1,684 research outputs found
Sobre redes y distancias en la Edad Moderna: Arte y cultura entre España e Hispanoamérica
Fracturas peritrocantéricas tratadas con el clavo proximal de fémur: Técnica y resultados
El Clavo Proximal de Fémur (PFN: Proximal Femoral Nail) es un sistema de osteosíntesis desarrollado por la AO/ASIF para el tratamiento quirúrgico de las fracturas de la región trocantérea del fémur y que se basa en los principios del enclavado endomedular a cielo cerrado. Se presenta un estudio prospectivo sobre 175 fracturas de cadera tratadas con P.F.N. en nuestro servicio, con un seguimiento mínimo exigido de 1 año. El 74,3% de los casos correspondieron a mujeres y el resto a hombres. La edad media fue de 81,87 años. Las fracturas se han clasificado según la AO, siendo el subtipo más frecuentemente registrado el A2. Se realizaron controles clínicos y radiológicos a los 1, 3, 6 y 12 meses. El sistema ha permitido la movilización y la deambulación precoz en la mayoría de nuestros pacientes, al igual que la consolidación de las fracturas en un tiempo aceptable (12 semanas de media). Se analizan los resultados y las diversas complicaciones registradas, así como la capacidad de recuperación de la capacidad funcional previa. El PFN se revela como un buen sistema de osteosíntesis para las fracturas de la región trocantérea del fémur, permitiendo una carga precoz que favorece la consolidación ósea. La técnica quirúrgica no es compleja, la tasa de complicaciones técnicas registradas es aceptable y los resultados globales obtenidos son equiparables e incluso superiores, en determinados aspectos, a los obtenidos con otros sistemas de osteosíntesis disponibles en el mercado para el tratamiento de este tipo de fracturas.The PFN ("proximal femoral nail") is an osteosynthesis system developed by the AO/ASIF group for the surgical treatment of fractures of the trochanteric region of the femur, which is based on the principles of closed endomedullary nailing. A prospective study of 175 hip fractures treated with the PFN is presented, with a minimum follow-up of 1 year. 74,3% of the patients were female, the rest male. The average age was 81,87 years. Fractures were classified according to the AO system, the most common sub-type recorded being the A2. Clinical and radiographic evaluations were performed at 1, 3, 6 and 12 months. The system allowed early mobilisation and walking in the majority of our patients, along with fracture consolidation in an acceptable time period (12 weeks on average). The results and the various complications recorded are analysed. The ability to recover previous walking ability was also studied. The PFN emerges as a good system of osteosynthesis for fractures of the trochanteric region of the femur, allowing early weight-bearing which favours bone consolidation. The surgical technique is not complex, the number of complications recorded is acceptable and the overall results obtained are comparable and even superior to those obtained with other osteosynthesis systems available on the market for treatment of this type of fracture
Tratamiento quirúrgico de las fracturas supracondíleas de húmero en la infancia
Presentamos un estudio retrospectivo de 130 niños tratados quirúrgicamente por fractura supracondílea desplazada de húmero. Todos los pacientes tuvieron un seguimiento de al menos 12 meses. Utilizando la clasificación de Gartland, el 16% fueron tipo II (21/130) y el 84% (109/130) tipo III. En 6 casos hubo ausencia de pulso radial, que se recuperó en 4 casos tras la reducción y estabilización de la fractura. El 70% (91/130) fueron tratados con agujas de Kirschner cruzadas. Se estudiaron los resultados siguiendo los criterios de Flynn, siendo éstos satisfactorios en el 85% (111/130). Hubo 6 fallos de reducción cerrada en el quirófano que requirieron reducción abierta. La secuela más frecuente fue el cúbito varo, en 9 casos, y 3 niños tenían cúbito valgo, con escasa repercusión funcional. El nervio más comúnmente afectado, tras el tratamiento quirúrgico, fue el mediano (5 casos) y el cubital (5 casos), con neuroapraxia resuelta en 6 meses salvo en un caso.A retrospective review of 130 children treated surgically for displaced supracondylar humeral fractures was conducted. All patients had a minimum of 12 months follow-up. According to Gartland classification, 16% were type II (21/130) and 84% (111/130) type III. A lack of radial pulse was reported in 6 cases, with a total recovery after the reduction and stabilization of the fracture, except in 2 cases. 70% (91/130) were treated with crossed Kirschner wires. The results were studied following Flynn criteria, 85% (111/130) were considered satisfactory. There were 6 failed closed reductions in the operating room, that required open reduction. The most frequent permanent damage was cubitus varus in 9 cases, and 3 children had cubitus valgus, but with little functional impairment. During the surgery, the most commonly affected nerve was median (5 cases) and ulnar (5 cases), with neurapraxias mostly recovered in 6 months
