Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Sensors (Basel) ; 23(2)2023 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-36679660

RESUMEN

Recently, unmanned aerial vehicle (UAV)-oriented applications have been growing worldwide. Thus, there is a strong interest in using UAVs for applications requiring wide-area connectivity coverage. Such applications might be power line inspection, road inspection, offshore site monitoring, wind turbine inspections, and others. The utilization of cellular networks, such as the fifth-generation (5G) technology, is often considered to meet the requirement of wide-area connectivity. This study quantifies the performance of 5G-enabled UAVs when sensor data throughput requirements are within the 5G network's capability and when throughput requirements significantly exceed the capability of the 5G network, respectively. Our experimental results show that in the first case, the 5G network maintains bounded latency, and the application behaves as expected. In the latter case, the overloading of the 5G network results in increased latency, dropped packets, and overall degradation of the application performance. Our findings show that offloading processes requiring moderate sensor data rates work well, while transmitting all the raw data generated by the UAV's sensors is not possible. This study highlights and experimentally demonstrates the impact of critical parameters that affect real-life 5G-enabled UAVs that utilize the edge-offloading power of a 5G cellular network.


Asunto(s)
Mantenimiento , Tecnología , Dispositivos Aéreos No Tripulados
2.
Sensors (Basel) ; 21(24)2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34960352

RESUMEN

This article proposes a novel decentralized two-layered and multi-sensorial based fusion architecture for establishing a novel resilient pose estimation scheme. As it will be presented, the first layer of the fusion architecture considers a set of distributed nodes. All the possible combinations of pose information, appearing from different sensors, are integrated to acquire various possibilities of estimated pose obtained by involving multiple extended Kalman filters. Based on the estimated poses, obtained from the first layer, a Fault Resilient Optimal Information Fusion (FR-OIF) paradigm is introduced in the second layer to provide a trusted pose estimation. The second layer incorporates the output of each node (constructed in the first layer) in a weighted linear combination form, while explicitly accounting for the maximum likelihood fusion criterion. Moreover, in the case of inaccurate measurements, the proposed FR-OIF formulation enables a self resiliency by embedding a built-in fault isolation mechanism. Additionally, the FR-OIF scheme is also able to address accurate localization in the presence of sensor failures or erroneous measurements. To demonstrate the effectiveness of the proposed fusion architecture, extensive experimental studies have been conducted with a micro aerial vehicle, equipped with various onboard pose sensors, such as a 3D lidar, a real-sense camera, an ultra wide band node, and an IMU. The efficiency of the proposed novel framework is extensively evaluated through multiple experimental results, while its superiority is also demonstrated through a comparison with the classical multi-sensorial centralized fusion approach.

3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 2642-2645, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29060442

RESUMEN

Evaluation of cardiotocogram (CTG) is a standard approach employed during pregnancy and delivery. But, its interpretation requires high level expertise to decide whether the recording is Normal, Suspicious or Pathological. Therefore, a number of attempts have been carried out over the past three decades for development automated sophisticated systems. These systems are usually (multiclass) classification systems that assign a category to the respective CTG. However most of these systems usually do not take into consideration the natural ordering of the categories associated with CTG recordings. In this work, an algorithm that explicitly takes into consideration the ordering of CTG categories, based on binary decomposition method, is investigated. Achieved results, using as a base classifier the C4.5 decision tree classifier, prove that the ordinal classification approach is marginally better than the traditional multiclass classification approach, which utilizes the standard C4.5 algorithm for several performance criteria.


Asunto(s)
Cardiotocografía , Algoritmos , Árboles de Decisión , Femenino , Humanos , Embarazo
4.
BMC Musculoskelet Disord ; 18(1): 407, 2017 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-28950843

