Ultra Low-Power Analog Median Filters

The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used

High Gain Amplifier with Enhanced Cascoded Compensation

A two-stage CMOS operational amplifier with both, gain-boosting and indirect current feedback frequency compensation performed by means of regulated cascode amplifiers, is presented. By using quasi-floating-gate transistors (QFGT) the supply requirements, the number of capacitors and the size of the compensation capacitors respect to other Miller schemes are reduced. A prototype was fabricated using a 0.5 μm technology, resulting, for a load of 45 pF and supply voltage of 1.65 V, in open-loop-gain of 129 dB, 23 MHz of gain-bandwidth product, 60o phase margin, 675 μW power consumption and 1% settling time of 28 ns

A 1.8 v Gm-C Highly Tunable Low Pass Filter for Sensing Applications

This paper presents a fully integrated, first-order Low Pass Filter with 2-tuning points giving a wide versatility to the filter. It allows for a fine/thick tuning with a cutoff frequency that spans over several orders of magnitude, from 220 mHz to 39.1 kHz. The Gm-C filter proposed is designed in a 180 nm CMOS technology with a total power consumption of 1.08 µW for a 1.8 V power supply and a dynamic range up to 73 dB. The proposed filter is a very competitive solution compared with previously reported works, meeting the requirements for portable on chip sensor interfaces based on impedance spectroscopy and biosignal front-end interfaces

A low-voltage low-power front-end for wearable EEG systems

A low-voltage and low-power front-end for miniaturized, wearable EEG systems is presented. The instrumentation amplifier, which removes the electrode drift and conditions the signal for a 10-bit A/D converter, combines a chopping strategy with quasi-FGMOS (QFG) transistors to minimize low frequency noise whilst enabling operation at 1 V supply. QFG devices are also key to the A/D converter operating at 1.2 V with 70dB of SNR and an oversampling ratio of 64. The whole system consumes less than 2uW at 1.2V.Published versio

Carbonatación de un hormigón hibrido con alto contenido de escoria siderurgica de alto horno y su impacto en la corrosión del acero estructural

The aim of this research was to study the carbonation resistance of a blast furnace slag concrete (80% GBFS/20%OPC), with and without alkaline activation, and its influence on the corrosion of structural reinforcement. An OPC-based concrete produced under the same specifications was used as a reference material. To do this, the material was subjected to an accelerated carbonation process under controlled conditions (65% relative humidity, 1% CO2, 25°C). The half-cell potential (Ecorr), linear polarization resistance (LPR) tests showed that both concretes based on GBFS led to depassivation of the reinforcing steel at approximately 99 days, which is the time required for full carbonation of the evaluated concretes.El objetivo de esta investigación fue estudiar la resistencia a la carbonatación de un hormigón a base de escoria granulada de alto horno (80% GBFS/20%OPC), con y sin activación alcalina, y su influencia sobre la corrosión del acero estructural. Un hormigón basado en cemento portland producido con las mismas especificaciones fue usado como material de referencia. Para ello, el material fue sometido a un proceso de carbonatación acelerada bajo condiciones controladas (Humedad Relativa 65 %, 1% CO2, 25 °C). Los ensayos de potencial de media celda (Ecorr) y Resistencia a la polarización lineal (LPR) mostraron que los aceros estructurales aproximadamente a los 99 días alcanzan la despasivación en los hormigones basados en escoria, coincide este tiempo con el requerido para la completa carbonatación de los hormigones evaluados

Assessing uncertainty and complexity in regional-scale crop model simulations

Crop models are imperfect approximations to real world interactions between biotic and abiotic factors. In some situations, the uncertainties associated with choices in model structure, model inputs and parameters can exceed the spatiotemporal variability of simulated yields, thus limiting predictability. For Indian groundnut, we used the General Large Area Model for annual crops (GLAM) with an existing framework to decompose uncertainty, to first understand how skill changes with added model complexity, and then to determine the relevant uncertainty sources in yield and other prognostic variables (total biomass, leaf area index and harvest index). We developed an ensemble of simulations by perturbing GLAM parameters using two different input meteorology datasets, and two model versions that differ in the complexity with which they account for assimilation. We found that added complexity improved model skill, as measured by changes in the root mean squared error (RMSE), by 5-10% in specific pockets of western, central and southern India, but that 85% of the groundnut growing area either did not show improved skill or showed decreased skill from such added complexity. Thus, adding complexity or using overly complex models at regional or global scales should be exercised with caution. Uncertainty analysis indicated that, in situations where soil and air moisture dynamics are the major determinants of productivity, predictability in yield is high. Where uncertainty for yield is high, the choice of weather input data was found critical for reducing uncertainty. However, for other prognostic variables (including leaf area index, total biomass and the harvest index) parametric uncertainty was generally the most important source, with a contribution of up to 90% in some cases, suggesting that regional-scale data additional to yield to constrain model parameters is needed. Our study provides further evidence that regional-scale studies should explicitly quantify multiple uncertainty sources