Reformulating Pro-Oxidant Microglia in Neurodegeneration
In neurodegenerative diseases, microglia-mediated neuroinflammation and oxidative stress are central events. Recent genome-wide transcriptomic analyses of microglial cells under different disease conditions have uncovered a new subpopulation named disease-associated microglia (DAM). These studies have challenged the classical view of the microglia polarization state's proinflammatory M1 (classical activation) and immunosuppressive M2 (alternative activation). Molecular signatures of DAM and proinflammatory microglia (highly pro-oxidant) have shown clear differences, yet a partial overlapping gene profile is evident between both phenotypes. The switch activation of homeostatic microglia into reactive microglia relies on the selective activation of key surface receptors involved in the maintenance of brain homeostasis (a.k.a. pattern recognition receptors, PRRs). Two relevant PRRs are toll-like receptors (TLRs) and triggering receptors expressed on myeloid cells-2 (TREM2), whose selective activation is believed to generate either a proinflammatory or a DAM phenotype, respectively. However, the recent identification of endogenous disease-related ligands, which bind to and activate both TLRs and TREM2, anticipates the existence of rather complex microglia responses. Examples of potential endogenous dual ligands include amyloid β, galectin-3, and apolipoprotein E. These pleiotropic ligands induce a microglia polarization that is more complicated than initially expected, suggesting the possibility that different microglia subtypes may coexist. This review highlights the main microglia polarization states under disease conditions and their leading role orchestrating oxidative stress
Design of splints based on the NiTi alloy for the correction of joint deformities in the fingers
<p>Abstract</p> <p>Background</p> <p>The proximal interphalange joint (PIP) is fundamental for the functional nature of the hand. The contracture in flexion of the PIP, secondary to traumatisms or illnesses leads to an important functional loss. The use of correcting splints is the common procedure for treating this problem. Its functioning is based on the application of a small load and a prolonged stress which can be dynamic, static progressive or static serial.</p> <p>It is important that the therapist has a splint available which can release a constant and sufficient force to correct the contracture in flexion. Nowadays NiTi is commonly used in bio-engineering, due to its superelastical characteristics. The experience of the authors in the design of other devices based on the NiTi alloy, makes it possible to carry out a new design in this work - the production of a finger splint for the treatment of the contracture in flexion of the PIP joint.</p> <p>Methods</p> <p>Commercial orthosis have been characterized using a universal INSTRON 5565 machine. A computational simulation of the proposed design has been conducted, reproducing its performance and using a model "ad hoc" for the NiTi material. Once the parameters have been adjusted, the design is validated using the same type of test as those carried out on commercial orthosis.</p> <p>Results and Discussion</p> <p>For commercial splint the recovering force falls to excessively low values as the angle increases. Angle curves for different lengths and thicknesses of the proposed design have been obtained, with a practically constant recovering force value over a wide range of angles that vary between 30° and 150° in every case. Then the whole treatment is possible with only one splint, and without the need of progressive replacements as the joint recovers.</p> <p>Conclusions</p> <p>A new model of splint based on NiTi alloy has been designed, simulated and tested comparing its behaviour with two of the most regularly used splints. Its uses is recommended instead of other dynamic orthosis used in orthopaedics for the PIP joint. Besides, its extremely simple design, makes its manufacture and use on the part of the specialist easier.</p
Multichannel QCM-based system for continuous monitoring of bacterial biofilm growth
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Quartz crystal microbalance (QCM) sensors are becoming a good alternative to analytical methods for the measurement of bacterial growth in liquid media culture. For this purpose, two essential resonance parameters allow monitoring of biofilm formation: the series resonance frequency shift and the change of the resistance at this frequency. Nevertheless, several problems arise in determining these parameters, as their relative variation is very small. This means that an accurate procedure must be implemented for the measurement of the QCM resonance parameters, including the automatic calibration of the frequency response effects of the measurement circuits and the automatic compensation of the static electrical capacitance of the QCM.
