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Wilson Luo, Pierangelo Gobbo, Praveen N Gunawardene, Mark Steven Workentin
The ability to regulate small molecule release from metallic nanoparticle substrates offers unprecedented opportunities for nanocarrier-based imaging, sensing, and drug delivery applications. Herein, we report a novel and highly specific release methodology off gold nanoparticle (AuNP) surfaces based on the bioorthogonal Staudinger-Bertozzi ligation. A thiol ligand bearing the molecular cargo - a Rhodamine B dye derivative - was synthesized and used to modify small water soluble 5 nm AuNPs. Upon incorporation into the AuNP monolayer, we observed efficient quenching of the dye emission, resulting in a very low level of fluorescence emission that provided the baseline from which cargo release was monitored...
January 6, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
E Ripley, G Clarke, F Settles
PURPOSE: The phosphocreatine (PCr) recovery rate after exercise is used an index of mitochondrial function in muscle 31P-MRS. We tested the hypothesis that the initial rate of PCr recovery after exercise reflects the equilibrium mitochondrial ATP production rate required to balance ATP requirements during exercise. METHODS: Exercise data is often analyzed by fitting the PCr recovery curve to the Levenberg-Marquardt algorithm to determine the rate constant, k. In this study, the initial rates of change for PCr and inorganic phosphate (Pi) were examined at the beginning and after the end of exercise in the vastus lateralis...
June 2016: Medical Physics
Pietro Buono, Antoine Duval, Luc Averous, Youssef Habibi
In the present work we propose an environmentally friendly approach to transform renewable feedstocks into value-added materials. This transformation pathway is conducted under green conditions, without the use of solvents and catalyst. First, controlled modification of lignin, a major biopolymer present in wood and plants, was achieved through the esterification with 11-maleimidoundecylenic acid (11-MUA), a derivative from ocastor oil that contains maleimide groups. Different degrees of substitution were achieved by using various amounts of the 11-MU acyl chloride leading to an efficient conversion of lignin hydroxyl groups as demonstrated by 1H and 31P NMR analyses...
January 2, 2017: ChemSusChem
Nikunj Satani, Yu-Hsi Lin, Naima Hammoudi, Sudhir Raghavan, Dimitra K Georgiou, Florian L Muller
Inhibition of glycolysis is of great potential for the treatment of cancer. However, inhibitors of glycolytic enzymes with favorable pharmacological profiles have not been forthcoming. Due to the nature of their active sites, most high-affinity transition-state analogue inhibitors of glycolysis enzymes are highly polar with poor cell permeability. A recent publication reported a novel, non-active site inhibitor of the glycolytic enzyme Enolase, termed ENOblock (N-[2-[2-2-aminoethoxy)ethoxy]ethyl]4-4-cyclohexylmethyl)amino]6-4-fluorophenyl)methyl]amino]1,3,5-triazin-2-yl]amino]benzeneacetamide)...
2016: PloS One
Clara Mukuria, Tracey Young, Anju Keetharuth, Simon Borghs, John Brazier
PURPOSE: Preference-based measures are required to measure the impact of interventions for cost-effectiveness analysis. This study assessed the psychometric performance of the EQ-5D-3L in adults with uncontrolled focal (partial-onset) seizures. METHODS: Data from three Phase III studies of an antiepileptic drug (adjunctive brivaracetam; n = 1095) were used. Analysis included correlations between EQ-5D-3L and Quality of Life in Epilepsy Inventory (QOLIE-31P) and seizure frequency...
December 21, 2016: Quality of Life Research
Eva-Maria Bertschler, Christian Dietrich, Jürgen Janek, Wolfgang Schnick
Li18P6N16 was synthesized by reaction of LiPN2 and Li7PN4 at 5.5 GPa and 1273 K employing the multianvil technique. It is the first lithium nitridophosphate obtained by high-pressure synthesis as well as by reaction of two ternary lithium nitrides. The combination of high-pressure conditions with Li3N flux enabled a complete structure determination using single crystal X-ray diffraction. The hitherto unknown tricyclic [P6N16]18- anion is composed of six vertex-sharing PN4 tetrahedra forming one vierer- and two additional dreier-rings...
December 15, 2016: Chemistry: a European Journal
Philip Kensbock, Dan Eugen Demco, Smriti Singh, Khosrow Rahimi, Radu Fechete, Andreas Walther, Annette Monika Schmidt, Martin Möller
In the presence of additives such as etidronic acid (1-hydroxyethane-1,1-diphosphonic acid, HEDP), a process of peptizing of Laponite clay gels takes place. The peptizing process at the molecular level was directly revealed by (31)P and (1)H high-resolution magic-angle sample spinning (HRMAS) NMR spectroscopy. Two NMR spectral components were detected and assigned to free etidronic acid and bound to the Laponite disk edges. Furthermore, with increase of temperature the ratio of bound-to-free etidronic acid increases...
