Visual stream connectivity predicts assessments of image quality.

Despite extensive study of early vision, new and unexpected mechanisms continue to be identified. We introduce a novel formal treatment of the psychophysics of image similarity, derived directly from straightforward connectivity patterns in early visual pathways. The resulting differential geometry formulation is shown to provide accurate and explanatory accounts of human perceptual similarity judgments. The direct formal predictions are then shown to be further improved via simple regression on human behavioral reports, which in turn are used to construct more elaborate hypothesized neural connectivity patterns. It is shown that the predictive approaches introduced here outperform a standard successful published measure of perceived image fidelity; moreover, the approach provides clear explanatory principles of these similarity findings.

Modulation of the exfoliated graphene work function through cycloaddition of nitrile imines.

After the feasibility of the 1,3-dipolar cycloaddition reaction between nitrile imines and exfoliated graphene by density functional theory calculations was proved, very few-layer graphene was effectively functionalized using this procedure. Hydrazones with different electronic properties were used as precursors for the 1,3-dipoles, and microwave irradiation as an energy source enabled the reaction to be performed in a few minutes. The anchoring of organic addends on the graphene surface was confirmed by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis. Ultraviolet photoelectron spectroscopy (UPS) was used to measure the work function and band gap of these new hybrids. Our results demonstrate that it is possible to modulate these important electronic valence band parameters by tailoring the electron richness of the organic addends and/or the degree of functionalization.

Design of Assembled Systems Based on Conjugated Polyphenylene Derivatives and Carbon Nanohorns.

Promising materials have been designed and fully characterised by an effective interaction between versatile platforms such as carbon nanohorns (CNHs) and conjugated molecules based on thiophene derivatives. Easy and non-aggressive methods have been described for the synthesis and purification of the final systems. Oligothiophenephenylvinylene (OTP) systems with different geometries and electron density are coupled to the CNHs. A wide range of characterization techniques have been used to confirm the effective interaction between the donor (OTP) and the acceptor (CNH) systems. These hybrid materials show potential for integration into solar cell devices. Importantly, surface-enhanced Raman spectroscopy (SERS) effects are observed without the presence of any metal surface in the system. Theoretical calculations have been performed to study the optimised geometries of the noncovalent interaction between the surface and the organic molecule. The calculations allow information on the monoelectronic energies of HOMO-LUMO orbitals and band gap of different donor systems to be extracted.

Stability of melamine-exfoliated graphene in aqueous media: quantum-mechanical insights at the nanoscale.

In recent experiments, melamine (1,3,5-triazine-2,4,6-triamine) has been proposed as an effective exfoliating agent to obtain high quality graphene from graphite. After washing out the melamine in excess, small amounts (ppm) are still needed to stabilize the dispersion of graphene flakes in aqueous media. To understand the origin of this behaviour, we investigated the melamine-graphene-water system and the fundamental interactions that determine its structure and energetics. To disentangle the subtle interplay of hydrogen-bonding and dispersive forces we used state-of-the-art ab initio calculations based on density functional theory. First, we focused on the case of water molecules interacting with melamine-graphene assemblies at different melamine coverages. We found that water-melamine interactions provide the driving force for washing off the melamine from graphene. Then, we addressed the interaction of single and double layers of water molecules with the graphene surface in the presence of an adsorbed melamine molecule. We found that this melamine acts as a non-covalent anchor for keeping a number of water molecules conveniently close to the graphene surface, thus helping its stabilization in aqueous media. Our analysis helps understanding how competing weak forces can lead to a stable graphene water suspension thanks to small amounts of adsorbed melamine. From our results, we derive simple indications on how the water-graphene interfacial properties can be tuned via non-covalent adsorption of small functional molecules with H-bond donor/acceptor groups. These new hints can be helpful to prepare stable graphene dispersions in water and so to unlock graphene potential in aqueous environments.

Determination of Kinetic Parameters within a Single Nonisothermal On-Flow Experiment by Nanoliter NMR Spectroscopy.

