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Leandro Araújo de Azevedo, Leonis Lourenço da Luz, Jamylle Nunes de Souza Ferro, Emiliano Barreto, Ricardo Oliveira Silva, Severino Alves, Iane Bezerra Vasconcelos Alves
The supramolecular nano-aggregate CUR-CB[7] (CUR = curcumin and CB[7] = cucurbit[7]uril) was efficiently prepared by mixing CUR and CB[7] at a molar ratio of 1 : 1 in ethanol at room temperature. The supramolecular aggregate formation was evidenced by mainly FTIR, (1)H NMR, DOSY and spectroscopy experiments. The supramolecular arrangement promotes the increase in the solubility and stability of CUR without affecting the biological properties of the A549 cells. The luminescence properties of CUR and CUR-CB[7] show anti-Kasha's rule fluorescence, and their remarkable NIR emission enables this material to be used as a luminescent probe and marker for in vivo tracking and structural integrity monitoring of the supramolecular complex...
February 22, 2017: Photochemical & Photobiological Sciences
Ioannis Dosis, Marina Ricci, Laszlo Majoros, Roberto Lava, Håkan Emteborg, Andrea Held, Hendrik Emons
In the context of supporting the EU Member States in the implementation of the EU Water Framework Directive (WFD), a project for the production of a fish reference material (ERM-CE100) certified for its content of the two priority substances hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) was carried out at the Joint Research Centre (JRC) of the European Commission. The starting material was naturally contaminated Wels catfish (Silurus glanis), caught in the Ebro River (Spain). A novel approach for the processing of the fish was tested that resulted in a homogeneous and stable reference material in the form of a wet paste...
February 21, 2017: Analytical Chemistry
Indrek Reile, Ruud L E G Aspers, Martin C Feiters, Floris P J T Rutjes, Marco Tessari
DOSY analysis can resolve analytes according to their molecular size, offering a complementary way to traditional 2D NMR spectroscopy in the study of chemical mixtures. Applications are, however, limited if analytes have similar shape and size, as is the case in isomer mixtures. Herein we show how solvent effects in methanol-d4 , a common solvent in NMR laboratories, allow to overcome this limitation and provide increased separation of isomeric compounds. Clear NMR signal separation of eight structurally related analytes within a molecular weight (MW) range of three units is demonstrated, allowing unambiguous analysis of a mixture that would have otherwise been unsuitable for DOSY...
February 20, 2017: Magnetic Resonance in Chemistry: MRC
Daniela Göppner, Stephan Nekwasil, Anne Jellestad, Alexander Sachse, Karl-Heinz Schönborn, Harald Gollnick
HINTERGRUND: Der Nachweis metastatischer Infiltrate im Sentinel-Lymphkoten (SLN) gilt als wesentlicher prognostischer Faktor des Melanoms. Alternativ zur Farbstoffmethode mit Patentblau zum Goldstandard der SLN-Biopsie (SLNB) mittels Radiokolloid wird die fluoreszenzoptische Darstellung mit Hilfe von Indocyaningrün (ICG) und Nahinfrarot (NIR)-Kamerasystem kommuniziert. Im Vergleich zur konventionellen Methode wurde die Wertigkeit des ICG-/NIR-Verfahrens in Abhängigkeit vom Body-Mass-Index (BMI) des Patienten und der Konzentration von ICG bezüglich der Visualisierung des Lymphabstroms und des SLNs untersucht...
February 2017: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
Andressa R Prado, Fabiano Yokaichiya, Margareth Kazuyo Kobayashi Dias Franco, Camila Morais Gonçalves da Silva, Laura Oliveira-Nascimento, Michelle Franz-Montan, Maria C Volpato, Luís F Cabeça, Eneida de Paula
OBJECTIVES: Oxethazaine (OXZ) is one of the few local anaesthetics that provides analgesia at low pH, but presents poor solubility, cytotoxicity and no parenteral formulations. To address these issues, we aimed to prepare OXZ host-guest inclusion complex with hydroxypropyl-beta-cyclodextrin (HP-β-CD). METHODS: The inclusion complex was formed by co-solubilization, followed by a job plot analysis to determine stoichiometry of complexation and dialysis equilibrium analysis (based on UV/VIS absorption and fluorescence profiles of OXZ)...
February 17, 2017: Journal of Pharmacy and Pharmacology
Hiroaki Watanabe, Yusuke Kamatani, Hitoshi Tamiaki
Zinc chlorophyll derivatives Zn-1~3 possessing a tertiary amino group at the C3¹ position were synthesized through reductive amination of methyl pyropheophorbide-d obtained from naturally occurring chlorophyll-a. In a concentrated CH₂Cl₂ solution as well as a diluted 10%(v/v) CH₂Cl₂-hexane solution, Zn-1 possessing a dimethylamino group at the C3¹ position showed red-shifted UV-Vis absorption and intensified exciton-coupling CD spectra at room temperature due to its dimer formation via coordination to the central zinc by the 3¹-N atom of the dimethylamino group...
