Impact of the HIV-1 env Genetic Context outside HR1–HR2 on Resistance to the Fusion Inhibitor Enfuvirtide and Viral Infectivity in Clinical Isolates

Resistance mutations to the HIV-1 fusion inhibitor enfuvirtide emerge mainly within the drug's target region, HR1, and compensatory mutations have been described within HR2. The surrounding envelope (env) genetic context might also contribute to resistance, although to what extent and through which determinants remains elusive. To quantify the direct role of the env context in resistance to enfuvirtide and in viral infectivity, we compared enfuvirtide susceptibility and infectivity of recombinant viral pairs harboring the HR1–HR2 region or the full Env ectodomain of longitudinal env clones from 5 heavily treated patients failing enfuvirtide therapy. Prior to enfuvirtide treatment onset, no env carried known resistance mutations and full Env viruses were on average less susceptible than HR1–HR2 recombinants. All escape clones carried at least one of G36D, V38A, N42D and/or N43D/S in HR1, and accordingly, resistance increased 11- to 2800-fold relative to baseline. Resistance of full Env recombinant viruses was similar to resistance of their HR1–HR2 counterpart, indicating that HR1 and HR2 are the main contributors to resistance. Strictly X4 viruses were more resistant than strictly R5 viruses, while dual-tropic Envs featured similar resistance levels irrespective of the coreceptor expressed by the cell line used. Full Env recombinants from all patients gained infectivity under prolonged drug pressure; for HR1–HR2 viruses, infectivity remained steady for 3/5 patients, while for 2/5 patients, gains in infectivity paralleled those of the corresponding full Env recombinants, indicating that the env genetic context accounts mainly for infectivity adjustments. Phylogenetic analyses revealed that quasispecies selection is a step-wise process where selection of enfuvirtide resistance is a dominant factor early during therapy, while increased infectivity is the prominent driver under prolonged therapy

Matériaux de transport de trous à base de petites molécules organiques pour cellules photovoltaïques hybrides solides

Issues de la technologie propre aux couches minces, les cellules solaires hybrides sensibilisées par un colorant comptent parmi les plus prometteuses dans le domaine des énergies renouvelables. Elles doivent leur succès non seulement à leur légèreté, à la possibilité de réaliser de grandes surfaces souples, mais aussi à leur rendement photovoltaïque de plus en plus appréciable (12 % avec un électrolyte liquide ; 7 % pour une cellule tout solide à base de verre moléculaire). Cet article met en évidence les progrès récents sur l’utilisation de verres moléculaires comme matériaux de transport de trous pour réaliser des cellules tout solide. En effet, ces derniers doivent posséder des propriétés physiques et chimiques particulières répondant à la fois au fonctionnement d’une cellule photovoltaïque et à sa mise en œuvre. Par un état de l’art, nous citerons et analyserons les caractéristiques de ces nouveaux matériaux

Conductive and photoactive nature of conjugated polymer based on thiophene functionalized thiazole or benzothiadiazole

New poly (thiophene vinyl thiazole) (PTVT) and poly (thiophene vinyl benzothiadiazole) (PTVBT) was synthesized by Wittig condensation route. The absorption maximum of PTVT and PTVBT appeared at 376 and 410 nm in a solution state, and it was red-shifted to 417 and 510 nm in a thin film state. The optical band gaps were 1.7 and 1.5 eV calculated from thin film absorption edges of the polymer. The photoluminescence spectra of PTVT and PTVBT have an emission peak at 457 nm with bluish green and 487 nm with greenish-yellow fluorescence in THF solution. Both polymers showed a short fluorescence decay time (τ1) of 2.31 and 0.73 ns respectively. Furthermore, the aggregation-caused quenching (ACQ) phenomenon observed in both polymers in decreased fluorescence intensity with different water fractions. The lower electrochemical band gaps were achieved for both polymers (1.4, and 1.3 eV) from cyclic voltammetry. Both polymers have a granular shaped morphology with good surface roughness was observed using AFM. High thermal stability was observed with 8% weight loss at 400 °C for PTVT and 6% weight loss at 460°C for PTVBT. The highest electrical conductivity was observed from electrochemical impedance measurement which was 7.68·10–6 Ω–1·cm–1 for PTVBT

Electronic transport in semiconductor nanoparticles for photocatalytic and photovoltaic applications

It is shown by contactless transient photoconductance measurements that electron transport in TiO2 is highly dispersive and is strongly influienced by surface treatments. A fast recombination process is observed after band to band excitation. Oxalic acid absorbed at the surface slows the decay appreciably, as does alcoho

Small molecule organic solar cells based on phthalocyanine/perylene-carbazole donor-acceptor couple.

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P and n dopable carbazole/perylene alternated materials for organic photovoltaic devices.

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Etude de Réseaux Interpenetrés de Polymères (RIP) à base de Gd2O3 :Tb (10%)@ p-tert-butyl-26,28-dihydroxy-25,27-dicarboxymethoxycalix[4+]arene

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Hole-transporting molecular glasses based on carbazole for photovoltaic systems.

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