291 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%
Investigations sur une crise de mortalitĂ© Ă Boulogne-sur-Mer (Pas-de-Calais, XVIIIe s.). HypothĂšses dâinterprĂ©tation
La fouille prĂ©ventive du site de lâIlot Saint-Louis Ă Boulogne-sur-Mer (Pas-de-Calais) a livrĂ© sept sĂ©pultures multiples, soit au total 39 individus datĂ©s du dĂ©but du XVIIIe s. La simultanĂ©itĂ© des dĂ©pĂŽts osseux associĂ©e Ă la contemporanĂ©itĂ© des diffĂ©rentes structures et Ă la rĂ©currence du phĂ©nomĂšne nous permet dâinterprĂ©ter ce site comme le rĂ©sultat dâune crise brutale de mortalitĂ©. Sur la base dâarguments historiques, archĂ©ologiques et anthropologiques, nous avons Ă©liminĂ© lâhypothĂšse dâun Ă©pisode belliqueux ou dâune famine et privilĂ©giĂ© celle dâune Ă©pidĂ©mie. La distribution des sexes est Ă©quilibrĂ©e et lâeffectif des adultes est sensiblement identique Ă celui des sujets immatures. Toutefois le rapport des diffĂ©rentes classes dâĂąge dâimmatures fait apparaĂźtre certaines particularitĂ©s lorsquâon le compare Ă celui dâune dĂ©mographie dite « naturelle ». Ces spĂ©cificitĂ©s discutĂ©es au regard de diverses sources (historiques, mĂ©dicales, dĂ©mographiques) nous permettent dâĂ©carter certaines Ă©pidĂ©mies. Seule la variole sâest rĂ©vĂ©lĂ©e ĂȘtre une piste de recherche intĂ©ressante bien quâil ne soit pas possible dâĂ©carter totalement dâautres maladies mal documentĂ©es et pourtant rĂ©currentes pour la pĂ©riode concernĂ©e. Une interprĂ©tation dĂ©finitive de lâĂ©pidĂ©mie responsable des dĂ©cĂšs survenus Ă Boulogne ne pourra ĂȘtre proposĂ©e quâĂ partir de recherches complĂ©mentaires, notamment par une Ă©tude plus complĂšte des sources archivistiques mais Ă©galement par des analyses en palĂ©obiochimie molĂ©culaire permettant lâidentiïŹcation de germes bien spĂ©ciïŹques.Seven simultaneous burials, representing a total of 39 individuals and dated as early as the 18th century, were found at the excavation site of lâIlot Saint-Louis at Boulogne-sur-Mer (Pas-de-Calais). The simultaneity of the bone deposits, the contemporaneity of the different burial structures and the recurrence of the phenomenon lead us to believe that the site is the result of an abrupt peak in mortality. Historical, archaeological and anthropological arguments rule out the hypotheses of war or famine as the cause of this peak, leaving that of an epidemic. Sex distribution is well-balanced and the number of adult and immature individuals is almost identical. However certain peculiarities in the ratio between the different groups of immature individuals and that of a demography considered ânaturalâ become apparent. These peculiarities, when studied historically, medically and demographically, permit us to eliminate certain epidemics from consideration. The most likely proposition would seem to be smallpox, although other poorly documented illnesses, known to be recurrent at that time, cannot be totally excluded. A more precise explanation of the epidemic responsible for the deaths at Boulogne will need further research, particularly a more thorough study of historical records, but also by molecular palaeobiochemical analysis, in order to identify speciïŹc pathogens
Doped and non-doped organic light-emitting diodes based on a yellow carbazole emitter into a blue-emitting matrix
A new carbazole derivative with a 3,3'-bicarbazyl core 6,6'-substituted by dicyanovinylene groups (6,6'-bis(1-(2,2'-dicyano)vinyl)-N,N'-dioctyl-3,3'-bicarbazyl; named (OcCz2CN)2, was synthesized by carbonyl-methylene Knovenagel condensation, characterized and used as a component of multilayer organic light-emitting diodes (OLEDs). Due to its -donor-acceptor type structure, (OcCz2CN)2 was found to emit a yellow light at max=590 nm (with the CIE coordinates x=0.51; y = 0.47) and was used either as a dopant or as an ultra-thin layer in a blue-emitting matrix of 4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi). DPVBi (OcCz2CN)2-doped structure exhibited, at doping ratio of 1.5 weight %, a yellowish-green light with the CIE coordinates (x = 0.31; y = 0.51), an electroluminescence efficiency EL=1.3 cd/A, an external quantum efficiency ext= 0.4 % and a luminance L= 127 cd/m2 (at 10 mA/cm2) whereas for non-doped devices utilizing the carbazolic fluorophore as a thin neat layer, a warm white with CIE coordinates (x = 0.40; y= 0.43), EL= 2.0 cd/A, ext= 0.7 %, L = 197 cd/m2 (at 10 mA/cm2) and a color rendering index (CRI) of 74, were obtained. Electroluminescence performances of both the doped and non-doped devices were compared with those obtained with 5,6,11,12-tetraphenylnaphtacene (rubrene) taken as a reference of highly efficient yellow emitter
Les crùnes déformés de Saint-Etienne (Beaune, CÎte d'Or, Ve-VIe siÚcles). Données archéologiques et anthropologiques
