621 research outputs found

    Flexible bronchoscopy in children: Utility and complications

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    AbstractBackground and objectivesThe flexible bronchoscope has become widely used by pediatric pulmonologists as a diagnostic and therapeutic tool. Nevertheless, there are several gaps in our knowledge to help refine its use and reduce its complications. In this study, we aimed to evaluate the utility and complications of pediatric bronchoscopy.Design and settingWe conducted a retrospective review of bronchoscopy cases between March 2006 and April 2015 at a tertiary care medical center (King Fahad Medical City). One-hundred forty nine patients were studied.Patients and methodsWe evaluated how bronchoscopy contributed to the patients' diagnosis, assessed the accuracy of bronchoalveolar lavage white blood cell count (BAL WBC) to differentiate between infectious and non-infectious conditions, assessed the ability of clinical factors to predict high risk of desaturation during bronchoscopy, and finally summarized the reported procedural complications.ResultsWe found pediatric bronchoscopy was a crucial diagnostic (confirming, ruling out, and discovering unexpected diagnosis) and therapeutic tool. The accuracy of BAL WBC counts is poor (AUC (95% CI) = 0.609 (0.497–0.712)); however, using two cutoff values (≤10 WBCs (sensitivity = 84.44% and specificity = 29.27%) to rule out, and ≥400 WBCs (sensitivity = 33.33% and specificity 81.49%) to rule in infection) helped in early differentiation between infectious and non-infectious conditions. From the factors that we test, none we found predictive of desaturation. The most common procedural complication was desaturation (pooled incidence (95% CI) = 13 (8–19)%) followed by cough, mild airway bleeding, and spasm.ConclusionsFlexible bronchoscopy is an important and relatively safe diagnostic and therapeutic tool in pediatric medicine, and utilization of this service should be encouraged after a careful consideration of which patient needs this procedure and a rigorous estimate of its pros and cons

    High Quality Delay Testing Scheme for a Self-Timed Microprocessor

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    RÉSUMÉ La popularité d’internet et la quantité toujours croissante de données qui transitent à travers ses terminaux nécessite d’importantes infrastructures de serveurs qui consomment énormément d’énergie. Par conséquent, et puisqu’une augmentation de la consommation d’énergie se traduit par une augmentation des coûts, la demande pour des processeurs efficaces en énergie est en forte hausse. Une manière d’augmenter l’efficacité énergétique des processeurs consiste à moduler la fréquence d’opération du système en fonction de la charge de travail. Les processeurs endochrones et asynchrones sont une des solutions mettant en œuvre ce principe de modulation de l’activité à la demande. Cependant, les méthodes de conception non conventionnelles qui leur sont associées, en particulier en termes de testabilité et d’automation, sont un frein au développement de ce type de systèmes. Ce travail s’intéresse au développement d’une méthode de test de haute qualité adressée aux pannes de retards dans une architecture de processeur endochrone spécifique, appelée AnARM. La méthode proposée consiste à détecter les pannes à faibles retards (PFR) dans l’AnARM en tirant profit des lignes à délais configurables intégrées. Ces pannes sont connues pour passer au travers des modèles de pannes de retards utilisés habituellement (les pannes de retards de portes). Ce travail s’intéresse principalement aux PFR qui échappent à la détection des pannes de retards de portes mais qui sont suffisamment longues pour provoquer des erreurs dans des conditions normales d’opération. D’autre part, la détection de pannes à très faibles retards est évitée, autant que possible, afin de limiter le nombre de faux positifs. Pour réaliser un test de haute qualité, ce travail propose, dans un premier temps, une métrique de test dédiée aux PFR, qui est mieux adaptée aux circuits endochrones, puis, dans un second temps, une méthode de test des pannes de retards basée sur la modulation de la vitesse des lignes à délais intégrés, qui s’adapte à un jeu de vecteurs de test préexistant.Ce travail présente une métrique de test ciblant les PFR, appelée pourcentage de marges pondérées (PoMP), ainsi qu’un nouveau modèle de test pour les PFR (appelé test de PFR idéal).----------ABSTRACT The popularity of the Internet and the huge amount of data that is transfered between devices nowadays requires very powerful servers that demand lots of power. Since higher power consumptions mean more expenses to companies, there is an increase in demand for power eÿcient processors. One of the ways to increase the power eÿciency of processors is to adapt the processing speeds and chip activity according the needed computation load. Self-timed or asynchronous processors are one of the solutions that apply this principle of activity on demand. However, their unconventional design methodology introduces several challenges in terms of testability and design automation. This work focuses on developing a high quality delay test for a specific architecture of self-timed processors called the AnARM. The proposed delay test focuses on catching e˙ective small-delay defects (SDDs) in the AnARM by taking advantage of built-in configurable delay lines. Those defects are known to escape one of the most commonly used delay fault models (the transition delay fault model). This work mainly focuses on e˙ective SDDs which can escape transition delay fault testing and are large enough to fail the circuit under normal operating conditions. At the same time, catching very small delay defects is avoided, when possible, to avoid falsely failing functional chips. To build the high quality delay test, this work develops an SDD test quality metric that is better suited for circuits with adaptable speeds. Then, it builds a delay test optimizer that adapts the built-in delay lines speeds to a preexisting at-speed pattern set to create a high quality SDD test. This work presents a novel SDD test quality metric called the weighted slack percentage (WeSPer), along with a new SDD testing model (named the ideal SDD test model). WeSPer is built to be a flexible metric capable of adapting to the availability of information about the circuit under test and the test environment. Since the AnARM can use multiple test speeds, WeSPer computation takes special care of assessing the effects of test frequency changes on the test quality. Specifically, special care is taken into avoiding overtesting the circuit. Overtesting will cause circuits under test to fail due to defects that are too small to affect the functionality of these circuits in their present state. A computation framework is built to compute WeSPer and compare it with other existing metrics in the literature over a large sets of process-voltage-temperature computation points. Simulations are done on a selected set of known benchmark circuits synthesized in the 28nm FD-SOI technology from STMicroelectronics

