Recursos de colección

Archivo Digital UPM (109.118 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Medicina

Mostrando recursos 1 - 20 de 706

  1. Automatic synthesis of anthropomorphic pulmonary CT phantoms

    Jimenez Carretero, Daniel; Estepar San José, Raúl; Díaz Cacio, Mario; Ledesma Carbayo, María Jesús
    The great density and structural complexity of pulmonary vessels and airways impose limitations on the generation of accurate reference standards, which are critical in training and in the validation of image processing methods for features such as pulmonary vessel segmentation or artery–vein (AV) separations. The design of synthetic computed tomography (CT) images of the lung could overcome these difficulties by providing a database of pseudorealistic cases in a constrained and controlled scenario where each part of the image is differentiated unequivocally. This work demonstrates a complete framework to generate computational anthropomorphic CT phantoms of the human lung automatically. Starting from...

  2. MEG functional network disorganization associates with cerebrospinal fluid biomarkers in early Alzheimer’s disease

    Canuet Delis, Leonides; Pusil Arce, Sandra; López García, María Eugenia; Bajo Breton, Ricardo; Pineda Pardo, José Ángel; Cuesta Prieto, Pablo; Gaztelu Quijano, José María; Lourido, Daniel; García Ribas, Guillermo; Maestú Unturbe, Fernando
    To determine whether functional connectivity patterns, as an index of synaptic dysfunction, associate with cerebrospinal fluid (CSF) biomarkers (i.e., phospho-tau and amyloid beta -A 42- levels) in patients with Mild Cognitive Impairment due to Alzheimer?s disease. We also assessed orrelations of aberrant functional connections with structural connectivity abnormalities and with cognitive deficits

  3. Impact of the BDNF Val66Met polymorphism within and beyond the retrosplenial cortex in females with Mild Cognitive Impairment: A magnetoencephalography study

    Rodríguez Rojo, Inmaculada C.; Cuesta Prieto, Pablo; López García, María Eugenia; Barabash, Ana; Cabranes, José Antonio; Delgado Losada, María Luisa; Yus, Miguel; Marcos Dolado, Alberto; Maestú Unturbe, Fernando
    Mild Cognitive Impairment (MCI) can be influenced by genetic risk factors. The Brain Derived Neurotrophic Factor Val66Met polymorphism is one of them. This mutation may affect the brain functional connectivity (FC), especially for those carriers of the Met allele (A). The retrosplenial cortex (RSC), essential component of the Default Mode Network (DMN), could be altered by this polymorphism. Our aim was to examine the influence of the Val66Met polymorphism within the RSC?s functional network, and its interconnections between the frontal medial cortex (FMC) and the anterior cingulate (ACC).

  4. Artificial-intelligence-augmented telemedicine applied to the management of diet-treated gestational diabetes

    Rigla Cros, Mercedes; García Sáez, Gema; Villaplana, María; Caballero Ruiz, Estefanía; Pons, Belén; Aguilar, Montserrat; Méndez, Anna; Gómez Aguilera, Enrique J.; Hernando Pérez, María Elena
    Gestational diabetes (GD) confers an increased risk of complications as well as future type 2 diabetes. We assess the safety and efficacy of an artificial intelligence (AI)-augmented telemedicine system (ruled-based reasoning) that includes a blood glucose (BG) classifier (C4.5 Quinlan decision tree) in comparison with the standard care in the management of GD while insulin is not required.

  5. Connexin-36 protects against suddent infant death syndrome

    Pérez Atencio, L,.; Ardaiz, M.; Barios Heredero, Juan Antonio; González Nieto, Daniel; Barrio, L.C.
    The sudden infant death syndrome (SIDS) is the main cause of postneonatal infant death; however the etiology of SIDS remains ill defined. The hypothesis that SIDS, or a subset of SIDS, is due to an abnormal brainstem mechanism is one of the current leading hypotheses on SIDS etiology. The brainstem is essential for cardiac and respiratory function, controlling autonomic and homeostatic responses including breathing, central chemosensitivity, heartbeat and blood pressure, all mechanisms that are thought to be involved in SIDS. Connexin-36 (Cx36), the principal component of neuron-to-neuron channels that form the electrical synapses, is present in the specific neural populations...

