Ingeniería de materiales, mechanical power, ventilación protectora y una de paracaídas / Materials engineering, mechanical power, protective ventilation and a parachute

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In Situ Forming Depot as Sustained-Release Drug Delivery Systems.

In situ forming systems can serve as promising alternative to existing long acting injectables like disperse systems and microspheres, owing to their biocompatibility, stability, ease of administration and scale up. Microspheres based on long-acting parenteral systems pose challenges in scaling up and process changes with the drug and polymer selected. In situ gelling systems are having low viscosity which is very conducive during various manufacturing unit operations and passing the formulation through hypodermic needle with lower applied pressure. Different mechanisms such as physical or physiological stimuli and cross linking reactions are involved in the gelling of in situ forming systems at the site of injection. Drug release from in situ forming systems can be altered according to the need by using different polymers, lipids and fatty acids. In situ forming systems can be evaluated by sol-gel transition time, temperature and pH, rheology, gel strength, texture analysis, syringeability and injectability. The present paper is an overview of the various in situ gelling polymers and their application in the preparation of depot formulations. Numerous products based on in situ forming systems such as Eligard®, Atridox® are available in market.

Oscillatory multiphase flow strategy for chemistry and biology.

Continuous multiphase flow strategies are commonly employed for high-throughput parameter screening of physical, chemical, and biological processes as well as continuous preparation of a wide range of fine chemicals and micro/nano particles with processing times up to 10 min. The inter-dependency of mixing and residence times, and their direct correlation with reactor length have limited the adaptation of multiphase flow strategies for studies of processes with relatively long processing times (0.5-24 h). In this frontier article, we describe an oscillatory multiphase flow strategy to decouple mixing and residence times and enable investigation of longer timescale experiments than typically feasible with conventional continuous multiphase flow approaches. We review current oscillatory multiphase flow technologies, provide an overview of the advancements of this relatively new strategy in chemistry and biology, and close with a perspective on future opportunities.

Las buenas prácticas en urodinámica como un indicador de calidad en un Servicio no especializado / Good urodynamic practices in a non-specialized center: quality control analysis

OBJETIVO: Evaluación de estudios urodinámicos realizados en un Centro no especializado para valorar su calidad en relación con las Guías de Buenas Prácticas en Urodinámica de la Sociedad Internacional de Incontinencia. MÉTODOS: Se analizaron 62 estudios urodinámicos realizados entre marzo 2012 y mayo 2013 de forma retrospectiva. Se empleó para ello una serie de parámetros característicos comunes en todos los trazados. Se realizó una uroflujometría previa para su comparación posterior con la del estudio presión-flujo. RESULTADO: El 10,17% de los trazados mostró un descenso significativo de la Pabd no informado en el estudio. En el 15,25% se constató "presión al orinar", la cual fue reconocida e informada en las conclusiones. No hemos encontrado mayores artefactos, salvo vibraciones por la bomba. Como hallazgo más relevante, el 50,8% de los estudios presentaba una uroflujometría previa no vaporable. CONCLUSIONES: La elevada tasa de uroflujometrías no valorables fue en la mayoría de los casos por un volumen miccional insuficiente. Creemos que alcanzamos una elevada performance en la realización de nuestros estudios, a pesar de no tratarse de un centro especializado. El análisis retrospectivo nos permite detectar nuestros errores para poder tomar las medidas de corrección pertinentes

OBJECTIVES: To review the quality of urodynamic studies performed in one Center in order to assess adherence to the ICS Good Urodynamic Practice Guidelines. METHODS: Sixty-two consecutive urodynamic studies performed between March 2012 and May 2013 were retrospectively reviewed. We followed a list of common features to analyze all records. RESULTS: 10.17% of the studies showed a significant drop in Pabd not mentioned in the study report. We found straining in 15.25% of the traces that was recognized and informed in the reports. We did not find many equipment artifacts, only pump vibrations. Uroflowmetry performed previously to the test is very important to compare its results with the ones obtained at the pressure-flow study. 50.8% of the studies had a non-valuable uroflowmetry. CONCLUSIONS: The high rate of non-valuable uroflowmetries was in most of the cases due to an insufficient voiding volume. We think we meet very good standards although this is not a reference unit; nevertheless we still need to improve in many aspects

Activated sludge rheology: a critical review on data collection and modelling.

Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling and filtration). It therefore is an important property related to process performance, including process economics. To account for this, rheological behaviour is being included in process design, necessitating its measurement. However, measurements and corresponding protocols in literature are quite diverse, leading to varying results and conclusions. In this paper, a vast amount of papers are critically reviewed with respect to this and important flaws are highlighted with respect to rheometer choice, rheometer settings and measurement protocol. The obtained rheograms from experimental efforts have frequently been used to build viscosity models. However, this is not that straightforward and a lot of errors can be detected with respect to good modelling practice, including fair model selection criteria, qualitative parameter estimations and proper model validation. These important steps are however recurrently violated, severely affecting the model reliability and predictive power. This is illustrated with several examples. In conclusion, dedicated research is required to improve the rheological measurements and the models derived from them. At this moment, there is no guidance with respect to proper rheological measurements. Moreover, the rheological models are not very trustworthy and remain very "black box". More insight in the physical background needs to be gained. A model-based approach with dedicated experimental data collection is the key to address this.

Uroterapia en el tratamiento de la incontinencia urinaria / The role of urotherapy in the management of urinary incontinence

El objetivo de este trabajo es presentar nuestros resultados del abordaje de la incontinencia diurna refractaria al tratamiento médico mediante uroterapia. Para ello, se han revisado retrospectivamente las historias de los niños sometidos a este tipo de tratamiento en nuestro centro. Los criterios de inclusión fueron niños con incontinencia diurna refractarios al tratamiento farmacológico, incontinencia de la risa, vejiga hipoactiva y niños en los que se detectó en la cistomanometría una hiperactividad del detrusor y/o incoordinación vesicoesfinteriana. Doce pacientes completaron el seguimiento, con una media de edad de 8,5 años. La indicación más frecuente fue la incontinencia con hiperactividad del detrusor (58,33%). Los resultados fueron satisfactorios en el 83,3% de los casos, con desaparición de los síntomas en 8 pacientes sin tratamiento médico asociado, y 2 más con tratamiento asociado para la eneuresis nocturna. Sólo dos pacientes no presentaron mejoría. La uroterapia es una parte importante del abordaje de la disfunción del tracto urinario inferior en la edad pediátrica. Cabe destacar la importancia de la correcta selección de pacientes y la aplicación adecuada de las diferentes intervenciones, entre las que el biofeedback con imágenes animadas desempeña un papel fundamental(AU)

The aim of this essay is to present our initial results in applying urotherapy to patients with urinary incontinence not responding to pharmacological treatment. We performed ach art review of all the patients treated with urotherapy in our institution. We included all children with incontinence refractory to pharmacological treatment, giggle incontinence, underactive bladder, overactive bladder and dysfunctional voiding. 12 patients completed follow up. Mean age was 8.5 years. The most frequent finding in cystomanometry was detrusor over activity (58.33%). We achieved full response in 83.3% of our patients, 8 of them without any pharmacological treatment, and another 2 with associated administration of desmopressin. Only two patients did not respond to therapy. Urotherapy is an important part of management of lower urinary tract dysfunction in children. Careful selection of the patients and adequate use of every intervention are crucial for its effectiveness(AU)

Emerging trends in CV flow visualization.

Blood flow patterns are closely linked to the morphology and function of the cardiovascular system. These patterns reflect the exceptional adaptability of the cardiovascular system to maintain normal blood circulation under a wide range of workloads. Accurate retrieval and display of flow-related information remains a challenge because of the processes involved in mapping the flow velocity fields within specific chambers of the heart. We review the potentials and pitfalls of current approaches for blood flow visualization, with an emphasis on acquisition, display, and analysis of multidirectional flow. This document is divided into 3 sections. First, we provide a descriptive outline of the relevant concepts in cardiac fluid mechanics, including the emergence of rotation in flow and the variables that delineate vortical structures. Second, we elaborate on the main methods developed to image and visualize multidirectional cardiovascular flow, which are mainly based on cardiac magnetic resonance, ultrasound Doppler, and contrast particle imaging velocimetry, with recommendations for developing dedicated imaging protocols. Finally, we discuss the potential clinical applications and technical challenges with suggestions for further investigations.

Rheological innovations for characterizing food material properties.

Rheological methods are continually evolving to encompass novel technologies and measurement methods. This review highlights novel techniques used to analyze the rheological properties of foods over the previous decade. Techniques reviewed include large amplitude oscillatory shear (LAOS) testing and rheological techniques coupled with other measurement methods, such as microscopy and nuclear magnetic resonance (NMR). Novel techniques are briefly overviewed and discussed in terms of advantages and disadvantages, previous use, and suggested future utilization.

The emerging role of large eddy simulation in industrial practice: challenges and opportunities.

