187 research outputs found
Harvesting indoor light to supply power to nomad embedded systems
International audienceIt is possible to design a system to supply power to low consumption systems (hundreds of µW to tens of mW) from industrial devices. To develop an autonomous system based on harvesting energy from mixed artificial and natural light, it is mandatory to know which solutions are available and suitable to the conditions of use of the system to be designed. In this paper a comparison of solar cells exposed to different indoor light sources is made. This allows to establish which technology is the most relevant to use in different light environments, in terms of power generation. In addition, the difference in behavior between the two most widely produced solar cells, crystallin and amorphous Si, is depicted. We conclude that for new efficient light sources as fluorescent tubes, CFLs and LEDs, amorphous silicon is the best solution to generate power. On the other hand, crystallin silicon is the most efficient under incandescent, halogen or sunlight exposition
Sequence polymorphism can produce serious artefacts in real-time PCR assays: hard lessons from Pacific oysters
<p>Abstract</p> <p>Background</p> <p>Since it was first described in the mid-1990s, quantitative real time PCR (Q-PCR) has been widely used in many fields of biomedical research and molecular diagnostics. This method is routinely used to validate whole transcriptome analyses such as DNA microarrays, suppressive subtractive hybridization (SSH) or differential display techniques such as cDNA-AFLP (Amplification Fragment Length Polymorphism). Despite efforts to optimize the methodology, misleading results are still possible, even when standard optimization approaches are followed.</p> <p>Results</p> <p>As part of a larger project aimed at elucidating transcriptome-level responses of Pacific oysters (<it>Crassostrea gigas</it>) to various environmental stressors, we used microarrays and cDNA-AFLP to identify Expressed Sequence Tag (EST) fragments that are differentially expressed in response to bacterial challenge in two heat shock tolerant and two heat shock sensitive full-sib oyster families. We then designed primers for these differentially expressed ESTs in order to validate the results using Q-PCR. For two of these ESTs we tested fourteen primer pairs each and using standard optimization methods (i.e. melt-curve analysis to ensure amplification of a single product), determined that of the fourteen primer pairs tested, six and nine pairs respectively amplified a single product and were thus acceptable for further testing. However, when we used these primers, we obtained different statistical outcomes among primer pairs, raising unexpected but serious questions about their reliability. We hypothesize that as a consequence of high levels of sequence polymorphism in Pacific oysters, Q-PCR amplification is sub-optimal in some individuals because sequence variants in priming sites results in poor primer binding and amplification in some individuals. This issue is similar to the high frequency of null alleles observed for microsatellite markers in Pacific oysters.</p> <p>Conclusion</p> <p>This study highlights potential difficulties for using Q-PCR as a validation tool for transcriptome analysis in the presence of sequence polymorphism and emphasizes the need for extreme caution and thorough primer testing when assaying genetically diverse biological materials such as Pacific oysters. Our findings suggest that melt-curve analysis alone may not be sufficient as a mean of identifying acceptable Q-PCR primers. Minimally, testing numerous primer pairs seems to be necessary to avoid false conclusions from flawed Q-PCR assays for which sequence variation among individuals produces artifactual and unreliable quantitative results.</p
Calidad del servicio y satisfacción del paciente en el área de emergencia de un hospital, Lima, 2023
Este trabajo de investigación titulado Calidad del servicio y satisfacción del
paciente en el área de emergencia de un hospital, Lima, 2023”, se realizó con el
objetivo de determinar la relación que existe entre la calidad del servicio y la
satisfacción del paciente en el área de emergencia de un hospital de Lima, 2023.
Se elaboró bajo un nivel correlacional, de tipo básica, descriptiva y transversal.