February 8, 2017: Chemistry, An Asian Journal
Karin Jahn-Bassler, Wolfgang Michael Bauer, Franz Karlhofer, Matthias G Vossen, Georg Stingl
HINTERGRUND: Schwere Verlaufsformen der Alopecia areata (AA) im Kindesalter sind aufgrund limitierter Optionen therapeutisch herausfordernd. Systemische, hochdosierte Glukokortikoide weisen die schnellste Ansprechrate auf, nach dem Absetzen kommt es allerdings zu Rezidiven. Eine längerfristige Hochdosis-Anwendung ist aufgrund der zu erwartenden Nebenwirkungen nicht empfehlenswert. Eine dauerhafte Steroiderhaltungstherapie unterhalb der Cushing-Schwellen-Dosis nach Bolustherapie könnte die Krankheitsaktivität ohne Nebenwirkungen längerfristig unterdrücken...
January 2017: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
Afef Cherni, Emilie Chouzenoux, Marc-André Delsuc
NMR is a tool of choice for the measurement of diffusion coefficients of species in solution. The DOSY experiment, a 2D implementation of this measurement, has been proven to be particularly useful for the study of complex mixtures, molecular interactions, polymers, etc. However, DOSY data analysis requires to resort to the inverse Laplace transform, in particular for polydisperse samples. This is a known difficult numerical task for which we present here a novel approach. A new algorithm based on a splitting scheme and on the use of proximity operators is introduced...
January 25, 2017: Analyst
Joanna Kruk, Marek Doskocz, Elżbieta Jodłowska, Anna Zacharzewska, Joanna Łakomiec, Kornelia Czaja, Jacek Kujawski
Metabolomics is a rapidly developing branch of science that concentrates on identifying biologically active molecules with potential biomarker properties. To define the best biomarkers for diseases, metabolomics uses both models (in vitro, animals) and human, as well as, various techniques such as mass spectroscopy, gas chromatography, liquid chromatography, infrared and UV-VIS spectroscopy and nuclear magnetic resonance. The last one takes advantage of the magnetic properties of certain nuclei, such as (1)H, (13)C, (31)P, (19)F, especially their ability to absorb and emit energy, what is crucial for analyzing samples...
2017: Applied Magnetic Resonance
Woldeamanuel A Birru, Dallas B Warren, Stephen J Headey, Hassan Benameur, Christopher J H Porter, Colin W Pouton, David K Chalmers
Improved models of the gastrointestinal environment have great potential to assist the complex process of drug formulation. Molecular dynamics (MD) is a powerful method for investigating phase behaviour at a molecular level. In this study we use multiple MD simulations to calculate phase diagrams for bile before and after digestion. In these computational models, undigested bile is represented by mixtures of palmitoyl-oleoylphosphatidylcholine (POPC), sodium glycodeoxycholate (GDX) and water. Digested bile is modelled using a 1:1 mixture of oleic acid and palmitoylphosphatidylcholine (lyso-phosphatidylcholine, LPC), GDX and water...
January 18, 2017: Molecular Pharmaceutics
A Müssigbrodt, A Weber, J Mandrola, Y van Belle, S Richter, M Döring, A Arya, P Sommer, A Bollmann, G Hindricks
An interesting and still not well-understood example for old medical wisdom "Sola dosis facit venenum" is the increased prevalence of atrial fibrillation (AF) in athletes. Numerous studies have shown a fourfold to eightfold increased risk of AF in athletes compared to the normal population. Analysis of the existing data suggests a dose-dependent effect of exercise. Moderate exercise seems to have a protective effect and decreases the risk of AF, whereas excessive exercise seems to increase the risk of AF. The described cases illustrate clinical manifestations within the spectrum of AF in elderly athletes, that is, exercise-induced AF, vagal AF, chronic AF, and atrial flutter...
January 16, 2017: Scandinavian Journal of Medicine & Science in Sports
Mario E Flores, Francisco Martínez, Andrés F Olea, Toshimichi Shibue, Natsuhiko Sugimura, Hiroyuki Nishide, Ignacio Moreno-Villoslada
Molecular aggregation in a mixture of Triton X-100/n-hexanol/cyclohexane at a molar ratio of 1/16/74 is studied upon addition of small amounts of water. The composition of organic components has been chosen at a ratio n-hexanol/cyclohexane where a well-formed hydrogen bond network has been described. The ratio Triton X-100/n-hexanol has been chosen to afford a stoichiometry of ethylene oxide (EO) residues/n-hexanol of 1/2. At these conditions the addition of water consecutively produces the appearance of three defined phases: a clear solution, a lamellar phase, and a microemulsion...
January 20, 2017: Journal of Physical Chemistry. B
G Gonzalez-Sprinberg, G Piriz
PURPOSE: To optimize the dose in bladder and rectum and show the different shapes of the isodose volumes in Co60-HDR brachytherapy, considering different utero and vaginal sources dwell ratio times (TU:TV). METHODS: Besides Ir192-HDR, new Co60-HDR sources are being incorporated. We considered different TU:TV times and computed the dosis in bladder, rectum and at the reference points of the Manchester system. Also, we calculated the isodose volume and shape in each case...