December 21, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Xianzhi Meng, Yunqiao Pu, Chang Geun Yoo, Mi Li, Garima Bali, Doh-Yeon Park, Erica Gjersing, Mark F Davis, Wellington Muchero, Gerald A Tuskan, Timothy J Tschaplinski, Arthur J Ragauskas
In an effort to better understand the biomass recalcitrance, six natural poplar variants were selected as feedstocks based on previous sugar release analysis. Compositional analysis and physicochemical characterizations of these poplars were performed and the correlations between these physicochemical properties and enzymatic hydrolysis yield were investigated. Gel permeation chromatography (GPC) and (13) C  solid state NMR were used to determine the degree of polymerization (DP) and crystallinity index (CrI) of cellulose, and the results along with the sugar release study indicated that cellulose DP likely played a more important role in enzymatic hydrolysis...
November 23, 2016: ChemSusChem
Pierre G Carlier, Benjamin Marty, Olivier Scheidegger, Paulo Loureiro de Sousa, Pierre-Yves Baudin, Eduard Snezhko, Dmitry Vlodavets
Recent years have seen tremendous progress towards therapy of many previously incurable neuromuscular diseases. This new context has acted as a driving force for the development of novel non-invasive outcome measures. These can be organized in three main categories: functional tools, fluid biomarkers and imagery. In the latest category, nuclear magnetic resonance imaging (NMRI) offers a considerable range of possibilities for the characterization of skeletal muscle composition, function and metabolism. Nowadays, three NMR outcome measures are frequently integrated in clinical research protocols...
March 3, 2016: Journal of Neuromuscular Diseases
Mario L Naitana, Sara Nardis, Giuseppe Pomarico, Michele Raggio, Fabrizio Caroleo, Daniel O Cicero, Sara Lentini, Luca Prodi, Damiano Genovese, Saisameera Mitta, Anna Sgarlata, Massimo Fanfoni, Luca Persichetti, Roberto Paolesse
The synthesis, spectroscopic, and optical properties of the water-soluble phosphorus complex of a 2-sulfonato-10-(4-sulfonatophenyl)-5,15-dimesitylcorrole have been investigated. The compound was prepared by adopting a novel strategy for the corrole sulfonation, leading to the regioselective isomer in an almost quantitative yield. The phosphorus coordination has a key role in determining the corrole substitution pattern, limiting the formation of poly-substituted species, which affected the reaction of the corrole free base...
October 27, 2016: Chemistry: a European Journal
Elisa Fabbri, Chee W Chia, Richard G Spencer, Kenneth W Fishbein, David A Reiter, Donnie Cameron, Ariel C Zane, Zenobia A Moore, Marta Gonzalez-Freire, Marco Zoli, Stephanie A Studenski, Rita R Kalyani, Josephine M Egan, Luigi Ferrucci
Whether individuals with insulin resistance (IR) but without criteria for diabetes exhibit reduced mitochondrial oxidative capacity is unclear; addressing this question could guide research for new therapeutics. We investigated 248 participants without diabetes from the Baltimore Longitudinal Study of Aging (BLSA) to determine whether impaired mitochondrial capacity is associated with prediabetes, IR, and duration and severity of hyperglycemia exposure. Mitochondrial capacity was assessed as the postexercise phosphocreatine recovery time constant (τPCr) by (31)P-magnetic resonance spectroscopy, with higher τPCr values reflecting reduced capacity...
January 2017: Diabetes
William L McClennan, Stephanie A Rufh, Justin A M Lummiss, Deryn E Fogg
Sterically accessible Lewis donors are shown to accelerate decomposition during catalysis, for a broad range of Grubbs-class metathesis catalysts. These include benzylidene derivatives RuCl2(NHC)(PCy3)(═CHPh) (Ru-2: NHC = H2IMes, a; IMes, b; H2IPr, c; IPr, d; H2ITol, e) and indenylidene complexes RuCl2(NHC)(PCy3)(═C15H10) (NHC = H2IMes, Ru-2f; IMes, Ru-2g). All of these precatalysts form methylidene complex RuCl2(NHC)(═CH2) Ru-3 as the active species in metathesis of terminal olefins, and generate RuCl2(NHC)(PCy3)(═CH2) Ru-4 as the catalyst resting state...
November 9, 2016: Journal of the American Chemical Society
Hannah Dengel, Crispin Lichtenberg
The synthetic access to cationic bismuth compounds based on simple, monodentate, synthetically useful amido ligands, [Bi(NR2 )2 (L)n ](+) , has been investigated (R=Me, iPr, Ph; L=neutral ligand). With [BPh4 ](-) as a counteranion, the formation of contact ion pairs and subsequent phenyl transfer from B to Bi is observed. An intermediate of this reaction, [Bi(NMe2 )2 (HNMe2 )(BPh4 )] (1), could be isolated and fully characterized. The use of a fluorinated tetraarylborate as a counteranion leads to more stable cationic bismuth amides...