El diseño es de metodología cuantitativa y la técnica de recopilación de datos
fue el cuestionario. Se realizó a un total de 195 pacientes que se atendieron en
el área de emergencia de un hospital de Lima, donde se les aplicó una encuesta
que estuvo conformada por 41 ítems, de los que 21 pertenecieron a la variable
Calidad del Servicio y 20 pertenecieron a la variable Satisfacción del paciente,
dicha encuesta se trabajó bajo la escala de Likert, colocando 5 posibles
respuestas que se puntuaron de la siguiente forma: 1 Nunca, 2 Casi Nunca, 3 A
Veces, 4 Casi Siempre y 5 Siempre. La participación del llenado de las encuestas
fue voluntaria y cada ficha de preguntas no llevó datos personales o de
identificación del encuestado, asegurando así la confidencialidad de la identidad
de cada paciente. La tabulación, orden y procesamiento de los datos fue a través
del programa SPSS V.25, lo que nos permitió elaborar cuadros y gráficos
estadísticos con el fin de analizar los resultados y elaborar las interpretaciones
de estas. Con el análisis de los resultados pudimos deducir que existe una
relación moderada entre las variables de estudio, esto se debe a que, el indicador
de correlación de Rho de Spearman mostró un resultado de 0.640 y un nivel de
significancia de 0,00 es decir >0,05, esto demuestra que hay una correlación
fuerte al estar cerca de 1. La frecuencia para la variable calidad fue de 68.9% y
27.0% para la valoración “regular” y “buena” respectivamente. Asimismo, la
frecuencia para la variable Satisfacción fue de 55.6% y 11.7% para la valoración
“satisfecho” y “muy satisfecho” respectivamente. Con esto, concluimos que los
pacientes estas medianamente satisfechos con la calidad de atención ofertada
por el centro asistencial
Image-based estimation of myocardial acceleration using TDFFD: a phantom study
International audienceIn this paper, we propose to estimate myocardial acceleration using a temporal di↵eomorphic free-form deformation (TDFFD) algorithm. The use of TDFFD has the advantage of providing B-spline parameterized velocities, thus temporally smooth, which is an asset for the computation of acceleration. The method is tested on 3D+t echocar-diographic sequences from a realistic physical heart phantom, in which ground truth displacement is known in some regions. Peak endocardial acceleration (PEA) error was 20.4%, the main hypothesis for error being the low temporal resolution of the sequences. The allure of the acceleration profile was reasonably preserved. Our method suggests a non-invasive technique to measure cardiac acceleration that may be used to improve the monitoring of cardiac mechanics and consecutive therapy planning
Multidimensional characterization, Landau levels and Density of States in epitaxial graphene grown on SiC substrates
Using high-temperature annealing conditions with a graphite cap covering the C-face of, both, on axis and 8° off-axis 4H-SiC samples, large and homogeneous single epitaxial graphene layers have been grown. Raman spectroscopy shows evidence of the almost free-standing character of these monolayer graphene sheets, which was confirmed by magneto-transport measurements. On the best samples, we find a moderate p-type doping, a high-carrier mobility and resolve the half-integer quantum Hall effect typical of high-quality graphene samples. A rough estimation of the density of states is given from temperature measurements
Aging Effect of Catechol Redox Polymer Nanoparticles for Hybrid Supercapacitors
[EN] Redox-polymer nanoparticles are a promising solution to avoid the detrimental dissolution of organic electrode materials while showing discrete redox processes. In this work, catechol-based redox-active polymer nanoparticles (cRPNs) were synthesized through one-step emulsion polymerization with a tunable size from 25 to 150 nm. The fresh cRPNs were characterized and showed a reversible redox process centered at 0.50 V (vs. Ag/AgCl) in 1 M H2SO4. Unexpectedly, the cRPN latex aged after days passing from white to pink. This aging resulted in a shift of its redox potential toward higher values, which could be associated to autoxidation of the catechol groups and subsequent crosslinking of NPs due to catechol dimer formation. Finally, we compared the performance of fresh and aged cRPNs in a hybrid supercapacitor device, proving how the aging effect had some benefits such as an increase in the voltage output, specific capacitance, cyclability and Coulombic efficiencies of the device.The authors thank for technical and human support provided by IZO-SGI SGIker of UPV/EHU. Technical and human support provided by IZO-SGI, SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) is gratefully acknowledged for assistance and generous allocation of computational resources. The authors would like to thank the European Commission for financial support through funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 823989. N.P. appreciates Spanish MINECO for the Juan de la Cierva-formation fellowship (FJC2018-037781-I). R.M. thanks the Spanish Ministry of Science, Innovation and Universities through the SUSBAT project (Ref.RTI2018-101049-B-I00) (MINECO/FEDER, UE) for financial support
