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Jérémy Salaam, Lilia Tabti, Sylvana Bahamyirou, Alexandre Lecointre, Oscar Hernandez Alba, Olivier Jeannin, Franck Camerel, Sarah Cianférani, Embarek Bentouhami, Aline M Nonat, Loïc J Charbonnière
A series of polynuclear assemblies based on ligand L (1,4,7-tris[hydrogen (6-methylpyridin-2-yl)phosphonate]-1,4,7-triazacyclononane) has been developed. The coordination properties of ligand L with LnIII (Ln = La, Eu, Tb, Yb, Lu) have been studied in water (pH = 7.0) and in D2 O (pD = 7.0) by UV-absorption spectrometry, spectrofluorimetry, 1 H and 31 P NMR, DOSY, ESI-mass spectrometry, and X-ray diffraction. This nonadentate ligand forms highly stable mononuclear complexes in water and provides a very efficient shielding of the Ln cations, as emphasized by the very good luminescence properties of the Yb complex in D2 O, especially regarding its lifetime (τD2 O = 10...
May 10, 2018: Inorganic Chemistry
Dinesh Mishra, Vladislav Lobodin, Chengqi Zhang, Fadi Aldeek, Eric Lochner, Hedi Mattoussi
We detail the characterization of atomically precise, luminescent silver and gold bimetallic nanoclusters (Ag and AgAuNCs) grown in the presence of bidentate lipoic acid (LA, the oxidized form) and dihydrolipoic acid (DHLA, the reduced form) ligands. We found that while doping AuNCs with Ag or Cu precursors using up to a 50% molar fraction (during growth) did not lead to any photoluminescence enhancement, doping of AgNCs with Au resulted in a six-fold enhancement of the PL emission compared to undoped AgNCs...
April 30, 2018: Physical Chemistry Chemical Physics: PCCP
Aurora L Ginzburg, Lisa Truong, Robert L Tanguay, James E Hutchison
Nanoparticle safety is usually determined using solutions of individual particles that are free of additives. However, the size-dependent properties of nanoparticles can be readily altered through interactions with other components in a mixture. In applications, nanoparticles are commonly combined with surfactants or other additives to increase dispersion or to enhance product performance. Surfactants might also influence the biological activity of nanoparticles; however, little is known about such effects...
April 26, 2018: ACS Nano
Kamal Malukani, Amit V Varma, Devashish Choudhary, Shilpi Dosi
Aggressive angiomyxoma (AAM) is an uncommon mesenchymal tumor that predominantly involves the pelvis and perineum of young females. It is often clinically mistaken for more common superficial lesions such as vaginal cysts, labial cysts, and lipomas. A review of the medical literature reveals very few cases of AAM reported in pregnancy. We describe a rare case of AAM in pregnancy, clinically misdiagnosed as prolapsed cervical fibroid.
April 2018: Journal of Laboratory Physicians
Kouhei Nadamoto, Kei Maruyama, Naoka Fujii, Toshiaki Ikeda, Shin-Ichi Kihara, Takeharu Haino
The homopolymeric sequence formed by the head-to-head association of tetrakisporphyrin 1 is completely dissociated via the competitive association of the ditopic guest G2 to result in the supramolecular copolymer poly-1*G2 with an alternatingly repeating host-guest sequence. The 1:1 stoichiometry of 1 and G2 is confirmed by a Job plot using UV/vis titration and diffusion-ordered NMR spectroscopy (DOSY). The solution viscometry for poly-1 and poly-1*G2 suggests that the supramolecular chain of poly-1 behaves like a rod, whereas the supramolecular copolymer chain of poly-1*G2 behaves like a swelled fat chain, which is entangled in the semi-dilute regime...
April 23, 2018: Angewandte Chemie
Patrick Jones, Grace Bennett, Alexios Dosis, Amelia Pietropaolo, Robert Geraghty, Omar Aboumarzouk, Andreas Skolarikos, Bhaskar K Somani
CONTEXT: Day case or ambulatory percutaneous nephrolithotomy (PCNL) has risen over the last few years with the aim of discharging patients within 24h. OBJECTIVE: We perform a systematic review of literature to evaluate the outcomes of day-case PCNL surgery. EVIDENCE ACQUISITION: A Cochrane style search was performed and the following bibliographic databases were accessed: PubMed, Science Direct, Scopus, and Web of Science. This was carried out in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines...
April 12, 2018: European Urology Focus
Marco Campetella, Alessandro Mariani, Claudia Sadun, Boning Wu, Edward W Castner, Lorenzo Gontrani
In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their1 H-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities. However, the magnitude of both phenomena for mixtures of propylammonium nitrate is smaller than those observed for ethylammonium nitrate mixtures with the same cosolvent, suggesting that the cation alkyl tail plays an important role in these observations...