RESUMEN

BACKGROUND: Sensorimotor disturbances of the hand such as altered neuromuscular control and reduced proprioception have been reported for various musculoskeletal disorders. This can have major impact on daily activities such as dressing, cooking and manual work, especially when involving high demands on precision and therefore needs to be considered in the assessment and rehabilitation of hand disorders. There is however a lack of feasible and accurate objective methods for the assessment of movement behavior, including proprioception tests, of the hand in the clinic today. The objective of this observational cross- sectional study was to develop and conduct preliminary validation testing of a new method for clinical assessment of movement sense of the wrist using a laser pointer and an automatic scoring system of test results. METHODS: Fifty physiotherapists performed a tracking task with a hand-held laser pointer by following a zig-zag pattern as accurately as possible. The task was performed with left and right hand in both left and right directions, with three trials for each hand movement. Each trial was video recorded and analysed with a specifically tailored image processing pipeline for automatic quantification of the test. The main outcome variable was Acuity, calculated as the percent of the time the laser dot was on the target line during the trial. RESULTS: The results showed a significantly better Acuity for the dominant compared to non-dominant hand. Participants with right hand pain within the last 12 months had a significantly reduced acuity (p < 0.05), and although not significant there was also a similar trend for reduced Acuity also for participants with left hand pain. Furthermore, there was a clear negative correlation between Acuity and Speed indicating a speed-accuracy trade off commonly found in manual tasks. The repeatability of the test showed acceptable intra class correlation (ICC2.1) values (0.68-0.81) and standard error of measurement values ranging between 5.0-6.3 for Acuity. CONCLUSIONS: The initial results suggest that the test may be a valid and feasible test for assessment of the movement sense of the hand. Future research should include assessments on different patient groups and reliability evaluations over time and between testers.


Asunto(s)
Pruebas Diagnósticas de Rutina/normas , Mano/fisiología , Propiocepción/fisiología , Desempeño Psicomotor/fisiología , Rango del Movimiento Articular/fisiología , Adulto , Estudios Transversales , Pruebas Diagnósticas de Rutina/tendencias , Femenino , Humanos , Masculino , Enfermedades Musculoesqueléticas/diagnóstico , Enfermedades Musculoesqueléticas/fisiopatología , Estimulación Luminosa/métodos , Reproducibilidad de los Resultados
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 2586-2589, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28268851

RESUMEN

This paper presents a software tool developed for assisting physicians during an examination process. The tool consists of a number of modules with the aim to make the examination process not only quicker but also fault proof moving from a simple electronic medical records management system towards an intelligent assistant for the physician. The intelligent component exploits users' inputs as well as well established standards to line up possible suggestions for filling in the examination report. As the physician continues using it, the tool keeps extracting new knowledge. The architecture of the tool is presented in brief while the intelligent component which builds upon the notion of multilabel learning is presented in more detail. Our preliminary results from a real test case indicate that the performance of the intelligent module can reach quite high performance without a large amount of data.


Asunto(s)
Sistemas de Apoyo a Decisiones Clínicas , Médicos , Programas Informáticos , Algoritmos , Diagnóstico por Computador , Procesamiento Automatizado de Datos , Registros Electrónicos de Salud , Costos de la Atención en Salud , Humanos , Modelos Estadísticos , Calidad de la Atención de Salud , Interfaz Usuario-Computador
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 518-21, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26736313

RESUMEN

Cardiotocogram (CTG) is the most widely used means for the assessment of fetal condition. CTG consists of two traces one depicting the Fetal Heart Rate (FHR), and the other the Uterine Contractions (UC) activity. Many automatic methods have been proposed for the interpretation of the CTG. Most of them rely either on a binary classification approach or on a multiclass approach to come up with a decision about the class that the tracing belongs to. This work investigates the use of a one-class approach to the assessment of CTGs building a model only for the healthy data. The preliminary results are promising indicating that normal traces could be used as part of an automatic system that can detect deviations from normality.


Asunto(s)
Cardiotocografía , Femenino , Frecuencia Cardíaca Fetal , Humanos , Embarazo , Contracción Uterina
7.
ACS Med Chem Lett ; 5(6): 662-7, 2014 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-24944740

RESUMEN

Because of the promise of BCL-2 antagonists in combating chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma (NHL), interest in additional selective antagonists of antiapoptotic proteins has grown. Beginning with a series of selective, potent BCL-XL antagonists containing an undesirable hydrazone functionality, in silico design and X-ray crystallography were utilized to develop alternative scaffolds that retained the selectivity and potency of the starting compounds.

