An unusual imported case of diphyllobothriosis in Mexico

The aim of the present study was to estimate the relative contribution of immunogenetic and microbiological factors in the development of recurrent tonsillitis in a Mexican population. Patients (n = 138) with recurrent tonsillitis and an indication of tonsillectomy (mean age: 6.05 years ± 3.00; median age: 5 years, female: 58; age range: 1±15 years) and 195 nonrelated controls older than 18 years and a medical history free of recurrent tonsillitis were included. To evaluate the microbial contribution, tonsil swab samples from both groups and extracted tonsil samples from cases were cultured. Biofilm production of isolated bacteria was measured. To assess the immunogenetic component, DNA from peripheral blood was genotyped for the TNFA-308G/A single-nucleotide polymorphism (SNP) and for the IL1B -31C/T SNP. Normal microbiota, but no pathogens or potential pathogens, were identified from all control sample cultures. The most frequent pathogenic species detected in tonsils from cases were Staphylococcus aureus (48.6%, 67/138) and Haemophilus influenzae (31.9%, 44/138), which were found more frequently in patient samples than in samples from healthy volunteers (P < 0.0001). Importantly, 41/54 (75.9%) S. aureus isolates were biofilm producers (18 weak and 23 strong), whereas 17/25 (68%) H. influenzae isolates were biofilm producers (10 weak, and 7 strong biofilm producers). Patients with at least one copy of the IL1B-31*C allele had a higher risk of recurrent tonsillitis (OR = 4.03; 95% CI = 1.27± 14.27; P = 0.013). TNFA-308 G/A alleles were not preferentially distributed among the groups. When considering the presence of IL1B-31*C plus S. aureus, IL1B-31*C plus S. aureus biofilm producer, IL1B-31*C plus H. influenzae or IL1B-31*C plus H. influenzae biofilm producer, the OR tended to infinite. Thus, the presence of IL1B-31*C allele plus presence of S. aureus and/or H. influenzae could be related to the development of tonsilitis in this particular Mexican population

Graft copolymers of ethyl methacrylate on waxy maize starch derivatives as novel excipients for matrix tablets: Drug release and fronts movement kinetics

A previous paper [1] deals with the physicochemical and technological characterization of novel graft copolymers of ethyl methacrylate (EMA) on waxy maize starch (MS) and hydroxypropylstarch (MHS). The results obtained suggested the potential application of these copolymers as excipients for compressed non-disintegrating matrix tablets. Therefore, the purpose of the present study was to investigate the mechanism governing drug release from matrix systems prepared with the new copolymers and anhydrous theophylline or diltiazem HCl as model drugs with different solubility. The influence of the carbohydrate nature, drying procedure and initial pore network on drug release kinetics was also evaluated. Drug release experiments were performed from free tablets. Radial drug release and fronts movement kinetics were also analysed, and several mathematical models were employed to ascertain the drug release mechanisms. The drug release markedly depends on the drug solubility and the carbohydrate nature but is practically not affected by the drying process and the initial matrix porosity. A faster drug release is observed for matrices containing diltiazem HCl compared with those containing anhydrous theophylline, in accordance with the higher drug solubility and the higher friability of diltiazem matrices. In fact, although diffusion is the prevailing drug release mechanism for all matrices, the erosion mechanism seems to have some contribution in several formulations containing diltiazem. A reduction in the surface exposed to the dissolution medium (radial release studies) leads to a decrease in the drug release rate, but the release mechanism is not essentially modified. The nearly constant erosion front movement confirms the behaviour of these systems as inert matrices where the drugs are released mainly by diffusion through the porous structure.Ministerio de Educación y Ciencia MAT2004-0159

Comparison between the methods of the norm L1, L2, hilbert transform and phase analysis to obtain the time of flight of ultrasonic signals

