Impact of different activation wavefronts on ischemic myocardial scar electrophysiological properties during high-density ventricular tachycardia mapping and ablation.

INTRODUCTION: Scar-related ventricular tachycardia (VT) usually results from an underlying reentrant circuit facilitated by anatomical and functional barriers. The later are sensitive to the direction of ventricular activation wavefronts. We aim to evaluate the impact of different ventricular activation wavefronts on the functional electrophysiological properties of myocardial tissue. METHODS: Patients with ischemic heart disease referred for VT ablation underwent high-density mapping using Carto®3 (Biosense Webster). Maps were generated during sinus rhythm, right and left ventricular pacing, and analyzed using a new late potential map software, which allows to assess local conduction velocities and facilitates the delineation of intra-scar conduction corridors (ISCC); and for all stable VTs. RESULTS: In 16 patients, 31 high-resolution substrate maps from different ventricular activation wavefronts and 7 VT activation maps were obtained. Local abnormal ventricular activities (LAVAs) were found in VT isthmus, but also in noncritical areas. The VT isthmus was localized in areas of LAVAs overlapping surface between the different activation wavefronts. The deceleration zone location differed depending on activation wavefronts. Sixty-six percent of ISCCs were similarly identified in all activating wavefronts, but the one acting as VT isthmus was simultaneously identified in all activation wavefronts in all cases. CONCLUSION: Functional based substrate mapping may improve the specificity to localize the most arrhythmogenic regions within the scar, making the use of different activation wavefronts unnecessary in most cases.

Novel "late potential map" algorithm: Abnormal potentials and scar channels detection for ventricular tachycardia ablation.

BACKGROUND: Automated systems for substrate mapping in the context of ventricular tachycardia (VT) ablation may annotate far-field rather than near-field signals, rendering the resulting maps hard to interpret. Additionally, quantitative assessment of local conduction velocity (LCV) remains an unmet need in clinical practice. We evaluate whether a new late potential map (LPM) algorithm can provide an automatic and reliable annotation and localized bipolar voltage measurement of ventricular electrograms (EGMs) and if LCV analysis allows recognizing intrascar conduction corridors acting as VT isthmuses. METHODS: In 16 patients referred for scar-related VT ablation, 8 VT activation maps and 29 high-resolution substrate maps from different activation wavefronts were obtained. In offline analysis, the LPM algorithm was compared to manually annotated substrate maps. Locations of the VT isthmuses were compared with the corresponding substrate maps in regard to LCV. RESULTS: The LPM algorithm had an overall/local abnormal ventricular activity (LAVA) annotation accuracy of 94.5%/81.1%, which compares to 83.7%/23.9% for the previous wavefront algorithm. The resultant maps presented a spatial concordance of 88.1% in delineating regions displaying LAVA. LAVA median localized bipolar voltage was 0.22 mV, but voltage amplitude assessment had modest accuracy in distinguishing LAVA from other abnormal EGMs (area under the curve: 0.676; p < .001). LCV analysis in high-density substrate maps identified a median of two intrascar conduction corridors per patient (interquartile range: 2-3), including the one acting as VT isthmus in all cases. CONCLUSION: The new LPM algorithm and LCV analysis may enhance substrate characterization in scar-related VT.

Experimental Susceptibility of North American Raccoons (Procyon lotor) and Striped Skunks (Mephitis mephitis) to SARS-CoV-2.