In this paper, a novel multichannel system for on-line monitoring of biofilm formation based on QCM sensors is proposed. QCM resonance parameters are determined from the electrical impedance analysis by means of an auto-balanced impedance bridge. This configuration has allowed the implementation of an affordable multichannel measurement instrument. Obtained results, based on binary mixtures of water-glycerol measurements and real microorganism experiments, are in good agreement with the theoretical behaviour. These results show the great potential of this instrument to be used for monitoring microbial growth and biofilm formation.Peer ReviewedPostprint (author's final draft
Divergent Effects of Metformin on an Inflammatory Model of Parkinson’s Disease
The oral antidiabetic drug metformin is known to exhibit anti-inflammatory properties through activation of AMP kinase, thus protecting various brain tissues as cortical neurons, for example. However, the effect of metformin on the substantia nigra (SN), the main structure affected in Parkinson’s disease (PD), has not yet been studied in depth. Inflammation is a key feature of PD and it may play a central role in the neurodegeneration that takes place in this disorder. The aim of this work was to determine the effect of metformin on the microglial activation of the SN of rats using the animal model of PD based on the injection of the pro-inflammogen lipopolysaccharide (LPS). In vivo and in vitro experiments were conducted to study the activation of microglia at both the cellular and molecular levels. Our results indicate that metformin overall inhibits microglia activation measured by OX-6 (MHCII marker), IKKβ (pro-inflammatory marker) and arginase (anti-inflammatory marker) immunoreactivity. In addition, qPCR experiments reveal that metformin treatment minimizes the expression levels of several pro- and anti-inflammatory cytokines. Mechanistically, the drug decreases the phosphorylated forms of mitogen-activated protein kinases (MAPKs) as well as ROS generation through the inhibition of the NADPH oxidase enzyme. However, metformin treatment fails to protect the dopaminergic neurons of SN in response to intranigral LPS. These findings suggest that metformin could have both beneficial and harmful pharmacological effects and raise the question about the potential use of metformin for the prevention and treatment of PD.España MINECO SAF2015-64171-
Effects of prescribed fire for pasture management on soil organic matter and biological properties: A 1-year study case in the Central Pyrenees
Prescribed burning has been readopted in the last decade in the Central Pyrenees to stop the regression of subalpine grasslands in favour of shrublands, dominated among others by Echinospartum horridum (Vahl) Rothm. Nevertheless, the effect of this practice on soil properties is uncertain. The aim of this work was to analyse the effects of these burnings on topsoil organic matter and biological properties. Soil sampling was carried out in an autumnal prescribed fire in Buisán (NE-Spain, November 2015). Topsoil was sampled at 0–1 cm, 1–2 cm and 2–3 cm depth in triplicate just before (U), ~ 1 h (B0), 6 months (B6) and 12 months (B12) after burning. We analysed soil total organic C (TOC), total nitrogen (TN), microbial biomass C (Cmic), soil respiration (SR) and ß-D-glucosidase activity. A maximum temperature of 438 °C was recorded at soil surface while at 1 cm depth only 31 °C were reached. Burning significantly decreased TOC (- 52%), TN (- 44%), Cmic (- 57%), SR (- 72%) and ß-D-glucosidase (- 66%) at 0–1 cm depth while SR was also reduced (- 45%) at 1–2 cm depth. In B6 and B12, no significant changes in these properties were observed as compared to B0. It can be concluded that the impact of prescribed burning has been significant and sustained over time, although limited to the first two topsoil centimetres
