75 research outputs found
Highly efficient multilayer organic pure-blue-light emitting diodes with substituted carbazoles compounds in the emitting layer
Bright blue organic light-emitting diodes (OLEDs) based on
1,4,5,8,N-pentamethylcarbazole (PMC) and on dimer of N-ethylcarbazole
(N,N'-diethyl-3,3'-bicarbazyl) (DEC) as emitting layers or as dopants in a
4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi) matrix are described. Pure
blue-light with the C.I.E. coordinates x = 0.153 y = 0.100, electroluminescence
efficiency \eta_{EL} of 0.4 cd/A, external quantum efficiency \eta_{ext.} of
0.6% and luminance L of 236 cd/m2 (at 60 mA/cm2) were obtained with PMC as an
emitter and the 2,9-dimethyl-4,7-diphenyl-1,10-phenantroline (BCP) as a
hole-blocking material in five-layer emitting devices. The highest efficiencies
\eta_{EL.} of 4.7 cd/A, and \eta_{ext} = 3.3% were obtained with a four-layer
structure and a DPVBi DEC-doped active layer (CIE coordinates x = 0.158,
y=0.169, \lambda_{peak} = 456 nm). The \eta_{ext.} value is one the highest
reported at this wavelength for blue OLEDs and is related to an internal
quantum efficiency up to 20%
Mutations in MAP3K7 that Alter the Activity of the TAK1 Signaling Complex Cause Frontometaphyseal Dysplasia.
Frontometaphyseal dysplasia (FMD) is a progressive sclerosing skeletal dysplasia affecting the long bones and skull. The cause of FMD in some individuals is gain-of-function mutations in FLNA, although how these mutations result in a hyperostotic phenotype remains unknown. Approximately one half of individuals with FMD have no identified mutation in FLNA and are phenotypically very similar to individuals with FLNA mutations, except for an increased tendency to form keloid scars. Using whole-exome sequencing and targeted Sanger sequencing in 19 FMD-affected individuals with no identifiable FLNA mutation, we identified mutations in two genes-MAP3K7, encoding transforming growth factor β (TGF-β)-activated kinase (TAK1), and TAB2, encoding TAK1-associated binding protein 2 (TAB2). Four mutations were found in MAP3K7, including one highly recurrent (n = 15) de novo mutation (c.1454C>T [ p.Pro485Leu]) proximal to the coiled-coil domain of TAK1 and three missense mutations affecting the kinase domain (c.208G>C [p.Glu70Gln], c.299T>A [p.Val100Glu], and c.502G>C [p.Gly168Arg]). Notably, the subjects with the latter three mutations had a milder FMD phenotype. An additional de novo mutation was found in TAB2 (c.1705G>A, p.Glu569Lys). The recurrent mutation does not destabilize TAK1, or impair its ability to homodimerize or bind TAB2, but it does increase TAK1 autophosphorylation and alter the activity of more than one signaling pathway regulated by the TAK1 kinase complex. These findings show that dysregulation of the TAK1 complex produces a close phenocopy of FMD caused by FLNA mutations. Furthermore, they suggest that the pathogenesis of some of the filaminopathies caused by FLNA mutations might be mediated by misregulation of signaling coordinated through the TAK1 signaling complex
Differentiation syndrome in patients with acute promyelocytic leukemia treated with all- trans retinoic acid and anthracycline chemotherapy: Characteristics, outcome, and prognostic factors
Differentiation syndrome (DS) can be a life-threatening complication in patients with acute promyelocytic leukemia (APL) undergoing induction therapy with all- trans retinoic acid (ATRA). Detailed knowl- edge about DS has remained limited. We present an analysis of the incidence, char- acteristics, prognostic factors, and out- come of 739 APL patients treated with ATRA plus idarubicin in 2 consecutive trials (Programa Espanol de Tratamientos en Hematologíc [PETHEMA] LPA96 and LPA99). Overall, 183 patients (24.8%) ex- perienced DS, 93 with a severe form (12.6%) and 90 with a moderate form (12.2%). Severe but not moderate DS was associated with an increase in mortality. A bimodal incidence of DS was observed, with peaks occurring in the first and third weeks after the start of ATRA therapy. A multivariate analysis indicated that a WBC count greater than 5 x 109/L and an abnor- mal serum creatinine level correlated with an increased risk of developing severe DS. Patients receiving systematic pred- nisone prophylaxis (LPA99 trial) in con- trast to those receiving selective prophy- laxis with dexamethasone (LPA96 trial) had a lower incidence of severe DS. Pa- tients developing severe DS showed a reduced 7-year relapse-free survival in the LPA96 trial (60% vs 85%, P = .003), but this difference was not apparent in the LPA99 trial
Characteristics and outcome of patients with low-/intermediate-risk acute promyelocytic leukemia treated with arsenic trioxide - an international collaborative study
The aim of this study was to characterize a large series of 154 patients with acute promyelocytic leukemia (APL; median age, 53 years; range, 18-90 years) and evaluate real-life outcome after up-front treatment with arsenic trioxide (ATO) and alltrans retinoic acid (ATRA). All patients were included in the prospective NAPOLEON registry (NCT02192619) between 2013 and 2019. APL was de novo in 91% (n=140) and therapy-related in 9% (n=14); 13% (n=20) were older than 70 years. At diagnosis bleeding/hemorrhage was present in 38% and thrombosis in 3%. Complete remission was achieved in 152 patients (99%), whereas two patients (1%) experienced induction death within 18 days after start of therapy. With a median follow-up of 1.99 years (95%-CI, 1.61-2.30 years) 1-year and 2-years overall survival (OS) rates were 97% (95%-CI, 94-100%) and 95% (95%-CI, 91-99%), respectively. Age above 70 years was associated with a significantly shorter OS (P<0.001) as compared to younger patients. So far no relapses were observed. Six patients (4%) died in CR after in median 0.95 years after diagnosis (range, 0.18-2.38 years). Our data confirm the efficiency and durability of ATO/ATRA in the primary management of adult low-/ intermediate-risk APL patients in the real life setting, irrespective of age
Skeletal manifestations of Marfan syndrome associated to heterozygous R2726W FBN1 variant: sibling case report and literature review
Polycroconaines de benzobisthiazoles : polymères à faible GAP ?
