1,360 research outputs found
Nível de concordância entre subespecialistas de glaucoma latino-americanos sobre o diagnóstico e tratamento do glaucoma: resultados de uma pesquisa digital
PURPOSE: The aim of this research was to assess the level of agreement among glaucoma experts in Latin America on key practices related to treatment and diagnosis of glaucoma. METHODS: An online questionnaire was sent to a multinational panel of glaucoma experts. The questionnaire contained 107 statements on the medical treatment (Part 1) and diagnosis (Part 2) of glaucoma, and was developed in Spanish and translated into English. Agreement was defined as >70% of respondents. RESULTS: Fifty participants from 14 countries completed the questionnaire. For the medical treatment of glaucoma, nearly all respondents (98% or greater) confirmed that medical treatment as first-line therapy is preferred to surgery, prostaglandin analogs are the medication of first choice for primary open-angle glaucoma (POAG), longitudinal monitoring of efficacy should include intraocular pressure, structural and functional status, as well as if patients' quality of life is impaired by the high cost of medication. For the diagnosis of glaucoma section, all respondents confirmed that, after initial examination, gonioscopy should be repeated over time, standard automated perimetry is the most important functional examination for diagnosis and monitoring of primary open-angle glaucoma, central corneal thickness is important in assessment of glaucoma, and computerized imaging tests help in clinical evaluation of optic disc. CONCLUSIONS: This survey shows a high level of agreement on most aspects of glaucoma diagnosis and treatment among Latin American glaucoma experts. Areas of disagreement highlight the need for further evidence or education. These findings will be useful for guiding future efforts to optimize glaucoma practice by clinicians in Latin America.OBJETIVO: Avaliar o nível de concordância entre os especialistas de glaucoma na América Latina sobre as práticas mais importantes relacionadas ao tratamento e diagnóstico de glaucoma. MÉTODOS: Um questionário digital foi enviado a um painel multinacional de especialistas em glaucoma. O questionário continha 107 declarações sobre o tratamento médico (Parte 1) e diagnóstico (Parte 2) de glaucoma, e foi desenvolvido em espanhol e traduzido para o Inglês. Concordância foi definida como > 70% dos entrevistados. RESULTADOS: Cinquenta participantes de 14 países responderam ao questionário. Para o tratamento médico de glaucoma, quase todas as respostas (98% ou mais), confirmaram que o tratamento médico como terapia de primeira linha é preferido para a cirurgia, os análogos das prostaglandinas são os medicamentos de primeira escolha para o glaucoma primário de ângulo aberto (GPAA), a monitoração longitudinal eficácia deve incluir a pressão intraocular o estado estrutural e funcional além da qualidade de vida do paciente ser prejudicada pelo alto custo da medicação. Para a seção sobre o diagnóstico de glaucoma, todos os entrevistados confirmaram que, após análise inicial, a gonioscopia deve ser repetida ao longo do tempo, a perimetria automatizada padrão é o exame funcional mais importante para o diagnóstico e monitoramento do glaucoma primário de ângulo aberto, a espessura corneana central é importante na avaliação do glaucoma e exames de imagem computadorizados ajudam na avaliação clínica do disco óptico. CONCLUSÕES: Este estudo mostra um alto nível de concordância na maioria dos aspectos do diagnóstico e tratamento de glaucoma entre os especialistas em glaucoma latino-americanos. Áreas de desacordo destacam a necessidade de novas evidências ou educação. Estes resultados serão úteis para orientar futuros esforços na otimização de práticas em relação ao glaucoma por médicos da América Latina.Hospital Oftalmologico Santa LuciaUniversidade Federal de São Paulo (UNIFESP)Universidade de São PauloUniversity of Buenos Aires School of Medicine Hospital de ClinicasInstituto de Glaucoma y CatarataHospital Universitario AustralUNIFESPSciEL
Raman Fingerprints of Atomically Precise Graphene Nanoribbons.
