Read by QxMD icon Read


Yiluo Hu, Hwanhee Kim, Vijay Vilas Shinde, Daham Jeong, Youngjin Choi, Eunae Cho, Seunho Jung
In the present study, cyclosophoraoses (CyS) (β-1,2 linked cyclic glucans, with glucopyranose units ranging from 17 to 23) isolated from Rhizobium leguminosarum biovar viciae VF-39 were modified with carboxymethyl (CM) groups, and the pH-sensitive complexation of CM CyS with pindolol was investigated. The solubility of pindolol increased 32-fold by its complexation with 5mM CM CyS at pH 10, whereas it shows no significant change at pH 3. Pindolol, a β-adrenergic blocking agent, has a hydrophobic nature at non-ionized state, and CM CyS could solubilize efficiently pindolol in a high alkaline solution...
November 1, 2017: Carbohydrate Polymers
Mateusz Gosecki, Slawomir Kazmierski, Monika Gosecka
We present biocompatible hydrogel systems suitable for biomineralization processes based on hyperbranched polyglycidol cross-linked with acrylamide copolymer bearing carbonyl-coordinated boronic acid. At neutral pH, diol functional groups of HbPGL react with boronic acid of polyacrylamide to generate 3D network in water by the formation of boronic ester cross-links. The dynamic associative/dissociative characteristics of the cross-links makes the network reversible. The presented hydrogels display self-healing properties and are injectable, facilitating gap filing of bone tissue...
September 13, 2017: Biomacromolecules
I E Nifant'ev, A V Shlyakhtin, V V Bagrov, M E Minyaev, A V Churakov, S G Karchevsky, K P Birin, P V Ivchenko
Numerous heteroleptic 2,6-di-tert-butyl-4-methylphenolate (BHT) magnesium complexes have been synthesized by treatment of (BHT)MgBu(THF)2 with various alcohols. Molecular structures of the complexes have been determined by X-ray diffraction. The magnesium coordination number in [(BHT)Mg(μ-OBn)(THF)]2 (3) and [(BHT)Mg(μ-O-tert-BuC6H4)(THF)]2 (4) is equal to 4. Complexes formed from esters of glycolic and lactic acids, [(BHT)Mg(μ-OCH2COOEt)(THF)]2 (5) and [(BHT)Mg(μ-OCH(CH3)COOCH2COO(t)Bu)(THF)]2 (6) contain chelate fragments with pentacoordinated magnesium...
September 28, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
M Grajda, M J Lewińska, A Szumna
Peptide-based cavitands (resorcin[4]arenes substituted with histidine and glutamine hydrazides) exist as monomeric species in polar solvents (DMSO and methanol). Upon complexation of fullerenes, the cavitands wrap around the hydrophobic guests forming dimeric capsular shells (as evidenced by DOSY). The self-assembly of the cavitands is based on the formation of beta-sheet-like binding motifs around the hydrophobic core. In a polar environment, these hydrogen bonded structures are kinetically stable and highly ordered as manifested by a 100-fold increase of intensity of circular dichroism bands, as well as a separate set of signals and substantial differences in chemical shifts in NMR spectra...
September 1, 2017: Organic & Biomolecular Chemistry
G Pagès, V Gilard, R Martino, M Malet-Martino
While NMR is the most used analytical method for determining the molecular structure of isolated chemical entities, small compounds as well as macromolecules, its capability of analysing complex mixtures is less known. The advent of Diffusion Ordered SpectroscopY (DOSY) NMR has made diffusion experiments popular, enabling diffusion coefficients to be routinely measured and used to characterize chemical systems in solution. Indeed, since the translational diffusion coefficients of molecular species reflect their effective sizes and shapes, DOSY NMR allows the separation of the chemical entities present in multicomponent systems and, as in all diffusion NMR experiments, provides information on their intermolecular interactions as well as on their size and shape...