  6. Avances en el diagnóstico de la discapacidad auditiva: técnica de la audiometría por Microfónicos Cocleares

    Félix González, Nazario; Casonava Carvajal, Óscar; Sánchez López de Pablo, Cristina; Blas Narváez, L; Padilla, M. F.; Serrano Olmedo, José Javier
    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 diagnóstico y a un dudoso tratamiento. Los microfónicos cocleares son señales eléctricas producidas por las células ciliadas internas y externas al estímulo de la presión sonora vibrátil del sonido. La determinación de la audición hasta la cóclea inclusive permite separar los problemas de audición según su...

  7. Study of resting state cortico-cortical synchronization aimed to accurately discriminate Parkinson and essential tremor patients: A MEG signal-space connectivity study

    Bruña Fernandez, Ricardo; Pineda Pardo, José Ángel; Rocón de Lima, Eduardo; Romero Muñoz, Juan Pablo; Benito León, Julián; Maestu Unturbe, Fernando
    Motor tremor-related syndromes like essential tremor (ET) and Parkinson?s disease (PD) have a common symptomatology in early stages: the presence of tremor. Even when both diseases have a different aetiology and, thus, different prognosis and treatment, the symptoms in early stages are quite similar. This usually leads to misdiagnosis, with the associated risks and limitations. A PD patient with an ET treatment will continue developing the disease, loosing an important window of action. On the other hand, an ET patient with a PD treatment will suffer strong side effects. A correct diagnosis is in both cases mandatory for the well-being...

  8. Mathematical modeling of neuronal connexin-36 channels

    Jaimes-Reátegui, Rider; Barrio, Luis C.; González Nieto, Daniel; Pisarchik, Alexander N.
    Neurotransmission through electrical synapses play an important role in the spike synchrony among neurons and oscillation of neuron networks. Connexin36 (Cx36) is the principal gap junction protein of electrical synapses between inhibitory interneurons in vertebrates. Coupling strength between coupled neurons is modulated, among other factor, by the voltage difference between cell interiors, termed transjunctional voltage (Vj), in a complex manner; with the Vj gradient junctional conductance of Cx36 channels first increases instantaneously (+ 20% for + 100 mV) and then it decreases slowly to half for a similar range of Vj. The significance of this regulation by voltage, a stimulus...

  9. Hyperconnectivity is a fundamental response to neurological disruption

    Hillary, Frank G.; Román, Cristina A.; Venkatesan, Umesh; Rajtmajer, Sarah; Bajo Breton, Ricardo; Castellanos, Nazareth
    In the cognitive and clinical neurosciences, the past decade has been marked by dramatic growth in a literature examining brain "connectivity" using noninvasive methods. We offer a critical review of the blood oxygen level dependent functional MRI (BOLD fMRI) literature examining neural connectivity changes in neurological disorders with focus on brain injury and dementia. The goal is to demonstrate that there are identifiable shifts in local and large-scale network connectivity that can be predicted by the degree of pathology. We anticipate that the most common network response to neurological insult is hyperconnectivity but that this response depends upon demand and...

  10. Emotion regulation of neuroticism: emotional information processing related to psychosomatic state evaluated by electroencephalography and exact low-resolution brain electromagnetic tomography.

    Ikeda, Shunichiro; Mizuno-Matsumoto, Yuko; Canuet Delis, Leonides; Ishii, Ryouhei; Aoki, Yasunori; Hata, Masahiro; Katsimichas, Themistoklis; Pascual Marqui, Roberto D.; Hayashi, T; Okamoto, Eika; Asakawa, Tetsuya; Iwase, Masao; Takeda, M.
    Emotion regulation is the process that adjusts the type or amount of emotion when we experience an emotional situation. The aim of this study was to reveal quantitative changes in brain activity during emotional information processing related to psychosomatic states and to determine electrophysiological features of neuroticism. Twenty-two healthy subjects (mean age 25 years, 14 males and 8 females) were registered. Electroencephalography (EEG) was measured during an emotional audiovisual memory task under three conditions (neutral, pleasant and unpleasant sessions). We divided the subjects into two groups using the Cornell Medical Index (CMI): (CMI-I: control group, n = 10: CMI-II, III...

