94 research outputs found
Desarrollo de un bot interactivo usando técnicas de Deep Learning para la comprensión de texto
Este Trabajo de Fin de Grado consiste en el desarrollo de un sistema utilizando técnicas de aprendizaje automático y comprensión de textos que sea capaz de mantener una conversación con un usuario. El sistema final es capaz de responder a preguntas sobre el corpus formado por datos abiertos del Gobierno de Aragón así como mantener una conversación sencilla con el usuario
Polímeros Covalentes Dinámicos en el Desarrollo de Vectores de Entrega de Material Genético
La QCD ha surgido debido a que la química supramolecular no puede suplir ciertas aplicaciones en las que se requiere mayor grado de adaptabilidad. Con la QCD se obtiene este grado de adaptabilidad mediante enlaces covalentes reversibles, junto con el carácter dinámico que otorga la reversibilidad de los enlaces. Para la transfección génica es necesario el uso de vectores. Se ha puesto énfasis durante los últimos años en diseñar vectores sintéticos no virales que tengan todos los requisitos necesarios para llevar a cabo la transfección génica de forma eficaz y segura. Los polímeros catiónicos son uno de los vectores sintéticos frecuentemente empleados. Sin embargo, los polímeros catiónicos tradicionales tienen desventajas tales como su citotoxicidad y la difícil liberación de los ácidos nucleicos. Es aquí donde se usa la QCD como estrategia para diseñar determinados vectores que respondan a estímulos pudiendo así liberar los ácidos nucleicos una vez llegan al sitio de entrega. Aquí se verán diferentes sistemas poliméricos basados en el uso de enlaces disulfuro e hidrazona propios de la QCD para llevar a cabo la transfección génica.<br /
Bioinspired Spike-Based Hippocampus and Posterior Parietal Cortex Models for Robot Navigation and Environment Pseudomapping
The brain has great capacity for computation and efficient resolution of complex problems, far surpassing modern computers. Neuromorphic engineering seeks to mimic the basic principles of the brain to develop systems capable of achieving such capabilities. In the neuromorphic field, navigation systems are of great interest due to their potential applicability to robotics, although these systems are still a challenge to be solved. This work proposes a spike-based robotic navigation and environment pseudomapping system formed by a bioinspired hippocampal memory model connected to a posterior parietal cortex (PPC) model. The hippocampus is in charge of maintaining a representation of an environment state map, and the PPC is in charge of local decision-making. This system is implemented on the SpiNNaker hardware platform using spiking neural networks. A set of real-time experiments are applied to demonstrate the correct functioning of the system in virtual and physical environments on a robotic platform. The system is able to navigate through the environment to reach a goal position starting from an initial position, avoiding obstacles and mapping the environment. To the best of the authors’ knowledge, this is the first implementation of an environment pseudomapping system with dynamic learning based on a bioinspired hippocampal memory. © 2023 The Authors. Advanced Intelligent Systems published by Wiley-VCH GmbH.Ministerio de Educación, Cultura y Deporte (MECD). España PID2019‐105556GB‐C33Horizonte 2020 (Unión Europea) CHIST‐ERA‐18‐ACAI‐004Horizonte 2020 (Unión Europea) PCI2019‐111841‐2/AEI/10.13039/501100011033Ministerio de Ciencia e Innovación (MCIN) España AEI/10.13039/50110001103
Preventive antibiotic therapy in the placement of immediate implants: a systematic review
Immediate implants present a high risk of early failure. To avoid this, preventive antibiotics
(PAs) are prescribed; however, their inappropriate administration leads to antimicrobial resistance.
The present study aims to clarify whether the prescription of PAs reduces the rate of early failure
of immediate implants and to establish guidelines to avoid the overprescription of these drugs.
An electronic search of the MEDLINE database (via PubMed), Web of Science, Scopus, LILACS
and OpenGrey was carried out. The criteria described in the PRISMA® statement were used. The
search was temporarily restricted from 2010 to 2021. The risk of bias was analysed using the
SIGN Methodological Assessment Checklist for Systematic Reviews and Meta-Analyses and the
JBI Prevalence Critical Appraisal Tool. After searching, eight studies were included that met the
established criteria. With the limitations of this study, it can be stated that antibiotic prescription in
immediate implants reduces the early failure rate. Preoperative administration of 2–3 g amoxicillin
one hour before surgery followed by 500 mg/8 h for five to seven days is recommended. It is
considered prudent to avoid the use of clindamycin in favour of azithromycin, clarithromycin or
metronidazole in penicillin allergy patients until further studies are conducted
Is Penicillin Allergy a Risk Factor for Early Dental Implant Failure? A Systematic Review
The prescription of preventive antibiotics in dental implant treatments reduces the incidence of early failures. This study has focused mainly on the influence of amoxicillin, which is contraindicated in penicillin-allergic patients. The present systematic review aimed to determine whether penicillin-allergic patients have a higher risk of implant failure compared to non-allergic patients. An electronic search was performed on Medline and Web of Science using the following MeSH terms: (penicillin allergy OR clindamycin OR erythromycin OR azithromycin OR metronidazole) AND (dental implant OR dental implant failure OR dental implant complications). The criteria employed were those described in the PRISMA® Declaration. Only five articles were included that analyzed the failure rates of implants placed in penicillin-allergic patients who were prescribed clindamycin compared to non-allergic patients who were prescribed amoxicillin. With the limitations of this study, it is not possible to state that penicillin allergy per se constitutes a risk factor for early dental implant failure as most of the studies included self-reported allergic patients. Clindamycin has been associated with a significantly elevated risk of failure and an up to six times increased risk of infection. Immediate implants also have a 5.7 to 10 times higher risk of failure