    Design and Implementation of Integrated High Efficiency Low-voltage CMOS DC-DC Converters

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    RÉSUMÉ De nos jours, les appareils portatifs sont utilisés dans plusieurs applications. Ils utilisent en général une batterie qui doit être remplacée ou rechargée régulièrement. Dans le cas d'applications biomédicales, la durée de vie de la batterie est un paramètre critique. Pour un appareil implantable, une longue durée de vie est un objectif primordial. Cet objectif est généralement atteint en réduisant la consommation de puissance des circuits constituant l'implant. Parmi les diverses techniques existantes qui permettent la réduction de la consommation en puissance des circuits CMOS, on retrouve la technique d'ajustement dynamique de la tension (dynamic voltage scaling - DVS). En réduisant la tension d'alimentation, la consommation totale des circuits peut être diminuée. Cependant cette technique ne peut être implémentée sans faire appel à des circuits dédiés à une gestion intelligente de l'énergie. Dans ce contexte, l'utilisation de convertisseurs de tension DC-DC devient nécessaire pour économiser la charge de la batterie. Mais pour garantir une réduction effective de la consommation globale, des convertisseurs DC-DC de haute efficacité doivent être utilisés. A cette contrainte se rajoute la miniaturisation en utilisant des circuits hautement intégrés pour les applications telles que les implants biomédicaux. Le défi réside dans la conception d'un convertisseur DC-DC totalement intégré tout en assurant une haute efficacité sur une grande plage de tension de sortie. De plus, les appareils tels que les implants électroniques fonctionnent souvent en mode de veille pour réduire la consommation, entrainant ainsi des variations conséquentes de la charge du convertisseur DC-DC. Ceci rajoute un défi supplémentaire pour le maintient d'une haute efficacité de la conversion DC-DC à faible charge. Dans ce mémoire, nous présentons la conception détaillée d'un convertisseur DC-DC hautement efficace et totalement intégré dans une technologie CMOS à faible tension. Nous proposons une implémentation originale et totalement intégrée d'un convertisseur DC-DC à capacités commutés (switched capacitor - SC) opérant avec un contrôle asynchrone. L'efficacité du convertisseur est maintenue élevée en ajustant sa topologie et sa fréquence d'opération selon la charge.----------ABSTRACT Today, battery-powered portable devices are used in many applications. In applications like biomedical implants, the battery life is a major concern. Since replacing the battery of an implant needs a surgical procedure, a long battery life is a goal that all implants try to achieve. This is normally done by reducing the power dissipation in the implant's circuitry. One of the various techniques that exist for reducing the power consumption in CMOS circuitry is the dynamic voltage scaling (DVS) technique. By reducing the supply voltage, the overall power consumption of the circuits can be decreased. This technique cannot be implemented without power management blocks. The use of DC-DC converters becomes a must to save battery power. The overall power reduction can be improved by introducing high efficiency DC-DC converters. Moreover, to provide patients with the most comfort, small integrated circuits should be used in applications such as biomedical implants. The challenging aspect of designing integrated DC-DC converters is keeping the efficiency high while providing an adjustable output voltage. Additionally, devices such as electronic implants go in and out of stand-by mode to reduce power consumption. From the perspective of the DC-DC converter, the output load power is varying according to the mode of operation of the implant. This adds another challenge of sustaining the DC-DC conversion efficiency high under various loading conditions. At very light loads, preserving a high conversion efficiency is a challenge. In this master thesis, a detailed design of a high-efficiency low-voltage fully integrated DC-DC converter is presented. A unique structure of a fully integrated switched-capacitor (SC) DC-DC converter with asynchronous control is proposed. The efficiency of the converter is maintained high by adjusting the converter topology and operating frequency according to the loading conditions. The proposed SC DC-DC converter uses three different topologies to achieve three different conversion ratios. By doing so, the converter maintains high conversion efficiency at various output voltage levels. Also, an adaptive operating frequency is used by the asynchronous control to reduce efficiency losses at various loading conditions

