Francisco Del Pozo Guerrero

Universidad Politécnica de Madrid | UPM · Centre for Biomedical Technology

Objective: The role of the central nervous system in the pathophysiology of frailty is controversial. We used magnetoencephalography (MEG) to search for abnormalities in the ongoing oscillatory neural activity of frail individuals without global cognitive impairment. Methods: Fifty four older (≥70 years) and cognitively healthy (Mini-Mental State E...

The ageing of the population poses a threat to both public and private health and social systems. In the last 50 years, life expectancy has increased by an average of 20 years, and by the year 2050, life expectancy will exceed 90 years of age. However, quality of life in the last years of life is not guaranteed due to conditions such as functional...

In this paper, we are interested in the question of how bistability can appear in coupled neurons. Concrete motivation for such a general problem is the search for a way to destroy an organism having a stable dynamics by destabilizing its metabolism. To address this issue, we consider the model of a pair of neuron cells coupled via an electrical sy...

Visits to simulations of real spaces in virtual reality have been proposed as a means for blind people to gain spatial knowledge regarding the disposition of obstacles within a place before actually visiting it. Within the present study, different configurations of distant and proximity exploration were compared to each other, in order to test whet...

This chapter analyses the current state of the art in the field of mobile apps for managing diabetes. It then focuses on the problems that have prevented these apps from reaching a broad audience. A novel approach for using mobile technologies to remotely manage the health status of older adults with diabetes, which can be easily extended to other...

Magnetic hyperthermia mediated by superparamagnetic particles is mainly based in sinusoidal waveforms as excitation signals. Temperature changes are conventionally explained by rotation of the particles in the surrounding medium. This is a hypothesis quite questionable since habitual experimental setups only produce changes in the magnetic module,...

Se presenta un estudio preliminar en el que se compara la operación de un resonador de cuarzo (qcr) con electrodos-oro, típicamente utilizados en biosensado, con un resonador de cuarzo con electrodos-aluminio, utilizados como osciladores en circuitos electrónicos. La principal motivación para realizar este estudio es indagar sobre la posibilidad de...

In magnetic resonance imaging (MRI), the use of magnetic nanoparticles (MNPs) as contrast agent (CA) greatly enhances the possibility to identify several diseases hardly diagnosed by other means. The efficacy of a new CA is described by the longitudinal and transverse relaxivity. Nuclear Magnetic Relaxation Dispersion (NMRD) profiles represent the...

The main objective of this article is to demonstrate by performing experimental measurements how the equivalent capacitance C0 changes when a fluid sample such as water is in contact with the crystal and to relate this change with the relative permittivity of the fluid. These measurements were compared with simulations of traditional models like Bu...

Brain plasticity is understood as the capacity of the brain to evolve, or recover after an aggression. Even in the adult brain, plasticity plays an important role in functional recovery after acquired brain injury, which might have significant relevance to the practice of neurorehabilitation. It is of special interest to identify the mechanisms und...

Los problemas de audición que hacen necesario el uso de audífonos afectan a todo tipo de personas, pero especialmente a aquellas que presentan dificultades para realizar la audiometría tonal subjetiva por su falta de colaboración en la prueba. La inexistencia de pruebas de audiometría objetivas equivalente a la tonal da lugar a un impreciso diagnós...

978-84-608-3354-3. Libro de actas, pp 418-421

Structural and functional connectivity (SC and FC) have received much attention over the last decade, as they offer unique insight into the coordination of brain functioning. They are often assessed independently with three imaging modalities: SC using diffusion-weighted imaging (DWI), FC using functional magnetic resonance imaging (fMRI), and magn...

High performance silk fibers were produced directly from the silk glands of silkworms (Bombyx mori) following an alternative route to natural spinning. This route is based on a traditional procedure that consists of soaking the silk glands in a vinegar solution and stretching them by hand leading to the so called silkworm guts. Here we present, to...