Conventional methods to determine the kinetic parameters for a certain reaction require multiple, separate isothermal experiments, resulting in time- and material-consuming processes. Here, an approach to determine the kinetic information within a single nonisothermal on-flow experiment is presented, consuming less than 10 µmol of reagents and having a total measuring time of typically 10 min. This approach makes use of a microfluidic NMR chip hyphenated to a continuous-flow microreactor and is based on the capabilities of the NMR chip to analyze subnanomole quantities of material in the 25 nL detection volume. Importantly, useful data are acquired from the microreactor platform in specific isothermal and nonisothermal frames. A model fitting the experimental data enables rapid determination of kinetic parameters, as demonstrated for a library of isoxazole and pyrazole derivatives.

Influence of Polarity and Activation Energy in Microwave-Assisted Organic Synthesis (MAOS).

The aim of this work was to determine the parameters that have decisive roles in microwave-assisted reactions and to develop a model, using computational chemistry, to predict a priori the type of reactions that can be improved under microwaves. For this purpose, a computational study was carried out on a variety of reactions, which have been reported to be improved under microwave irradiation. This comprises six types of reactions. The outcomes obtained in this study indicate that the most influential parameters are activation energy, enthalpy, and the polarity of all the species that participate. In addition to this, in most cases, slower reacting systems observe a much greater improvement under microwave irradiation. Furthermore, for these reactions, the presence of a polar component in the reaction (solvent, reagent, susceptor, etc.) is necessary for strong coupling with the electromagnetic radiation. We also quantified that an activation energy of 20-30 kcal mol(-1) and a polarity (µ) between 7-20 D of the species involved in the process is required to obtain significant improvements under microwave irradiation.

Primary cutaneous anaplastic large cell lymphomas with 6p25.3 rearrangement exhibit particular histological features.

AIMS: CD30-positive primary cutaneous lymphoproliferative disorders include several entities with differing clinical presentation but overlapping histological features, including lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma (C-ALCL). DUSP22-IRF4 locus translocation is present in 20-57% of C-ALCLs, and has also been described in a series of 11 lymphomatoid papulosis patients, where it was associated with a particular biphasic histological pattern, including pagetoid reticulosis-type epidermal infiltration. We aimed to study whether the presence of this translocation may define distinctive histological features in C-ALCL. METHODS AND RESULTS: We collected three cases of C-ALCL with histological features similar to those described in the new variant of lymphomatoid papulosis with 6p25.3 rearrangement. We studied their histological features and immunophenotype, using a panel of antibodies against CD30, TCR-ßF1, TCR-γ, CD4, CD8, CD20, Ki-67 and ALK. FISH analyses were performed using an IRF4-DUSP22 break-apart probe for the study of the 6p25.3 rearrangement. FISH results were positive in the three cases, which all showed distinctive histological and immunohistochemical features: a diffuse dermal infiltrate of atypical medium-to-large cells, and marked epidermotrophism with small, atypical intra-epidermal lymphocytes. CONCLUSIONS: Our findings suggest that the presence of 6p25.3 rearrangement might be related to this particular biphasic pattern.

Agudización grave de asma en una unidad de cuidados respiratorios intermedios: ¿realidad o controversia? / Severe Asthma Exacerbation in an Intermediate Respiratory Care Unit: Fact or Controversy?

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Exfoliation of graphite with triazine derivatives under ball-milling conditions: preparation of few-layer graphene via selective noncovalent interactions.

A ball-milling treatment can be employed to exfoliate graphite through interactions with commercially available melamine under solid conditions. This procedure allows the fast production of relatively large quantities of material with a low presence of defects. The milling treatment can be modulated in order to achieve graphene flakes with different sizes. Once prepared, the graphene samples can be redispersed in organic solvents, water, or culture media, forming stable dispersions that can be used for multiple purposes. In the present work, we have screened electron-rich benzene derivatives along with triazine derivatives in their respective ability to exfoliate graphite. The results suggest that the formation of a hydrogen-bonding network is important for the formation of multipoint interactions with the surfaces of graphene, which can be used for the exfoliation of graphite and the stabilization of graphene in different solvents. Aminotriazine systems were found to be the best partners in the preparation and stabilization of graphene layers in different solvents, while the equivalent benzene derivatives did not show comparable exfoliation ability. Computational studies have also been performed to rationalize the experimental results. The results provide also the basis for further work in the preparation of noncovalently modified graphene, where derivatives of aminotriazines can be designed to form extensive hydrogen-bond 2D networks on the graphene surface with the aim of manipulating their electronic and chemical properties.