August 31, 2017: Analyst
Ludmilla Guduff, Dennis Kurzbach, Carine van Heijenoort, Daniel Abergel, Jean-Nicolas Dumez
Diffusion-ordered NMR spectroscopy (DOSY) is a powerful approach for the analysis of molecular mixtures, yet its application range is limited by the relatively low sensitivity of NMR. We show here that spectrally resolved 13C DOSY data can be collected, in a single scan, for substrates hyperpolarised by dissolution dynamic nuclear polarisation (D-DNP), which provides signal enhancements of several orders of magnitude. For this we use a convection-compensation pulse scheme, which we also analyse by numerical simulation...
August 31, 2017: Chemistry: a European Journal
Mhamad Aly Moussawi, Nathalie Leclerc-Laronze, Sébastien Floquet, Pavel A Abramov, Maxim N Sokolov, Stéphane Cordier, Anne Ponchel, Eric Monflier, Hervé Bricout, David Landy, Mohamed Haouas, Jérôme Marrot, Emmanuel Cadot
Herein, we report on a three-component supramolecular hybrid system built from specific recognition processes involving a Dawson-type polyoxometalate (POM), [P2W18O62](6-), a cationic electron-rich cluster [Ta6Br12(H2O)6](2+), and γ-cyclodextrin (γ-CD). Such materials have been investigated using a bottom-up approach by studying the specific interactions between γ-CD and both types of inorganic units. Their ability to interact has been investigated in the solid state by single-crystal X-ray diffraction (XRD) and in solution using multinuclear NMR methods (including DOSY, EXSY, and COSY), electrospray ionization mass and UV-vis spectroscopies, electrochemistry, and isothermal titration calorimetry experiments...
September 1, 2017: Journal of the American Chemical Society
F Berride, E Troche-Pesqueira, G Feio, E J Cabrita, T Sierra, A Navarro-Vázquez, M M Cid
Chromonic liquid crystals (CLC) are lyotropic phases formed by discotic mesogens in water. Simple chiral dopants such as amino acids have been reported to turn chromonic liquid crystals into their cholesteric counterparts. Here we report a chirality amplification effect in the nematic phase of a 9 wt% disodium cromoglycate (DSCG) lyotropic liquid crystal (LLC) upon doping with a water-soluble codeine derivative. The transition on cooling the isotropic to the nematic phase showed the presence of homochiral spindle-shaped droplets (tactoids)...
August 18, 2017: Soft Matter
Sharadrao M Patil, David A Keire, Kang Chen
Particle size distribution, a measurable physicochemical quantity, is a critical quality attribute of drug products that needs to be controlled in drug manufacturing. The non-invasive methods of dynamic light scattering (DLS) and Diffusion Ordered SpectroscopY (DOSY) NMR can be used to measure diffusion coefficient and derive the corresponding hydrodynamic radius. However, little is known about their use and sensitivity as analytical tools for particle size measurement of formulated protein therapeutics. Here, DLS and DOSY-NMR methods are shown to be orthogonal and yield identical diffusion coefficient results for a homogenous monomeric protein standard, ribonuclease A...
August 8, 2017: AAPS Journal
Yamina Belabassi, Juliette Moreau, Virginia Gheran, Celine Henoumont, Anthony Robert, Maité Callewaert, Guillaume Rigaux, Cyril Cadiou, Luce Vander Elst, Sophie Laurent, Robert N Muller, Anca Dinischiotu, Sorina N Voicu, Françoise Chuburu
To synthesize chitosan nanoparticles (CS NPs), ionic gelation is a very attractive method. It relies on the spontaneous supramolecular assembly of cationic CS with anionic compounds, which leads to nanohydrogels. To extend ionic gelation to functionalized CS, the assessment of CS degree of substitution (DSCS) is a key step. In this paper, we have developed a hyphenated strategy for functionalized CS characterization, based upon (1)H, DOSY and, when relevant, 1D diffusion-filtered (19)F NMR spectroscopies. For that, we have synthesized two series of water-soluble CS via amidation of CS amino groups with mPEG2000-COOH or fluorinated synthons (TFB-COOH)...