Cancer is one of the leading causes of death worldwide. It is expected that annual cases of cancer will increase from 14 million in 2012 to 22 million in the next two decades according to the World Health Organization [1]. On the other hand, the estimates of the Spanish Society of Medical Oncology for 2015 point out 227076 new cases only in Spain [...

Cancer is a leading cause of mortality worldwide. There were an estimated 8.2 million deaths and around 14 million new cases in 2012. It is anticipated that in the next 20 years, the number of people affected will increase by approximately 70% [1,2]. Currently, the magnetic hyperthermia mediated superparamagnetic magnetite particles (SMPs) is a pro...

Parkinsons disease is a complex neurodegenerative disorder for which patients present many symptoms, tremor being the main one. In advanced stages of the disease, Deep Brain Stimulation is a generalized therapy which can significantly improve the motor symptoms. However despite its beneficial effects on treating the symptomatology, the technique ca...

A power electronics circuit allows the generation of high frequency magnetic field that can be used to increase the temperature of cancer cells previously invaded with magnetic nanoparticles. The circuit designed for this purpose is a high frequency phase-shift inverter implemented with SiC devices and natural Zero Voltage Switching (ZVS). The indu...

Synaptic disruption is an early pathological sign of the neurodegeneration of Dementia of Alzheimer's type (DAT). The changes in network synchronization are evident in patients with Mild Cognitive Impairment (MCI) at the group level, but there are very few Magnetoencephalography (MEG) studies regarding discrimination at the individual level. In...

This paper shows an example of collaboration of people of different areas working together and achieving a promising result. In this case, a power electronics circuit allows the generation of high frequency magnetic field that can be used to increase the temperature of cancer cells previously invaded with magnetic nanoparticles. Although the resear...

Generalized Fixation-off Sensitivity (CGE-FoS) patients present abnormal EEG patterns when losing fixation. In the present work, we studied two CGE-FoS epileptic patients with simultaneous EEG-fMRI. We aim to identify brain areas that are specifically related to the pathology by identifying the brain networks that are related to the EEG brain alter...

Graph theory provides a useful framework to study functional brain networks from neuroimaging data. In epilepsy research, recent findings suggest that it offers unique insight into the fingerprints of this pathology on brain dynamics. Most studies hitherto have focused on seizure activity during frontal focal epilepsy, but less is known about funct...

The Alternating Gradient Field Magnetometer (AGFM) is an instrument whose high sensitivity (10-8 emu) allows the detection of small amounts of magnetic nanoparticles (MNPs) with high accuracy. Over the last few years, different magnetic techniques have been used for in vitro measurements of magnetic nanostructures inside biological tissues. However...

We investigate how hubs of functional brain networks are modified as a result of mild cognitive impairment (MCI), a condition causing a slight but noticeable decline in cognitive abilities, which sometimes precedes the onset of Alzheimer's disease. We used magnetoencephalography (MEG) to investigate the functional brain networks of a group of patie...

The irradiation of small suspensions of gold nanorods (GNRs) using laser pulses at 808nm and 25KHz, produces a series of effects occurring during the interaction of each laser pulse with the amount of gold nanorods in suspension. The result of the interaction laser-GNRs is the generation of acoustic waves, which may influence on cell death in an op...

Fragile X syndrome in humans is caused by a mutation in the FMR1 gene and it is associated with severe mental retardation, hyperactivity and anxiety. Here we compare FMR1 Knock-Out mice, a model of Fragile-X syndrome, and wild-type mice with respect to the neuronal density of the insular cortex, a brain area associated with pain processing and anxi...

Fragile X syndrome in humans is caused by a mutation in the FMR1 gene and it is associated with severe mental retardation, hyperactivity and anxiety. Here we compare FMR1 Knock-Out mice, a model of Fragile-X syndrome, and wild-type mice with respect to the neuronal density of the insular cortex, a brain area associated with pain processing and anxi...

