsy specimens with the corresponding DCE-derived Ktrans ...
January 13, 2018: Journal of Medical Imaging and Radiation Oncology
https://www.readbyqxmd.com/read/29330621/nonuniversal-behaviour-of-helical-two-dimensional-three-component-turbulence
#4
Moritz Linkmann, Michele Buzzicotti, Luca Biferale
The dynamics of two-dimensional three-component (2D3C) flows is relevant to describe the long-time evolution of strongly rotating flows and/or of conducting fluids with a strong mean magnetic field. We show that in the presence of a strong helical forcing, the out-of-plane component ceases to behave as a passive advected quantity and develops a nontrivial dynamics which deeply changes its large-scale properties. We show that a small-scale helicity injection correlates the input on the 2D component with the one on the out-of-plane component...
January 15, 2018: European Physical Journal. E, Soft Matter
https://www.readbyqxmd.com/read/29329228/current-nmr-techniques-for-structure-based-drug-discovery
#5
REVIEW
Toshihiko Sugiki, Kyoko Furuita, Toshimichi Fujiwara, Chojiro Kojima
A variety of nuclear magnetic resonance (NMR) applications have been developed for structure-based drug discovery (SBDD). NMR provides many advantages over other methods, such as the ability to directly observe chemical compounds and target biomolecules, and to be used for ligand-based and protein-based approaches. NMR can also provide important information about the interactions in a protein-ligand complex, such as structure, dynamics, and affinity, even when the interaction is too weak to be detected by ELISA or fluorescence resonance energy transfer (FRET)-based high-throughput screening (HTS) or to be crystalized...
January 12, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29326984/using-parahydrogen-to-hyperpolarize-amines-amides-carboxylic-acids-alcohols-phosphates-and-carbonates
#6
Wissam Iali, Peter J Rayner, Simon B Duckett
Hyperpolarization turns weak nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) responses into strong signals, so normally impractical measurements are possible. We use parahydrogen to rapidly hyperpolarize appropriate 1H, 13C, 15N, and 31P responses of analytes (such as NH3) and important amines (such as phenylethylamine), amides (such as acetamide, urea, and methacrylamide), alcohols spanning methanol through octanol and glucose, the sodium salts of carboxylic acids (such as acetic acid and pyruvic acid), sodium phosphate, disodium adenosine 5'-triphosphate, and sodium hydrogen carbonate...
January 2018: Science Advances
https://www.readbyqxmd.com/read/29324249/disability-in-progressive-ms-is-associated-with-t2-lesion-changes
#7
C Ammitzbøll, T B Dyrby, M Lyksborg, K Schreiber, R Ratzer, J Romme Christensen, P Iversen, M Magyari, E Garde, P S Sørensen, H R Siebner, F Sellebjerg
BACKGROUND: Progressive multiple sclerosis (MS) is characterised by diffuse changes on brain magnetic resonance imaging (MRI), which complicates the use of MRI as a diagnostic and prognostic marker. The relationship between MRI measures (conventional and non-conventional) and clinical disability in progressive MS therefore warrants further investigation. OBJECTIVE: To investigate the relationship between clinical disability and MRI measures in patients with progressive MS...
December 18, 2017: Multiple Sclerosis and related Disorders
https://www.readbyqxmd.com/read/29324182/recent-advances-in-solid-state-nuclear-magnetic-resonance-spectroscopy
#8
Sharon E Ashbrook, John M Griffin, Karen E Johnston
The sensitivity of nuclear magnetic resonance (NMR) spectroscopy to the local atomic-scale environment offers great potential for the characterization of a diverse range of solid materials. Despite offering more information than its solution-state counterpart, solid-state NMR has not yet achieved a similar level of recognition, owing to the anisotropic interactions that broaden the spectral lines and hinder the extraction of structural information. Here, we describe the methods available to improve the resolution of solid-state NMR spectra and the continuing research in this area...