Automated image analysis in the study of lymphocyte subpopulation in eosinophilic oesophagitis.

BACKGROUND: Eosinophilic oesophagitis (EoE) is characterized by the presence of eosinophils in oesophageal mucosa. Other inflammatory cells, mainly lymphocytes, dendritic cells, and mast cells may also play an important role in this disease. The aim of this study is to compare the inflammatory pattern of the mucosa between EoE and gastro-oesophageal reflux disease (GERD), using automatic image analysis in digital slides, and to assess treatment response after elimination diet and food challenge test. METHODS: From 2010 to 2013, 35 oesophageal biopsies from EoE and GERD patients were randomly selected. In six EoE biopsies, patients had been treated with selective food exclusion diet. Immunohistochemical study with CD3, CD20, CD4, and CD8 for lymphocyte populations, CD1a for dendritic cells, and CD117/c-kit for mast cells was performed. Slides were scanned using Leica Aperio Scanscope XT with 40× magnification. Immunohistochemical expression was quantified in 245 immunohistochemistry digital slides with Leica Aperio positive pixel count algorithm using two different approaches: whole slide analysis versus selection of a 2 mm2 hot spot area. RESULTS: Average eosinophil cell count was significantly higher (p < 0.001) in the first biopsy of EoE patients before treatment (30.75 eosinophils per high power field - HPF) than in GERD patients (0.85 eosinophils/HPF) or in EoE patients after treatment with elimination diet (1.60 eosinophils/HPF). In the immunohistochemical study, manual count and automatic image analysis showed a significant increase in the number of CD3 and CD8 cells in EoE patients, compared with GERD patients. However, the increase of CD117/c-kit was only statistically significant when manual counting procedures were used. CD20 positive cell count also showed a non-statistically significant tendency to reduce after elimination diet treatment. CONCLUSIONS: Positive pixel count algorithm can be a useful tool to quantify the immunohistochemical expression of inflammatory cells in the diagnosis and follow up of eosinophilic oesophagitis.

Evolución del uso de la ventilación mecánica no invasiva en enfermedad pulmonar obstructiva crónica en una región española, 1997-2010 / Evolution of the Use of Noninvasive Mechanical Ventilation in Chronic Obstructive Pulmonary Disease in a Spanish Region, 1997-2010

Introducción: La ventilación mecánica no invasiva (VMNI) aparece, en los 80, como alternativa a la ventilación mecánica invasiva (VMI) en pacientes con fracaso respiratorio agudo. Se pretende valorar la introducción de la VMNI y los resultados sobre los pacientes hospitalizados por agudización de enfermedad pulmonar obstructiva crónica en la Región de Murcia. Sujetos y métodos: Estudio observacional retrospectivo basado en el conjunto mínimo básico de datos al alta hospitalaria de todos los pacientes hospitalizados en todos los hospitales públicos de la región entre 1997-2010. Se realizó análisis de tendencias temporales en la frecuentación hospitalaria, el uso de cada intervención ventilatoria y la mortalidad hospitalaria mediante regresión joinpoint. Resultados: En los 14 años estudiados se identificaron 30.027 casos. Análisis joinpoint: tendencia descendente de la frecuentación (porcentaje de cambio anual [PCA] = −3,4; IC95%: 4,8; -2,0; p < 0,05) y en el grupo sin intervención ventilatoria (PCA = −4,2; −5,6;−2,8; p < 0,05), ascendente en el uso de VMNI (PCA = 16,4; 12,0;20,9; p < 0,05); el uso de la VMI presenta una tendencia descendente sin significación estadística (PCA = −4,5; −10,3;1,7). Se aprecia una tendencia ascendente sin significación estadística en la mortalidad global (PCA = 0,5; −1,3;2,4) y en el grupo sin intervención (PCA = 0,1; −1,6;1,9); decreciente con significación estadística en el grupo VMNI (PCA = −7,1; −11,7;−2,2; p < 0,05) y sin significación estadística en el grupo VMI (PCA = −0,8; −6,1;4,8). La estancia media no varía sustancialmente. Conclusiones: La introducción de la VMNI ha hecho disminuir el grupo de pacientes que no reciben ventilación asistida. No se aprecia mejora de los resultados en términos de mortalidad o estancia media global (AU)