That class of methods for treating turbulence gathered under the banner of large eddy simulation is poised to enter mainstream engineering practice. There is a growing body of evidence that such methods offer a significant stretch in industrial capability over solely Reynolds-averaged Navier-Stokes (RANS)-based modelling. A key enabling development will be the adaptation of innovative processor architectures, resulting from the huge investment in the gaming industry, to engineering analysis. This promises to reduce the computational burden to practicable levels. However, there are many lessons to be learned from the history of the past three decades. These lessons should be analysed in order to inform, if not modulate, the unfolding of this next cycle in the development of industrial modelling capability. This provides the theme for this paper, which is written very much from the standpoint of the informed practitioner rather than the innovator; someone with a strong motivation to improve significantly the competence with which industrial turbulent flows are treated. It is asserted that the reliable deployment of the methodology in the industrial context will prove to be a knowledge-based discipline, as was the case with RANS-based modelling, if not more so. The community at large should collectively make great efforts to put in place that knowledge base from which best practice advice can be derived at the very start of this cycle of advancement and continue to enrich it as the cycle progresses.

Tratamiento quirúrgico de la estenosis uretral. Resutado de 100 uretroplastias / Surgical treatment of urethral stenosis. Results of 100 urethroplasties

OBJETIVO: Presentar nuestros resultados tras realizar 100 uretroplastias como tratamiento de estenosis uretral tanto a nivel peneano como bulbar, utilizando distintas técnicas.MÉTODOS: 100 pacientes diagnosticados de estenosis uretral, que fueron sometidos a uretroplastia en el período 1997-2007. De ellos, 57 tratados mediante anastómosis término terminal. 4 pacientes en los que se utilizó una técnica de anastómosis ampliada con un injerto libre. En 16 pacientes se realizó un injerto libre de mucosa bucal y en 23 la técnica usada fue el colgajo pediculado.RESULTADOS: En conjunto hemos obtenido un 84% de buenos resultados en la totalidad de los pacientes. En aquellos a los que realizamos una anástomosis término terminal obtuvimos un 91,2% de buenos resultados. De cuatro pacientes con técnica combinada de anastómosis con injerto libre, tuvimos un 75% de buenos resultados. En los casos en que utilizamos mucosa bucal en forma de parche obtuvimos un 90% en uretra bulbar y un 67% en uretra peneana. Cuando se utilizaron colgajos pediculados los buenos resultados fueron del 70,6% en uretra peneana y del 66,7% en uretra bulbar.CONCLUSIONES: La cirugía abierta es la mejor forma de tratamiento de la estenosis de uretra. La uretroplastia término terminal es la técnica que, aplicada en uretra bulbar, permite obtener mejores resultados. Para estenosis mayores de dos centímetros disponemos de otros procedimientos, siendo de elección, en uretra peneana, los colgajos pediculados, salvo que exista Liquen Escleroatrófico, en que la preferencia seran los injertos libres extragenitales y en uretra bulbar los injertos libres, preferentemente con mucosa bucal. En estenosis largas y complejas la opción que debemos contemplar es la cirugía en dos tiempos. Cualquier tipo de uretroplastia puede recidivar, y ese riesgo aumenta conforme pasa el tiempo(AU)

OBJECTIVES: We report our results after 100 urethroplasties for the treatment of urethral stricture both at the bulbar and penile urethra, using different techniques.METHODS: 100 patients with the diagnosis of anterior urethral stricture, that were submitted for urethroplasty in the period 1997-2007. Of them, 57 treated by end to end urethroplasty. 4 patients underwent augmented free graft anastomotic urethroplasty. Buccal mucosa free graft was used in 16 patients and penile skin onlay flap in 23.RESULTS: We have obtained 84% good results overall.In patients undergoing end to end urethroplasty we obtained 91.2% success rate. We had 75 % of good re-sults with the free graft anastomosis. In the cases in which we used buccal mucosa patch we obtained 90% success in bulbar urethra and 67 % in penile urethra. When we used onlay flaps good results were 70.6% in penile urethra and 66,7 % in bulbar urethra.CONCLUSIONS: Open surgery is the best form of treatment for urethral strictures. The anastomotic urethroplasty is the technique that, applied in bulbar urethra, enables better results. For strictures over two centimeters we have other procedures of choice in penile urethra, pediculated skin flaps, except in cases with Lichen Esclerosus, in which the use of buccal mucosa as a graft is preferable, and in the bulbar urethra in which augmented onlay graft urethroplasty or free grafts, mainly buccal mucosa, are preferred. In long and complex strictures, the option that we must contemplate is two-stage surgery. Any type of urethroplasty can fail, and this risk increases as the time passes(AU)

Optimal prediction and the rate of decay for solutions of the Euler equations in two and three dimensions.