December 19, 2016: Chemistry: a European Journal
Fernando López Ortiz, Jesús García López, María Casimiro, María José Iglesias
The structure of the dianion (SP,RC)-10 formed in the diastereoselective N,Cortho dilithiation of the phosphinimidic amide (RC)-Ph2P(═NCO2Me)NHCH(Me)Ph (5; dr of 95:5) with tert-butyllithium in THF has been elucidated using multinuclear magnetic resonance methods, including 2D (7)Li,(n)X-HMQC ((n)X = (15)N, (31)P) correlations. (SP,RC)-10 consists of a monomer in which C,N and N,O chelation of the lithium cations generates a system containing a five- and a six-membered metallacycle, respectively, sharing a P-N bond with the lithium atoms connected through the NCO moiety of the phosphazenyl group...
November 18, 2016: Journal of Organic Chemistry
Juho Roukala, Simon Orr, John V Hanna, Juha Vaara, Alexander V Ivanov, Oleg N Antzutkin, Perttu Lantto
Polycrystalline bis(dialkyldithiophosphato)Pt(II) complexes of the form Pt{S2P(OR)2}2 (R = ethyl, iso-propyl, iso-butyl, sec-butyl or cyclo-hexyl group) were studied using solid-state 31P and 195Pt NMR spectroscopy to determine the influence of the alkyl substituents to the structure of the central chromophore. Measured anisotropic chemical shift (CS) parameters for 31P and 195Pt tensors afford more detailed chemical and structural information as compared to isotropic NMR parameters, such as chemical shifts and J-couplings, alone...
September 30, 2016: Journal of Physical Chemistry. A
Veronique Deschodt-Arsac, Laurent Arsac, Julie Magat, Jerome Naulin, Bruno Quesson, Pierre Dos Santos
INTRODUCTION: Gradual alterations in cardiac energy balance, as assessed by the myocardial PCr/ATP-ratio, are frequently associated with the development of cardiac disease. Despite great interest for the follow-up of myocardial PCr and ATP content, cardiac MR-spectroscopy in rat models in vivo is challenged by sensitivity issues and cross-contamination from other organs. METHODS: Here we combined MR-Imaging and MR-Spectroscopy (Bruker BioSpec 9.4T) to follow-up for the first time in vivo the cardiac energy balance in the SHR, a genetic rat model of cardiac hypertrophy known to develop early disturbances in cytosolic calcium dynamics...
2016: PloS One
Masha M Rosenberg, Alfred G Redfield, Mary F Roberts, Lizbeth Hedstrom
Guanosine-5'-monophosphate reductase (GMPR) catalyzes the reduction of GMP to IMP and ammonia with concomitant oxidation of NADPH. Here we investigated the structure and dynamics of enzyme-bound substrates and cofactors by measuring (31)P relaxation rates over a large magnetic field range using high resolution field cycling NMR relaxometry. Surprisingly, these experiments reveal differences in the low field relaxation profiles for the monophosphate of GMP compared with IMP in their respective NADP(+) complexes...
October 28, 2016: Journal of Biological Chemistry
Ling Gao, Weina Cui, Pengyuan Zhang, Albert Jang, Wuqiang Zhu, Jianyi Zhang
Utilizing a fast 31P magnetic resonance spectroscopy (MRS) 2-dimensional chemical shift imaging (2D-CSI) method, this study examined the heterogeneity of creatine kinase (CK) forward flux rate of hearts with postinfarction left ventricular (LV) remodeling. Immunosuppressed Yorkshire pigs were assigned to 4 groups: 1) A sham-operated normal group (SHAM, n = 6); 2) A 60 minutes distal left anterior descending coronary artery ligation and reperfusion (MI, n = 6); 3) Open patch group; ligation injury plus open fibrin patch over the site of injury (Patch, n = 6); and 4) Cell group, hiPSCs-cardiomyocytes, -endothelial cells, and -smooth muscle cells (2 million, each) were injected into the injured myocardium pass through a fibrin patch (Cell+Patch, n = 5)...
2016: PloS One
David G Harper, J Eric Jensen, Caitlin Ravichandran, Roy H Perlis, Maurizio Fava, Perry F Renshaw, Dan V Iosifescu
Brain bioenergetic abnormalities have been observed frequently in adults with major depressive disorder (MDD); however, results have been inconsistent regarding whether decreased or increased metabolism was observed. Phosphorus-31 magnetic resonance spectroscopy (31P MRS) allows for the quantification of bioenergetic molecules, containing high-energy phosphates, over the whole brain as well as measuring the differences between gray matter and white matter. We recruited 50 subjects with a current diagnosis of MDD, not currently treated with psychotropic medication, between ages of 18 and 65 (mean±SD age: 43...
October 5, 2016: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
Jian-She Zhu, Nicole E McCormick, Shannon C Timmons, David L Jakeman
Eight fluorinated isosteric α-d-glucopyranosyl 1-phosphate (Glc 1P) analogues have been synthesized. A promiscuity investigation of the thymidylyltransferase Cps2L and the guanidylyltansferase GDP-ManPP with these analogues showed that all were accepted by either enzyme, with the exception of 1,6-diphosphate 6. Kinetic parameters were determined for these analogues using a continuous coupled assay. These data demonstrated the broad substrate promiscuity of Cps2L, with kcat/Km changes for monofluoro substitution at C-2, C-4, and C-6 and difluoro substitution at C-2 within two orders of magnitude...
October 7, 2016: Journal of Organic Chemistry
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