1,742 research outputs found
High-efficiency orange and yellow organic light-emitting devices using platinum(II) complexes containing extended Ï -conjugated cyclometalated ligands as dopant materials
Two luminescent platinum(II) complexes 1 and 2 containing extended Ï -conjugated cyclometalated ligands have been used as dopant materials for the construction of two high-efficiency organic light-emitting devices I and II. Device I (containing dopant 1) emits orange emission and exhibits a maximum external quantum efficiency of 12.4%, a maximum luminous efficiency of 32.3 cdA, and a maximum power efficiency of 11.2 lmW. Device II (containing dopant 2) emits yellow light and exhibits a maximum external quantum efficiency of 16.1%, a maximum luminous efficiency of 51.8 cdA, and a maximum power efficiency of 23.2 lmW. © 2007 American Institute of Physics.published_or_final_versio
Warning signs for stabilizing global CO2 emissions
Carbon dioxide (CO2) emissions from fossil fuels and industry comprise ~90% of all CO2 emissions from human activities. For the last three years, such emissions were stable, despite continuing growth in the global economy. Many positive trends contributed to this unique hiatus, including reduced coal use in China and elsewhere, continuing gains in energy efficiency, and a boom in low-carbon renewables such as wind and solar. However, the temporary hiatus appears to have ended in 2017. For 2017, we project emissions growth of 2.0% (range: 0.8%â3.0%) from 2016 levels (leap-year adjusted), reaching a record 36.8â±â2 Gt CO2. Economic projections suggest further emissions growth in 2018 is likely. Time is running out on our ability to keep global average temperature increases below 2 °C and, even more immediately, anything close to 1.5â°C
Tectonic influences on late Holocene relative sea levels from the central-eastern Adriatic coast of Croatia
Differential tectonic activity is a key factor responsible for variable relative sea-level (RSL) changes during the late Holocene in the Adriatic. Here, we compare reconstructions of RSL from the central-eastern Adriatic coast of Croatia with ICE-7G_NA (VM7) glacial-isostatic model RSL predictions to assess underlying driving mechanisms of RSL change during the past ⌠2700 years. Local standardized published sea-level index points (n = 23) were combined with a new salt-marsh RSL reconstruction and tide-gauge measurements. We enumerated fossil foraminifera from a short salt-marsh sediment core constrained vertically by modern foraminiferal distributions, and temporally by radiometric analyses providing sub-century resolution within a Bayesian age-depth framework. We modelled changes in RSL using an Errors-In-Variables Integrated Gaussian Process (EIV-IGP) model with full consideration of the available uncertainty. Previously established index points show RSL rising from â1.48 m at 715 BCE to â1.05 m by 100 CE at 0.52 mm/yr (â0.82-1.87 mm/yr). Between 500 and 1000 CE RSL was â0.7 m below present rising to â0.25 m at 1700 CE. RSL rise decreased to a minimum rate of 0.13 mm/yr (â0.37-0.64 mm/yr) at âŒ1450 CE. The salt-marsh reconstruction shows RSL rose âŒ0.28 m since the early 18th century at an average rate of 0.95 mm/yr. Magnitudes and rates of RSL change during the twentieth century are concurrent with long-term tide-gauge measurements, with a rise of âŒ1.1 mm/yr. Predictions of RSL from the ICE-7G_NA (VM7) glacial-isostatic model (â0.25 m at 715 BCE) are consistently higher than the reconstruction (â1.48 m at 715 BCE) during the Late Holocene suggesting a subsidence rate of 0.45 ± 0.6 mm/yr. The new salt-marsh reconstruction and regional index points coupled with glacial-isostatic and statistical models estimate the magnitude and rate of RSL change and subsidence caused by the Adriatic tectonic framework. © 2018 Elsevier Lt
Empirical Bayesian Mixture Models for Medical Image Translation
Automatically generating one medical imaging modality from another is known
as medical image translation, and has numerous interesting applications. This
paper presents an interpretable generative modelling approach to medical image
translation. By allowing a common model for group-wise normalisation and
segmentation of brain scans to handle missing data, the model allows for
predicting entirely missing modalities from one, or a few, MR contrasts.
