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141.
Peter G. K. Clark Dr. Lucas C. C. Vieira Dr. Cynthia Tallant Dr. Oleg Fedorov Dr. Dean C. Singleton Dr. Catherine M. Rogers Octovia P. Monteiro James M. Bennett Dr. Roberta Baronio Dr. Susanne Müller Dr. Danette L. Daniels Jacqui Méndez Prof. Dr. Stefan Knapp Dr. Paul E. Brennan Prof. Dr. Darren J. Dixon 《Angewandte Chemie (International ed. in English)》2015,54(21):6217-6221
The bromodomain‐containing proteins BRD9 and BRD7 are part of the human SWI/SNF chromatin‐remodeling complexes BAF and PBAF. To date, no selective inhibitor for BRD7/9 has been reported despite its potential value as a biological tool or as a lead for future therapeutics. The quinolone‐fused lactam LP99 is now reported as the first potent and selective inhibitor of the BRD7 and BRD9 bromodomains. Development of LP99 from a fragment hit was expedited through balancing structure‐based inhibitor design and biophysical characterization against tractable chemical synthesis: Complexity‐building nitro‐Mannich/lactamization cascade processes allowed for early structure–activity relationship studies whereas an enantioselective organocatalytic nitro‐Mannich reaction enabled the synthesis of the lead scaffold in enantioenriched form and on scale. This epigenetic probe was shown to inhibit the association of BRD7 and BRD9 to acetylated histones in vitro and in cells. Moreover, LP99 was used to demonstrate that BRD7/9 plays a role in regulating pro‐inflammatory cytokine secretion. 相似文献
142.
Macedo Jde S da Costa Júnior NB Almeida LE Vieira EF Cestari AR Gimenez Ide F Villarreal Carreño NL Barreto LS 《Journal of colloid and interface science》2006,298(2):515-522
Mesoporous activated carbon has been prepared from coconut coir dust as support for adsorption of some model dye molecules from aqueous solutions. The methylene blue (MB) and remazol yellow (RY) molecules were chosen for study of the adsorption capacity of cationic and anionic dyes onto prepared activated carbon. The adsorption kinetics was studied with the Lagergren first- and pseudo-second-order kinetic models as well as the intraparticle diffusion model. The results for both dyes suggested a multimechanism sorption process. The adsorption mechanisms in the systems dyes/AC follow pseudo-second-order kinetics with a significant contribution of intraparticle diffusion. The samples simultaneously present acidic and basic sites able to act as anchoring sites for basic and acidic dyes, respectively. Calorimetric studies reveal that dyes/AC interaction forces are correlated with the pH of the solution, which can be related to the charge distribution on the AC surface. These AC samples also exhibited very short equilibrium times for the adsorption of both dyes, which is an economically favorable requisite for the activated carbon described in this work, in addition to the local abundance of the raw material. 相似文献
143.
Analysis of a system related to a model for phase transitions in dissipative isochoric thermoviscoelastic materials 下载免费PDF全文
Welington Vieira Assunção José Luiz Boldrini 《Mathematical Methods in the Applied Sciences》2017,40(10):3504-3527
We analyze a highly nonlinear system of partial differential equations related to a model solidification and/or melting of thermoviscoelastic isochoric materials with the possibility of motion of the material during the process. This system consists of an internal energy balance equation governing the evolution of temperature, coupled with an evolution equation for a phase field whose values describe the state of material and a balance equation for the linear moments governing the material displacements. For this system, under suitable dissipation conditions, we prove global existence and uniqueness of weak solutions. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
144.
Maria de Ftima Vieira Marques Carla Camargo Pombo Rodrigo Azevedo Silva Anunciata Conte 《Journal of polymer science. Part A, Polymer chemistry》2002,40(17):2979-2986
In this work, propylene was polymerized with isospecific and syndiospecific catalysts in homogeneous and heterogeneous systems. The binary metallocene system of both isospecific and syndiospecific catalysts in the heterogeneous system was also used. Besides the type of catalyst, parameters such as polymerization temperature and pressure were varied to achieve the better conditions for the polymerization. The objective of this work is to investigate the influence of these parameters on the characteristics of the produced polymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2979–2986, 2002 相似文献
145.
Fabrício Lopes Sanchez Sylvio Barbon Júnior Lucimar Sasso Vieira Rodrigo Capobianco Guido Everthon Silva Fonseca Paulo Rogério Scalassara Carlos Dias Maciel José Carlos Pereira Shi-Huang Chen 《Journal of Computational and Applied Mathematics》2009
In this paper we present a new wavelet-based algorithm for low-cost computation of the cepstrum. It can be used for real time precise pitch determination in automatic speech and speaker recognition systems. Many wavelet families are examined to determine the one that works best. The results confirm the efficacy and accuracy of the proposed technique for pitch extraction. 相似文献
146.