January 11, 2018: Annual Review of Analytical Chemistry
https://www.readbyqxmd.com/read/29323363/high-efficiency-x-ray-luminescence-in-eu3-activated-tungstate-nanoprobes-for-optical-imaging-through-energy-transfer-sensitization
#9
Tao Guo, Yan Lin, Wei-Jian Zhang, Jin-Sheng Hong, Ru-Hui Lin, Xiao-Ping Wu, Juan Li, Chun-Hua Lu, Huang-Hao Yang
X-ray luminescence optical imaging has been recognized as a powerful technique for medical diagnosis due to its deep penetration and low auto-fluorescence in tissues. However, the low luminescence efficiency of current X-ray luminescence nanoprobes remains a major hurdle for sensitive bioimaging in practical medical applications. Here we present a new kind of energy transfer-sensitized X-ray luminescence nanoprobe (PEG-NaGd(WO4)2:Eu) for highly effective optical bioimaging. Under X-ray excitation, the tungstate host absorbs the X-ray photons and then transfers the energy to the Eu3+ luminescence center, thus enhancing the luminescence efficiency of the nanoprobes for high sensitivity optical in vivo imaging...
January 11, 2018: Nanoscale
https://www.readbyqxmd.com/read/29322571/selective-single-site-pd-in-hydrogenation-catalyst-for-production-of-enhanced-magnetic-resonance-signals-using-parahydrogen
#10
Dudari Burueva, Kirill Viktorovich Kovtunov, Valerii Bukhtiyarov, Andrey Bukhtiyarov, Danila Barskiy, Igor Prosvirin, Igor Mashkovsky, Galina Baeva, Aleksandr Stakheev, Igor Koptyug
Pd-In/Al2O3 single-site catalyst was able to show high selectivity (up to 98%) in the gas phase semihydrogenation of propyne. Formation of intermetallic Pd-In compound was studied by XPS during reduction of the catalyst. FTIR-CO spectroscopy confirmed single-site nature of the intermetallic Pd-In phase reduced at high temperature. Utilization of Pd-In/Al2O3 in semihydrogenation of propyne with parahydrogen allowed to produce ~3400-fold NMR signal enhancement for reaction product propene (polarization = 9.3%) demonstrating the large contribution of pairwise hydrogen addition route...
January 11, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29322559/cest-dixon-for-human-breast-lesion-characterization-at-3-t-a-preliminary-study
#11
Shu Zhang, Stephen Seiler, Xinzeng Wang, Ananth J Madhuranthakam, Jochen Keupp, Emily E Knippa, Robert E Lenkinski, Elena Vinogradov
PURPOSE: Chemical exchange saturation transfer (CEST) MRI for breast lesion characterization is promising. However, artifacts are prone to develop in breast CEST imaging as a result of strong lipid signals. The aims of the study are (i) to develop and validate the CEST-Dixon imaging sequence for simultaneous water-fat separation and B0 mapping; and (ii) use the CEST-Dixon method to characterize suspicious lesions in patients undergoing percutaneous biopsy. METHODS: The gradient-echo multi-echo Dixon acquisition is used to create fat-free CEST and B0 maps...
January 10, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29322131/steric-control-in-the-metal-ligand-electron-transfer-of-iminopyridine-ytterbocene-complexes
#12
Alexander A Trifonov, Tatyana V Mahrova, Lapo Luconi, Giuliano Giambastiani, Dmitry M Lyubov, Anton V Cherkasov, Lorenzo Sorace, Elisa Louyriac, Laurent Maron, Konstantin A Lyssenko
A systematic study of reactions between Cp*2Yb(THF) (Cp* = η5-C5Me5, 1) and iminopyridine ligands (IPy = 2,6-iPr2C6H3N[double bond, length as m-dash]CH(C5H3N-R), R = H (2a), 6-C4H3O (2b), 6-C4H3S (2c), 6-C6H5 (2d)) featuring similar electron accepting properties but variable denticity and steric demand, has provided a new example of steric control on the redox chemistry of ytterbocenes. The reaction of the unsubstituted IPy 2a with 1, either in THF or toluene, gives rise to the paramagnetic species Cp*2YbIII(IPy)˙- (3a) as a result of a formal one-electron oxidation of the YbII ion along with IPy reduction to a radical-anionic state...