    Fibrous dysplasia and aneurysmal bone cyst of the skull base presenting with blindness: a report of a rare locally aggressive example

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    Fibrous dysplasia (FD) and aneurysmal bone cyst (ABC) are uncommon benign intraosseous lesions. Simultaneous occurrence of both lesions is extremely rare. We present an example of concomitant FD and ABC in a 7 year-old with left eye blindness and discharge of one month duration. Physical examination revealed a proptotic left eye and bulging of the hard palate. CT and MRI are consistent with FD and ABC that involved the sphenoid and ethmoidal bones bilaterally. Incomplete combined endonasalcranial resection was performed. The patient presented five months postoperatively with a large recurrence and subsequent follow up was lost. Concomitant FD with ABC may occur in paranasal sinuses and may develop rapidly and exhibit locally aggressive behavior

    Ultrasound for the Anesthesiologists: Present and Future

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    Ultrasound is a safe, portable, relatively inexpensive, and easily accessible imaging modality, making it a useful diagnostic and monitoring tool in medicine. Anesthesiologists encounter a variety of emergent situations and may benefit from the application of such a rapid and accurate diagnostic tool in their routine practice. This paper reviews current and potential applications of ultrasound in anesthesiology in order to encourage anesthesiologists to learn and use this useful tool as an adjunct to physical examination. Ultrasound-guided peripheral nerve blockade and vascular access represent the most popular ultrasound applications in anesthesiology. Ultrasound has recently started to substitute for CT scans and fluoroscopy in many pain treatment procedures. Although the application of airway ultrasound is still limited, it has a promising future. Lung ultrasound is a well-established field in point-of-care medicine, and it could have a great impact if utilized in our ORs, as it may help in rapid and accurate diagnosis in many emergent situations. Optic nerve sheath diameter (ONSD) measurement and transcranial color coded duplex (TCCD) are relatively new neuroimaging modalities, which assess intracranial pressure and cerebral blood flow. Gastric ultrasound can be used for assessment of gastric content and diagnosis of full stomach. Focused transthoracic (TTE) and transesophageal (TEE) echocardiography facilitate the assessment of left and right ventricular function, cardiac valve abnormalities, and volume status as well as guiding cardiac resuscitation. Thus, there are multiple potential areas where ultrasound can play a significant role in guiding otherwise blind and invasive interventions, diagnosing critical conditions, and assessing for possible anatomic variations that may lead to plan modification. We suggest that ultrasound training should be part of any anesthesiology training program curriculum

    ENFOQUE SISTÉMICO COMO PROPUESTA METODOLÓGICA PARA EL DISEÑO DE VIVIENDAS DE INTERÉS SOCIAL EN ESTUDIANTES DE ARQUITECTURA DE LA UNIVERSIDAD DE GUAYAQUIL