  11. An efficient implementation of the synchronization likelihood algorithm for functional connectivity

    Rosales García, Francisco Javier; García Dopico, Antonio; Bajo Breton, Ricardo; Nevado, Angel
    Measures of functional connectivity are commonly employed in neuroimaging research. Among the most popular measures is the Synchronization Likelihood which provides a non-linear estimate of the statistical dependencies between the activity time courses of different brain areas. One aspect which has limited a wider use of this algorithm is the fact that it is very computationally and memory demanding. In the present work we propose new implementations and parallelizations of the Synchronization Likelihood algorithm with significantly better performance both in time and in memory use. As a result both the amount of required computational time is reduced by 3 orders...

  12. Changes in anatomical and functional connectivity related to lower hippocampal volume

    Pineda Pardo, José Ángel; Cristóbal Huerta, Alexandra; Manzanedo Sáenz, Eva; Pozo Guerrero, Francisco del; Álvarez Linera, Juan; Hernández Tamames, J.A.
    Anatomical 3D T1 weighted images have been widely used to assess the volume of subcortical structures. It has been demonstrated that volume loss of hippocampi, entorhinal cortex and amygdala are early biomarkers for the diagnosis of cognitive impairments and AD1. In this work, we investigate AD biomarkers based on brain connectivity. SC-FC differences have been reported between controls and patients at risk for AD2. We will try to anticipate to MCI or AD diagnoses by differentiating in a sample of healthy subjects, i.e. with no cognitive impairment, other than related to ageing, using as criterion of separation the normalized hippocampal...

  13. TIDA: A spanish EHR semantic search engine

    Costumero Moreno, Roberto; Gonzalo Martín, Consuelo; Menasalvas Ruiz, Ernestina
    Electronic Health Records (EHR) and the constant adoption of Information Technologies in healthcare have dramatically increased the amount of unstructured data stored. The extraction of key information from this data will bring better caregivers decisions and an improvement in patients? treatments. With more than 495 million people talking Spanish, the need to adapt algorithms and technologies used in EHR knowledge extraction in English speaking countries, leads to the development of different frameworks. Thus, we present TIDA, a Spanish EHR semantic search engine, to give support to Spanish speaking medical centers and hospitals to convert pure raw data into information understandable...

  14. Selective monostability in multi-stable systems

    Sevilla Escoboza, Ricardo; Pisarchik, Alexander N.; Jaimes-Reátegui, Rider; Huerta Cuellar, Guillermo
    We propose a robust method that allows a periodic or a chaotic multi-stable system to be transformed to a monostable system at an orbit with dominant frequency of any of the coexisting attractors. Our approach implies the selection of a particular attractor by periodic external modulation with frequency close to the dominant frequency in the power spectrum of a desired orbit and simultaneous annihilation of all other coexisting states by positive feedback, both applied to one of the system parameters. The method does not require any preliminary knowledge of the system dynamics and the phase space structure. The efficiency of...

  15. Long-term dynamics of somatosensory activity in a stroke model of distal middle cerebral artery oclussion

    Barios Heredero, Juan Antonio; Pisarchyk, Liudmila; Fernández García, Laura; C. Barrio, Luis; Ramos Gomez, Milagros; Martínez Murillo, Ricardo; González Nieto, Daniel
    A constant challenge in experimental stroke is the use of appropriate tests to identify signs of recovery and adverse effects linked to a particular therapy. In this study, we used a long-term longitudinal approach to examine the functional brain changes associated with cortical infarction in a mouse model induced by permanent ligation of the middle cerebral artery (MCA). Sensorimotor function and somatosensory cortical activity were evaluated with fault-foot and forelimb asymmetry tests in combination with somatosensory evoked potentials. The stroke mice exhibited both long-term deficits in the functional tests and impaired responses in the infarcted and intact hemispheres after contralateral...