Implementation of a Multimodal Analgesic Strategy Including Continuous Femoral Nerve Block in Patients Undergoing Total Knee Arthroplasty

El remplazo total de rodilla es un procedimiento quirúrgico doloroso. El inadecuado control del dolor postoperatorio se asocia a desenlaces adversos a corto, y largo plazo. El bloqueo femoral continuo ha demostrado ser eficaz y eficiente como parte de la analgesia multimodal. Esta serie de 48 pacientes sometidos a remplazo total de rodilla, quienes recibieron tratamiento analgésico multimodal incluyendo bloqueo continuo de nervio femoral, documenta el perfil de control del dolor durante las primeras 48 horas. Esta es una experiencia exitosa de implementación de técnicas regionales como parte del alivio de dolor perioperatorio, como es documentado en la literatura. Hacemos hincapié en que cada institución debe conocer su recurso técnico y humano, y caracterizar a sus pacientes, para poder implementar protocolos de analgesia multimodal que incluyan esta técnica regional. Así mismo sugerimos hacer un seguimiento e implementar procesos de mejoramiento continuo.Total knee replacement is a painful surgical procedure. The inadequate control of postoperative pain is associated with adverse outcomes in the short and long term. Continuous femoral block has been shown to be effective and efficient as part of multimodal analgesia. This series of 48 patients who underwent total knee replacement, who received multimodal analgesic treatment including continuous femoral nerve block, documents the pain control profile during the first 48 hours. This is a successful experience of implementing regional techniques as part of perioperative pain relief, as documented in the literature. We emphasize that each institution must know its technical and human resource and characterize its patients, in order to implement multimodal analgesia protocols that include this regional technique. We also suggest to monitor and implement continuous improvement processes.https://orcid.org/0000-0001-7777-6630https://orcid.org/0000-0002-8043-716Xhttps://orcid.org/0000-0002-6305-153Xhttps://orcid.org/0000-0003-0326-3394Revista Nacional - Indexad

Machine-Learning Enhanced Photometric Analysis of the Extremely Bright GRB 210822A

We present analytical and numerical models of the bright long GRB 210822A at $z=1.736$. The intrinsic extreme brightness exhibited in the optical, which is very similar to other bright GRBs (e.g., GRBs 080319B, 130427A, 160625A 190114C, and 221009A), makes GRB 210822A an ideal case for studying the evolution of this particular kind of GRB. We use optical data from the RATIR instrument starting at $T+315.9$ s, with publicly available optical data from other ground-based observatories, as well as X-ray data from the Swift/X-ray Telescope (XRT) and data from the Swift/Ultraviolet/Optical Telescope (UVOT). The temporal profiles and spectral properties during the late stages align consistently with the conventional forward shock model, complemented by a reverse shock element that dominates optical emissions during the initial phases ($T<300$ s). Furthermore, we observe a break at $T=80000$ s that we interpreted as evidence of a jet break, which constrains the opening angle to be about $\theta_\mathrm{j}=(3-5)$ degrees. Finally, we apply a machine-learning technique to model the multi-wavelength light curve of GRB 210822A using the AFTERGLOWPY library. We estimate the angle of sight $\theta_{obs}=(6.4 \pm 0.1) \times 10^{-1}$ degrees, the energy $E_0= (7.9 \pm 1.6)\times 10^{53}$ ergs, the electron index $p=2.54 \pm 0.10$, the thermal energy fraction in electrons $\epsilon_e=(4.63 \pm 0.91) \times 10^{-5}$ and in the magnetic field $\epsilon_B= (8.66 \pm 1.01) \times 10^{-6}$, the efficiency $\chi = 0.89 \pm 0.01$, and the density of the surrounding medium $n_\mathrm{0} = 0.85 \pm 0.01$.Comment: Submitted to MNRAS, 11 pages, 6 figures. Fixed typo

Transcriptional Shift Identifies a Set of Genes Driving Breast Cancer Chemoresistance