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    El siguiente artículo está relacionado con la problemática de la vivienda la cual tiene su principal componente en el aumento de la población del Ecuador. A partir de los datos censales del INEC en el año 2012, la población del Ecuador se estima pasará de 15 millones a 23 millones para el año 2050. En Guayaquil por ejemplo, la proporción de habitantes de barrios populares ha ido creciendo de un 41% en el año 82; a un 72% según datos del Censo de Población y Vivienda del año 2010. Esta problemática demanda urgentes respuestas y alternativas de parte de la academia para aportar con soluciones espaciales acordes a las diversas realidades humanas, geográficas e históricas. Tradicionalmente se define a los hogares de las personas de bajos ingresos como “Vivienda de bajo costo” sin embargo, el concepto de Vivienda de Interés Social (VIS) definida en esta investigación, se realiza para destacar que es prioridad encontrar un compromiso razonable entre los costos y otros indicadores como son el confort y el cuidado al medioambiente, con el fin de ofertar viviendas saludables y seguras para los sectores menos favorecidos de la población. El diseño de prototipos de viviendas de interés social parte del estudio del contexto social, económico y medio ambiental, caracterizando así el territorio donde se implantará el proyecto. Con este conocimiento, será posible dar respuestas coherentes, integrando además el diseño del mobiliario interior a las viviendas de interés social, mediante el análisis ergonómico y antropométrico de la comunidad. Abstract The following article is related to the problem of housing, which has its main component in the increase of the population of Ecuador. From the census data of the INEC in 2012, the population of Ecuador is estimated to increase from 15 million to 23 million by the year 2050. In Guayaquil, for example, the proportion of inhabitants of working class neighborhoods has grown by 41% in the year 82; to 72% according to data from the Population and Housing Census of 2010. This problem demands urgent responses and alternatives from the academy to provide spatial solutions according to the different human, geographical and historical realities. Traditionally, low-income households are defined as "Low-cost housing"; however, the concept of Social Interest Housing (VIS) defined in this research is made to emphasize that it is a priority to find a reasonable compromise between costs and other indicators such as comfort and care for the environment, in order to offer safe and healthy homes for the less favored sectors of the population. The design of prototypes of social housing starts from the study of the social, economic and environmental context, thus characterizing the territory where the project will be implemented. With this knowledge, it will be possible to give coherent answers, integrating also the design of the interior furniture to the houses of social interest, through the ergonomic and anthropometric analysis of the community. Key Words: social interest housing, prefabricated system, bioclimatic design, interior design, systemic approac

    Vacuolization of hematopoietic precursors: an enigma with multiple etiologies

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    Cytoplasmic vacuoles in precursors can be seen in a number of clinical settings, including copper deficiency, zinc toxicity, alcohol abuse, antibiotic treatment, myelodysplasia, and VEXAS syndrome. Gurnari et al asked how common VEXAS syndrome is in patients whose bone marrow aspirates show this distinctive feature, finding 2 diagnoses of VEXAS among 24 cases with vacuoles

    Involvement of β-defensin 130 (DEFB130) in the macrophage microbicidal mechanisms for killing Plasmodium falciparum

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    金沢大学医薬保健研究域薬学系Understanding the molecular defense mechanism of macrophages and identifying their effector molecules against malarial parasites may provide important clues for the discovery of new therapies. To analyze the immunological responses of malarial parasite-induced macrophages, we used DNA microarray technology to examine the gene profile of differentiated macrophages phagocytizing Plasmodium falciparum-parasitized erythrocytes (iRBC). The transcriptional gene profile of macrophages in response to iRBCs represented 168 down-regulated genes, which were mainly involved in the cellular immune response, and 216 upregulated genes, which were involved in cellular proteolysis, growth, and adhesion. Importantly, the specific upregulation of β-defensin 130 (DEFB130) in these macrophages suggested a possible role for DEFB130 in malarial parasite elimination. Differentiated macrophages phagocytizing iRBCs exhibited an increase in intracellular DEFB130 levels and DEFB130 appeared to accumulate at the site of iRBC engulfment. Transfection of esiRNA-mediated knockdown of DEFB130 into macrophages resulted in a remarkable reduction in their antiplasmodial activity in vitro. Furthermore, DEFB130 synthetic peptide exhibited a modest toxic effect on P. falciparum in vitro and P. yoelii in vivo, unlike scrambled DEFB130 peptide, which showed no antiplasmodial activity. Together, these results suggest that DEFB130 might be one of the macrophage effector molecules for eliminating malarial parasites. Our data broaden our knowledge of the immunological response of macrophages to iRBCs and shed light on a new target for therapeutic intervention. © The Author(s) 2017

    Clinical and basic implications of dynamic T cell receptor clonotyping in hematopoietic cell transplantation

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    TCR repertoire diversification constitutes a foundation for successful immune reconstitution after allogeneic hematopoietic cell transplantation (allo-HCT). Deep TCR V beta sequencing of 135 serial specimens from a cohort of 35 allo-HCT recipients/donors was performed to dissect posttransplant TCR architecture and dynamics. Paired analysis of clonotypic repertoires showed a minimal overlap with donor expansions. Rarefied and hyperexpanded clonotypic patterns were hallmarks of T cell reconstitution and influenced clinical outcomes. Donor and pretransplant TCR diversity as well as divergence of class I human leukocyte antigen genotypes were major predictors of recipient TCR repertoire recovery. Complementary determining region 3-based specificity spectrum analysis indicated a predominant expansion of pathogen- and tumor-associated clonotypes in the late post-allo-HCT phase, while autoreactive clones were more expanded in the case of graft-versus-host disease occurrence. These findings shed light on post-allo-HCT adaptive immune reconstitution processes and possibly help in tracking alloreactive responses
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