April 7, 2018: Journal of Chemical Physics
Svend Berger, Jürgen Nolde, Timucin Yüksel, Wolfgang Tremel, Mihail Mondeshki
Soluble inorganic aluminium compounds like aluminium sulfate or aluminium chloride have been challenged by the European Chemical Agency to induce germ cell mutagenicity. Before conducting mutagenicity tests, the hydrolysis products in water and in physiological solutions should be determined as a function of the concentration and pH. We used different27 Al NMR spectroscopic techniques (heteronuclear Overhauser effect spectroscopy (HOESY), exchange spectroscopy (EXSY), diffusion ordered (DOSY)) in this work to gain the information to study the aluminium species in solutions with Al₂(SO₄)₃ concentrations of 50...
April 2, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Alistair William Thomas King, Valtteri Mäkelä, Stephanie A Kedzior, Tiina Laaksonen, Gabriel J Partl, Sami Heikkinen, Harri Koskela, Harri August Heikkinen, Ashley John Holding, Emily D Cranston, Ilkka Antero Kilpeläinen
Recent developments in ionic liquid electrolytes for cellulose or biomass dissolution has also allowed for high-resolution1 H and13 C NMR on very high molecular weight cellulose. This permits the development of advanced liquid-state quantitative NMR methods for characterization of unsubstituted and low degree of substitution celluloses, e.g. surface-modified nanocelluloses, which are insoluble in all molecular solvents. As such, we present the use of the tetrabutylphosphonium acetate ([P4444 ][OAc]):DMSO-d6 electrolyte in the 1D and 2D NMR characterization of poly(methylmethacrylate) (PMMA)-grafted cellulose nanocrystals (CNCs)...
April 3, 2018: Biomacromolecules
Anna-Bea Bornhof, Antonio Bauzá, Alexander Aster, Marion Pupier, Antonio Frontera, Eric Vauthey, Naomi Sakai, Stefan Matile
In this report, we demonstrate that synergistic effects between π-π stacking and anion-π interactions in π-stacked foldamers provide access to unprecedented catalytic activity. To elaborate on anion-(π)n -π catalysis, we have designed, synthesized and evaluated a series of novel covalent oligomers with up to four face-to-face stacked naphthalenediimides (NDIs). NMR analysis including DOSY confirms folding into π stacks, cyclic voltammetry, steady-state and transient absorption spectroscopy the electronic communication within the π stacks...
April 2, 2018: Journal of the American Chemical Society
Ramón Medel Jiménez, Juan C Sánchez España, Luz M Vasquez, Alejandra Tapia Bahamondes, Max Rondón, Treserra Francesc, Eva Ayala Barroso
Our objective was to describe our experience with orbital amyloidosis, and illustrate the different forms of presentation. This was a retrospective case series of four patients with biopsy-proven orbital amyloi- dosis, over the period from 2014 to 2016. We describe its diagnostic and clinical characteristics, management and systemic study. The series comprised three women and one man of mean age 52 ± 9.4 years. Affected sites were the lacrimal gland, tarsal conjunctiva, lacrimal sac and orbit. In three of the four patients, calcifications were observed...
March 22, 2018: Orbit
Dong An, Chengchen Guo, Yanan Chen
Analysis of polycyclic aromatic hydrocarbons (PAHs) in air and water sources is a key part of environmental chemistry research, since most PAHs are well known to be associated with negative health impacts on humans. This study explores an approach for analyzing PAH mixtures with advanced nuclear magnetic resonance (NMR) spectroscopic techniques including high-resolution one-dimensional (1D) NMR spectroscopy and diffusion-ordered NMR spectroscopy (DOSY NMR). With this method, different kinds of PAHs can be detected and differentiated from a mixture with high resolution...
March 21, 2018: Materials
D Valenzuela, F Moya, M Luco, J L Tapia
50 years ago, Northway described Broncopulmonary Dysplasia (BPD) in preterm infants exposed to mechanical ventilation. Since then, their survival has increased, nevertheless a "new BPD" has appeared and its incidence has not diminished. One of the characteristics of this pathology is the the abnormal vascular remodeling, which in its most severe expression is known as Pulmonary Hyper tension (PH); with an incidence of 17% in patients with BPD, which is proportional to the severity of the disease (33% in severe BPD), and as mortality factor (up to 48% 2-year mortality in PH-BPD)...
December 2017: Revista Chilena de Pediatría
Kyle A Grice, Graham B Griffin, Phoebus Sun Cao, Cesar Saucedo, Aeshah H Niyazi, Fatimah A Aldakheel, George E Sterbinsky, Robert J LeSuer
The solution-phase structure and electronic relaxation dynamics of zinc bis-8-hydroxyquinoline [Zn(8HQ)2 ] in dimethyl sulfoxide (DMSO) were examined using a broad array of spectroscopic techniques, complimented by ab initio calculations of molecular structure. The ground-state structure was determined using extended X-ray absorption fine structure (EXAFS) data collected on the Zn K-edge and diffusion ordered spectroscopy (DOSY) NMR. The complex was found to be monomeric and octahedral, with two bidentate 8-hydroxyquinolate ligands and two DMSO molecules coordinated to the zinc through oxygen atoms...
