TiO2 nanotubes for room temperature toluene sensor

TiO2 nanotubes were used to prepare gas sensor and the gas sensing properties towards toluene were analyzed. Titania nanotube arrays were fabricated via electrochemical anodization method in glycerol electrolytes containing NH4F. The sensor fabricated from these nanotubes exhibits a good response to toluene at room temperature with good sensitivity. The toluene sensing properties were tested from 20 to 150 ppm concentrations.Fil: Perillo, Patricia Maria. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; ArgentinaFil: Rodriguez, Daniel Fabian. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; ArgentinaFil: Boggio, Norberto Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; Argentin

Three-dimensional electrode array for brain slice culture

Multielektroder arrays (MEA) er rækker af elektroder mest i mikrometer størrelse, som er blevet brugt i stor omfang til at stimulere og måle elektrisk aktivitet fra neuronale netværker. Brug af disse for at analysere hjerne slices (hjerneskiver) kan give indsigt i interaktioner mellem neuroner, eftersom dyrkninger af hjerneskiver in vitro beholder funktionaliteten af netværkerne i den levende hjerne. Elektroder var designet og fabrikeret med det formal at optimere MEA præstationen ved stimulering af og måling fra hjerneskiver in vitro. Meget af arbejdet beskrevet her beskæftiger sig med studiet af silicium mikrofabrikations teknikker for at opnå 3D elektroder med en høj dimensionsforhold, som er de mest egnede til at interagere med hjerneskiver. Elektroderne blev karakteriseret bade elektrisk og mekanisk for at demonstrere deres bedre egenskaber ved elektriske malinger og væv indtrægningsevne. Ved et andet sæt eksperimenter, det fabrikeret MEA system blev forsøgt integreret med et dyrkningsplatform som skal gøre længerevarende målinger mulige. Baseret på eksisterende litteratur mange forskellige platformer blev udviklet og tested med hjerneskiver. Selvom dyrkningen af væv ikke var mulig i disse systemer, eksperimenterne viser at de mikrofluidiske dele af systemet var funktionelle og det var muligt at integrere MEA systemet med ved at modificere den og lave den del af gennemstrømningsmekanismen. Til sidst en mekanisme som var I stand til at flytte elektroderne ind og ud af hjerneskiveren blev udviklet, simuleret og testet. Systemet var i stand til at flytte MEA chippen. Selvom mindre modifikationer vil være ønskelige for at forbedre bevægelsespræcisionen, integrering af denne mekanisme med MEA chippen var mulig og funktionaliteten af systemet blev påvist

Segmented assimilation trajectories and Latino health : an analysis of the adaptation process over time

Cultural adaptation factors likely influence health status and social mobility. Using data from the Corazón Life Journey Studies, cross-sectional interviews of immigrant Latino, U.S.-born Latino, and Non-Hispanic White adults (n=272), we investigated acculturation factors, social mobility, and health outcomes across four time points, elementary school, middle school, high school and current adulthood. Using growth mixture modeling, lifetime segmented assimilation trajectories were developed describing different acculturation and social mobility changes. A four-class model best described the data. Significant differences emerged among the ethnic groups. Family Traditionalism significantly predicted acculturations starting point and change over time. Initial acculturation values predicted social mobility. Differences were also found in health outcomes. Findings have implications for clinical work, research and policy. Early life experiences can influence social mobility later in life, affecting individuals\u27 health. We encourage researchers to employ more complex models in order to reveal mechanisms underlying Latinos\u27 and other ethnic groups\u27 health inequities

Inversion of multiconfiguration complex EMI data with minimum gradient support regularization: A case study

Frequency-domain electromagnetic instruments allow the collection of data in different configurations, that is, varying the intercoil spacing, the frequency, and the height above the ground. Their handy size makes these tools very practical for near-surface characterization in many fields of applications, for example, precision agriculture, pollution assessments, and shallow geological investigations. To this end, the inversion of either the real (in-phase) or the imaginary (quadrature) component of the signal has already been studied. Furthermore, in many situations, a regularization scheme retrieving smooth solutions is blindly applied, without taking into account the prior available knowledge. The present work discusses an algorithm for the inversion of the complex signal in its entirety, as well as a regularization method that promotes the sparsity of the reconstructed electrical conductivity distribution. This regularization strategy incorporates a minimum gradient support stabilizer into a truncated generalized singular value decomposition scheme. The results of the implementation of this sparsity-enhancing regularization at each step of a damped Gauss-Newton inversion algorithm (based on a nonlinear forward model) are compared with the solutions obtained via a standard smooth stabilizer. An approach for estimating the depth of investigation, that is, the maximum depth that can be investigated by a chosen instrument configuration in a particular experimental setting is also discussed. The effectiveness and limitations of the whole inversion algorithm are demonstrated on synthetic and real data sets

