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https://www.readbyqxmd.com/read/27922140/construction-and-function-of-a-highly-efficient-supramolecular-luminescent-system
#1
Yingjie Liu, Suqian Ma, Bin Xu, Wenjing Tian
Aggregation-induced emission (AIE) provides a new way of achieving highly efficient luminescent materials. In this contribution, the self-assembly behavior, molecular stacking structure and photophysical properties of two polymorphs of a supramolecular co-crystal (C1 and C2) are investigated. The block-like crystal C1, packed in segregated stacking with strong π-π interactions between the H and G molecules, shows weak green emission with a low efficiency (ΦF) of 2%. In comparison, the needle-like crystal C2, packed in segregated stacking with no obviously strong intermolecular interactions, shows bright yellow emission...
December 6, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27922133/photoluminescence-changes-of-c70-nano-submicro-crystals-induced-by-high-pressure-and-high-temperature
#2
Dedi Liu, Bingbing Liu, Bertil Sundqvist, Dapeng Dong, Zhenghua Li, Dongping Liu
Hollow C70 nano/submicro-crystals with a fcc lattice structure were treated under various high pressure and high temperature conditions. The energy band structure was visibly changed by the high pressure and high temperature treatment, and the luminescence of the treated C70 nano/submicro-crystals were tuned from the visible to the near infrared range. In-situ high pressure experiments at room temperature indicate that pressure plays a key role in the tuning of the band gap and PL properties in C70 nanocrystals, and temperature plays an important role in the formation of stable intermolecular bonds and thus to define the final red-shift of the PL peaks...
December 6, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27922006/structural-basis-of-myelin-associated-glycoprotein-adhesion-and-signalling
#3
Matti F Pronker, Suzanne Lemstra, Joost Snijder, Albert J R Heck, Dominique M E Thies-Weesie, R Jeroen Pasterkamp, Bert J C Janssen
Myelin-associated glycoprotein (MAG) is a myelin-expressed cell-adhesion and bi-directional signalling molecule. MAG maintains the myelin-axon spacing by interacting with specific neuronal glycolipids (gangliosides), inhibits axon regeneration and controls myelin formation. The mechanisms underlying MAG adhesion and signalling are unresolved. We present crystal structures of the MAG full ectodomain, which reveal an extended conformation of five Ig domains and a homodimeric arrangement involving membrane-proximal domains Ig4 and Ig5...
December 6, 2016: Nature Communications
https://www.readbyqxmd.com/read/27921994/the-structure-of-sv40-large-t-hexameric-helicase-in-complex-with-at-rich-origin-dna
#4
Dahai Gai, Damian Wang, Shu-Xing Li, Xiaojiang S Chen
DNA replication is a fundamental biological process. The initial step in eukaryotic DNA replication is the assembly of the pre-initiation complex, including the formation of two head-to-head hexameric helicases around the replication origin. How these hexameric helicases interact with their origin dsDNA remains unknown. Here, we report the co-crystal structure of the SV40 Large-T Antigen (LT) hexameric helicase bound to its origin dsDNA. The structure shows that the six subunits form a near-planar ring that interacts with the origin, so that each subunit makes unique contacts with the DNA...
December 6, 2016: ELife
https://www.readbyqxmd.com/read/27921346/bottom-up-meets-top-down-patchy-hybrid-nonwovens-as-an-efficient-catalysis-platform
#5
Judith Schöbel, Matthias Burgard, Christian Hils, Roland Dersch, Martin Dulle, Kirsten Volk, Matthias Karg, Andreas Greiner, Holger Schmalz
Heterogeneous catalysis with supported nanoparticles (NPs) is a highly active field of research. However, the efficient stabilization of NPs without deteriorating their catalytic activity is challenging. By combining top-down (coaxial electrospinning) and bottom-up (crystallization-driven self-assembly) approaches, we prepared patchy nonwovens with functional, nanometer-sized patches on the surface. These patches can selectively bind and efficiently stabilize gold nanoparticles (AuNPs). The use of these AuNP-loaded patchy nonwovens in the alcoholysis of dimethylphenylsilane led to full conversion under comparably mild conditions and in short reaction times...
