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New hybrid materials featuring the dipolar fragment 6H-indolo[2,3-b]quinoxaline attached to the bulkier polyaromatic hydrocarbons such as fluoranthene, triphenylene, or polyphenylated benzene have been synthesized by a two-step procedure involving Sonogashira and Diels-Alder reactions. They were characterized by absorption, emission, electrochemical, thermal, and theoretical investigations. The electronic properties of the compounds were dominated by the 6H-indolo[2,3-b]quinoxaline chromophore, and the incorporation of polyaromatic hydrocarbons reduces the chances of nonradiative deactivation processes associated with the excited state and improves the emission properties. The compounds displayed cyan emission with moderate quantum efficiency when excited at the absorption maximum. All of the compounds exhibited an irreversible reduction process corresponding to the addition of electron at the quinoxaline segment. They showed moderate thermal stability and glass transition temperature greater than 100 °C. The presence of rigid 6H-indolo[2,3-b]quinoxaline and bulkier polyaromatic hydrocarbon segments enhances the thermal stability and glass transition temperature significantly. Finally, the dyes were successfully applied as an electron-transporting and emitting layer in multilayered organic light-emitting diodes comprising a N,N'-bis(l-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine hole-transporting layer. The cyan emitting devices were characterized by moderate device performance parameters.
RESUMO
Triarylamines containing a 6H-indolo[2,3-b]quinoxaline core and aromatic units such as phenyl, naphthyl, pyrene, anthracene, or fluorene have been synthesized by employing palladium-catalyzed C-N and C-C coupling reactions and characterized by optical absorption and emission spectra, electrochemical behavior, and thermal studies. Even though the electronic absorption spectra of the compounds were influenced by the nature of the peripheral amines, the emission spectra indicated close similarity for the excited states in these compounds. For the derivatives in which the amines were directly anchored on the 6H-indolo[2,3-b]quinoxaline nucleus, the emission appeared to be dominated by the state localized on the 6H-indolo[2,3-b]quinoxaline chromophore, while in the compounds containing the extended conjugation the fluorescence originated from the polyaromatic linker. The compounds displayed green or yellow emission depending on the nature of the amine segment. All of the dyes displayed one-electron quasi-reversible oxidation couple in the cyclic voltammograms, which is attributable to the oxidation of the peripheral amines at the 6H-indolo[2,3-b]quinoxaline core. An additional one-electron oxidation process observable at the high positive potentials for the compounds 7 and 8 probably arises from the oxidation of the arylthiophene segment. The enhanced thermal stability and relatively higher glass transition temperatures observed for these compounds were attributed to the presence of dipolar 6H-indolo[2,3-b]quinoxaline segment. The origin of the optical spectra and the trends observed therein were rationalized using TDDFT simulations.
RESUMO
BACKGROUND: The effect of baseline resistance-associated substitutions (RAS) on the sustained virologic response at 12 weeks (SVR12) among chronic hepatitis C (CHC) patients receiving the second generation, pan-genotypic glecaprevir/pibrentasvir (G/P) regimen is unclear. AIM: To assess the effect of RAS on the SVR12 in CHC patients treated with G/P regimen. METHODS: The EMBASE, MEDLINE and Cochrane central register of controlled trials databases were searched for relevant studies published before 1 March 2019. The principal outcome was to compare the SVR12 in CHC patients with and without baseline RAS, particularly in genotype-1, genotype-3 and direct-acting anti-virals (DAAs) failure patients. The outcomes were pooled using a random-effects model and odds ratio (OR) was calculated. The risk of bias was assessed using the Cochrane risk of bias tools for randomised and nonrandomised interventional studies. RESULTS: After initially identifying 410 studies, 3302 patients from 17 studies were included. Among 50 cases of virologic failures, 48% had genotype-3 infection, 44% genotype-1 infection and 36% DAA-failure patients. Baseline RAS were present in 44(88%) patients. The most common NS5a and NS3 mutations were Y93H and A166S respectively. The odds of SVR12 were significantly reduced in patients with any baseline RAS (NS3 and/or NS5a) (OR 0.32, 95%C I[0.15, 0.65], I2 = 0%) and NS5a substitutions (OR 0.36, 95%CI [0.18,0.73]). The impact of RAS on SVR12 was significant among genotype-3 patients, but not among genotype-1 or DAA-failure cases. The presence of Y93H and A30K mutations significantly impacted SVR12 rates in genotype-3 patients. CONCLUSION: Baseline NS3 or NS5a RAS, especially the NS5a substitutions-A30K, Y93H, decrease the odds of achieving SVR12 in genotype-3 CHC patients.
Assuntos
Antivirais/administração & dosagem , Benzimidazóis/administração & dosagem , Farmacorresistência Viral/genética , Hepatite C Crônica/tratamento farmacológico , Quinoxalinas/administração & dosagem , Sulfonamidas/administração & dosagem , Proteínas não Estruturais Virais/genética , Substituição de Aminoácidos/genética , Ácidos Aminoisobutíricos , Ciclopropanos , Farmacorresistência Viral/fisiologia , Quimioterapia Combinada , Genótipo , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/patologia , Hepatite C Crônica/virologia , Humanos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Ensaios Clínicos Controlados não Aleatórios como Assunto/estatística & dados numéricos , Prolina/análogos & derivados , Pirrolidinas , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Resposta Viral Sustentada , Resultado do TratamentoRESUMO
The inverse problem is studied in multi-body systems with nonlinear dynamics representing, e.g., phase-locked wave systems, standard multimode and random lasers. Using a general model for four-body interacting complex-valued variables we test two methods based on pseudolikelihood, respectively with regularization and with decimation, to determine the coupling constants from sets of measured configurations. We test statistical inference predictions for increasing number of sampled configurations and for an externally tunable temperature-like parameter mimicing real data noise and helping minimization procedures. Analyzed models with phasors and rotors are generalizations of problems of real-valued spherical problems (e.g., density fluctuations), discrete spins (Ising and vectorial Potts) or finite number of states (standard Potts): inference methods presented here can, then, be straightforward applied to a large class of inverse problems. The high versatility of the exposed techniques also concerns the number of expected interactions: results are presented for different graph topologies, ranging from sparse to dense graphs.