Introduction: Noninvasive mechanical ventilation (NIV) appeared in the 1980s as an alternative to invasive mechanical ventilation (IMV) in patients with acute respiratory failure. We evaluated the introduction of NIV and the results in patients with acute exacerbation of chronic obstructive pulmonary disease in the Region of Murcia (Spain). Subjects and methods: A retrospective observational study based on the minimum basic hospital discharge data of all patients hospitalised for this pathology in all public hospitals in the region between 1997 and 2010. We performed a time trend analysis on hospital attendance, the use of each ventilatory intervention and hospital mortality through JoinPoint regression. Results: We identified 30 027 hospital discharges. JoinPoint analysis: downward trend in attendance (annual percentage change [APC]=−3.4, 95% CI : −4.8 to −2.0, P<0.05) and in the group without ventilatory intervention (APC=−4.2%, −5.6 to −2.8, P<0.05); upward trend in the use of NIV (APC=16.4, 12.0–20.9, P<0.05), and downward trend that was not statistically significant in IMV (APC=−4.5%, −10.3 to 1.7). We observed an upward trend without statistical significance in overall mortality (APC=0.5, −1.3 to 2.4) and in the group without intervention (APC=0.1, −1.6 to 1.9); downward trend with statistical significance in the NIV group (APC=−7.1, −11.7 to −2.2, P<0.05) and not statistically significant in the IMV group (APC=−0.8, −6, 1–4.8). The mean stay did not change substantially. Conclusions: The introduction of NIV has reduced the group of patients not receiving assisted ventilation. No improvement in results was found in terms of mortality or length of stay (AU)

Evolution of the use of noninvasive mechanical ventilation in chronic obstructive pulmonary disease in a Spanish region, 1997-2010.

INTRODUCTION: Noninvasive mechanical ventilation (NIV) appeared in the 1980s as an alternative to invasive mechanical ventilation (IMV) in patients with acute respiratory failure. We evaluated the introduction of NIV and the results in patients with acute exacerbation of chronic obstructive pulmonary disease in the Region of Murcia (Spain). SUBJECTS AND METHODS: A retrospective observational study based on the minimum basic hospital discharge data of all patients hospitalised for this pathology in all public hospitals in the region between 1997 and 2010. We performed a time trend analysis on hospital attendance, the use of each ventilatory intervention and hospital mortality through joinpoint regression. RESULTS: We identified 30.027 hospital discharges. Joinpoint analysis: downward trend in attendance (annual percentage change [APC]=-3.4, 95% CI: - 4.8; -2.0, P <.05) and in the group without ventilatory intervention (APC=-4.2%, -5.6; -2.8, P <.05); upward trend in the use of NIV (APC=16.4, 12.0; 20. 9, P <.05), and downward trend that was not statistically significant in IMV (APC=-4.5%, -10.3; 1.7). We observed an upward trend without statistical significance in overall mortality (APC=0.5, -1.3; 2.4) and in the group without intervention (APC=0.1, -1.6; 1.9); downward trend with statistical significance in the NIV group (APC=-7.1, -11.7; -2.2, P <.05) and not statistically significant in the IMV group (APC=-0,8, -6, 1; 4.8). The mean stay did not change substantially. CONCLUSIONS: The introduction of NIV has reduced the group of patients not receiving assisted ventilation. No improvement in results was found in terms of mortality or length of stay.