International audienceThe sector of the Saint-Ătienne necropolis (Beaune), reveals the existence of two clearly separated zones which are characterized by different funeral and cultural practices: tomb architecture, archaeological material and artificially deformed crania. This seems to provide evidence of two distinct groups. A preliminary morpho-metrical study of four skulls and the examination of several CT scans of three of them, allow us to confirm the presence of artificial antero-posterior cranial deformations.Le secteur de la nĂ©cropole Saint-Ătienne (Beaune), sur lequel a portĂ© notre Ă©tude, a rĂ©vĂ©lĂ© l'existence de deux zones nettement sĂ©parĂ©es se caractĂ©risant par des pratiques funĂ©raires et culturelles diffĂ©rentes : architecture des tombes, matĂ©riel d'accompagnement et crĂąnes dĂ©formĂ©s artificiellement. Ces diffĂ©rences semblent tĂ©moigner de l'existence de deux groupes distincts. Une Ă©tude prĂ©liminaire morphomĂ©trique de quatre crĂąnes ainsi que l'examen de plusieurs coupes scanographiques de trois d'entre eux, ont permis de confirmer l'existence de dĂ©formations crĂąniennes artificielles de type antĂ©ro-postĂ©rieur
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The human remains from the Lumentxa cave (Lekeitio, Biscay, Northern Iberian Peninsula): Paleobiology, Taphonomy and Chronology
Lumentxa is a classic site in Basque Prehistory, excavated in three different phases during the 20th century, which has yielded evidence of both Pleistocene and Holocene occupations. In this article, we present a detailed study of the human remains from this site including paleobiological, taphonomic, biomechanical and chronological
perspectives. The human assemblage comprises of a minimum number of seven individuals: three subadult and four adults, with both sexes represented, although part of the human collection is currently lost. We have obtained C14 dates from 4 of these 7 individuals indicating a prolonged funerary use of the cave from the Early Neolithic until
the Bronze Age. We observed some biases in the skeletal representation which could be due to differences in the excavation methods between field seasons and/or the action of carnivores, the latter being evident in at least three of the individuals. The taphonomic modifications are typical off those found in the post-abandonment phases in cave funerary contexts. The relatively low number of individuals compared with other
sites in the region and extended timespan over which the remains were deposited suggest that the cave was used only sporadically for funerary purposes. We report the first biomechanical data for a Neolithic individual from the Iberian Peninsula, which show greatest overall similarity to the Neolithic sample from France and Italy. Finally, the broad time period covered by the direct dates and the more complex taphonomic history than was previously assumed for such sites indicate that caution is warranted when assigning sepulchral caves to cultural periods in the Western Pyrenees when no direct 14C dates have been obtained
A novel dietary multi-strain yeast fraction modulates intestinal toll-like-receptor signalling and mucosal responses of rainbow trout (Oncorhynchus mykiss)
This study was conducted to evaluate the mucosal immune responses of rainbow trout when supplementing an experimental formulated feed with multi-strain yeast fraction product (Saccharomyces cerevisiae and Cyberlindnera jardinii). In total, 360 fish (initial BW 23.1 ± 0.2 g) were randomly allotted into three dietary treatments in an 8-week feeding trial. The dietary treatments included basal diet (control) and control + 1.5 g/kg multi-strain yeast fraction product (MsYF) fed continuously and pulsed every two weeks between control and MsYF diet. No negative effects on growth performance of feeding the MsYF supplemented diet were observed. SGR and FCR averaged 2.30 ± 0.03%/day and 1.03 ± 0.03, respectively, across experimental groups. Muscularis thickness in the anterior intestine after 8 weeks of feeding was significantly elevated by 44.3% in fish fed the MsYF continuously, and by 14.4% in fish fed the MsYF pulsed (P 50% increase) intestine were observed after 8 weeks of feeding the MsYF supplemented diet (P10% reduction). The gene expression analysis of the intestine revealed significant elevations in expression of tlr2, il1r1, irak4, and tollip2 after 4 weeks of feeding the MsYF. Significant elevations in effector cytokines tnfα, il10 and tgfÎČ were observed after 4 weeks of feeding the MsYF regime. After 8 weeks significant elevations in the gene expression levels of il1ÎČ, ifnÎł, and il12 were observed in fish fed the MsYF. Likewise, the expression of the transcription factor gata3 was significantly elevated (P<0.01). Supplementation of the multi-strain yeast fraction product positively modulates the intestinal mucosal response of rainbow trout through interaction with toll-like receptor two signalling pathway and potential for increased capacity of delivery of antigens to the underlying mucosal associated lymphoid tissue
Ancient Yersinia pestis genomes from across Western Europe reveal early diversification during the First Pandemic (541â750)