August 24, 2017: Biomacromolecules
Saikat Santra, Somnath Bej, Mandira Nandi, Partha Mondal, Pradyut Ghosh
Herein, a bis-amido tris-amine macrocycle and five bipyridine-based bidentate chelating ligands were investigated towards various divalent transition metal ion (Ni(II), Co(II), Cu(II), and Zn(II))-templated syntheses of metallo [2]pseudorotaxanes. The formation of these ternary complexes was elucidated via different spectroscopic techniques such as ESI-MS, absorption spectroscopy, EPR spectroscopy, and single-crystal X-ray diffraction studies wherever possible. Azide-terminated Ni(II), Co(II), Cu(II), Zn(II)-templated [2]pseudorotaxanes were explored to generate [2]rotaxane, ROT, via reaction with an alkyne-terminated triphenylene unit as a stopper under the mild reaction condition of the Cu(I)-catalyzed azide-alkyne cycloaddition reaction...
August 3, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Philipp A Elvang, Paul C Stein, Annette Bauer-Brandl, Martin Brandl
No abstract text is available yet for this article.
October 25, 2017: Journal of Pharmaceutical and Biomedical Analysis
Onkei Tai, Russell Hopson, Paul G Williard
Solution characterizations and ligand binding constants were determined for n-butyllithium in hydrocarbon and ethereal solvents using diffusion-ordered NMR. In hydrocarbon solvents, n-butyllithium exists primarily as an octamer at -40 °C and deaggregates to a hexamer when the temperature is increased. In the presence of THF or diethyl ether, n-butyllithium exists predominantly as a tetra-solvated tetramer and deaggregates to a tetra-solvated dimer in the presence of a large excess or neat THF. The ligand binding constants for the tetra-solvated tetramers were measured using (1)H NMR/DOSY titration...
July 27, 2017: Organic Letters
Alexandra Epp, Juliane Hobusch, Yannic C Bartsch, Janina Petry, Gina-Maria Lilienthal, Carolien A M Koeleman, Simon Eschweiler, Christian Möbs, Ashley Hall, Suzanne C Morris, Dominique Braumann, Christine Engellenner, Josephine Bitterling, Johann Rahmöller, Alexei Leliavski, Robina Thurmann, Mattias Collin, Kelley W Moremen, Richard T Strait, Véronique Blanchard, Arnd Petersen, Timo Gemoll, Jens K Habermann, Frank Petersen, Andreas Nandy, Helga Kahlert, Michael Hertl, Manfred Wuhrer, Wolfgang Pfützner, Uta Jappe, Fred D Finkelman, Marc Ehlers
No abstract text is available yet for this article.
July 18, 2017: Journal of Allergy and Clinical Immunology
Alberto Vascellari, Carlo Ramponi, Davide Venturin, Giulia Ben, Davide Blonna, Nicolò Coletti
PURPOSE: The purpose of this study was to evaluate validity and responsiveness of the Degree of Shoulder Involvement in Sport (DOSIS) scale. METHODS: A web-based survey was developed to test the construct validity of the DOSIS scale. Fifty-three patients with a median age of 33 years (range 17-59) were included in the study. Convergent validity was evaluated by external correlation (Spearman's rank correlation coefficient, r) of the DOSIS with the Brophy-Marx and Tegner activity scales, the Western Ontario shoulder instability index (WOSI), the Simple Shoulder Test (SST), and the Short-Form 36 (SF-36)...
July 18, 2017: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
Zhanyao Hou, Wim Dehaen, Joël Lyskawa, Patrice Woisel, Richard Hoogenboom
A novel supramolecular miktoarm star polymer was successfully constructed in water from a pyridine end-decorated polymer (Py-PmDEGA) and a metalloporphyrin based star polymer (ZnTPP-(PEG)4) via metal-ligand coordination. The Py-PmDEGA moiety was prepared via a combination of reversible addition-fragmentation chain transfer polymerization (RAFT) and subsequent aminolysis and Michael addition reactions to introduce the pyridine end-group. The ZnTPP(PEG)4 star-polymer was synthesized by the reaction between tetrakis(p-hydroxyphenyl)porphyrin and toluenesulfonyl-PEG, followed by insertion of a zinc ion into the porphyrin core...