January 11, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29320488/analysis-of-ferrite-nanoparticles-in-the-flow-of-ferromagnetic-nanofluid
#13
Noor Muhammad, Sohail Nadeem, M T Mustafa
Theoretical analysis has been carried out to establish the heat transport phenomenon of six different ferromagnetic MnZnFe2O4-C2H6O2 (manganese zinc ferrite-ethylene glycol), NiZnFe2O4-C2H6O2 (Nickel zinc ferrite-ethylene glycol), Fe2O4-C2H6O2 (magnetite ferrite-ethylene glycol), NiZnFe2O4-H2O (Nickel zinc ferrite-water), MnZnFe2O4-H2O (manganese zinc ferrite-water), and Fe2O4-H2O (magnetite ferrite-water) nanofluids containing manganese zinc ferrite, Nickel zinc ferrite, and magnetite ferrite nanoparticles dispersed in a base fluid of ethylene glycol and water mixture...
2018: PloS One
https://www.readbyqxmd.com/read/29320473/systems-of-mechanized-and-reactive-droplets-powered-by-multi-responsive-surfactants
#14
Zhijie Yang, Jingjing Wei, Yaroslav I Sobolev, Bartosz A Grzybowski
Although 'active' surfactants, which are responsive to individual external stimuli such as temperature, electric or magnetic fields, light, redox processes or chemical agents, are well known, it would be interesting to combine several of these properties within one surfactant species. Such multi-responsive surfactants could provide ways of manipulating individual droplets and possibly assembling them into larger systems of dynamic reactors. Here we describe surfactants based on functionalized nanoparticle dimers that combine all of these and several other characteristics...
January 10, 2018: Nature
https://www.readbyqxmd.com/read/29318102/extending-the-scope-of-19f-hyperpolarization-through-signal-amplification-by-reversible-exchange-in-mri-and-nmr-spectroscopy
#15
Alexandra M Olaru, Thomas B R Robertson, Jennifer S Lewis, Alex Antony, Wissam Iali, Ryan E Mewis, Simon B Duckett
Fluorinated ligands have a variety of uses in chemistry and industry, but it is their medical applications as 18F-labelled positron emission tomography (PET) tracers where they are most visible. In this work, we illustrate the potential of using 19F-containing ligands as future magnetic resonance imaging (MRI) contrast agents and as probes in magnetic resonance spectroscopy studies by significantly increasing their magnetic resonance detectability through the signal amplification by reversible exchange (SABRE) hyperpolarization method...
January 2018: ChemistryOpen
https://www.readbyqxmd.com/read/29315081/mechanisms-of-optical-orientation-of-an-individual-mn2-ion-spin-in-a-ii-vi-quantum-dot
#16
T Smoleński, Ł Cywiński, P Kossacki
We provide a theoretical description of the optical orientation of a single Mn2+ ion spin under quasi-resonant excitation demonstrated experimentally by Goryca et al (2009 Phys. Rev. Lett. 103 087401). We build and analyze a hierarchy of models by starting with the simplest assumptions (transfer of perfectly spin-polarized excitons from Mn-free dot to the other dot containing a single Mn2+ spin, followed by radiative recombination) and subsequently adding more features, such as spin relaxation of electrons and holes...