Recent spillback events of SARS-CoV-2 from humans to animals has raised concerns about it becoming endemic in wildlife. A sylvatic cycle of SARS-CoV-2 could present multiple opportunities for repeated spillback into human populations and other susceptible wildlife. Based on their taxonomy and natural history, two native North American wildlife species -the striped skunk (Mephitis mephitis) and the raccoon (Procyon lotor) -represent a high likelihood of susceptibility and ecological opportunity of becoming infected with SARS-CoV-2. Eight skunks and raccoons were each intranasally inoculated with one of two doses of the virus (103 PFU and 105 PFU) and housed in pairs. To evaluate direct transmission, a naïve animal was added to each inoculated pair 48 h post-inoculation. Four control animals of each species were handled like the experimental groups. At predetermined intervals, we collected nasal and rectal swabs to quantify virus shed via virus isolation and detect viral RNA via rRT-PCR and blood for serum neutralization. Lastly, animals were euthanized at staggered intervals to describe disease progression through histopathology and immunohistochemistry. No animals developed clinical disease. All intranasally inoculated animals seroconverted, suggesting both species are susceptible to SARS-CoV-2 infection. The highest titers in skunks and raccoons were 1:128 and 1:64, respectively. Low quantities of virus were isolated from 2/8 inoculated skunks for up to day 5 post-inoculation, however no virus was isolated from inoculated raccoons or direct contacts of either species. Neither species had gross lesions, but recovering mild chronic pneumonia consistent with viral insult was recorded histologically in 5/8 inoculated skunks. Unlike another SARS-CoV-2 infection trial in these species, we detected neutralizing antibodies in inoculated raccoons; thus, future wildlife serologic surveillance results must be interpreted with caution. Due to the inability to isolate virus from raccoons, the lack of evidence of direct transmission between both species, and low amount of virus shed by skunks, it seems unlikely for SARS-CoV-2 to become established in raccoon and skunk populations and for virus to spillback into humans. Continued outbreaks in non-domestic species, wild and captive, highlight that additional research on the susceptibility of SARS-CoV-2 in wildlife, especially musteloidea, and of conservation concern, is needed.

Long-Term Underwater Hydrophobicity: Exploring Topographic and Chemical Requirements.

A family of hybrid organoinorganic silica-based particles with varied chemical natures and morphologies has been synthesized to test their ability to develop coatings with underwater hydrophobicity. The particles were characterized by elemental microanalysis, scanning electron microscopy, and dynamic light scattering to evaluate the organic content, observe the morphology, and estimate the aggregate size, respectively. These morphologies were transferred into surface topographies by spraycoating dispersions made from the particles onto glass supports, resulting in coatings with an ample range of profiles and roughness but all of them being superhydrophobic. Atomic force microscopy and optical profilometry were used to map the coating surfaces and analyze the topography. Then, underwater hydrophobicity endurance was tested by immersion under a 2 cm 20 °C water column perpendicular to circular glass supports coated with the particles. The so-called mirror effect derived from the occurrence of the primary plastron (continuous air layer occluded between the surface and the water) was observed on the surface of all of the coatings tested. Apart from the dependency of plastrons on the water temperature and substrate shape, the plastron quality and lifetime is notably different depending on the particle morphology and thus on the coating topography. These experiments have demonstrated that the most persistent mirror effects, and therefore underwater superhydrophobicity, were produced on coatings that exhibited the smoothest topographies at the micrometric scale. In addition, these particle-only coatings can be made mechanically stable and robust by blending with a polymer matrix.

Identification of canine papillomavirus by PCR in Greyhound dogs.

BACKGROUND: Corns are hard protuberances that occur on the digital footpads of Greyhound dogs. The cause of these lesions is unknown and there is little information about them in the veterinary literature. We received anecdotal examples of dog to dog spread of corns suggesting an infectious cause. The aim of this study was to determine if papillomavirus (PV) is associated with Greyhound corns. METHODS: We examined four corns from two unrelated adult Greyhound dogs that resided in Florida and Washington, respectively, for PV by PCR. The samples were obtained by owner coring of two lesions from one dog and laser removal of two lesions from the other dog. Total nucleic acid was extracted and DNA was amplified using two PCR primer sets that have been shown to amplify a broad range of PVs from humans and animals: FAP59/ FAP64 and MY11/ MY09. The DNA sequences were compared with all sequences in GenBank. Formalin-fixed, paraffin-embedded tissue from the footpads of four dogs with other inflammatory dermatoses were also examined. RESULTS: PV DNA was amplified from all four corn lesions, while no PV DNA was amplified from other tissues. Comparison of the 444-bp sequences amplified by the MY11/ MY09 primers identified two different PVs. One showed 96% nucleotide sequence similarity with the L1 gene of canine PV type 12. The other showed 78% similarity to canine PV type 16 and, therefore, represents a novel PV. In one of the corns, infection by two of the identified PVs was found. DISCUSSION: These results suggest PV infection could be involved in the pathogenesis of corns in Greyhound dogs.

Superhydrophobic and highly luminescent polyfluorene/silica hybrid coatings deposited onto glass and cellulose-based substrates.