July 25, 2017: Chemical Communications: Chem Comm
Madeleine Piot, Sébastien Hupin, Hélène Lavanant, Carlos Afonso, Laurent Bouteiller, Anna Proust, Guillaume Izzet
The metal-driven self-assembly of a Keggin-based hybrid bearing two remote pyridine units was investigated. The resulting supramolecular species were identified by combination of 2D diffusion NMR spectroscopy (DOSY) and electrospray ionization mass spectrometry (ESI-MS) as a mixture of molecular triangles and squares. This behavior is different from that of the structural analogue Dawson-based hybrid displaying a higher charge, which only led to the formation of molecular triangles. This study highlights the decisive effect of the charge of the POMs in their self-assembly processes that disfavors the formation of large assemblies...
July 17, 2017: Inorganic Chemistry
Shigeto Ueda, Toshiaki Saeki, Akihiko Osaki, Tomohiko Yamane, Ichiei Kuji
Bevacizumab, an antibody against endothelial growth factor, is a key but controversial drug in the treatment of metastatic breast cancer. We, therefore, aimed to determine the intrinsic resistance to bevacizumab at the physiological and molecular levels in advanced breast cancer using positron emission tomography (PET), dynamic contrast-enhanced MRI, diffuse optical spectroscopic imaging (DOSI), and multiplex cytokine assays.<br />Experimental Design: In total, 28 patients diagnosed with stage III/IV advanced breast cancer receiving single-agent bevacizumab for 1 week followed by paclitaxel combined with bevacizumab underwent (18)F-fluorodeoxyglucose (FDG)-PET, (18)F-fluoromisonidazole (FMISO)-PET, and MRI at both baseline and two courses after treatment initiation...
July 5, 2017: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
Falco Beer, Felix Urbat, Jan Steck, Melanie Huch, Diana Bunzel, Mirko Bunzel, Sabine E Kulling
The heterocyclic aromatic amine (HAA) 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is converted into 7-hydroxy-5-methyl-3-phenyl-6,7,8,9-tetrahydropyrido[3',2':4,5]imidazo[1,2-a]pyrimidin-5-ium chloride (PhIP-M1) via a chemical reaction with 3-hydroxypropionaldehyde or acrolein derived from glycerol by reuterin producing gut bacteria. Because it is unknown whether this reaction also applies to other HAAs, seven foodborne HAAs (2-amino-9H-pyrido[2,3-b]indole (AαC), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-3H-imidazo[4,5-f]quinoxaline (MeIQx), 9H-pyrido[3,4-b]indole (norharman), and 1-methyl-9H-pyrido[3,4-b]indole (harman)) were anaerobically incubated with Lactobacillus reuteri DSM 20016 in the presence of glycerol...
August 16, 2017: Journal of Agricultural and Food Chemistry
Sophia Boyoung Strobel, Sylvie Pätzold, Lisa Zimmer, Alexandra Jensen, Alexander Enk, Jessica Cecile Hassel
HINTERGRUND: In der letzten Zeit wurden in der Literatur vermehrt erhöhte Hauttoxizitäten während einer Kombinationstherapie mit BRAF Inhibitoren und Radiotherapie beschrieben. MATERIAL UND METHODIK: Wir berichten über sieben Melanompatienten in einem nicht resezierbaren Stadium III oder IV, die eine kombinierte Behandlung aus Bestrahlung und BRAF-Inhibitor erhielten. ERGEBNISSE: Bei allen Patienten konnte durch die Kombinationstherapie ein gutes lokales Ansprechen erreicht werden...
July 2017: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"