The first historically documented pandemic caused by Yersinia pestis began as the Justinianic Plague in 541 within the Roman Empire and continued as the so-called First Pandemic until 750. Although paleogenomic studies have previously identified the causative agent as Y. pestis, little is known about the bacteriumâs spread, diversity, and genetic history over the course of the pandemic. To elucidate the microevolution of the bacterium during this time period, we screened human remains from 21 sites in Austria, Britain, Germany, France, and Spain for Y. pestis DNA and reconstructed eight genomes. We present a methodological approach assessing single-nucleotide polymorphisms (SNPs) in ancient bacterial genomes, facilitating qualitative analyses of low coverage genomes from a metagenomic background. Phylogenetic analysis on the eight reconstructed genomes reveals the existence of previously undocumented Y. pestis diversity during the sixth to eighth centuries, and provides evidence for the presence of multiple distinct Y. pestis strains in Europe. We offer genetic evidence for the presence of the Justinianic Plague in the British Isles, previously only hypothesized from ambiguous documentary accounts, as well as the parallel occurrence of multiple derived strains in central and southern France, Spain, and southern Germany. Four of the reported strains form a polytomy similar to others seen across the Y. pestis phylogeny, associated with the Second and Third Pandemics. We identified a deletion of a 45-kb genomic region in the most recent First Pandemic strains affecting two virulence factors, intriguingly overlapping with a deletion found in 17th- to 18th-century genomes of the Second Pandemic. © 2019 National Academy of Sciences. All rights reserved
The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths
We present the Planck Sky Model (PSM), a parametric model for the generation
of all-sky, few arcminute resolution maps of sky emission at submillimetre to
centimetre wavelengths, in both intensity and polarisation. Several options are
implemented to model the cosmic microwave background, Galactic diffuse emission
(synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H-II
regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic
Sunyaev-Zeldovich signals from clusters of galaxies. Each component is
simulated by means of educated interpolations/extrapolations of data sets
available at the time of the launch of the Planck mission, complemented by
state-of-the-art models of the emission. Distinctive features of the
simulations are: spatially varying spectral properties of synchrotron and dust;
different spectral parameters for each point source; modeling of the clustering
properties of extragalactic sources and of the power spectrum of fluctuations
in the cosmic infrared background. The PSM enables the production of random
realizations of the sky emission, constrained to match observational data
within their uncertainties, and is implemented in a software package that is
regularly updated with incoming information from observations. The model is
expected to serve as a useful tool for optimizing planned microwave and
sub-millimetre surveys and to test data processing and analysis pipelines. It
is, in particular, used for the development and validation of data analysis
pipelines within the planck collaboration. A version of the software that can
be used for simulating the observations for a variety of experiments is made
available on a dedicated website.Comment: 35 pages, 31 figure
Planck intermediate results. VIII. Filaments between interacting clusters
About half of the baryons of the Universe are expected to be in the form of
filaments of hot and low density intergalactic medium. Most of these baryons
remain undetected even by the most advanced X-ray observatories which are
limited in sensitivity to the diffuse low density medium. The Planck satellite
has provided hundreds of detections of the hot gas in clusters of galaxies via
the thermal Sunyaev-Zel'dovich (tSZ) effect and is an ideal instrument for
studying extended low density media through the tSZ effect. In this paper we
use the Planck data to search for signatures of a fraction of these missing
baryons between pairs of galaxy clusters. Cluster pairs are good candidates for
searching for the hotter and denser phase of the intergalactic medium (which is
more easily observed through the SZ effect). Using an X-ray catalogue of
clusters and the Planck data, we select physical pairs of clusters as
candidates. Using the Planck data we construct a local map of the tSZ effect
centered on each pair of galaxy clusters. ROSAT data is used to construct X-ray
maps of these pairs. After having modelled and subtracted the tSZ effect and
X-ray emission for each cluster in the pair we study the residuals on both the
SZ and X-ray maps. For the merging cluster pair A399-A401 we observe a
significant tSZ effect signal in the intercluster region beyond the virial
radii of the clusters. A joint X-ray SZ analysis allows us to constrain the
temperature and density of this intercluster medium. We obtain a temperature of
kT = 7.1 +- 0.9, keV (consistent with previous estimates) and a baryon density
of (3.7 +- 0.2)x10^-4, cm^-3. The Planck satellite mission has provided the
first SZ detection of the hot and diffuse intercluster gas.Comment: Accepted by A&
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