Neat poly(9,9-dioctyl-9H-fluorene) (PFO) and composites of PFO and a modified organonanosilica P(7) at weight ratios 90/10, 70/30, and 50/50 have been employed to prepare fluorescent and superhydrophobic coatings by spraying onto three different substrates: glass, Whatman paper, and a filtration membrane of mixed cellulose esters. The water repellency of the coatings and their photophysical properties are therein studied. It is found that, irrespective of the substrate and the composite composition, all coatings remain fluorescent. In some of the coatings prepared, confined morphologies are created, which fluoresce with a wavelength distribution resembling that of an ordered planar ß-phase. Among the coatings prepared in this work, those with a ratio PFO/P(7) of 50/50 are the ones with the strongest chain confinement and the highest surface roughness, being highly emissive at the ß-phase wavelengths and also superhydrophobic. Depending on the substrate these materials are also tough and flexible (cellulose based substrates) or display a remarkable light transmittance (glass). A final merit of these multifunctional materials is the simplicity of the preparation procedure, adequate for large surfaces and industrial applications.

Multipurpose ultra and superhydrophobic surfaces based on oligodimethylsiloxane-modified nanosilica.

Nonfluorinated hydrophobic surfaces are of interest for reduced cost, toxicity, and environmental problems. Searching for such surfaces together with versatile processing, A200 silica nanoparticles are modified with an oligodimethylsiloxane and used by themselves or with a polymer matrix. The goal of the surface modification is controlled aggregate size and stable suspensions. Characterization is done by NMR, microanalysis, nitrogen adsorption, and dynamic light scattering. The feasibility of the concept is then demonstrated. The silica aggregates are sprayed in a scalable process to form ultrahydrophobic and imperceptible coatings with surface topographies of controlled nanoscale roughness onto different supports, including nanofibrillated cellulose. To improve adhesion and wear properties, the organosilica was mixed with polymers. The resulting composite coatings are characterized by FE-SEM, AFM, and contact angle measurements. Depending on the nature of the polymer, different functionalities can be developed. Poly(methyl methacrylate) leads to almost superhydrophobic and highly transparent coatings. Composites based on commercial acrylic car paint show "pearl-bouncing" droplet behavior. A light-emitting polyfluorene is synthesized to prepare luminescent and water repellent coatings on different supports. The interactions between polymers and the organosilica influence coating roughness and are critical for wetting behavior. In summary, the feasibility of a facile, rapid, and fluorine-free hydrophobization concept was successfully demonstrated in multipurpose antiwetting applications.

[School meals: planning, production, distribution, and adequacy]. / Alimentação escolar: planejamento, produção, distribuição e adequação.

OBJETIVE: To evaluate the planning, production, distribution, and nutritional adequacy of meals served at city schools. METHODS: This descriptive cross-sectional study was conducted between March 2011 and April 2012 and included a representative sample (n = 42 schools) of extended shift city schools from Belo Horizonte, Minas Gerais, Brazil. Five meals from each school were randomly selected and analyzed by direct weighing. Production indicators and nutritional adequacy were evaluated in contrast to the recommendations of the city food security bureau and the Brazilian National Program of School Meals (PNAE). RESULTS: Seventy-nine percent of the analyzed meals did not meet the recommendations of the city food security bureau. The rate of waste (food left on plates) was acceptable at 4,90%, but the rates of cooked and not served food (7,06%) and counter leftovers (5,30%) were high. Both the city planned meals and the meals served in the schools were nutritionally inadequate in terms of the PNAE, particularly for children aged 11-15 years. There was a relationship between consumption by school staff and the amount of food that was cooked (r = 0.353; P < 0.001) and the rate of cooked and not served food (r = 0.138; P = 0.045). Waste was positively correlated with the rate of counter leftovers (r = 0.145; P = 0.035), and inversely correlated with fiber intake (r = -0.143; P = 0.038). CONCLUSIONS: The results indicate the importance of monitoring the planning, production, and distribution of school meals and of food and nutrition education in order to improve the quality of food and to reduce waste in schools.