December 6, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27921336/magnetic-anisotropy-in-pentacoordinate-ni-ii-and-co-ii-complexes-unraveling-electronic-and-geometrical-contributions
#6
Talal Mallah, Benjamin Cahier, Mauro Perfetti, Georges Zakhia, Daoud Naoufal, Fatima El-Khatib, Régis Guillot, Eric Rivière, Roberta Sessoli, Anne-Laure Barra, Nathalie Guihéry
The magnetic properties of the pentacoordinated [MII(Me4cyclam)N3]+ (Me4cyclam = tetramethylcyclam; N3 = azido and M = Ni and Co) complexes were investigated. Magnetization and EPR studies indicate that they possess an easy plane of magnetization with the axial anisotropy parameters D being close to 22 and larger than 30 cm-1 for the Ni and Co derivative, respectively. Ab initio calculations reproduce the experimental values of the zero field splitting parameters and allow determining the orientation of the anisotropy tensor axes with respect to the molecular frame...
December 6, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27921335/reduction-of-cp-sb-4-with-subvalent-main-group-metal-reductants-syntheses-and-structures-of-l1mg-4-sb4-and-l2ga-2-sb4-containing-edge-missing-sb4-units
#7
Stephan Schulz, Chelladurai Ganesamoorthy, Julia Krüger, Christoph Wölper, Anton S Nizovtsev
[Cp*Sb]4 (Cp* = C5Me5) reacts with [L1Mg]2 and L2Ga with for-mation of [(L1Mg)4(4,1:2:2:2-Sb4)] {L1 = i-Pr2NC[N(2,6-i-Pr2C6H3)]2, 1} and [(L2Ga)2(,2:2-Sb4)] {L2 = HC[C(Me)N(2,6-i-Pr2C6H3)]2, 2}. The cleavage of the Sb-Sb and Sb-C bonds in [Cp*Sb]4 are the crucial steps in both reactions. The formation of 1 occurred via elimination of the Cp* anion and formation of Cp*MgL1, while 2 was formed by reductive elimination of Cp*2 and oxidative addition of L2Ga to the Sb4 unit. 1 and 2 were characterized by heteronuclear NMR spectroscopy and single crystal X-ray diffraction and their bonding situation was studied by quantum chemical calculations...
December 6, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27921237/structure-and-activation-of-the-tsh-receptor-transmembrane-domain
#8
Ricardo Núñez Miguel, Jane Sanders, Jadwiga Furmaniak, Bernard Rees Smith
PURPOSE: The thyroid-stimulating hormone receptor (TSHR) is the target autoantigen for TSHR-stimulating autoantibodies in Graves' disease. The TSHR is composed of: a leucine-rich repeat domain (LRD), a hinge region or cleavage domain (CD) and a transmembrane domain (TMD). The binding arrangements between the TSHR LRD and the thyroid-stimulating autoantibody M22 or TSH have become available from the crystal structure of the TSHR LRD-M22 complex and a comparative model of the TSHR LRD in complex with TSH, respectively...
December 2017: Auto- Immunity Highlights
https://www.readbyqxmd.com/read/27921145/compressive-loading-of-the-murine-tibia-reveals-site-specific-micro-scale-differences-in-adaptation-and-maturation-rates-of-bone
#9
I Bergström, J G Kerns, A E Törnqvist, C Perdikouri, N Mathavan, A Koskela, H B Henriksson, J Tuukkanen, G Andersson, H Isaksson, A E Goodship, S H Windahl
: Loading increases bone mass and strength in a site-specific manner; however, possible effects of loading on bone matrix composition have not been evaluated. Site-specific structural and material properties of mouse bone were analyzed on the macro- and micro/molecular scale in the presence and absence of axial loading. The response of bone to load is heterogeneous, adapting at molecular, micro-, and macro-levels. INTRODUCTION: Osteoporosis is a degenerative disease resulting in reduced bone mineral density, structure, and strength...
December 5, 2016: Osteoporosis International
https://www.readbyqxmd.com/read/27921101/the-effect-of-common-anticoagulants-in-detection-and-quantification-of-malaria-parasitemia-in-human-red-blood-cells-by-atr-ftir-spectroscopy
#10
Miguela Martin, David Perez-Guaita, Dean W Andrew, Jack S Richards, Bayden R Wood, Philip Heraud
Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) has the potential to become a new diagnostic tool for malaria and other diseases. For point-of-care testing, the use of ATR-FTIR in malaria diagnosis enables the analysis of blood in the aqueous state, which represents an enormous advantage by minimising the sample preparation by removing the need for cell fixation. Here we report the quantification of malaria parasitemia in human RBCs in their normal physiological aqueous state...