  16. Functional brain networks: great expectations, hard times and the big leap forward

    Papo, David; Zanin, Massimiliano; Pineda Pardo, José Ángel; Boccaletti, Stefano; Martín Buldú, Javier
    Many physical and biological systems can be studied using complex network theory, a new statistical physics understanding of graph theory. The recent application of complex network theory to the study of functional brain networks has generated great enthusiasm as it allows addressing hitherto non-standard issues in the field, such as efficiency of brain functioning or vulnerability to damage. However, in spite of its high degree of generality, the theory was originally designed to describe systems profoundly different from the brain. We discuss some important caveats in the wholesale application of existing tools and concepts to a field they were not...

  17. Deployment of a smart telecare system to carry out an intelligent health monitoring at home

    Vadillo Moreno, Laura; Martín Ruiz, María Luisa; Valero Duboy, Miguel Ángel
    Information and Communication Technologies together appropriate reasoning tools can add value to current telecare systems, including smart tele-monitoring solutions to enhance the capability for identifying risk situations at home. Cooperation between Home Area Networks (HAN) and Body Area Networks (BAN) at home can provide smart systems to support effective health solutions for ageing people living alone, improving service quality and security to the users and relatives. This paper details the development of a reasoning platform to monitor situations of the person at home, and react in risk situations that demanding care support of remote careers. The system integrates BAN and...

  18. Enhancing dendritic cell immunotherapy for melanoma using a simple mathematical model

    Tello del Castillo, José Ignacio; Castillo-Montiel, E.; Chimal-Eguía, J. C.; Piñon-Zárate, G.; Herrera-Enríquez, M.; Castell-Rodríguez, A. E.
    ABSTRACT Background: The immunotherapy using dendritic cells (DCs) against different varieties of cancer is an approach that has been previously explored which induces a specific immune response. This work presents a mathematical model of DCs immunotherapy for melanoma in mice based on work by Experimental Immunotherapy Laboratory of the Medicine Faculty in the Universidad Autonoma de Mexico (UNAM). Method: The model is a five delay differential equation (DDEs) which represents a simplified view of the immunotherapy mechanisms. The mathematical model takes into account the interactions between tumor cells, dendritic cells, naive cytotoxic T lymphocytes cells (inactivated cytotoxic cells), effector cells (cytotoxic T activated cytotoxic cells)...

  19. Evaluation of Hyaluronic Acid Dilutions at Different Concentrations Using a Quartz Crystal Resonator (QCR) for the Potential Diagnosis of Arthritic Diseases

    Carvajal Ahumada, Luis Armando; Rivera González, Marco Xavier; Herrera Sandoval, Oscar Leonardo; Serrano Olmedo, Jose Javier
    The main objective of this article is to demonstrate through experimental means the capacity of the quartz crystal resonator (QCR) to characterize biological samples of aqueous dilutions of hyaluronic acid according to their viscosity and how this capacity may be useful in the potential diagnosis of arthritic diseases. The synovial fluid is viscous due to the presence of hyaluronic acid, synthesized by synovial lining cells (type B), and secreted into the synovial fluid thus making the fluid viscous. In consequence, aqueous dilutions of hyaluronic acid may be used as samples to emulate the synovial fluid. Due to the viscoelastic and...

  20. Involvement of cortico-subcortical circuits in normoacousic chronic tinnitus: A source localization EEG study

    Houdayer, Elise; Teggi, Roberto; Velikova, Svetla; Gonzalez Rosa, Javier Jesus; Bussi, Mario; Comi, Giancarlo; Leocani, Letizia
    To better characterize brain circuits dysfunctions in normoacousic tinnitus sufferers. Methods: 17 normoacousic chronic, unilateral high-pitched tinnitus sufferers (6 females, 43.6 ± 9.8 y.o, disease duration 22 ± 35 months) underwent a 29-channel resting-state electroencephalography (EEG – 5 min opened-eyes, 5 min closed-eyes) and auditory oddball paradigm for event-related potentials analyses (ERPs – N1, P2 and P300). Cortical 3D distribution of current source density was computed with sLORETA. Results were compared with 17 controls (9 females, 45.7 ± 15.1 y.o). Results: Eyes opened, tinnitus sufferers had lower alpha and beta sources in the left inferior parietal lobule. Eyes closed, tinnitus...

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