8.
J Med Chem ; 57(4): 1252-75, 2014 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-24471857

RESUMEN

A small-molecule natural product, euodenine A (1), was identified as an agonist of the human TLR4 receptor. Euodenine A was isolated from the leaves of Euodia asteridula (Rutaceae) found in Papua New Guinea and has an unusual U-shaped structure. It was synthesized along with a series of analogues that exhibit potent and selective agonism of the TLR4 receptor. SAR development around the cyclobutane ring resulted in a 10-fold increase in potency. The natural product demonstrated an extracellular site of action, which requires the extracellular domain of TLR4 to stimulate a NF-κB reporter response. 1 is a human-selective agonist that is CD14-independent, and it requires both TLR4 and MD-2 for full efficacy. Testing for immunomodulation in PBMC cells shows the induction of the cytokines IL-8, IL-10, TNF-α, and IL-12p40 as well as suppression of IL-5 from activated PBMCs, indicating that compounds like 1 could modulate the Th2 immune response without causing lung damage.


Asunto(s)
Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Quinolonas/farmacología , Receptor Toll-Like 4/agonistas , Animales , Citocinas/metabolismo , Humanos , Relación Estructura-Actividad
9.
J Med Chem ; 56(13): 5514-40, 2013 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-23767404

RESUMEN

Developing potent molecules that inhibit Bcl-2 family mediated apoptosis affords opportunities to treat cancers via reactivation of the cell death machinery. We describe the hit-to-lead development of selective Bcl-XL inhibitors originating from a high-throughput screening campaign. Small structural changes to the hit compound increased binding affinity more than 300-fold (to IC50 < 20 nM). This molecular series exhibits drug-like characteristics, low molecular weights (Mw < 450), and unprecedented selectivity for Bcl-XL. Surface plasmon resonance experiments afford strong evidence of binding affinity within the hydrophobic groove of Bcl-XL. Biological experiments using engineered Mcl-1 deficient mouse embryonic fibroblasts (MEFs, reliant only on Bcl-XL for survival) and Bax/Bak deficient MEFs (insensitive to selective activation of Bcl-2-driven apoptosis) support a mechanism-based induction of apoptosis. This manuscript describes the first series of selective small-molecule inhibitors of Bcl-XL and provides promising leads for the development of efficacious therapeutics against solid tumors and chemoresistant cancer cell lines.


Asunto(s)
Apoptosis/efectos de los fármacos , Benzotiazoles/farmacología , Hidrazonas/farmacología , Proteína bcl-X/antagonistas & inhibidores , Animales , Benzotiazoles/síntesis química , Benzotiazoles/metabolismo , Unión Competitiva , Línea Celular Tumoral , Células Cultivadas , Descubrimiento de Drogas , Embrión de Mamíferos/citología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Hidrazonas/síntesis química , Hidrazonas/metabolismo , Cinética , Ratones , Ratones Noqueados , Modelos Químicos , Estructura Molecular , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/deficiencia , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/genética , Resonancia por Plasmón de Superficie , Proteína Destructora del Antagonista Homólogo bcl-2/deficiencia , Proteína Destructora del Antagonista Homólogo bcl-2/genética , Proteína X Asociada a bcl-2/deficiencia , Proteína X Asociada a bcl-2/genética , Proteína bcl-X/química , Proteína bcl-X/metabolismo
10.
J Biomol Screen ; 16(10): 1196-205, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22086725

RESUMEN

Epigenetic aberrations are increasingly regarded as key factors in cancer progression. Recently, deregulation of histone acetyltransferases (HATs) has been linked to several types of cancer. Monocytic leukemia zinc finger protein (MOZ) is a member of the MYST family of HATs, which regulate gene expression in cell proliferation and differentiation. Deregulation of these processes through constitutively active MOZ fusion proteins gives rise to the formation of leukemic stem cells, rendering MOZ an excellent target for treating myeloid leukemia. The authors implemented a hit discovery campaign to identify small-molecule inhibitors of MOZ-HAT activity. They developed a robust, homogeneous assay measuring the acetylation of synthetic histone peptides. In a primary screening campaign testing 243 000 lead-like compounds, they identified inhibitors from several chemical classes. Secondary assays were used to eliminate assay-interfering compounds and prioritize confirmed hits. This study establishes a new high-throughput assay for HAT activity and could provide the foundation for the development of a new class of drugs for the treatment of leukemias.