Furthermore, the model can be trained on a fairly small number of subjects. The
proposed model is validated on three clinically relevant scenarios. Results
appear promising and show that a principled, probabilistic model of the
relationship between multi-channel signal intensities can be used to infer
missing modalities -- both MR contrasts and CT images.Comment: Accepted to the Simulation and Synthesis in Medical Imaging (SASHIMI)
workshop at MICCAI 201
Frozen and Invariant Quantum Discord under Local Dephasing Noise
In this chapter, we intend to explore and review some remarkable dynamical
properties of quantum discord under various different open quantum system
models. Specifically, our discussion will include several concepts connected to
the phenomena of time invariant and frozen quantum discord. Furthermore, we
will elaborate on the relation of these two phenomena to the non-Markovian
features of the open system dynamics and to the usage of dynamical decoupling
protocols.Comment: 29 pages, 8 figure
Evolution of Multidrug Resistance during Staphylococcus aureus Infection Involves Mutation of the Essential Two Component Regulator WalKR
Antimicrobial resistance in Staphylococcus aureus is a major public health threat, compounded by emergence of strains with resistance to vancomycin and daptomycin, both last line antimicrobials. Here we have performed high throughput DNA sequencing and comparative genomics for five clinical pairs of vancomycin-susceptible (VSSA) and vancomycin-intermediate ST239 S. aureus (VISA); each pair isolated before and after vancomycin treatment failure. These comparisons revealed a frequent pattern of mutation among the VISA strains within the essential walKR two-component regulatory locus involved in control of cell wall metabolism. We then conducted bi-directional allelic exchange experiments in our clinical VSSA and VISA strains and showed that single nucleotide substitutions within either walK or walR lead to co-resistance to vancomycin and daptomycin, and caused the typical cell wall thickening observed in resistant clinical isolates. Ion Torrent genome sequencing confirmed no additional regulatory mutations had been introduced into either the walR or walK VISA mutants during the allelic exchange process. However, two potential compensatory mutations were detected within putative transport genes for the walK mutant. The minimal genetic changes in either walK or walR also attenuated virulence, reduced biofilm formation, and led to consistent transcriptional changes that suggest an important role for this regulator in control of central metabolism. This study highlights the dramatic impacts of single mutations that arise during persistent S. aureus infections and demonstrates the role played by walKR to increase drug resistance, control metabolism and alter the virulence potential of this pathogen
Factors related to the incorrect use of inhalers by asthma patients
PereiraResumoObjetivo: Avaliar a tĂ©cnica inalatĂłria em pacientes com asma atendidos ambulatorialmente, estabelecendo associaçÔes dessa com o grau de controle da doença. MĂ©todos: Estudo transversal envolvendo pacientes com idade â„ 14 anos e diagnĂłstico mĂ©dico de asma, recrutados no AmbulatĂłrio de Asma do Hospital de ClĂnicas de Porto Alegre, na cidade de Porto Alegre (RS). Os pacientes completaram dois questionĂĄrios (um geral e um questionĂĄrio de controle da asma baseado nas diretrizes da Global Initiative for Asthma de 2011). Os pacientes demonstraram a tĂ©cnica inalatĂłria e realizaram testes de função pulmonar. A tĂ©cnica inalatĂłria incorreta foi definida como a execução incorreta de pelo menos duas etapas da avaliação. Resultados: Foram incluĂdos 268 pacientes. Desses, 81 (30,2%) apresentaram tĂ©cnica inalatĂłria incorreta, que foi associada com falta de controle da asma (p = 0,002). A regressĂŁo logĂstica identificou os seguintes fatores associados com a tĂ©cnica inalatĂłria incorreta: ser viĂșvo (OR = 5,01; IC95%, 1,74-14,41; p = 0,003); utilizar inalador pressurizado (OR = 