Flavonoides y Fenoles totales con actividad hipoglicemiante en semillas de Syzygium jambos
The present work sought to quantify flavonoids and total phenols in Syzygium jambos seeds and determine their hypoglycemic activity. In the dry extract of the seeds, total phenols were quantified by Folin-Ciocalteu method, with gallic acid (GAE) as standard, obtaining 309.40 mg GAE / g extract. Total flavonoids were quantified by the aluminum trichloride method; with quercetin (QE) standard, obtaining 19.13 mg QE/g extract. The hypoglycemic activity of Syzygium jambos seeds was determined on the glucose tolerance curve in groups I and II with 8 Rattus norvegicus specimens. var Holtzman, normoglycemic males, to which glucose (1 g / ml) was administered at a dose of 2.5 g / Kg b. w; Group II, 30 minutes before, was orally administered S. jambos seed extract (400 mg/Kg b. w). Glycemia at baseline and at 30, 60, 90, 120 and 180 minutes post-administration was determined with the Accu-Chek Active glucometer. Results showed minor increase in glycemia of group II, when comparing the glycemia values through the student t test, significant difference was produced with p<0.05. It is concluded that Syzygium jambos seeds have hypoglycemic activity in Rattus norvegicus var. Holtzman, due to its content in flavonoids and total phenolsEl presente trabajo buscó cuantificar flavonoides y fenoles totales en semillas de Syzygium jambos y determinar su actividad hipoglicemiante. En el extracto seco de las semillas, se cuantificó los fenoles totales aplicando Folin-Ciocalteu, con ácido gálico (GAE) como patrón, obteniéndose 309.40 mg GAE/g extracto. Los flavonoides totales se cuantificaron por el método de tricloruro de aluminio; con patrón quercetina (QE), obteniéndose 19.13 mg QE/g extracto. Se determinó la actividad hipoglicemiante de las semillas de Syzygium jambos sobre la curva de tolerancia a la glucosa en los grupos I y II con 8 especímenes Rattus norvegicus. var Holtzman, machos normoglicémicos, a los que se administró glucosa (1 g/ml) a dosis de 2.5 g/Kg p. c.; al grupo II, 30 minutos antes se le administró vía oral extracto de semillas de S. jambos (400 mg/Kg p.c). Se determinó la glicemia basal y a los 30 min, 60 min, 90 min, 120 min y 180 min post-administración con glucómetro Accu-Chek Active. Los resultados mostraron menor incremento de la glicemia del grupo II, al comparar los valores de glicemia mediante la prueba t de student, se observó una diferencia significativa con P<0.05. Se concluye que las semillas de Syzygium jambos poseen actividad hipoglicemiante en Rattus norvegicus var. Holtzman, por su contenido en flavonoides y fenoles totale
An efficient strategy for modeling the human auditory system from Micro-Computed Tomography Imaging.
Finite Element modeling is a widely used methodology to build numerical models and simulate the
behavior of the human auditory system; this has allowed essential advances in understanding the
biomechanics of that complex system. There are two key points in modeling: the construction of an
adequate geometry that allows efficient meshing and the correct use of mechanical properties of the
materials. This research aims to show a new strategy for automating the build Finite Element Model
process of the human auditory system using the FEM from Micro-Computed Tomography (Micro-CT)
Imaging. The idea behind this methodology is to build a Finite Element Model with a computational and
temporal low cost. This work allowed us to design the first semi-automatic algorithm to build a finite
element model of the human middle ear that will later be used to incorporate the other components
of the auditory system for different types of studies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
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