The apolipoprotein E (APOE) ε4 allele constitutes the major genetic risk for the development of late onset Alzheimer's disease (AD). However, its influence on the neurodegeneration that occurs in early AD remains unresolved. In this study, the resting state magnetoencephalography(MEG) recordings were obtained from 27 aged healthy controls and 36 mi...

Macroscopic brain networks have been widely described with the manifold of metrics available using graph theory. However, most analyses do not incorporate information about the physical position of network nodes. Here, we provide a multimodal macroscopic network characterization while considering the physical positions of nodes. To do so, we examin...

Over the past years, several studies on Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) have reported Default Mode Network (DMN) deficits. This network is attracting increasing interest in the AD community, as it seems to play an important role in cognitive functioning and in beta amyloid deposition. Attention has been particularly dra...

Optical hyperthermia systems based on the laser irradiation of gold nanorods seem to be a promising tool in the development of therapies against cancer. After a proof of concept in which the authors demonstrated the efficiency of this kind of systems, a modeling process based on an equivalent thermal-electric circuit has been carried out to determi...

Identifying early-onset schizophrenia spectrum disorders (SSD) at a very early stage remains challenging. To assess the diagnostic predictive value of multiple types of data at the emergence of early-onset first-episode psychosis (FEP), various support vector machine (SVM) classifiers were developed. The data were from a 2-year, prospective, longit...

The heating produced by the absorption of radiofrequency (RF) has been considered a secondary undesirable effect during MRI procedures. In this work, we have measured the power absorbed by distilled water, glycerol and egg-albumin during NMR and non-NMR experiments. The samples are dielectric and examples of different biological materials. The samp...

The irradiating a small suspension of gold na-norods (GNRs) using pulses of laser at 808nm and 25KHz, produces a series of events occurring during the interaction of each laser pulse with the amount of gold nanorods in suspension. The result of these events is the generation of acoustic waves, these acoustic waves may have an influence on cell deat...

Mild cognitive impairment (MCI) is a stage between healthy aging and dementia. It is known that in this condition the connectivity patterns are altered in the resting state and during cognitive tasks, where an extra effort seems to be necessary to overcome cognitive decline. We aimed to determine the functional connectivity pattern required to deal...

Although progressive functional brain network disruption has been one of the hallmarks of Alzheimer's Disease, little is known about the origin of this functional impairment that underlies cognitive symptoms. We investigated how the loss of white matter (WM) integrity disrupts the organization of the functional networks at different frequency bands...

When aqueous suspensions of gold nanorods are irradiated with a pulsing laser (808 nm), pressure waves appear even at low frequencies (pulse repetition rate of 25 kHz). We found that the pressure wave amplitude depends on the dynamics of the phenomenon. For fixed concentration and average laser current intensity, the amplitude of the pressure waves...

This work analyses the statistical significant changes in the EEG signal after the supply of olfactory stimuli during simultaneous EEG/fMRI olfactory experiments. Different spectral parameters are evaluated including the spectral power in different EEG bands of interest and spectral morphology measures, such as median frequency or statistical compl...

Background: Magnetoencephalography (MEG) provides a direct measure of brain activity with high combined spatiotemporal resolution. Preprocessing is necessary to reduce contributions from environmental interference and biological noise. New method: The effect on the signal-to-noise ratio of different preprocessing techniques is evaluated. The sig...

To perceive a coherent environment, incomplete or overlapping visual forms must be integrated into meaningful coherent percepts, a process referred to as "Gestalt" formation or perceptual completion. Increasing evidence suggests that this process engages oscillatory neuronal activity in a distributed neuronal assembly. A separate line of evidence s...

Gold nanorods (GNRs) have shown a huge potential for different biomedical applications because of their large light absorption and scattering cross sections in the near-infrared (NIR) region. Thanks to this optical behavior, GNRs are able to transform the absorbed energy into localized heat. This optical effect is used to develop cancer therapies s...