Asunto(s)
Epigénesis Genética/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento/métodos , Histona Acetiltransferasas/metabolismo , Activación Enzimática/efectos de los fármacos , Histona Acetiltransferasas/antagonistas & inhibidores , Histona Acetiltransferasas/genética , Humanos , Reproducibilidad de los Resultados , Bibliotecas de Moléculas Pequeñas
12.
Sensors (Basel) ; 10(8): 7170-91, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-22163598

RESUMEN

In this article a scheme for image transmission over Wireless Sensor Networks (WSN) with an adaptive compression factor is introduced. The proposed control architecture affects the quality of the transmitted images according to: (a) the traffic load within the network and (b) the level of details contained in an image frame. Given an approximate transmission period, the adaptive compression mechanism applies Quad Tree Decomposition (QTD) with a varying decomposition compression factor based on a gradient adaptive approach. For the initialization of the proposed control scheme, the desired a priori maximum bound for the transmission time delay is being set, while a tradeoff among the quality of the decomposed image frame and the time needed for completing the transmission of the frame should be taken under consideration. Based on the proposed control mechanism, the quality of the slowly varying transmitted image frames is adaptively deviated based on the measured time delay in the transmission. The efficacy of the adaptive compression control scheme is validated through extended experimental results.


Asunto(s)
Redes de Comunicación de Computadores/instrumentación , Compresión de Datos/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Tecnología Inalámbrica/instrumentación , Algoritmos , Reproducibilidad de los Resultados
13.
J Org Chem ; 74(3): 1304-13, 2009 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-19105637

RESUMEN

Inspired by the novel spiro structures of a number of bioactive natural products such as the histrionicotoxins, a series of novel spiro scaffolds have been designed and robust syntheses developed. The scaffolds are ready-to-use building blocks and can be easily prepared on a 5-20 g scale. They contain two amino groups (one Boc-protected) and have been designed for ease of conversion to a lead generation library, using either amide formation or reductive amination procedures. The synthesis of the 1,9-diazaspiro[5.5]undecane and 3,7-diazaspiro[5.6]dodecane ring systems was achieved using RCM as the key step. A simple workup procedure is reported for the removal of highly colored ruthenium residues. The synthesis of the 1,8-diazaspiro[4.5]decane scaffold has been achieved using a bromine-mediated 5-endo cyclization of the corresponding 4-aminobutene intermediate under acidic conditions. This is the first example of this type of cyclization to be reported. A novel mechanism involving a bromine transfer reaction from an initially formed bromonium ion to a neighboring nitrogen atom is suggested as the reason for the failure of this type of reaction under "normal" bromination conditions. An unusual rearrangement of a 1-acyl-1,9-diazaspiro[5.5]undecane to the corresponding 9-acyl-1,9-diazaspiro[5.5]undecane is reported.


Asunto(s)
Aminas/química , Productos Biológicos/síntesis química , Compuestos de Espiro/química , Aminas/síntesis química , Ciclización , Diseño de Fármacos , Compuestos de Espiro/síntesis química
14.
Sensors (Basel) ; 9(9): 7320-42, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-22399998

RESUMEN

The power awareness issue is the primary concern within the domain of Wireless Sensor Networks (WSNs). Most power dissipation ocurrs during communication, thus routing protocols in WSNs mainly aim at power conservation. Moreover, a routing protocol should be scalable, so that its effectiveness does not degrade as the network size increases. In response to these issues, this work describes the development of an efficient routing protocol, named SHPER (Scaling Hierarchical Power Efficient Routing).

15.
Bioorg Med Chem ; 14(7): 2358-65, 2006 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-16314104

RESUMEN

Three series of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene and 2-amino-5,6,7,8-tetrahydrocyclohepta[b]thiophenes with 3-carboxylates and carboxamides have been prepared using the Gewald synthesis and evaluated as A(1)AR allosteric enhancers. The structure-activity relationships of these classes of compound are described. A number of compounds, notably 7b, are more potent and efficacious than PD81,723 (1).


Asunto(s)
Amidas/farmacología , Ácidos Carboxílicos/farmacología , Receptor de Adenosina A1/efectos de los fármacos , Tiofenos/farmacología , Regulación Alostérica/efectos de los fármacos , Amidas/síntesis química , Amidas/química , Ácidos Carboxílicos/síntesis química , Ácidos Carboxílicos/química , Relación Dosis-Respuesta a Droga , Humanos , Estructura Molecular , Relación Estructura-Actividad , Tiofenos/síntesis química , Tiofenos/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...