Humenny WJ Mitzinger S Khadka CB Najafabadi BK Vieira I Corrigan JF 《Dalton transactions (Cambridge, England : 2003)》2012,41(15):4413-4422
The ligation of a N-heterocyclic carbene (NHC) to group 11 metal salts (Cu, Ag) was explored as an alternative to PR(3) ligands for the formation of copper- and silver-chalcogenolate cluster complexes. AgOAc and CuCl salts ligate with the NHC 1,3-di-isopropylbenzimidazole-2-ylidene ((i)Pr(2)-bimy) forming [Ag(OAc)((i)Pr(2)-bimy)] 1, [Ag(OAc)((i)Pr(2)-bimy)(2)] 2, [CuCl((i)Pr(2)-bimy)](2)3 and [CuCl((i)Pr(2)-bimy)(2)] 4 depending on the ratio of ligand to metal used. These have been characterized via spectroscopic and crystallographic methods. Complexes 1 and 3 were reacted with S(Ph)SiMe(3) and Se(Ph)SiMe(3) to form the polynuclear metal-chalcogenolates [Ag(4)(μ-EPh)(4)((i)Pr(2)-bimy)(4)] (5, E = S; 6, E = Se) and [Cu(3)(μ-EPh)(3)((i)Pr(2)-bimy)(3)] (7, E = S; 8, E = Se) in good yields. The structures of 5-8, as determined by single crystal X-ray crystallography, are described. 相似文献
147.
Eduardo Zapp Daniela Brondani Iolanda C. Vieira Jairton Dupont Carla W. Scheeren 《Electroanalysis》2011,23(3):764-776
A matrix comprising iridium nanoparticles and 1‐butyl‐3‐methylimidazolium tetrafluoroborate ionic liquid (Ir‐BMI.BF4) supported in montmorillonite (MMT) was obtained through an efficient incorporation process. This modified clay matrix (Ir‐BMI.BF4‐MMT) was used for the immobilization of the enzymes laccase (LAC) and polyphenol oxidase (PPO) and employed in the construction of a bi‐enzymatic biosensor for determination of rutin by square‐wave voltammetry. Under optimized conditions, the analytical curve showed a linear range for rutin concentrations from 9.17×10?8 to 3.10×10?6 mol L?1 with a detection limit of 3.09×10?8 mol L?1. The method was successfully applied to the determination of rutin content in pharmaceutical samples. 相似文献
148.
Hugo Gallardo Fernando R. Bryk André A. Vieira Tiago E. Frizon Gilmar Conte Bruno S. Souza 《Liquid crystals》2013,40(8):839-845
The thermal and optical properties of two series of unsymmetrical liquid crystalline compounds based on an isoxazole ring are described. Of these materials, 3–7 and 8–12 displayed strong absorption at 285 nm and a weak blue fluorescence in solution at around 377 nm, even with the presence of a high conjugated core. The fluorescence quantum yields observed varied from low to moderate (Φ F ?=?1–62%), with large Stokes shifts (60–178 nm). All compounds exhibited liquid crystalline behaviour with a wide mesomorphism temperature range and characteristic phases of calamitic compounds, among them smectic A (SmA), smectic C (SmC) and nematic (N) phases. Their phases were characterised using polarising optical microscopy and differential scanning calorimetry. In addition, with X-ray diffraction experiments, layer spacing of 33.3–40.0 Å were observed for the smectic phases. 相似文献
149.
A new tetranuclear copper(II) complex which mimics the active site of catechol oxidase was synthesized and characterized by IR, CHN, electronic spectroscopic and 1H NMR methods. The title complex [Cu2(μ-OH)(bpbpmp-NO2)]2[ClO4]2 was employed in the construction of a novel biomimetic sensor and used in the determination of chlorogenic acid by square wave voltammetry. The performance and optimization of the resulting biomimetic sensor were studied in detail. The best response of this sensor was obtained for 75:15:10% (w/w/w) ratio of the graphite powder:nujol:Cu(II) complex, 0.1 mol L−1 phosphate buffer solution (pH 7.0), with frequency, pulse amplitude, and scan increment at 30 Hz, 100 mV, and 3.0 mV, respectively. The chlorogenic acid concentration was linear in the range of 5.0 × 10−6 to 1.45 × 10−4 mol L−1 (r = 0.9985) with a detection limit of 8.0 × 10−7 mol L−1. This biomimetic sensor demonstrated long-term stability (250 days; 640 determinations) and reproducibility, with a relative standard deviation of 10.0%. The recovery study of chlorogenic acid in coffee samples gave values from 93.2% to 106.1% and the concentrations determined showed good agreement when compared with those obtained using capillary electrophoresis at the 95% confidence level. 相似文献
150.
L. C. Courrol R. E. Samad L. Gomes I. M. Ranieri S. L. Baldochi A. Z. Freitas S. P. Morato N. D. Vieira Jr. 《Laser Physics》2006,16(2):331-335
Color centers are lattice vacancy defects trapping electrons or holes. They are easily created in single crystals by irradiation with ionizing radiation. We report the production of color centers in LiF and LiYF4 single crystals by ultrashort high-intensity laser pulses (60 fs, 12.5 GW). An intensity threshold for color center creation of 1.9 and 2 TW/cm2 was determined in YLF and LiF, respectively, which is slightly smaller than the continuum generation threshold. Due to the high energy density of the coherent radiation of the focused laser beam, we were able to identify a large amount of F centers, which gave rise to aggregates such as F2, F 2 + , and F 3 + . The proposed mechanism of formation is based on multiphoton excitation, which also produces short-lived F 2 + centers. It is also shown that it is possible to write tracks in the LiF crystals with dimensional control. 相似文献