March 22, 2018: Journal of Physical Chemistry. A
Yuichiro Uemura, Kairi Yamato, Ryo Sekiya, Takeharu Haino
Graphene quantum dot (GQD)-organic hybrid compounds (GQD-2 b-e) were prepared by introducing 3,4,5-tri(hexadecyloxy)benzyl groups (C16) and linear chains terminated with a 2-ureido-4-[1H]-pyrimidinone (UPy) moiety onto the periphery of GQD-1. GQD-2 b-e formed supramolecular assemblies through hydrogen bonding between the UPy units. GPC analysis showed that GQDs with high loadings of the UPy group formed larger assemblies, and this trend was confirmed by DOSY and viscosity measurements. AFM images showed the polymeric network structures of GQD-2 e on mica with flat structures (ca...
April 23, 2018: Angewandte Chemie
Yulia B Monakhova, Jawed Fareed, Yiming Yao, Bernd W K Diehl
Nuclear magnetic resonance (NMR) spectroscopy is regarded as one of the most powerful and versatile analytical approaches to assure the quality of heparin preparations. In particular, it was recently demonstrated that by using 1 H NMR coupled with chemometrics heparin and low molecular weight heparin (LMWH) samples derived from three major animal species (porcine, ovine and bovine) can be differentiated [Y.B. Monakhova et al. J. Pharm. Anal. 149 (2018) 114-119]. In this study, significant improvement of existing chemometric models was achieved by switching to 2D NMR experiments (heteronuclear multiple-quantum correlation (HMQC) and diffusion-ordered spectroscopy (DOSY))...
May 10, 2018: Journal of Pharmaceutical and Biomedical Analysis
Robert Evans, Guilherme Dal Poggetto, Mathias Nilsson, Gareth A Morris
Diffusion-ordered NMR spectroscopy (DOSY) is increasingly widely used for the analysis of mixtures by NMR spectroscopy, dispersing the signals of different species according to their diffusion coefficients. DOSY is used primarily to distinguish between the signals of different species, with the interpretation of the diffusion coefficients observed usually being purely qualitative, for example to deduce whether one species is bigger or smaller than another. In principle, the actual values of diffusion coefficient obtained carry important information about the sizes of different species and on interactions between species, but the relationship between diffusion coefficient and molecular mass is in general a very complex one...
March 20, 2018: Analytical Chemistry
Hajime Abe, Daisuke Hashikawa, Takaya Minami, Kohei Ohtani, Kentaro Masuda, Shinya Matsumoto, Masahiko Inouye
Coordination cages were composed by self-organization of rigid C3 v -symmetric heptaarene tridentates and Pd(II) precursors. The heptaarene framework involves one mesitylene, three phenol, and three pyridine moieties, which were connected by Suzuki coupling reactions. The treatment of the tridentates with Pd(dppp)(OTf)2 or Pd(en)(NO3 )2 in a 2:3 molar ratio furnished coordination cages, which was ascertained by crystallography, 1 H NMR and DOSY measurements, and ESI-TOFMS and UV-vis spectra. The cages have six phenolic hydroxy groups inside and were expected to incorporate hydrogen-bonding guest molecules such as saccharides...
March 16, 2018: Journal of Organic Chemistry
Felipe Benavente-Villegas, Francisco Ferrando-Roca, Raquel Dolz-Gaitón, María Royo-Peiró
Vemurafenib ha probado ser una herramienta útil en el tratamiento de melanoma metastásico con mutación BRAF-V600E. Los efectos adversos incluyen artralgias, fatiga y toxicidad cutánea, siendo infrecuente la paniculitis. Presentamos el caso de una paciente de 43 años con melanoma metastásico que desarrolla lesiones subcutáneas dolorosas en miembros inferiores y superiores, asociadas a clínica sistémica después de 2 semanas de inicio de tratamiento con Vemurafenib + Cobimetinib. La histología demostró paniculitis linfocitaria septal y lobulillar...
October 15, 2017: Dermatology Online Journal
Isabelle Delsarte, François Delattre, Catherine Rafin, Etienne Veignie
Starch nanoparticles were produced by dialysis method from octenyl succinic anhydre (OSA) and 1,4-butane sultone (BS). The properties of the self-assembled nanoparticles were characterized by NMR spectroscopy (DOSY), fluorescence spectroscopy and dynamic light scattering (DLS). In order to investigate the formation of hydrophobic microdomains, the Nile Red dye was used as a fluorescent probe to evaluate the critical aggregation concentration (CAC) of modified starch in aqueous solution. The results show that the entrapment of the molecular guest was effective and only restricted by the solubility limit of the starch...
April 15, 2018: Carbohydrate Polymers
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