Alimentação escolar: planejamento, produção, distribuição e adequação / School meals: planning, production, distribution, and adequacy

OBJETIVO: Avaliar o planejamento, processo produtivo, distribuição e adequação nutricional do cardápio da refeição principal ofertada em escolas municipais. MÉTODOS: Este estudo descritivo transversal, realizado de março de 2011 a abril de 2012, utilizou uma amostra representativa (n = 42 escolas) das escolas municipais integradas de Belo Horizonte, estado de Minas Gerais, Brasil. Foram coletados randomicamente cinco cardápios da refeição principal de cada escola para análise por meio da pesagem direta. Realizou-se avaliação dos índices de produção e da adequação nutricional ao planejamento da Secretaria Municipal Adjunta de Segurança Alimentar e Nutricional e às recomendações do Programa Nacional de Alimentação Escolar. RESULTADOS: A análise revelou 79% de alteração dos cardápios servidos em relação aoscardápios planejados por nutricionistas da Secretaria Municipal Adjunta de Segurança Alimentar e Nutricional. Foram observados valores aceitáveis para resto-ingestão (4,90%) e índices elevados de sobras limpa (7,06%) e suja (5,30%). Foram verificadas inadequações nutricionais tanto nos cardápios planejados quanto nos cardápios consumidos nas escolas municipais em termos do Programa Nacional de Alimentação Escolar, principalmente para a faixa etária de 11 a 15 anos. Identificou-se relação da porção consumida pelos funcionários da escola com a quantidade produzida de alimentos (r = 0,353; P < 0,001) e a sobra limpa (r = 0,138; P = 0,046). Ademais, houve correlação significativa proporcional de resto-ingestão com sobra suja (r = 0,145; P = 0,035) e inversamente proporcional com consumo de fibras (r = -0,143; P = 0,038). CONCLUSIONES: Evidencia-se a importância do acompanhamento da elaboração, preparo e distribuição da alimentação escolar, assim como da educação alimentar e nutricional, no intuito de melhorar a oferta e consumo alimentar das crianças e reduzir o desperdício no ambiente escolar.

OBJETIVE: To evaluate the planning, production, distribution, and nutritional adequacy of meals served at city schools. METHODS: This descriptive cross-sectional study was conducted between March 2011 and April 2012 and included a representative sample (n = 42 schools) of extended shift city schools from Belo Horizonte, Minas Gerais, Brazil. Five meals from each school were randomly selected and analyzed by direct weighing. Production indicators and nutritional adequacy were evaluated in contrast to the recommendations of the city food security bureau and the Brazilian National Program of School Meals (PNAE). RESULTS: Seventy-nine percent of the analyzed meals did not meet the recommendations of the city food security bureau. The rate of waste (food left on plates) was acceptable at 4,90%, but the rates of cooked and not served food (7,06%) and counter leftovers (5,30%) were high. Both the city planned meals and the meals served in the schools were nutritionally inadequate in terms of the PNAE, particularly for children aged 11-15 years. There was a relationship between consumption by school staff and the amount of food that was cooked (r = 0.353; P < 0.001) and the rate of cooked and not served food (r = 0.138; P = 0.045). Waste was positively correlated with the rate of counter leftovers (r = 0.145; P = 0.035), and inversely correlated with fiber intake (r = -0.143; P = 0.038). CONCLUSIONS: The results indicate the importance of monitoring the planning, production, and distribution of school meals and of food and nutrition education in order to improve the quality of food and to reduce waste in schools.

Microwave versus conventional heating in the grafting of alkyltrimethoxysilanes onto silica particles.

The scope of this work is the comparative analysis in terms of grafting rate, structure of the grafted layer, and wetting behavior of three series of silica nanoparticles modified with alkyltrimethoxysilanes by using conventional heating with and without acid catalysis, and microwave irradiation. A comprehensive characterization of the grafted layer by means of Fourier transform infrared (FTIR), microanalysis, and solid state NMR techniques has shown that microwave irradiation provokes a pronounced increase in the loading rate compared to conventional heating. This microwave effect is outstanding in the case of the reactions with methyltrimethoxysilane, because of the acceleration of the condensation rate. Moreover, solid state NMR spectra ((29)Si and (13)C) strongly suggest structural differences in the grafted layer obtained by the two heating sources. The wetting behavior of the modified nanoparticles was studied, concluding that these changes in the structure of the grafted layer induced by the synthetic procedure do not determine the values of the dynamic water contact angles.