January 9, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/29313753/compared-to-an-oatmeal-breakfast-two-eggs-day-increased-plasma-carotenoids-and-choline-without-increasing-trimethyl-amine-n-oxide-concentrations
#17
Amanda Missimer, Maria Luz Fernandez, Diana M DiMarco, Gregory H Norris, Christopher N Blesso, Ana Gabriela Murillo, Marcela Vergara-Jimenez, Bruno S Lemos, Isabel Medina-Vera, Olga V Malysheva, Marie A Caudill
BACKGROUND: Habitual consumption of eggs has been hypothesized to positively modify biomarkers of cardiovascular disease risk through proposed antioxidant properties. OBJECTIVES: To examine this relationship, 50 young, healthy men and women were enrolled into a randomized crossover clinical intervention. METHODS: Participants consumed either 2 eggs per day or one packet of oatmeal a day for 4 weeks, followed by a 3-week wash-out and crossed over to the alternate breakfast...
January 9, 2018: Journal of the American College of Nutrition
https://www.readbyqxmd.com/read/29313159/improved-differentiation-of-low-grade-and-high-grade-gliomas-and-detection-of-tumor-proliferation-using-apt-contrast-fitted-from-z-spectrum
#18
Jiaxuan Zhang, Wenzhen Zhu, Rongwen Tain, Xiaohong Joe Zhou, Kejia Cai
PURPOSE: The purpose of the study is to demonstrate the value of quantitative amide proton transfer (APT) imaging for differentiating glioma grades and detecting tumor proliferation. PROCEDURES: This study included 32 subjects with 16 low-grade gliomas (LGG) and 16 high-grade gliomas (HGG) confirmed by histopathology. Chemical exchange saturation transfer (CEST) magnetic resonance imaging with APT weighting was performed on a 3 T scanner. After B0 correction, Z-spectra were fitted with Lorentzian functions corresponding to the upfield semi-solid magnetization transfer and nuclear overhauser enhancement (MT&NOE) effect, the direct saturation (DS) effect, and the downfield APT effect centered at around - 1...
January 8, 2018: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
https://www.readbyqxmd.com/read/29313106/neural-correlates-of-instrumental-responding-in-the-context-of-alcohol-related-cues-index-disorder-severity-and-relapse-risk
#19
Daniel J Schad, Maria Garbusow, Eva Friedel, Christian Sommer, Miriam Sebold, Claudia Hägele, Nadine Bernhardt, Stephan Nebe, Sören Kuitunen-Paul, Shuyan Liu, Uta Eichmann, Anne Beck, Hans-Ulrich Wittchen, Henrik Walter, Philipp Sterzer, Ulrich S Zimmermann, Michael N Smolka, Florian Schlagenhauf, Quentin J M Huys, Andreas Heinz, Michael A Rapp
The influence of Pavlovian conditioned stimuli on ongoing behavior may contribute to explaining how alcohol cues stimulate drug seeking and intake. Using a Pavlovian-instrumental transfer task, we investigated the effects of alcohol-related cues on approach behavior (i.e., instrumental response behavior) and its neural correlates, and related both to the relapse after detoxification in alcohol-dependent patients. Thirty-one recently detoxified alcohol-dependent patients and 24 healthy controls underwent instrumental training, where approach or non-approach towards initially neutral stimuli was reinforced by monetary incentives...
January 8, 2018: European Archives of Psychiatry and Clinical Neuroscience
https://www.readbyqxmd.com/read/29312876/assessing-tissue-metabolism-by-phosphorous-31-magnetic-resonance-spectroscopy-and-imaging-a-methodology-review
#20
REVIEW
Yuchi Liu, Yuning Gu, Xin Yu
Many human diseases are caused by an imbalance between energy production and demand. Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide the unique opportunity for in vivo assessment of several fundamental events in tissue metabolism without the use of ionizing radiation. Of particular interest, phosphate metabolites that are involved in ATP generation and utilization can be quantified noninvasively by phosphorous-31 (31P) MRS/MRI. Furthermore, 31P magnetization transfer (MT) techniques allow in vivo measurement of metabolic fluxes via creatine kinase (CK) and ATP synthase...
December 2017: Quantitative Imaging in Medicine and Surgery
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