Homogeneous immunoassay for cyclopiazonic acid based upon mimotopes and upconversion-resonance energy transfer
Strains of Penicillium spp. are used for fungi-ripened cheeses and Aspergillus spp. routinely contaminate maize and other crops. Some of these strains can produce toxic secondary metabolites (mycotoxins), including the neurotoxin α-cyclopiazonic acid (CPA). In this work, we developed a homogeneous upconversion-resonance energy transfer (UC-RET) immunoassay for the detection of CPA using a novel epitope mimicking peptide, or mimotope, selected by phage display. CPA-specific antibody was used to isolate mimotopes from a cyclic 7-mer peptide library in consecutive selection rounds. Enrichment of antibody binding phages was achieved, and the analysis of individual phage clones revealed four different mimotope peptide sequences. The mimotope sequence, ACNWWDLTLC, performed best in phage-based immunoassays, surface plasmon resonance binding analyses, and UC-RET-based immunoassays. To develop a homogeneous assay, upconversion nanoparticles (UCNP, type NaYF4:Yb3+, Er3+) were used as energy donors and coated with streptavidin to anchor the synthetic biotinylated mimotope. Alexa Fluor 555, used as an energy acceptor, was conjugated to the anti-CPA antibody fragment. The homogeneous single-step immunoassay could detect CPA in just 5 min and enabled a limit of detection (LOD) of 30 pg mL-1 (1.5 μg kg-1) and an IC50 value of 0.36 ng mL-1. No significant cross-reactivity was observed with other co-produced mycotoxins. Finally, we applied the novel method for the detection of CPA in spiked maize samples using high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) as a reference method.This work has been funded by the Ministry of Science, Innovation and Universities (MSIU) (RTI2018-096410-B-C21, PID2021-127457OB-C21 and PID2019-105237 GB-I00). FP acknowledges the MSIU for an FPU contract.S
Correction: A feasible pathway to stabilize monoclinic and tetragonal phase coexistence in barium titanate-based ceramics
Depto. de Física de MaterialesFac. de Ciencias FísicasTRUEpu
Recombinant Peptide Mimetic NanoLuc Tracer for Sensitive Immunodetection of Mycophenolic Acid
Mycophenolic acid (MPA) is an immunosuppressant drug commonly used to prevent organ rejection in transplanted patients. MPA monitoring is of great interest due to its small therapeutic window. In this work, a phage-displayed peptide library was used to select cyclic peptides that bind to the MPA-specific recombinant antibody fragment (Fab) and mimic the behavior of MPA. After biopanning, several phage-displayed peptides were isolated and tested to confirm their epitope-mimicking nature in phage-based competitive immunoassays. After identifying the best MPA mimetic (ACEGLYAHWC with a disulfide constrained loop), several immunoassay approaches were tested, and a recombinant fusion protein containing the peptide sequence with a bioluminescent enzyme, NanoLuc, was developed. The recombinant fusion enabled its direct use as the tracer in competitive immunoassays without the need for secondary antibodies or further labeling. A bioluminescent sensor, using streptavidin-coupled magnetic beads for the immobilization of the biotinylated Fab antibody, enabled the detection of MPA with a detection limit of 0.26 ng mL(-1) and an IC50 of 2.9 +/- 0.5 ng mL(-1). The biosensor showed good selectivity toward MPA and was applied to the analysis of the immunosuppressive drug in clinical samples, of both healthy and MPA-treated patients, followed by validation by liquid chromatography coupled to diode array detection
Optimization of multilayer graphene-based gas sensors by ultraviolet photoactivation
Nitrogen dioxide (NO2) is a potential hazard to human health at low concentrations, below one part per million (ppm). NO2 can be monitored using gas sensors based on multi-layered graphene operating at ambient temperature. However, reliable detection of concentrations on the order of parts per million and lower is hindered by partial recovery and lack of reproducibility of the sensors after exposure. We show how to overcome these longstanding problems using ultraviolet (UV) light. When exposed to NO2, the sensor response is enhanced by 290 % − 550 % under a 275 nm wavelength light emitting diode irradiation. Furthermore, the sensor’s initial state is completely restored after exposure to the target gas. UV irradiation at 68 W/m2 reduces the NO2 detection limit to 30 parts per billion (ppb) at room temperature. We investigated sensor performance optimization for UV irradiation with different power densities and target gases, such as carbon oxide and ammonia. Improved sensitivity, recovery, and reproducibility of UV-assisted graphene-based gas sensors make them suitable for widespread environmental applications
Comparative Study of the Performance of Two Different Luciferases for the Analysis of Fumonisin B1 in Wheat Samples
The development of two different immunoassays for the determination of fumonisin B1 in wheat samples is reported. A previously described mimopeptide for fumonisin B1 (FB1) was used to produce fusion proteins in combination with two different luciferases: Gaussia luciferase (GLuc) and NanoLuc luciferase (NLuc). The production, expression and the development of two immunoassays based on these fusion proteins (A2- GLuc and A2-NLuc) is detailed. The assay showing the best performance, A2-NLuc, with a limit of detection of 0.61 ngmL 1 and a dynamic range from 1.9 to 95 ngmL 1 , was employed for the analysis of spiked wheat samples, a reference matrix material, as well as naturally contaminated wheat samples. The recoveries obtained in the spiked samples were acceptable, between 81.5 and 109%, with relative standard deviations lower than 14%. The analysis of naturally contaminated wheat was validated by a liquid chromatography coupled to tandem mass detection method
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