December 6, 2016: Analyst
https://www.readbyqxmd.com/read/27921074/initial-performance-studies-of-a-wearable-brain-positron-emission-tomography-camera-based-on-autonomous-thin-film-digital-geiger-avalanche-photodiode-arrays
#11
Charles R Schmidtlein, James N Turner, Michael O Thompson, Krishna C Mandal, Ida Häggström, Jiahan Zhang, John L Humm, David H Feiglin, Andrzej Krol
Using analytical and Monte Carlo modeling, we explored performance of a lightweight wearable helmet-shaped brain positron emission tomography (PET), or BET camera, based on thin-film digital Geiger avalanche photodiode arrays with Lutetium-yttrium oxyorthosilicate (LYSO) or [Formula: see text] scintillators for imaging in vivo human brain function of freely moving and acting subjects. We investigated a spherical cap BET and cylindrical brain PET (CYL) geometries with 250-mm diameter. We also considered a clinical whole-body (WB) LYSO PET/CT scanner...
January 2017: Journal of Medical Imaging
https://www.readbyqxmd.com/read/27921069/reaching-200-ps-timing-resolution-in-a-time-of-flight-and-depth-of-interaction-positron-emission-tomography-detector-using-phosphor-coated-crystals-and-high-density-silicon-photomultipliers
#12
Sun Il Kwon, Alessandro Ferri, Alberto Gola, Eric Berg, Claudio Piemonte, Simon R Cherry, Emilie Roncali
Current research in the field of positron emission tomography (PET) focuses on improving the sensitivity of the scanner with thicker detectors, extended axial field-of-view, and time-of-flight (TOF) capability. These create the need for depth-of-interaction (DOI) encoding to correct parallax errors. We have proposed a method to encode DOI using phosphor-coated crystals. Our initial work using photomultiplier tubes (PMTs) demonstrated the possibilities of the proposed method, however, a major limitation of PMTs for this application is poor quantum efficiency in yellow light, corresponding to the wavelengths of the converted light by the phosphor coating...
October 2016: Journal of Medical Imaging
https://www.readbyqxmd.com/read/27921023/effects-of-hydrophilic-extract-of-nasturtium-officinale-on-prevention-of-ethylene-glycol-induced-renal-stone-in-male-wistar-rats
#13
Sadrollah Mehrabi, Eslam Askarpour, Farhad Mehrabi, Ramin Jannesar
BACKGROUND: Nasturtium officinale is a traditional herb that is used for diuresis. OBJECTIVES: The aim of this study is to determine the effects of hydrophilic extract of Nasturtium officinale on ethylene glycol-induced renal stone in male Wistar rats. MATERIALS AND METHODS: In this study 32 male Wistar rats were randomly divided in six groups and studied during 30 days. Two groups of negative and healthy control received 1% ethylene glycol in water respectively...
October 2016: Journal of Nephropathology
https://www.readbyqxmd.com/read/27920934/crystal-structure-of-3-2-hy-droxy-eth-yl-2-methyl-sulfanyl-6-nitro-3h-benzimidazol-1-ium-chloride-monohydrate
#14
Akoun Abou, Siomenan Coulibali, Rita Kakou-Yao, T Jérémie Zoueu, A Jules Tenon
In the cation of the title hydrated molecular salt, C10H12N3O3S(+)·Cl(-)·H2O, the benzimidazolium ring system is almost planar (r.m.s. deviation = 0.006 Å) and the nitro group is inclined at an angle of 4.86 (9)° to this plane. In the crystal, C-H⋯O hydrogen bonds form centrosymmetric R2(2)(20) dimers and these are further aggregated through N-H⋯O and O-H⋯Cl hydrogen bonds involving the water mol-ecules and chloride anions. Aromatic π-π stacking inter-actions are also found between two parallel benzene rings or the benzene and imidazolium rings, with centroid-centroid distances of 3...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920933/crystal-structure-of-1-3-bis-3-tert-butyl-2-hy-droxy-5-methyl-benz-yl-1-3-diazinan-5-ol-monohydrate
#15
Augusto Rivera, Ingrid Miranda-Carvajal, Jaime Ríos-Motta, Michael Bolte
In the title hydrate, C28H42N2O3·H2O, the central 1,3-diazinan-5-ol ring adopts a chair conformation with the two benzyl substituents equatorial and the lone pairs of the N atoms axial. The dihedral angle between the aromatic rings is 19.68 (38)°. There are two intra-molecular O-H⋯N hydrogen bonds, each generating an S(6) ring motif. In the crystal, classical O-H⋯O hydrogen bonds connect the 1,3-diazinane and water mol-ecules into columns extending along the b axis. The crystal structure was refined as a two-component twin with a fractional contribution to the minor domain of 0...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920932/solvent-inclusion-in-the-crystal-structure-of-bis-adamantan-1-yl-methanaminium-chloride-1-4-dioxane-hemisolvate-monohydrate-explained-using-the-computed-crystal-energy-landscape