Des polycroconaines de N,N'-didodécylbenzobisthiazole angulaire (I) et de N,N'-dipropylsulfonate benzobisthiazole centro-symétrique (II) ont été synthétisées par condensation de
Knoevenagel et caractérisées. La polycroconaine (I) est soluble en milieu organique, alors que la polycroconaine (II) est pratiquement insoluble tant en milieu organique qu'en milieu aqueux. La
comparaison des caractéristiques spectroscopiques visible-proche IR des matériaux avec celles des molécules modèles a permis de montrer que dans ces polymères la conjugaison est limitée
une unité? structurale, le véritable gap se situant des énergies supérieures à 0,85 eV
Copolymères (carbazolylène-pyrrolylène) : synthèse par oxydation chimique et propriétés
Les conditions dans lesquelles des copolymères statistiques (carbazo lylène-pyrrolylène) pouvaient être synthétisés directement par oxydation chimique par FeCl3 ont été étudiées. Des quantités
substantielles de copolymères solubles en milieu organique sont obtenues par extraction lorsque les proportions molaires en réactifs carbazole/pyrrole/2 FeCl3 sont utilisées. Une fraction
importante de polypyrrole est obtenue à côté d'une fraction d'espèces solubles dans l'éthanol (carbazole et son dimère) et d'une fraction de produits solubles dans l'eau (pyrrole et les premiers
termes oligomères). Les copolymères solubles ont été caractérisés par CES, spectroscopies RMN et UV-Visible. L'analyse voltampérométrique de ces matériaux révèle qu'ils possèdent à la
fois les caractéristiques des entités carbazolylènes et celles des entités pyrrolylènes
Réalisation de réseaux sur polymères par laser UV
Nous présentons ici une méthode très simple de réalisation de réseaux d'amplitude de pas sub-micronique
sur des films polymères à base de carbazote déposés sur des substrat de silice. Les réseaux sont fabriqués en irradiant avec un
faisceau laser à 193 nm un masque de phase placé au contact du film. La qualité des réseaux obtenus permet désormais
d'envisager la réalisation de micro-cavités lasers de type planaire permettant de sélectionner une émission laser monomode
autour de 400 nm
Electroactive multifunctional telechelic stairs-shaped poly(bicarbazyl-alkylene)s
Chemical oxidation of α,ω-bis(N-carbazolyl)alkanes by FeCl3 in the presence of N-(ω-functional alkyl)carbazoles allowed the obtention of telechelic stairs-shaped poly(bicarbazyl-alkylene)s bearing terminal groups such as halogens, nitrile, carboxylic acid. High molar masses materials were obtained exhibiting a particularly good solubility in organic solvents due to their special architecture. Electrochemical studies disclosed that redox polymers were obtained displaying a remarkable colourlessgreenblue electrochromism. Furthermore materials could be used as a blue lightemitting layer into diodes
Synthesis and blue luminescence of a soluble newly designed carbazole main-chain polymer
A new electroactive polymer with alternating conjugated–nonconjugated repeating units in the main chain was synthesized by step growth polymerization of α,ω-bis(N-carbazolyl)octane in chloroform solution with excess of iron trichloride, and in the presence of N-ethylcarbazole as a terminating agent. The resulting α,ω-N-ethylcarbazole terminated poly(3,3′-bicarbazyl-N,N′-octylene)s are readily soluble in common organic solvents and have good film-forming capabilities, partly because of the special design of the polymer backbone constituted by stiff bicarbazyl chromophores linked by flexible eight-carbon segments. Soluble materials with molecular weights up to 105 g/mol and polydispersity indices around 3.3 were obtained. Purified samples exhibiting quite low polydispersity indices (in the range 1.5–1.7) can be prepared by a selective fractionation of the crude polymer from benzene/methanol mixtures. Structural analysis of these new ‘stairs-like’ polymers disclosed their well-defined character with an aromatic linkage exclusively at position 3 on the carbazole moieties. Electrochemical studies of polymer films exhibited two reversible redox processes between 0 and 1.5 V vs saturated calomel electrode. The photoluminescence (PL) of the polymer in solution and as cast films revealed an intense blue emission and the same intensity level than that of the N,N′-diethyl-3,3′-bicarbazyl molecule, taken as a model of the aromatic segment of the repeating unit. Such a processable and purifiable polymer with bicarbazyl-isolated fluorophores is quite promising for the fabrication of efficient blue light-emitting devices
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