The "t-model" for dimensional reduction is applied to the estimation of the rate of decay of solutions of the Burgers equation and of the Euler equations in two and three space dimensions. The model was first derived in a statistical mechanics context, but here we analyze it purely as a numerical tool and prove its convergence. In the Burgers case, the model captures the rate of decay exactly, as was previously shown. For the Euler equations in two space dimensions, the model preserves energy as it should. In three dimensions, we find a power law decay in time and observe a temporal intermittency.

Medical ultrasound imaging.

The paper gives an introduction to current medical ultrasound imaging systems. The basics of anatomic and blood flow imaging are described. The properties of medical ultrasound and its focusing are described, and the various methods for two- and three-dimensional imaging of the human anatomy are shown. Systems using both linear and non-linear propagation of ultrasound are described. The blood velocity can also be non-invasively visualized using ultrasound and the basic signal processing for doing this is introduced. Examples for spectral velocity estimation, color flow imaging and the new vector velocity images are presented.

Ultrasonic flowmeters: half-century progress report, 1955-2005.

Ultrasonic flowmeters are one of the fastest-growing technologies within the general field of instruments for process monitoring, measurement and control. Today, acoustic/ultrasonic flowmeters utilize clamp-on and wetted transducers, single and multiple paths, paths on and off the diameter, passive and active principles, contrapropagating transmission, reflection (Doppler), tag correlation, vortex shedding, liquid level sensing of open channel flow or flow in partially-full conduits, and other interactions. Ultrasonic flowmeters are applicable to liquids, gases, and multiphase mixtures, but not without limits. However, no single technology, nor one type of interaction within a technology, can be best for all fluids, occasions and situations. Users who select a particular type of ultrasonic flowmeter over one based on a competing (nonultrasonic) technology often do so for one (or more) of the following reasons: ultrasonic equipment provides a useful measurement whether the fluid is single-phase or not single-phase; equipment is easy to use; flow regime can be laminar, transitional or turbulent; transducers are totally external (no penetration of the pressure boundary); transducers, if not clamp-on, are minimally invasive; no excess pressure drop; when certain conditions are met, accuracy can be better than 0.5%; fast (ms) response; reliable despite temperature extremes; reasonable purchase price, installation, operating and maintenance costs. Sometimes mass flowrate is obtainable. Energy flowrate might be achieved for natural gas and biogas in the near future. How did ultrasonic flowmeters advance in the past fifty years to support such claims? This paper tries to answer this question by looking at ultrasonic flowmeter inventions and publications since 1955, to see how four key problems were solved.

Inland and coastal flooding: developments in prediction and prevention.

We review the scientific and engineering understanding of various types of inland and coastal flooding by considering the different causes and dynamic processes involved, especially in extreme events. Clear progress has been made in the accuracy of numerical modelling of meteorological causes of floods, hydraulics of flood water movement and coastal wind-wave-surge. Probabilistic estimates from ensemble predictions and the simultaneous use of several models are recent techniques in meteorological prediction that could be considered for hydraulic and oceanographic modelling. The contribution of remotely sensed data from aircraft and satellites is also considered. The need to compare and combine statistical and computational modelling methodologies for long range forecasts and extreme events is emphasized, because this has become possible with the aid of kilometre scale computations and network grid facilities to simulate and analyse time-series and extreme events. It is noted that despite the adverse effects of climatic trends on flooding, appropriate planning of rapidly growing urban areas could mitigate some of the worst effects. However, resources for flood prevention, including research, have to be considered in relation to those for other natural disasters. Policies have to be relevant to the differing geology, meteorology and cultures of the countries affected.

Extraction of primary and secondary metabolites.

Several new methods besides the usual organic solvent extraction have been developed over the last few years for the extraction of primary and secondary metabolites. These are: alcohol extraction with various biocompatible solvents, recovery of carboxylic acids and antibiotics with reactive extraction, dissociation extraction, aqueous two-phase extraction, and supercritical and near critical fluid extraction. Extraction and re-extraction processes are integrated into a single step by emulsion liquid membrane and solid supported liquid membrane extractions. These extraction processes are discussed and compared in this review, along with extraction with reversed micelles, and reactive extraction with the formation of a third phase at the organic-aqueous interface.