Ponencia presentada en el XIX Congreso Internacional de Acústica (ICA2007), Madrid, 2-7 Sep 2007.-- PACS: 43.60.Bf.Some techniques to estimate the time of flight (TOF) allow getting a larger resolution, more than a sampling period. Therefore, it is possible to obtain a greater accuracy in the measurement of acoustic parameters using the TOF.In this work a comparison between the mentioned methods is carried out; analyzing the standard deviation of the time of flight in relation to the sign to noise ratio (SNR) between 5 dB to 40 dB and a bandwidth of 4 MHz, 5 MHz and 6 MHz to -6 dB of simulated ultrasound signals, with the purpose of analyzing the performance of each method.The results demonstrate that the method of the phase estimation presents the bigger values of standard deviation. For high-SNRs the methods of the L1 and L2 norm present similar values; furthermore, they exhibit the lowest values of standard deviation of the TOF estimation of the four methods. Finally, it was observed that for low SNR the method of Hilbert transform allows to obtain values of standard deviation similar to the methods of the norm L1 and L2 with a smaller time of processing of the signal.Peer reviewe

Propagation of Rayleighs waves in cracked media

Este trabajo está enfocado a la obtención de resultados numéricos que permitan la detección y caracterización de grietas sub-superficiales en sólidos mediante la incidencia de ondas elásticas de Rayleigh. Los resultados se obtienen a partir de ecuaciones integrales de frontera, que pertenecen al campo de la elastodinámica. Una vez que se aplican las condiciones de frontera se obtiene un sistema de ecuaciones integrales del tipo Fredholm de segunda especie y orden cero, el cual es resuelto mediante eliminación gaussiana. El método que se emplea para la discretización de dichas ecuaciones es conocido como «método indirecto de elementos frontera», el cual puede ser visto como una derivación del teorema clásico de Somigliana. A partir de los análisis realizados en el dominio de la frecuencia emergen picos de resonancia que permiten inferir la presencia de grietas mediante los cocientes espectrales. Se analizaron varios modelos de medios agrietados donde se pretende evidenciar la gran utilidad que presenta el uso de los cocientes espectrales para identificar grietas. Se estudiaron los efectos de la orientación y la localización de las grietas. Los resultados obtenidos presentan buena concordancia con los publicados previamente.This work is focused on the finding of numerical results for detection and characterization of sub-surface cracks in solids under the incidence of Rayleighs elastic waves. The results are obtained from boundary integral equations, which belong to the field of dynamics of elasticity. Once applied the boundary conditions, a system of Fredholms integral equations of second kind and zero order is obtained, which is solved using Gaussian elimination. The method that is used for the solution of such integral equations is known as the Indirect Boundary Element Method, which can be seen as a derivation of the Somiglianas classic theorem. On the basis of the analysis made in the frequency domain, resonance peaks emerge and allow us to infer the presence of cracks through the spectral ratios. Several models of cracked media were analyzed, where analyses reveal the great utility that displays the use of spectral ratios to identify cracks. We studied the effects of orientation and location of cracks. The results show good agreement with the previously published.Peer Reviewe

Análise estática dos elementos de suspensão de um monopólio do tipo de formato eletrônico