Bottom-up approaches allow the production of ultranarrow and atomically precise graphene nanoribbons (GNRs) with electronic and optical properties controlled by the specific atomic structure. Combining Raman spectroscopy and ab initio simulations, we show that GNR width, edge geometry, and functional groups all influence their Raman spectra. The low-energy spectral region below 1000 cm(-1) is particularly sensitive to edge morphology and functionalization, while the D peak dispersion can be used to uniquely fingerprint the presence of GNRs and differentiates them from other sp(2) carbon nanostructures.We acknowledge funding from: the Alexander von Humboldt Foundation in the framework of the Sofja Kovalevskaja Award, endowed by the Federal Ministry for Education and Research of Germany; the ESF project GOSPEL (Ref. No. 09-EuroGRAPHENE-FP-001); the European Research Council (grant NOC-2D, NANOGRAPH, and Hetero2D); the Italian Ministry of Research through the national projects PRIN-GRAF (Grant No. 20105ZZTSE) and FIRB-FLASHit (Grant No. RBFR12SWOJ); the DFG Priority Program SPP 1459; the Graphene Flagship (Ref. No. CNECT-ICT-604391); the EU project MoQuaS; EPSRC Grants (EP/K01711X/1, EP/K017144/1); the EU grant GENIUS; a Royal Society Wolfson Research Merit Award. Computer time was granted by PRACE at the CINECA Supercomputing Center (Grant No. PRA06 1348), and by the Center for Functional Nanomaterials at Brookhaven National Laboratory, supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under contract number DE-SC0012704.This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/acs.nanolett.5b0418
First-principles modeling of the polycyclic aromatic hydrocarbons reduction
Density functional theory modelling of the reduction of realistic
nanographene molecules (C42H18, C48H18 and C60H24) by molecular hydrogen
evidences for the presence of limits in the hydrogenation process. These limits
caused the contentions between three-fold symmetry of polycyclic aromatic
hydrocarbon molecules and two-fold symmetry of adsorbed hydrogen pairs.
Increase of the binding energy between nanographenes during reduction is also
discussed as possible cause of the experimentally observed limited
hydrogenation of studied nanographenes.Comment: 18 pages, 7 figures, accepted to J. Phys. Chem.
Heterostructures produced from nanosheet-based inks.
The new paradigm of heterostructures based on two-dimensional (2D) atomic crystals has already led to the observation of exciting physical phenomena and creation of novel devices. The possibility of combining layers of different 2D materials in one stack allows unprecedented control over the electronic and optical properties of the resulting material. Still, the current method of mechanical transfer of individual 2D crystals, though allowing exceptional control over the quality of such structures and interfaces, is not scalable. Here we show that such heterostructures can be assembled from chemically exfoliated 2D crystals, allowing for low-cost and scalable methods to be used in device fabrication.This work was supported by The Royal Society, U.S. Army, European Science Foundation (ESF) under the EUROCORES Programme EuroGRAPHENE (GOSPEL), European Research Council, and EC under the Graphene Flagship (contract no. CNECT-ICT-604391). Y.-J.K.’s work was supported by the Global Research Laboratory (GRL) Program (2011-0021972) of the Ministry of Education, Science and Technology, Korea. F.W. acknowledges support from the Royal Academy of Engineering; A.F. is a FRS-FNRS Research Fellow
Fish fillet authentication by image analysis
The work aims at developing an image analysis procedure able to distinguish high value fillets of Atlantic
cod (Gadus morhua) from those of haddock (Melanogrammus aeglefinus). The images of fresh G. morhua
(n \ubc 90) and M. aeglefinus (n \ubc 91) fillets were collected by a flatbed scanner and processed at different
levels. Both untreated and edge-based segmented (Canny algorithm) regions of interest were submitted
to surface texture evaluation by Grey Level Co-occurrence Matrix analysis. Twelve surface texture variables
selected by Principal Component Analysis or by SELECT algorithm were then used to develop Linear
Discriminant Analysis models. An average correct classification rate ranging from 86.05 to 92.31% was
obtained in prediction, irrespective the use of raw or segmented images. These findings pave the way for
a simple machine vision system to be implemented along fish market chain, in order to provide
stakeholders with a simple, rapid and cost-effective system useful in fighting commercial frauds
Continuous-distribution puddle model for conduction in trilayer graphene
An insulator-to-metal transition is observed in trilayer graphene based on
the temperature dependence of the resistance under different applied gate
voltages. At small gate voltages the resistance decreases with increasing