1,58; IC95%, 1,35-1,85; p < 0,001); ter renda familiar mensal < 3 salĂĄrios mĂnimos (OR = 2,67; IC95%, 1,35-1,85; p = 0,008); e ter â„ 2 comorbidades (OR = 3,80; IC95%, 1,03-14,02; p = 0,045). ConclusĂ”es: Na amostra estudada, a tĂ©cnica inalatĂłria incorreta se associou com a falta de controle da asma. Viuvez, uso de inalador pressurizado, baixo nĂvel socioeconĂŽmico e presença de â„ 2 comorbidades se associaram Ă tĂ©cnica inalatĂłria incorreta.AbstractObjective: To evaluate inhaler technique in outpatients with asthma and to determine associations between the correctness of that technique and the level of asthma control. Methods: This was a cross-sectional study involving patients â„ 14 years of age with physician-diagnosed asthma. The patients were recruited from the Asthma Outpatient Clinic of the Hospital de ClĂnicas de Porto Alegre, in the city of Porto Alegre, Brazil. The patients completed two questionnaires (a general questionnaire and an asthma control questionnaire based on the 2011 Global Initiative for Asthma guidelines), demonstrated their inhaler technique, and performed pulmonary function tests. Incorrect inhaler technique was defined as the incorrect execution of at least two of the predefined steps. Results: We included 268 patients. Of those, 81 (30.2%) showed incorrect inhaler technique, which was associated with poor asthma control (p = 0.002). Logistic regression analysis identified the following factors associated with incorrect inhaler technique: being widowed (OR = 5.01; 95% CI, 1.74-14.41; p = 0.003); using metered dose inhalers (OR = 1.58; 95% CI, 1.35-1.85; p < 0.001); having a monthly family income < 3 times the minimum wage (OR = 2.67; 95% CI, 1.35-1.85; p = 0.008), and having â„ 2 comorbidities (OR = 3.80; 95% CI, 1.03-14.02; p = 0.045). Conclusions: In the sample studied, incorrect inhaler technique was associated with poor asthma control. Widowhood, use of metered dose inhalers, low socioeconomic level, and the presence of â„ 2 comorbidities were associated with incorrect inhaler technique
New algorithm improves fine structure of the barley consensus SNP map
<p>Abstract</p> <p>Background</p> <p>The need to integrate information from multiple linkage maps is a long-standing problem in genetics. One way to visualize the complex ordinal relationships is with a directed graph, where each vertex in the graph is a bin of markers. When there are no ordering conflicts between the linkage maps, the result is a directed acyclic graph, or DAG, which can then be linearized to produce a consensus map.</p> <p>Results</p> <p>New algorithms for the simplification and linearization of consensus graphs have been implemented as a package for the R computing environment called DAGGER. The simplified consensus graphs produced by DAGGER exactly capture the ordinal relationships present in a series of linkage maps. Using either linear or quadratic programming, DAGGER generates a consensus map with minimum error relative to the linkage maps while remaining ordinally consistent with them. Both linearization methods produce consensus maps that are compressed relative to the mean of the linkage maps. After rescaling, however, the consensus maps had higher accuracy (and higher marker density) than the individual linkage maps in genetic simulations. When applied to four barley linkage maps genotyped at nearly 3000 SNP markers, DAGGER produced a consensus map with improved fine structure compared to the existing barley consensus SNP map. The root-mean-squared error between the linkage maps and the DAGGER map was 0.82 cM per marker interval compared to 2.28 cM for the existing consensus map. Examination of the barley hardness locus at the 5HS telomere, for which there is a physical map, confirmed that the DAGGER output was more accurate for fine structure analysis.</p> <p>Conclusions</p> <p>The R package DAGGER is an effective, freely available resource for integrating the information from a set of consistent linkage maps.</p
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