June 2016: Medical Physics
A De Quintana Sancho, X Piris García, J N Valle García, M Hierro Cámara
La alopecia frontal fibrosante (AFF) es un tipo de alopecia cicatricial cuya incidencia está aumentando de forma significativa en nuestro país. Se caracteriza por un retroceso en la línea de implantación del pelo a nivel frontotemporal que afecta mayoritariamente a mujeres postmenopaúsicas, con un impacto negativo en su calidad de vida. Se asocia a menopausia precoz en un 14% de los casos y a hipotiroidismo en un 15%. Con respecto al tratamiento, son los inhibidores de la 5α-reductasa, los fármacos que han demostrado mejoría de la enfermedad en un mayor número de casos...
December 30, 2016: Anales del Sistema Sanitario de Navarra
A M Varizhuk, A V Sekridova, M V Tankevich, V S Podgorsky, I P Smirnov, G E Pozmogova
Three evolutionary conserved sites of Alu repeats (PQS2, PQS3 and PQS4) were shown to form stable inter- and intramolecular G-quadruplexes (GQs) in vitro. Structures and topologies of these GQs were elucidated using spectral methods. Self-association of G-rich Alu fragments was studied. Dimeric GQ formation from two distal identical or different putative quadruplex sites - (PQS2)2, (PQS3)2 or PQS2-PQS3 - within one lengthy DNA strand was demonstrated by a FRET-based method. Oligomer PQS4 (folded into a parallel intramolecular GQ) was shown to form stacks of quadruplexes that are stabilized by stacking interactions of external G-tetrads (this was confirmed by DOSY NMR, AFM microscopy and differential CD spectroscopy)...
November 2016: Biomedit︠s︡inskai︠a︡ Khimii︠a︡
Markus M Zieger, Ognen Pop-Georgievski, Andres de Los Santos Pereira, Elisseos Verveniotis, Corinna M Preuss, Matthias Zorn, Bernd Reck, Anja S Goldmann, Cesar Rodriguez-Emmenegger, Christopher Barner-Kowollik
We introduce a newly designed catechol-based compound and its application for the preparation of homogeneous monomolecular layers as well as for robust assemblies on various substrates. The precisely defined cyclic catechol material (CyCat) was prepared from ortho-dimethoxybenzene in a phenolic resin-like synthesis and subsequent deprotection, featuring molecules with up to 32 catechol units. The CyCat's chemical structure was carefully assessed via matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF), proton nuclear magnetic resonance ((1)H NMR), diffusion ordered spectroscopy (2D DOSY) and high resolution electrospray ionization mass spectrometry (ESI MS) experiments...
January 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Ross McLellan, Alan R Kennedy, Samantha A Orr, Stuart D Robertson, Robert E Mulvey
In reactions restricted previously to a ruthenium catalyst, a 1-lithium-2-alkyl-1,2-dihydropyridine complex is shown to be a competitive alternative dehydrogenation catalyst for the transformation of diamine boranes into cyclic 1,3,2-diazaborolidines, which can in turn be smoothly arylated in good yields. This study established the conditions and solvent dependence of the catalysis through NMR monitoring, with mechanistic insight provided by NMR (including DOSY) experiments and X-ray crystallographic studies of several model lithio intermediates...
December 21, 2016: Angewandte Chemie
Arda Alkan, Sarah Wald, Benoit Louage, Bruno G De Geest, Katharina Landfester, Frederik R Wurm
An important and usually the only function of most surfactants in heterophase systems is stabilizing one phase in another, for example, droplets or particles in water. Surfactants with additional chemical or physical handles are promising in controlling the colloidal properties by external stimuli. The redox stimulus is an attractive feature; however, to date only a few ionic redox-responsive surfactants have been reported. Herein, the first nonionic and noncytotoxic ferrocene-containing block copolymers are prepared, carrying a hydrophilic poly(ethylene glycol) (PEG) chain and multiple ferrocenes in the hydrophobic segment...
December 29, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Yuan Fang, Pavel V Yushmanov, István Furó
Electrophoretic displacement of charged entities phase modulates the spectrum acquired in electrophoretic NMR experiments and this modulation can be presented via 2D FT transformation as 2D MOSY (MObility SpectroscopY) spectra. We compare in various mixed solutions the chemical selectivity provided by 2D MOSY spectra to that provided by 2D DOSY (Diffusion Ordered SpectroscopY) spectra and demonstrate, under the conditions explored, a superior performance of the former method. 2D MOSY compares also favourably to closely related LC-NMR methods...
December 8, 2016: Magnetic Resonance in Chemistry: MRC
Ludmilla Guduff, Ilya Kuprov, Carine van Heijenoort, Jean-Nicolas Dumez
We show that the acquisition of 3D diffusion-ordered NMR spectroscopy (DOSY) experiments can be accelerated significantly with the use of spatial encoding (SPEN). The SPEN DOSY approach is discussed, analysed with numerical simulation, and illustrated on a mixture of small molecules.
December 5, 2016: Chemical Communications: Chem Comm
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