Profil épidémiologique des paralysies flasques aiguës (PFA) de 2009 à 2018 en Guinée: Epidemiological profile of acute flaccid paralysis (AFP) from 2009 to 2018 in Guinea
Introduction: En 2015, la Guinée a connu une épidémie de poliovirus dérivant d'une souche vaccinale type 2 avec un total de 7 cas dont une riposte a permis d'arrêter. L'objectif de cette étude était de décrire le profil épidémiologique des cas de Paralysie Flasque Aiguë (PFA) en termes de temps, lieu et personne. Méthodes: Il s'agissait d'une étude transversale descriptive des données de PFA, 2009-2018 de la Coordination Nationale du programme élargi de vaccination (PEV). Un cas de PFA était défini comme tout enfant de moins de 15 ans présentant une PFA ou une suspicion de poliomyélite par médecin. Résultats: Au total, 3034 cas de PFA ont été notifiés. La proportion de PFA non polio était de 7,09/100000. La quasi-totalité des cas présentait la fièvre (94%). La paralysie des membres inférieurs était observée chez 86,18% des cas. La proportion de cas de PFA notifiés dans les 24 heures de détection était de 83,06%. Celle des cas de PFA investigués dans les 48 heures de notification était de 90,38%. Dans 96,14% des cas, deux échantillons de selles avaient été prélevés et envoyés au laboratoire dans les 14 jours, seulement 72,51% étaient arrivés à temps. Parmi les cas, 70,07% avaient reçu au moins 3 doses de vaccin polio oral. Conclusion: Les indicateurs de performance de PFA en Guinée répondaient aux normes de l'OMS. Cependant, la proportion d'échantillons de selles envoyés au laboratoire à temps était faible, d'où la nécessité de mettre en place une politique cohérente de transport des échantillons.
Introduction: In 2015, Guinea experienced an epidemic of poliovirus derived from a type 2 vaccine strain with a total of 7 cases which were stopped in response. The objective of our study was to describe the epidemiological profile of Acute Flaccid Paralysis (AFP) cases in terms of time, place and person. Methods: This was a descriptive cross-sectional study of AFP data from 2009-2018 from the National Coordination of the Expanded Immunization Program (EPI). A case of AFP was defined as any child under 15 years of age with AFP or anyone with paralysis with suspected polio by the doctor. Results: A total of 3034 AFP cases have been reported. The proportion of non-polio AFP was 7.09%. Almost all cases presented with fever (94%). Paralysis of the lower limbs was observed in 86.18% of cases. The proportion of AFP cases notified within 24 hours of detection was 83.06%. That of AFP cases investigated within 48 hours of notification was 90.38%. In 96.14% of cases, two stool samples were taken and sent to the lab within 14 days of the onset of paralysis, but only 72.51% reached the lab within 72 hours. Of the cases, 70.07% had received at least 3 doses of oral polio vaccine. Conclusion: PFA's performance indicators in Guinea met WHO standards. However, the proportion of stool samples sent to the laboratory on time was low, hence the need for a coherent sample transport policy
Temporal Diffeomorphic Free-Form Deformation for Strain Quantification in 3D-US Images
International audienceThis paper presents a new diffeomorphic temporal registration algorithm and its application to motion and strain quantification from a temporal sequence of 3D images. The displacement field is computed by forward eulerian integration of a non-stationary velocity field. The originality of our approach resides in enforcing time consistency by representing the velocity field as a sum of continuous spatiotemporal B-Spline kernels. The accuracy of the developed diffeomorphic technique was first compared to a simple pairwise strategy on synthetic US images with known ground truth motion and with several noise levels, being the proposed algorithm more robust to noise than the pairwise case. Our algorithm was then applied to a database of cardiac 3D+t Ultrasound (US) images of the left ventricle acquired from height healthy volunteers and three Cardiac Resynchronization Therapy (CRT) patients. On healthy cases, the measured regional strain curves provided uniform strain patterns over all myocardial segments in accordance with clinical literature. On CRT patients, the obtained normalization of the strain pattern after CRT agreed with clinical outcome for the three cases
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