Nowadays, it is essential that the suspension elements of the emulation cars have the capacity to withstand a great amount of effort to which they will be submitted and have an optimal per-formance for competitions, being indispensable that the material used meets physical require-ments and / or resistant mechanical properties.  Method: In the first instance, an electric formula type car was designed, being manufactured with university-level engineering studies such as: finite element analysis, redesign and solutions to problems; to give validation of the elements of suspension that can be used in competition, where the evaluation and optimization of the parts of the car are important for its performance, such as the suspension to which a finite element analysis process was carried out in ANSYS used to perfect the vehicle, hoping to give it a stable control by reducing its weight, validating the resistance of the material and the piece designed. It showed a technological breakthrough that proposes advances in engineering studies to feed the ambition of the automotive sector and design engineering, as seen in the big teams of formula 1 in creating suspension elements for their competition vehicles. This example of a single-seater fulfills the objectives of having a rocker as a solid lightweight structure and scissors as a vital element of connection between the frame and chassis, representing benefits to the automotive sector, with the ability of the material to withstand applied loads.En la actualidad es esencial que los elementos de suspensión de los autos de competencia so-porten una gran cantidad de esfuerzos, también que el material cumpla con los requerimientos físicos y mecánicos para tener un desempeño óptimo. Este documento muestra la aplicación de estudios ingenieriles de nivel universitario, tales como el análisis de elementos finitos, rediseño y soluciones a problemas, para validar los elementos de suspensión de un monoplaza utilizado en competencia. Se analizaron los balancines y las tijeras de la suspensión por elementos finitos usando el software ANSYS, para evaluar y optimizar su desempeño en el monoplaza, esperando darle un control estable, reducción del peso y validar su diseño. Este estudio busca un avance tecnológico desde la academia, aplicando métodos de elementos finitos (FEM) a problemas automotrices que puedan aplicarse posteriormente en la industria, como se ve en las grandes escuderías de la fórmula 1 durante el desarrollo de nuevos elementos para sus vehículos de competencia que posteriormente se usan en los vehículos de calle. Esta metodología para el de-sarrollo de nuevos componentes demostró ser segura y eficiente ya que los diseños generados se pusieron a prueba en el monoplaza generando un excelente desempeño.Atualmente, é essencial que os elementos de suspensão dos carros de emulação tenham a capacidade de suportar uma grande quantidade de esforço ao qual serão submetidos e tenham um ótimo desempenho para competições, sendo indispensável que o material usado atenda aos requisitos físicos e / ou ou propriedades mecânicas resistentes. Método: Na primeira estadia, um carro tipo fórmula elétrica foi projetado, sendo fabricado com estudos de engenharia de nível universitário, tais como: análise de elementos finitos, redesenho e soluções para problemas; para dar a validação dos elementos de suspensão que podem ser usados na competição. Onde a avaliação e otimização das partes do monoposto são importantes para o seu desempenho, como a suspensão para a qual um processo de análise de elementos finitos foi realizado no ANSYS usado para aperfeiçoar o veículo, na esperança de dar a ele um controle estável re-duzindo seu peso, validando a resistência do material e da peça projetada. Mostrou um avanço tecnológico que propõe avanços em estudos de engenharia para alimentar a ambição do setor automotivo e de engenharia em desenho, como visto nas grandes equipes da fórmula 1 na criação de elementos de suspensões para seus veículos de competição.  Este exemplo de um monoposto cumpre os objetivos de ter um balancim como uma estrutura sólida, de fôrma leve e umas tesouras como um elemento vital de conexão entre o chassi e o montante de cubo de roda, representando benefícios para o setor automotivo, tendo a capacidade que o material re-siste antes das cargas aplicadas

Ecosystem services show variable responses to future climate conditions in the Colombian páramos

Background: The páramos, the high-elevation ecosystems of the northern Andes, are well-known for their high species richness and provide a variety of ecosystem services to local subsistence-based communities and regional urbanizations. Climate change is expected to negatively affect the provision of these services, but the level of this impact is still unclear. Here we assess future climate change impact on the ecosystem services provided by the critically important páramos of the department of Boyacá in Colombia, of which over 25% of its territory is páramo. Methods: We first performed an extensive literature review to identify useful species of Boyacá, and selected 103 key plant species that, based on their uses, support the provision of ecosystem services in the páramos. We collated occurrence information for each key species and using a Mahalanobis distance approach we applied climate niche modelling for current and future conditions. Results: We show an overall tendency of reduction in area for all ecosystem services under future climate conditions (mostly a loss of 10% but reaching up to a loss of 40%), but we observe also increases, and responses differ in intensity loss. Services such as Food for animals, Material and Medicinal, show a high range of changes that includes both positive and negative outcomes, while for Food for humans the responses are mostly substantially negative. Responses are less extreme than those projected for individual species but are often complex because a given ecosystem service is provided by several species. As the level of functional or ecological redundancy between species is not yet known, there is an urgency to expand our knowledge on páramos ecosystem services for more species. Our results are crucial for decision-makers, social and conservation organizations to support sustainable strategies to monitor and mitigate the potential consequences of climate change for human livelihoods in mountainous settings.publishedVersio