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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 Bailey Griffin, Phoebus Sun Cao, Cesar Saucedo, Aeshah H Niyazi, Fatimah Aldakheel, George E Sterbinsky, Robert J LeSuer
The solution-phase structure and electronic relaxation dynamics of zinc bis-8-hydroxyquinoline [Zn(8HQ)2 ] in dimethylsulfoxide (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 DOSY NMR spectroscopy. 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 6, 2018: Journal of Physical Chemistry. A
Yuichiro Uemura, Kairi Yamato, Ryo Sekiya, Takeharu Haino
Hydrogen bonding has been employed as a powerful tool for developing multi-component assemblies such as supramolecular polymers. We have prepared graphene quantum dot (GQD)-organic hybrid compounds (GQD-2b-e) by introducing 3,4,5-tri(hexadecyloxy)benzyl groups (C16) and linear chains terminated with a 2-ureido-4-[1H]-pyrimidione (UPy) moiety onto the periphery of GQD-1. GQD-2b-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...
March 5, 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 using1 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))...
February 26, 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...
February 26, 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 C3v-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, 1H 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...
February 23, 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
Jiancheng Luo, Kun Chen, Panchao Yin, Tao Li, Gang Wan, Jin Zhang, Songtao Ye, Xiaoman Bi, Yi Pang, Yongge Wei, Tianbo Liu
A series of rod-shaped polyoxometalates (POMs) were chosen to study the effects of cation-π interaction on the macroionic self-assembly. Diffusion Ordered Spectroscopy (DOSY) and Isothermal Titration Calorimetry (ITC) techniques show that the binding affinity between the POMs and Zn2+ ions is enhanced significantly after grafting aromatic groups onto the clusters, leading to the effective replacement of TBAs upon the addition of ZnCl₂. The incorporation of aromatic groups results in the significant contribution of cation-π interaction to the self-assembly, as confirmed by the opposite trend of assembly size vs...
February 13, 2018: Angewandte Chemie
Dulce María Rascón-Martínez, Joaquín Antonio Guzmán-Sánchez, Nora Paulina Corral-Urdapilleta, Gema Damaris Arguelles-Uribe, Jazmín Velázquez-Loeza, Gustavo Soto-Palma, Orlando Carrillo-Torres
Objetivo: Observar el comportamiento de la gabapentina para aminorar la hipertensión reactiva secundaria a ansiedad y dolor en pacientes sometidos a cirugía oftálmica, así como el consumo de opiáceos entre los grupos. Método: Ensayo clínico controlado aleatorizado y doble ciego que analizó a 125 pacientes divididos en tres grupos: grupo A, gabapentina 300 mg; grupo B, gabapentina 450 mg; grupo C, amaranto en grageas como control 2 horas antes del procedimiento quirúrgico...
2018: Gaceta Médica de México
Chak-Shing Kwan, Rundong Zhao, Michel A Van Hove, Zongwei Cai, Ken Cham-Fai Leung
Type III-B rotaxane dendrimers (T3B-RDs) are hyperbranched macromolecules with mechanical bonds on every branching unit. Here we demonstrate the design, synthesis, and characterization of first to third (G1-G3), and up to the fourth (G4) generation (MW > 22,000 Da) of pure organic T3B-RDs and dendrons through the copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. By utilizing multiple molecular shuttling of the mechanical bonds within the sphere-like macromolecule, a collective three-dimensional contract-extend molecular motion is demonstrated by diffusion ordered spectroscopy (DOSY) and atomic force microscopy (AFM)...
February 5, 2018: Nature Communications
Laura Castañar, Guilherme Dal Poggetto, Adam Colbourne, Gareth A Morris, Mathias Nilsson
The GNAT (General NMR Analysis Toolbox) is a free and open-source software package for processing, visualizing and analysing NMR data. It supersedes the popular DOSY Toolbox, which has a narrower focus on diffusion NMR. Data import of most common formats from the major NMR platforms is supported, as well as a GNAT generic format. Key basic processing of NMR data (e.g. Fourier transformation, baseline correction, phasing) is catered for within the programme, as well as more advanced techniques (e.g. reference deconvolution, pure shift FID reconstruction)...
February 2, 2018: Magnetic Resonance in Chemistry: MRC
Anaïs Leproux, Thomas D. O'Sullivan, Albert Cerussi, Amanda Durkin, Brian Hill, Nola Hylton, Arjun G. Yodh, Stefan A. Carp, David Boas, Shudong Jiang, Keith D. Paulsen, Brian Pogue, Darren Roblyer, Wei Yang, Bruce J. Tromberg
We present a framework for characterizing the performance of an experimental imaging technology, diffuse optical spectroscopic imaging (DOSI), in a 2-year multicenter American College of Radiology Imaging Network (ACRIN) breast cancer study (ACRIN-6691). DOSI instruments combine broadband frequency-domain photon migration with time-independent near-infrared (650 to 1000 nm) spectroscopy to measure tissue absorption and reduced scattering spectra and tissue hemoglobin, water, and lipid composition. The goal of ACRIN-6691 was to test the effectiveness of optically derived imaging endpoints in predicting the final pathologic response of neoadjuvant chemotherapy (NAC)...