Background Distant recurrences after antineoplastic treatment remain a serious problem for breast cancer clinical management, which threats patients’ life. Systemic therapy is administered to eradicate cancer cells from the organism, both at the site of the primary tumor and at any other potential location. Despite this intervention, a significant proportion of breast cancer patients relapse even many years after their primary tumor has been successfully treated according to current clinical standards, evidencing the existence of a chemoresistant cell subpopulation originating from the primary tumor.Methods/Findings To identify key molecules and signaling pathways which drive breast cancer chemoresistance we performed gene expression analysis before and after anthracycline and taxane-based chemotherapy and compared the results between different histopathological response groups (good-, mid- and bad-response), established according to the Miller & Payne grading system. Two cohorts of 33 and 73 breast cancer patients receiving neoadjuvant chemotherapy were recruited for whole-genome expression analysis and validation assay, respectively. Identified genes were subjected to a bioinformatic analysis in order to ascertain the molecular function of the proteins they encode and the signaling in which they participate. High throughput technologies identified 65 gene sequences which were over-expressed in all groups (P ≤ 0·05 Bonferroni test). Notably we found that, after chemotherapy, a significant proportion of these genes were over-expressed in the good responders group, making their tumors indistinguishable from those of the bad responders in their expression profile (P ≤ 0.05 Benjamini-Hochgerg`s method).Conclusions These data identify a set of key molecular pathways selectively up-regulated in post-chemotherapy cancer cells, which may become appropriate targets for the development of future directed therapies against breast cancer.Thanks are due to the Consejería de Economia, Innovación y Ciencia (CEIC) from the Junta de Andalucía and Fondo Europeo de Desarrollo Regional (FEDER)/Fondo de Cohesión Europeo (FSE) to financial support through the Programa Operativo FEDER/FSE de Andalucía 2007-2013 and the research project CTS-5350. The authors also acknowledge financial support by the PN de I+D+i 2006-2009/ISCIII/Ministerio de Sanidad, Servicios Sociales e Igualdad (Spain) and Fondo Europeo de Desarrollo Regional (FEDER) from the European Union, through the research project PI06/90388

Ultrasoud-Guided diaphragmatic motility evaluation in patients under-going orthopaedic surgery of the upper limb under regional anesthesia using infraclavicular block

Introducción: el bloqueo de plexo braquial por vía infraclavicular ofrece anestesia completa, efectiva y segura para cirugías del miembro superior desde el tercio distal del brazo. El presente estudio evaluó la afectación de la motilidad diafragmática mediante evaluación ecográfica estandarizada en pacientes a quienes se les realizó esta técnica anestésica. Materiales y métodos: se reclutaron 53 pacientes programados para cirugía ortopédica del miembro superior distal al hombro. Se realizó escaneo ultrasonográfico del diafragma de manera bilateral, antes y después de la realización del bloqueo. Se obtuvieron mediciones de motilidad diafragmática en inspiración forzada y espiración, utilizando un transductor Convex de baja frecuencia. Se localizó el punto más profundo de visualización del diafragma que permitiera su seguimiento durante inspiración/espiración en el modo M. Resultados: la medición de la motilidad diafragmática fue hecha de forma estandarizada en todos los pacientes antes y después del bloqueo, mediante una evaluación tanto cualitativa como cuantitativa, a fin de obtener un valor promedio absoluto de 6,63 cm (DE ± 0,35) y 6,75 cm (DE ± 0,42), respectivamente. La prueba de t de Student no mostró diferencia estadísticamente significativa en el desplazamiento diafragmático antes y después de la intervención. Conclusiones: el uso de la ultrasonografía en la evaluación de la motilidad diafragmática es una herramienta simple, no invasiva y reproducible. En el bloqueo de plexo braquial por vía infraclavicular no se encontró evidencia de parálisis diafragmática ipsilateral; sin embargo, el resultado podría estar relacionado con la baja prevalencia de esta complicación en el abordaje evaluado y con la ausencia de estandarización de las variables medidas.Artículo original155-162Introduction: Infraclavicular brachial-plexus block provides complete, effective and safe anesthesia for upper-limb surgical interventions from the distal third of the arm onwards. This study evaluated the possible compromise of dia-phragmatic motility using standardized ultrasonographic evaluation in patients who underwent this anesthetic technique. Methods: 53 patients were recruited for upper-limb orthopedic surgery distal to the shoulder. Bilateral ultrasonographic exploration of the diaphragm was made both be-fore and after the regional anesthesia was per-formed. Diaphragmatic motility measurements were taken in forced inspiration and expiration utilizing a Convex, low frequency transducer. The deepest point of diaphragmatic visualization was identified and followed during inspiration and expiration maneuvers using M Mode Ultra-sonography. Results: A standardized measure-ment of diaphragmatic motility was performed in every patient both before and after the block was undertaken. We obtained both qualitative and quantitative measurements obtaining an average absolute value of 6.63 cm (SD±0,35) and 6.75 cm (SD±0.42), respectively. A statisti-cal Student t test was performed demonstrating no significant difference in diaphragm move-ment before and after the anesthetic procedu-re. Discussion: The use of ultrasonography in the evaluation of diaphragmatic motility is asimple, non-invasive and reproducible tool. The-re is no evidence of diaphragmatic paralysis after infraclavicular brachial-plexus block. However, the result may be related toe the low prevalen-ce of this complication and with the absence of normal, standardized values of the variables of interest