#16
Sharmarke Mohamed
Repeated attempts to crystallize 1-adamantane-methyl-amine hydro-chloride as an anhydrate failed but the salt was successfully crystallized as a solvate (2C11H20N(+)·2Cl(-)·0.5C4H8O2·H2O), with water and 1,4-dioxane playing a structural role in the crystal and engaging in hydrogen-bonding inter-actions with the cation and anion. Computational crystal-structure prediction was used to rationalize the solvent-inclusion behaviour of this salt by computing the solvent-accessible voids in the predicted low-energy structures for the anhydrate: the global lattice-energy minimum structure, which has the same packing of the ions as the solvate, has solvent-accessible voids that account for 3...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920931/crystal-structures-of-n-4-phenyl-thia-zol-2-yl-carbamo-thio-yl-benzamide-and-n-4-4-bromo-phen-yl-thia-zol-2-yl-carbamo-thio-yl-benzamide-from-synchrotron-x-ray-diffraction
#17
Ekaterina S Gantimurova, Alexander S Bunev, Kristina Yu Talina, Gennady I Ostapenko, Pavel V Dorovatovskii, Nikolai N Lobanov, Victor N Khrustalev
The title compounds, C17H13N3OS2, (I), and C17H12BrN3OS2, (II), are potential active pharmaceutical ingredients. Compound (I) comprises two almost planar fragments. The first is the central (carbamo-thio-yl)amide (r.m.s. deviation = 0.038 Å), and the second consists of the thia-zole and two phenyl rings (r.m.s. deviation = 0.053 Å). The dihedral angle between these planes is 15.17 (5)°. Unlike (I), compound (II) comprises three almost planar fragments. The first is the central N-(thia-zol-2-ylcarbamo-thio-yl)amide (r...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920930/crystal-structure-of-e-4-hy-droxy-n-3-meth-oxy-benzyl-idene-benzohydrazide
#18
Suchada Chantrapromma, Patcharawadee Prachumrat, Pumsak Ruanwas, Nawong Boonnak, Mohammad B Kassim
The title compound, C15H14N2O3, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit that differ in the orientation of the 3-meth-oxy-phenyl group with respect to the methyl-idenebenzohydrazide unit. The dihedral angles between the two benzene rings are 24.02 (10) and 29.30 (9)° in mol-ecules A and B, respectively. In mol-ecule A, the meth-oxy group is twisted slightly relative to its bound benzene ring, with a Cmeth-yl-O-C-C torsion angle of 14.2 (3)°, whereas it is almost co-planar in mol-ecule B, where the corresponding angle is -2...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920929/crystal-structure-of-methyl-4-4-hy-droxy-phen-yl-6-methyl-2-oxo-1-2-3-4-tetra-hydro-pyrimidine-5-carboxyl-ate-monohydrate
#19
Keshab M Bairagi, Katharigatta N Venugopala, Pradip Kumar Mondal, Bharti Odhav, Susanta K Nayak
The title hydrate, C13H14N2O4·H2O, crystallizes with two formula units in the asymmetric unit (Z' = 2). The dihedral angles between the planes of the tetra-hydro-pyrimidine ring and the 4-hy-droxy-phenyl ring and ester group are 86.78 (4) and 6.81 (6)°, respectively, for one mol-ecule and 89.35 (4) and 3.02 (4)° for the other. In the crystal, the organic mol-ecules form a dimer, linked by a pair of N-H⋯O hydrogen bonds. The hydroxy groups of the organic mol-ecules donate O-H⋯O hydrogen bonds to water mol-ecules...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920928/-trans-chlorido-2-rp-2-methyl-sulfan-yl-ferro-cen-yl-2-5-6-7-tetra-hydro-pyrrolo-1-2-c-imidazol-3-yl-idene-bis-tri-phenyl-phosphane-%C3%AE%C2%BAp-palladium-ii-hexa-fluorido-phosphate-di-chloro-form-disolvate
#20
Cody Wilson-Konderka, Alan J Lough, Costa Metallinos
The title solvated complex, [FePd(C5H5)(C12H13N2S)Cl(C18H15P)2]PF6·2CHCl3, bearing a chiral ferrocenyl pyrrolo-imidazolyl-idene N-heterocyclic carbene (NHC) ligand, was synthesized by oxidative addition of a chloro-imidazolium salt to Pd(PPh3)4. The Pd(II) ion is coordinated in a slightly distorted square-planar coordination geometry, with the Cl atom trans to the coordinating C atom of the pyrrolo-imidazolyl-idene ligand. The complex features a pendant thio-ether group that is not involved in coordination to Pd...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
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