December 1, 2017: Journal of Biomedical Optics
Ilche Gjuroski, Julien Furrer, Martina Vermathen
Photodynamic Therapy (PDT) with porphyrinic photosensitizers largely relies on efficient drug formulations in order to prevent porphyrin aggregation and enhance water solubility and stability in physiologic environments. In this study, we compare two polymeric carrier systems, polyvinylpyrrolidone (PVP) and block copolymer micelles (BCMs) formed by the poloxamer Kolliphor P188 (KP) for their encapsulation efficiencies of porphyrin- (xPP) and chlorin e6 (xCE) derivatives. Monomerization, loading efficiency and dynamic properties were examined by 1H NMR spectroscopic chemical shift titration, DOSY and T2 relaxation time measurements...
January 31, 2018: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
James A Findlay, C John McAdam, Joshua J Sutton, Dan Preston, Keith C Gordon, James D Crowley
The self-assembly of ligands of different geometries with metal ions gives rise to metallosupramolecular architectures of differing structural types. The rotational flexibility of ferrocene allows for conformational diversity, and, as such, self-assembly processes with 1,1'-disubstituted ferrocene ligands could lead to a variety of interesting architectures. Herein, we report a small family of three bis-bidentate 1,1'-disubstituted ferrocene ligands, functionalized with either 2,2'-bipyridine or 2-pyridyl-1,2,3-triazole chelating units...
January 30, 2018: Inorganic Chemistry
Elisabet Segredo-Morales, Manuel Martin-Pastor, Ana Salas, Carmen Evora, Angel Concheiro, Carmen Alvarez-Lorenzo, Araceli Delgado
The aim of this work was to prepare polypseudorotaxane-based supramolecular gels combining αCD with two temperature-responsive copolymers of different architecture (i.e., linear poloxamer P and X-shaped poloxamine T), at the lowest concentration as possible to form syringeable depots, and to shed light on the self-diffusion and spatial closeness of all components (including water) which in turn may determine the cooperative self-assembly phenomena and the performance of the gels at the macroscopic level. The exchange rate between bound water and bulk water was measured with a novel NMR experiment Water Diffusion Exchange-Diffusion Optimized Spectroscopy (WDE-DOSY)...
January 22, 2018: Bioconjugate Chemistry
Clara Oliveras, Adriana Fortea, Laura Espinosa, Pablo Barrio, Anna Lligoña, Mercè Balcells-Olivero
Las benzodiacepinas se usan para tratar la abstinencia alcohólica siguiendo varias estrategias: dosis descendiente, dosis de carga, tratamiento en función de sintomatología. La carga de diazepam ha demostrado ser un tratamiento válido para la abstinencia alcohólica en ensayos controlados aleatorizados. Tras una búsqueda bibliográfica no sistemática, no hemos encontrado antecedentes en la literatura de una estrategia de carga de diazepam sin posterior administración de benzodiacepinas para el tratamiento de la abstinencia a éstas...
January 15, 2018: Adicciones
Roberto Nolla-Saltiel, Ana M Geer, William Lewis, Alexander J Blake, Deborah L Kays
Group 1 salts containing carbazolido NNN pincer ligands are precatalysts for the dehydrogenation of Me2NH·BH3. NMR monitoring and DOSY studies show a heavy dependence on the metal and solvent, allowing in some cases selective formation of dehydrogenation products consistent with hydrogen liberation.
January 11, 2018: Chemical Communications: Chem Comm
Alla Malinenko, Alban Jonchere, Luc Girard, Sandra Parrès-Maynadié, Olivier Diat, Pierre Bauduin
Owing to their multiple charges and their nanometric size polyoxometalates (POMs) are at the frontier between ions and charged colloids. We investigated here the effect of POM-POM electrostatics repulsions on their self-diffusion in water by varying POM and supporting salt concentrations. The self-diffusion coefficients of two Keggin's POMs: silicotungstate (SiW4-) and phosphotungstate (PW3-) were determined by dynamic light scattering (DLS) and DOSY 1H/31P NMR whereas POM-POM electrostatic repulsions were investigated by the determination of the static structure factors using small angle X-ray scattering (SAXS)...
December 26, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Tarek S Awad, Dalal Asker, Laurence S Romsted
Optimizing the macroscopic properties, shelf-life and stability of emulsion products requires a better understanding of the microstructural characteristics such as the type (nano, micro and macro) and the relative distribution of components (i.e., oil and surfactant) within the emulsion droplets. We used Diffusion-Ordered NMR Spectroscopy (DOSY NMR) to evaluate these characteristics in model oil-in-water emulsion containing Tween 80 and medium chain triglycerides (MCT). At low MCT concentrations, the solutions were transparent but from 1 to 5 wt% MCT, they became translucent then opaque...
December 7, 2017: Journal of Colloid and Interface Science
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