Concrete Swelling in Existing Dams

Several chemical reactions are able to produce swelling of concrete for decades after its initial curing, a problem that affects a considerable number of concrete dams around the world. Principia has had several contracts to study this problem in recent years, which have required reviewing the state-of-the-art, adopting appropriate mathematical descriptions, programming them into user routines in Abaqus, determining model parameters on the basis of some parts of the dams’ monitored histories, ensuring reliability using some other parts, and finally predicting the future evolution of the dams and their safety margins. The paper describes some of the above experience, including the programming of sophisticated non-isotropic swelling models, that must be compatible with cracking and other nonlinearities involved in concrete behaviour. The applications concentrate on two specific cases, an archgravity dam and a double-curvature arch dam, both with a long history of concrete swelling and which, interestingly, entailed different degrees of success in the modelling effort

Putting the pieces together : elucidation of podocyte biology in the homeostasis of the kidney filtration barrier

End-stage renal disease (ESRD) is a devastating condition that can only be treated with chronic dialysis or kidney transplantation. ESRD treatment costs account for up to 10% of healthcare budgets in the Western world. The 5-year survival for patients in dialysis is only about 40%. Glomerular disease processes are the main cause of ESRD. Despite this, our basic knowledge on the biology and disease processes of the glomerulus is poor. As a result, we still lack effective therapy options to stop the progression of glomerular diseases. In this thesis we have identified a number of candidate genes and proteins that could have an essential role in the glomerular homeostasis. In the first project, we identified a group of neural proteins, Hip1, Nfasc and Olfml2, which are enriched in podocytes. We used these markers to provide further evidence that podocytes are present in glomerular crescent lesions that occur in inflammatory diseases of the glomerulus. In project 2, we studied the functional role of another neural protein, dendrin, in the kidney by generating and characterizing a knockout (KO) mouse line. Previously, we and others have shown that dendrin is very specific to podocytes and interacts with cd2ap and nephrin, two podocyte proteins imperative for the maintenance of the kidney barrier. The KO mouse model showed that dendrin is not needed for the development or maintenance of the glomerulus filtration barrier. Furthermore, the outcome of glomerular disease in two injury models was unaffected by the absence of dendrin. This suggests that dendrin does not have a role in the development of glomerular damage in these two models. In project 3, we identified Tmem234, Slfn5, Lrrc49 and Znf185 as highly podocyte-enriched molecules. Morpholino knockdown experiments in zebrafish showed that the silencing of Tmem234 results in podocyte foot effacement and proteinuria in pronephros. Thus, Tmem234 seems to have an important role in the formation of functional filtration barrier in zebrafish pronephros, and therefore it is reasonable to speculate that it can have also an important role in the mammalian kidney. Lastly, in project 4 we identified a mediator protein subunit, Med22, to be essential for the kidney filtration barrier. In zebrafish pronephros, Med22 morphants exhibit defective capillary loop formation and leak large proteins to tubuli. In mice, full KO mice die during embryonic development. In podocyte-specific KO animals kidney development proceeds normally. However, these mice exhibit proteinuria starting from 8 weeks of age that progresses to ESRD by 16 weeks of age. Histological analysis shows the accumulation of caveolin-positive vesicles in the cytoplasm of podocytes. As these vesicles became larger, we detected the loss of podocytes that leads to glomerulosclerosis and ESRD. Thus, Med22 seems to regulate vesicular trafficking in podocytes and be essential for podocyte survival. This thesis provides novel insights into podocyte biology and obviously opens up new possibilities to study these candidate genes in glomerular function and pathology

Funciones que cumple el cuaderno resolutor al abordar una situación problema

Este artículo está especialmente elaborado para docentes y/o alumnos para profesores que deseen trabajar en la búsqueda de la solución de problemas a partir de la metodología del cuaderno resolutor, partiendo de la experiencia en el aula con un grupo de estudiantes donde se lleva a cabo una situación – problema (lugares geométricos), haciendo énfasis en la resolución de problemas que se plantea desde la teoría y contrastando con la experiencia propia que se tiene para llegar a la solución del problema.se formulen preguntas: ¿Qué es un cuaderno resolutor?, ¿Cómo lo manejan los estudiantes?, ¿Qué instrucciones se le daban para escribir en el cuaderno?, clarifique el objetivo, defina y ejecuta el plan de acción y finalmente se evalúe la solución