temperature due to the increase in carrier concentration resulting from thermal
excitation of electron-hole pairs. At large gate voltages excitation of
electron-hole pairs is suppressed, and the resistance increases with increasing
temperature because of the enhanced electron-phonon scattering. We find that
the simple model with overlapping conduction and valence bands, each with
quadratic dispersion relations, is unsatisfactory. Instead, we conclude that
impurities in the substrate that create local puddles of higher electron or
hole densities are responsible for the residual conductivity at low
temperatures. The best fit is obtained using a continuous distribution of
puddles. From the fit the average of the electron and hole effective masses can
be determined.Comment: 18 pages, 5 figure
The colors of ideology: Chromatic isomorphism and political party logos
Despite growing attention to electoral brands, political scientists have largely remained "color blind," neglecting parties' chromatic choices. Moreover, scholars dedicated limited attention to how party organizations converge on the use of similar structures and communication strategies, thereby engaging in a process of institutional isomorphism. We seek to simultaneously fill both gaps by examining the logos of more than 300 parties in 35 democracies during the latest political elections. Our findings show that a strong relationship exists between ideology and the use of certain color hues: left-wing party logos mainly display hues at the red end of the color spectrum, while blue hues prevail among right-wing parties. Likeminded parties' chromatic isomorphism, however, is moderated by country and party-specific factors. Notably, the correlation between color hue and ideology is stronger in Western Europe and among older parties
Effect of fresh pork meat conditioning on quality characteristics of salami
The aim of this work was to evaluate the effect of pork meat conditioning under different relative humidity (RH) values on salami quality characteristics. During a 6 days conditioning period at 0 \ub0C under two levels of RH (95% vs. 80%), meat pH and weight loss were measured. Salami characteristics (moisture, weight loss, texture, appearance properties) were evaluated during 20 days of ripening. Results showed that conditioning at 80% RH yielded a significantly drier meat, being the weight loss rate 1.6 times higher than at 95% RH. The lower water content of meat allowed a shorter salami ripening phase, guaranteeing an appropriate weight loss and the development of the desired texture, while maintaining good appearance properties. The acceleration of this production phase represents a clear economic advantage for producers and consumers, leading to higher profit margins and lower retail prices. The possibility of using FT-NIR spectroscopy as a valid tool for the rapid evaluation of salami ripening was also demonstrated
TMS over the Cerebellum Interferes with Short-term Memory of Visual Sequences
Growing evidence suggests that the cerebellum is not only involved in motor functions, but it significantly contributes to sensory and cognitive processing as well. In particular, it has been hypothesized that the cerebellum identifies recurrent serial events and recognizes their violations. Here we used transcranial magnetic stimulation (TMS) to shed light on the role of the cerebellum in short-term memory of visual sequences. In two experiments, we found that TMS over the right cerebellar hemisphere impaired participants' ability to recognize the correct order of appearance of geometrical stimuli varying in shape and/or size. In turn, cerebellar TMS did not affect recognition of highly familiar short sequences of letters or numbers. Overall, our data suggest that the cerebellum is involved in memorizing the order in which (concatenated) stimuli appear, this process being important for sequence learning
Anomalous Lattice Vibrations of Single and Few-Layer MoS2
Molybdenum disulfide (MoS2) of single and few-layer thickness was exfoliated
on SiO2/Si substrate and characterized by Raman spectroscopy. The number of
S-Mo-S layers of the samples was independently determined by contact-mode
atomic-force microscopy. Two Raman modes, E12g and A1g, exhibited sensitive
thickness dependence, with the frequency of the former decreasing and that of
the latter increasing with thickness. The results provide a convenient and
reliable means for determining layer thickness with atomic-level precision. The
opposite direction of the frequency shifts, which cannot be explained solely by
van der Waals interlayer coupling, is attributed to Coulombic interactions and
possible stacking-induced changes of the intralayer bonding. This work
exemplifies the evolution of structural parameters in layered materials in
changing from the 3-dimensional to the 2-dimensional regime.Comment: 14 pages, 4 figure
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