This paper addresses two key technological barriers to the wider adoption of patient telemonitoring systems for chronic disease management, namely usability and sensor device interoperability. As a great percentage of chronic patients are elderly patients as well, usability of the system has to be adapted to their needs. This paper identifies (from...

The analysis of the interdependence between time series has become an important field of research in the last years, mainly as a result of advances in the characterization of dynamical systems from the signals they produce, the introduction of concepts such as generalized and phase synchronization and the application of information theory to time s...

When aqueous suspensions of gold nanorods are irradiated with a pulsing laser (808 nm), pressure waves appear even at low frequencies (pulse repetition rate of 25 kHz). We found that the pressure wave amplitude depends on the dynamics of the phenomenon. For fixed concentration and average laser current intensity, the amplitude of the pressure waves...

Here, we have applied this approach to study brain networks of effective connectivity from planar gradiometers and magnetometers recorded during rest with closed eyes in three groups of subjects, one of healthy controls and two of patients suffering from different kinds of epilepsy: generalized and frontal focal. The connectivity index used was the...

Neuroimage experiments have been essential for identifying active brain networks. During cognitive tasks as in, e.g., aesthetic appreciation, such networks include regions that belong to the default mode network (DMN). Theoretically, DMN activity should be interrupted during cognitive tasks demanding attention, as is the case for aesthetic apprecia...

Objective: Recent research has focused on interference resolution deficits as the main cause of short-term memory decreases in aging. To determine whether activation of brain compensatory mechanisms occur during the encoding process in older people. Moreover, two different levels of interference (distraction and interruption) were presented during...

New diagnostic criteria for Alzheimer's disease (AD) stress the role of in vivo biomarkers. Neurophysiological markers are usually not considered as such criteria, although theoretical and practical reasons would justify them. In order to assess the value of neurophysiology as an AD biomarker, whole-head magnetoencephalographic (MEG) resting state...

Many biological and man-made networked systems are characterized by the simultaneous presence of different sub-networks organized in separate layers, with links and nodes of qualitatively different types. While during the past few years theoretical studies have examined a variety of structural features of complex networks, the outstanding question...

Operant conditioning is a type of associative learning involving different and complex sensorimotor and cognitive processes. Because the hippocampus has been related to some motor and cognitive functions involved in this type of learning (such as object recognition, spatial orientation, and associative learning tasks), we decided to study in behavi...

Information and Communication Technologies has led to a biomedical data explosion. A proportional growth has been produced regarding the amount of scientific literature, but information retrieval methods did not follow the same pattern. By using specialized clinical search engines such as PubMed, Medscape and Cochrane, biomedical publications has b...

Many biological and man-made networked systems are characterized by the simultaneous presence of different sub-networks organized in separate layers, with links and nodes of qualitatively different types. While during the past few years theoretical studies have examined a variety of structural features of complex networks, the outstanding question...

One of the current issues of debate in the study of mild cognitive impairment (MCI) is deviations of oscillatory brain responses from normal brain states and its dynamics. This work aims to characterize the differences of power in brain oscillations during the execution of a recognition memory task in MCI subjects in comparison with elderly control...

Objective: The precise pathophysiology of fibromyalgia, a syndrome characterized by chronic widespread pain, remains to be clarified. When subjected to the same amount of stimulation, patients show enhanced brain responses as compared to controls, providing evidence of central pain augmentation in this syndrome. We aimed to characterize brain resp...

http://euretina.org/milan2012/default.asp

By combining complex network theory and data mining techniques, we provide objective criteria for optimization of the functional network representation of generic multivariate time series. In particular, we propose a method for the principled selection of the threshold value for functional network reconstruction from raw data, and for proper identi...

Inter-individual differences in cognitive performance are based on an efficient use of task-related brain resources. However, little is known yet on how these differences might be reflected on resting-state brain networks. Here we used Magnetoencephalography resting-state recordings to assess the relationship between a behavioral measurement of ver...

Hithertothelong-term memory (LTM)and the working memory (WM) have beenconsidered two completely separate processes because they have been associat